The question is tricky: it speaks of a burn of 10% of the body surface and the treatment of choice for second degree burns less than 20% of the BSA should be topical and monitored. However, there is a warning sign: there is no arterial pulse and the burn is circumferential to the limb. This is an emergency that, if allowed to evolve, will compromise the viability of the affected limb and end in amputation: an emergency escharotomy must be performed in order to relieve the pressure of the third space on the arterial vascular trunk.

A young man comes to the emergency room with a second-degree flame burn of 10% of the body surface, affecting the right arm in an extensive and circular manner. There is no arterial pulse in the hand measured by Doppler. What is the treatment of choice?

Occlusive sulfadiazine-arginine cures and depth assessment at one week.

Lymphatic drainage and assess a vascular by-pass.

Escharotomy or emergency decompression incisions.

Escharotomy

Neurovascular integrity should similarly be monitored frequently and in a scheduled manner. Capillary refilling time, Doppler signals, pulse oximetry, and sensation distal to the burned area should be checked every hour. Limb deep compartment pressures should be checked initially to establish a baseline. Subsequently, any increase in capillary refill time, decrease in Doppler signal, or change in sensation should lead to rechecking the compartment pressures. Compartment pressures greater than 30 mm Hg should be treated by immediate decompression via escharotomy and fasciotomy, if needed.

Surgery_Schwartz

explored to evaluate for bleeding points. One must be very cautious if attempting to ligate these to ensure that adjacent structures such as nerves are not included in the ligature.The hand must be evaluated for adequacy of perfusion to the hand as a whole as well as the individual digits. Capillary refill, turgor, Doppler signal, and bleeding to pinprick all pro-vide useful information regarding vascular status. The finger or hand with vascular compromise requires urgent operative explo-ration. Unlike the complete amputation, in which the amputated part can be cold preserved (see later section, “Amputation and Replantation”), devascularization without amputation produces warm ischemia, which is tolerated only for a matter of hours.For the noncritical vascular injury, two treatment options exist. Simple ligation will control hemorrhage. At least one of the palmar arterial arches is intact in 97% of patients, so this will usually not compromise hand perfusion.5 Each digit also has two

Ankle–brachial pressure index

A Doppler ultrasound blood flow detector, commonly called Doppler wand or Doppler probe, and a sphygmomanometer (blood pressure cuff) are usually needed. The blood pressure cuff is inflated proximal to the artery in question. Measured by the Doppler wand, the inflation continues until the pulse in the artery ceases. The blood pressure cuff is then slowly deflated. When the artery's pulse is re-detected through the Doppler probe the pressure in the cuff at that moment indicates the systolic pressure of that artery. The higher systolic reading of the left and right arm brachial artery is generally used in the assessment. The pressures in each foot's posterior tibial artery and dorsalis pedis artery are measured with the higher of the two values used as the ABI for that leg. Where PLeg is the systolic blood pressure of dorsalis pedis or posterior tibial arteries and PArm is the highest of the left and right arm brachial systolic blood pressure

Pressure guided surgery of compartment syndrome of the limbs in burn patients.

Compartment syndrome is a serious complication of high voltage electrical burns, limb carbonization and deep circular burns with delayed escharotomy. Without treatment, ischemic tissue damage leads to irreversible necrosis. Treatment is emergency surgical decompression. The burned patient is usually not searchable and cannot always be readily examined because of bulky dressings; diagnosis of compartment syndrome is always hard to make. The pressure transducer used in central arterial catheters is easy available. We used it to measure pressure in muscular compartments. We measured compartment pressure three times at different depths in all cases of electrical burn, carbonization and deep circumferential burns with delayed escharotomy. We also took the pressure in the uninjured limb. The pressure assessment device was composed of a blood pressure transducer commonly used in arterial catheters for arterial pressure monitoring with three connecting branches. The first branch was connected to the 'arterial pressure exit' in the monitoring device. The second, an IV tube, was connected to one litre of physiological serum in a pressure bag inflated to 200 mmHg. The third, also an IV tube with a sterile extension cable, was directly connected to an 18G standard straight needle to be inserted in the tissues for which interstitial pressure had to be measured. In patients with thermal burns, we measured pressure before and after escharotomy. Threshold intracompartmental pressure was 35 mmHg. We carried out pressure assessment of all muscular compartments during and at the end of surgery. The pressure transducer provides a pressure value in all muscular compartments with a time of installation and measuring of less than 5 minutes. Sensitivity is measured at +/- 1 mmHg. Operation is simple, non-operator dependent, and accessible to medical and paramedic teams. The pressure transducer allows accurate diagnosis of early or established compartment syndrome. It requires no additional equipment and its application does not delay therapeutic management. Its use helps with fasciotomy decision, especially after escharotomy, guides the surgeon in the exploration of different compartments and verifies the effectiveness of surgery.

Revascularization in distal lesions of upper extremity arteries.

A study was made of the course of ischemia and hemodynamic disorders in 53 patients with occlusion of the distal arterial system of the upper extremities. Circulation was examined by ultrasound Doppler, tetrapolar rheology, transcutaneous oxymetry and angiography. Critical ischemia was discovered in 58.5% of patients. In occlusion of one of the forearm arteries, extremity circulation was made for. Circulatory decompensation was recorded in occlusion of both forearm arteries with intact distal bed and non-functioning palmar arches of the hand as well as in lesions of hand and finger arteries. All 53 patients were operated on, 66 operations were accomplished using magnifying optic appliances. Provided the distal bed was well preserved, use was made of direct revascularization techniques (36) whereas non-standard methods were employed in the event of its obliteration: arterialization of the outlets of the subcutaneous veins of the hand and autotransplantation of the greater omentum (30). Beneficial results were obtained in 91.5% and unsatisfactory in 8.5% of patients. The lethality accounted for 1.2% while the incidence of amputations was quoted as 5.7%. Good results offer the period as long as 5 years were well preserved in 87.6% of patients. Our experience indicates the efficacy of the use of revascularization techniques for the treatment of different versions of occlusion of the distal segments of upper extremity arteries.

Paramedic

Thorocostomy and pericardiocentesis to relieve pneumothorax and pericardial tamponade Intravenous (IV) and intraosseous (IO) cannulation Oxygen administration and positive pressure ventilation via bag-valve-mask, CPAP device, or ventilator Fluid resuscitation Administration of emergency drugs/medications (see section below) Bleeding control and management of shock Spinal injury management, including immobilization and safe transport Fracture management, including assessment, splinting, and dislocation reduction Obstetrics, including assessment, childbirth, and recognition of and procedures for obstetrical emergencies such as breech presentation, cord presentation, and placental abruption Management of burns, including classification, estimate of surface area, recognition of more serious burns, and treatment Triage of patients in a mass casualty incident Surgical procedures such as field amputation, escharotomy, or thorocotomy (if trained and credentialed)

[Prevention of extremities amputation in patients with diabetic foot complications].

In order to decrease the number of amputations for "diabetic foot", these patients should undergo elective or delayed operations. It is obligatory before the operation to correct carbohydrate metabolism and hemodynamics. Sodium succinate in combination with conventional angioprotective treatment is used for this purpose. Microcirculation is evaluated using oxymonitor ISM-2 and tetrapolar rheography. Blood flow disturbances are evaluated according to ultrasound dopplerography data. Operations are performed with the use of a primary or delayed suture at the definite level of the extremity where oxygen tension of the skin is not lower than 33 mm Hg, and the index of minute blood flow--not lower than 1.8 ml/min per 100 cm3 of the tissue. When operating on the foot it is obligatory to leave loose excessive brims of tissues to facilitate the placement of broad-grip sutures without tension. It is advisable to use through flowing--aspiration drainage and to perform surgical treatment of the deep phlegmon of the foot through club-shaped approach.

Hand burns in children under 5 years of age.

In order to evaluate the epidemiology and functional results of hand burns in young children, 92 consecutive patients (126 hand burns) under age 5 years admitted to a Burn Center were reviewed. Scald burns (49 per cent) were most common, followed by flame (34 per cent), contact (14 per cent) and electrical burns (3 per cent). The child was left unattended by an adult in 53 per cent of cases and documented abuse was present in 6 per cent. The mean total body surface area (TBSA) burned was 17 per cent, and 77 patients (85 per cent) had additional burns in other areas (arms 34 per cent, legs 31 per cent, chest 29 per cent and face 27 per cent). Palmar burns occurred in 24 hands (19 per cent), dorsal in 41 (33 per cent), while both surfaces were burned in 61 (48 per cent). Joints involved included the MP in 96 (76 per cent), PIP in 87 (69 per cent) and DIP in 80 (63 per cent). The depth was superficial partial thickness in 53 (47 per cent), deep partial in 55 (44 per cent), and full thickness in 18 hands (14 per cent); a total of 29 hands were grafted (15 deep partial and 14 full thickness). Escharotomies were required in 12 hands (9 per cent) (9 flame and 3 scald) and partial amputation of digits was required in 3 (2 per cent). Follow-up was available in 46 hands from 7 to 120 months (mean 39 months). Partial thickness burns (34) healed with normal (32) or near-normal (2) hand function and developmental delay occurred in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

[Estimation of regional blood flow in reimplanted segments of upper extremity].

To examine the state of regional circulation in replanted segment of upper limb and hand, to determine diagnostic and prognostic value of radionuclide scintigraphy. The study included 26 patients who underwent replantation of upper extremity segments. The control group included 12 patients who underwent autologous transplantation of toes on hand. All patients underwent isotope scintigraphy, ultrasound Doppler and pulse oximetry. Groups were comparable by gender, age, severity of injury. Depending on postoperative course two groups were determined: with favorable (27 patients) and complicated postoperative period (11 patients). Two types of regional circulation were identified according to dynamic scintigraphy: prevalence of blood flow in operated limb (type 1); prevalence of blood flow in healthy limb, or equal volumetric blood flow in operated and healthy limbs (type 2). Favorable early postoperative period was associated with prevalence of blood flow in operated limb. Only in 2 (7.7%) patients patients in this group acute arterial thrombosis was diagnosed. At the same time thrombosis of microanastomosis occurred in 45.4% of cases in the second group what is 5.5 times higher than in the first group. Significant prevalence of blood flow in operated limb is favorable prognostic sign of the early postoperative period. On the other hand the identity of blood flow or prevalence of such in healthy limb predispose to acute vascular complications in replantate or autoplantate. Radionuclide scintigraphy provides detailed assessment of regional blood flow in operated limb. However clinical monitoring has leading role in diagnosis of acute circulatory disorders in replantate or autoplantate.

[Early treatment of high-voltage electric burn wound in the limbs].

To summarize the experience of early treatment of high-voltage electric burn wounds in the limbs. Fifty-four patients (50 males and 4 females, aged from 10 to 56 years) with high-voltage electric burn wounds in 97 limbs (67 upper limbs and 30 lower limbs) were hospitalized in our burn wards from January 2003 to December 2010. A total of 119 burn wounds in wrist-forearm, forearm-elbow-upper arm, shoulder-axillary region, ankle-foot, lower leg, around the knee, thigh-inguinal region were treated with incision for decompression within 10 days after burn. Under the premise of relatively stable systemic condition of the patients, certain surgical operations were performed as follows. (1) Sixteen limbs with 16 wounds were amputated, among them forearm amputation was performed for 5 upper limbs with necrosis, with preservation of elbow joints, and the residual wounds of the elbow and upper arm were repaired with pedicled latissimus dorsi musculo-cutaneous flaps; 1 upper limb with upper arm amputated, with preservation of shoulder joint, was repaired with pedicled latissimus dorsi musculo-cutaneous flap. (2) Ninety-five wounds were covered with various tissue flaps with abundant blood supply after early debridement, in which 3 brachial arteries, 1 vein, 1 brachial artery and vein were reconstructed in 5 wrist wounds, artery reconstruction was performed in elbow wound of 1 case with injured brachial artery. (3) Eight wounds were treated with free skin grafting. Wound healing conditions were observed and followed up. Wounds in 16 limbs healed after amputation and repair. Blood supply and (or) venous return of hands were restored in 5 wrist wounds after vessel reconstruction. After artery reconstruction, abundant blood supply was observed in 1 case with injured brachial artery and amputation was avoided. Necrosis occurred in distal parts of tissue flaps in 5 wounds after grafting, in which 2 wounds healed after removal of necrotic tissue followed by closure with suture, and 3 wounds healed after debridement and free skin grafting. Tissue flap infection occurred in wrist (5 wounds), elbow (1 wound), ankle-foot (2 wounds), and healed after debridement and suture. The other tissue flaps survived after grafting. Six wounds healed after skin grafting. Partial necrosis occurred in 2 wounds after skin grafting, and they were healed after second skin grafting. Thirty-seven patients were followed up for 6 to 12 months, the skin flaps survived with satisfactory appearance and texture. Early extensive compartment release through fasciectomies and escharectomies, early debridement, early vascular grafting, early wound coverage with contemporary reparative and reconstructive surgical techniques are rational options for the treatment of high-voltage electric burns in the limbs.

[Preoperative Doppler evaluation of vascular perforators in the anterolateral thigh flap harvest].

To evaluate the accuracy of Hadeco ES-1000spm hand-held doppler during the anterolateral thigh (ALT) flap harvest. Twenty-five patients (26 sides) with ALT flaps for head and neck reconstruction between May 2005 and May 2010 received preoperative Doppler examination for the location of the cutaneous perforators of ALT flaps. The Doppler signals and body mass index (BMI) were recorded preoperatively according to ABC system. The locations of Doppler signals and of the actual cutaneous perforators at surgery were plotted and compared. The diameter of perforators was measured. One to three cutaneous perforators of the ALT flap were consistently found at specific locations. They were named perforators A, B, C from proximal to distal. Perforators A, B and C were present in 15 (58%), 24 (92%) and 20 (77%) cases and the diameter (> 0.5 mm) of A, B and C were 11/15, 22 (92%) and 8 (40%) respectively. The Doppler signal was within 0.5 cm of the actual perforator location in 85% flaps. The accuracy of Doppler decreased with increase of BMI. Preoperative assessment by hand-held Doppler is useful in predicting the perforator vessels' locations and diameter although it's accuracy is limited.

[Early treatment of third degree burns of the entire hand].

Treatment and result of burned total hand was reported here in 4 hands (4 cases). According to the treatment and anatomical characteristics, burned hand was divided into 4 areas: dorsum of hand, dorsum of finger, thenar-wrist area and volar-digit area. The treatment of total hand in third degree burns included emergency escharotomy of hand and digits, early escharotomy and immediate skin grafting on the dorsum of hand, thenar-wrist and volar-digit area. But on the dorsum of digit area this sort of hand was often deepen to the phalangeal bones and joints. After healing of early graft, the exposed bones and joints were decorticated with immediate grafting on the fresh bone marrow surface and with the finger tip repair so as to preserve the length of digits. When the bone marrow surface grafting healed metallic finger splints were bent sequentially to functional position for 8 weeks in order to ankylosis of interphalangeal joints. Followed up 4 hands with good results. And only 5 distal phalanges were loss in 20 digits. But in previous cases this kinds of digits were often amputated with poor results.

[Economic amputations of the lower limbs due to ischemia. I].

The problem relating to leg amputation following ischemia are analysed in the first part of this study, bearing in mind that amputation must be as conservative as possible in order to ensure the best quality of life. Following a short review of the topic and the introduction of recent trends, the case for amputation, which must be early in order to be conservative, is studied. The first part of this article concludes with a discussion of Doppler and clinical evaluations as techniques used to determine the level of amputation.

Burn wound management.

In this chapter the local therapy for burns is discussed. Between 400 and 500 children with burns are treated every year at the Red Cross War Memorial Children's Hospital in Cape Town, but in only 10% of them do the burns affect over 20% of the body surface. These latter patients are treated in special rooms equipped for intensive therapy. Open and closed methods of treatment for burns used in addition to early excision are compared. The first aim is early skin cover for areas with skin loss preserving as much function as possible and achieving the best possible cosmetic result. Local therapy must be atraumatic to prevent extension of the skin lesion. Bacterial contamination must be prevented as far as possible by keeping the wound clean. Emergency treatment and the course of wound healing up to the third week after the injury using the appropriate dressings are described. Early excision until the fifth day after the accident should be used mainly for burns of the hand, deep second degree burns of up to 10% of the body surface, deep second degree burns over the joints and deep second degree burns of the neck. It must be admitted that the depth of the burn can only be definitely estimated between the seventh and tenth day after the accident. If no autografts are available homografts or grafts from animals are used. The age of the patient, associated injuries, associated diseases and the extent of the burn all play a role in determining the prognosis. Furthermore endogenous bacterial infections, absorption of local therapeutic agents and the state of the surrounding skin do also influence the healing process. Finally the various local therapeutic agents like sulphamylon, silver sulphadiazine and betadine are discussed. A 0.05% solution of silver nitrate is also active against gram-negative infections. Skin transplants are disinfected with a solution containing one third 0.25% acetic acid, one third 3% cent hydrogen peroxide and one third saline. Hydrogen peroxide must not be applied to burns that are healing spontaneously. A classification of burns to help to choose the appropriate local therapy is proposed.

The prediction of healing in ischemic lesions of the foot. A comparison of Doppler ultrasound and elevation reactive hyperemia.

The results of the Elevation Reactive Hyperemia Test (ERHT) and the transcutaneous Doppler ultrasound ankle blood pressure (DAP) have been compared in a series of 115 cases with ischemic lesions of the foot. The ERHT was carried out by simple elevation of the foot or elevation with the circulation temporarily obstructed by a blood pressure cuff following which the foot was gradually lowered until the reactive hyperemia was seen in the skin and the height above the right atrium was estimated. The appearance of the hyperemia at 35 cm above the right atrium will allow healing of local ischemic lesions and at the height of 45 cm or above indicates a zone at which amputation may be carried out successfully. In the same series the DAP using 60 mmHg as the cut off point showed 40% healing with a pressure less than this level and 40% failed with a pressure above this level. The DAP gave no consistent prediction of the healing of ischemic lesions or of amputations.

Iatrogenic Compartment Syndrome Secondary to Burn Dressing in a 2-Year-Old Child.

We report a severe case of compartment syndrome due to a compressive burn dressing. An otherwise healthy 2-year-old girl presented at her local health center with a superficial partial-thickness thermal burn on the dorsum of the mid phalanx of the second finger of her right hand. A compressive dressing was applied solely to the affected finger. Forty-eight hours afterward, the patient presented in the emergency room with severe pain of the finger. After removal of the dressing, a circular constrictive eschar was observed at the base of the finger, secondary to ischemia due to the compressive dressing. Emergent lateral escharotomies were performed, with immediate recovery of distal perfusion. One week afterward, the patient underwent surgical debridement of the burn on the dorsum of her finger and escharectomy of the ischemic eschar at the base. The lesions were covered with partial-thickness skin grafts. This case shows that acute compartment syndrome can lead to severe sequelae, such as the loss of an extremity or body segment. We must take utmost care in all our actions to avoid any (negligent) act that could lead to severe or permanent damage to our patients.

[Surgical therapy of acute and chronic arterial occlusions below the inguinal ligament].

The history and physical examination are extremely important in the management of vascular surgical patients because a correct diagnosis can usually be made on the basis of information obtained from these two modalities. The severity of the chronic occlusive process leads to characteristic symptoms in the extremity: claudication, rest pain, skin ulcerations and gangrene. Chronic progressive lesions permit enlargement of collateral blood supply which, for a time, minimizes the severity of symptoms. Milde degrees of arterial insufficiency (claudication) can be treated conservatively. Unreconstructed chronic critical ischemia predicts a poor outcome in terms of survival and limb salvage. The outlook with arterial reconstructive surgery is by far better. Arteriography ist the most reliable diagnostic test for occlusive lesions. It ist essential for the operative planning. Vein-bypass procedures are, if feasible, very effective in most cases. Acute embolic occlusion: Sudden occlusion of a previously patent artery is usually a dramatic event producing severe ischemia of the distal tissue. The characteristic symptoms and signs are the 5 P's: pallor, pain, paresthesia, paralysis, pulselessness. Emergent restoration of blood flow by operation may be essential to prevent limb loss. Milder forms of ischemia (acute thrombosis--acute or chronic disease) can be treated initially with intravenous heparin if the extremity is not threatened (minimal sensory loss, no muscle weakness). Elective surgery at a later date is highly successful.

Intramuscular pressure in the burned arm: measurement and response to escharotomy.

Using a wick catheter technique, sequential measurements of intramuscular pressure were obtained in 31 burned arms in 18 patients. Abnormally high pressures were recorded in 90 percent of extremities and exceeded the potentially harmful level of 30 mm Hg in 42 percent. Correlation of intramuscular pressure with signs and symptoms of extremity compression, including Doppler pulses, was poor. Intramuscular pressure elevation appeared to parallel edema formation beneath the burn wound. A high incidence of pressure measurements in excess of 30 mm Hg was found in patients who had 30 percent or greater total body surface area injury (67 percent), 10 percent or greater full-thickness burns (75 percent), and extremities with circumferential involvement (57 percent). In every case echarotomy produced a dramatic decrease in intramuscular pressure, while a randomized group of extremities that were not decompressed developed sustained pressures as high as 64 mm Hg despite the presence of intact Doppler pulses. Extremities treated in this manner appeared slower in resolving edema and regaining motion and strength. Measurement of intramuscular pressure beneath the burn eschar is recommended in evaluating all patients at risk from extremity burns.

Below-Knee Amputation -- Contraindications

Doppler may assess for gross blood flow, and ankle-brachial indices can evaluate an individual and lower versus upper extremities. Oxygen pressures in the toes and transcutaneous oxygen pressure are useful for determining oxygenation on a microvascular level. In cases of profound vascular insufficiency, bypass grafting or the placement of stents may be necessary before performing a BKA. Some researchers used indocyanine green near-infrared (ICG NIR) fluorescence imaging to predict postoperative skin flap necrosis. [18] [19]

Civilian blast-related burn injuries.

There is limited English literature describing the experience of a civilian hospital managing blast-related burn injuries. As the largest regional burn unit, we reviewed our cases with the aim of identifying means to improve current management. A 6-year retrospective analysis of all patients coded as sustaining blast-related burns was conducted through the unit's burns database. Medical case notes were reviewed for information on burn demographics, management and outcomes. 42 patients were identified. Male to female ratio was 37:5. Age range was 12-84 years, (mean=33 years). Total body surface area (%TBSA) burn ranged from 0.25% to 60%, (median=1%). The most common burn injury was flame (31/42, 73.8%). Gas explosions were the most common mechanism of injury (19 cases; 45.2%). 7/42 cases (16.7%) had full ATLS management pre-transfer to the burns unit. The Injury Severity Score (ISS) ranged from 0-43 (median=2). 17/42 (40.4%) patients required admission. 37/36 (88.1%) patients were managed conservatively of which 1 patient later required surgery due to deeper burns. 5/42 (11.9%) patients required surgical management at presentation and these were noted to be burns with >15% TBSA requiring resuscitation. One case required emergency escharotomies and finger amputations. All patients survived their burn injuries. Blast-related burn injuries are generally uncommon in the civilian setting. Following proper assessment, most of these cases can be deemed as minor injuries and managed conservatively. Improvement in burns management education and training at local emergency departments would provide efficient patient care and avoid unnecessary referrals to a burns unit.

Determining End Points for Critical Limb Ischemia Interventions.

Critical limb ischemia is a condition that has increased in prevalence and carries a high degree of morbidity. Although endovascular therapy for treatment of patients with critical limb ischemia has undergone significant advances with improved outcomes over the past decade, these patients often have multilevel disease, and it may take weeks or months for ulceration healing. For this reason, the acceptable therapeutic end points during and immediately following revascularization remain somewhat obscure. There are multiple tools available to guide the treating vascular specialist in this regard. Establishment of in-line flow to the foot and the angiosome containing the ulceration, appearance of a "wound blush," restoration of pulses, and bleeding at the ulcer site are basic tenets intraprocedurally. Postprocedural noninvasive testing including the ankle-brachial and toe-brachial indices, segmental pressure measurements, pulse volume recordings, transcutaneous oxygen tension, skin perfusion pressures (SPPs), and toe pressures all play a role in determining the likelihood of clinical improvement. Newer technologies such as two-dimensional (2D) perfusion angiography, fluorescence angiography, and tissue oxygen saturation mapping may allow better real-time assessment of flow restoration. In combination with close clinical follow-up and wound care, these tools provide treating physicians with a better grasp of the necessary end points to optimize patients for clinical improvement.

InternalMed_Harrison

usually are used in conjunction with pharmacologic thrombolysis. Surgical revascularization is preferred when restoration of blood flow must occur within 24 h to prevent limb loss or when symptoms of occlusion have been present for more than 2 weeks. Amputation is performed when the limb is not viable, as characterized by loss of sensation, paralysis, and the absence of Doppler-detected blood flow in both arteries and veins.

[Analysis of causes and treatment methods of complication of early acute kidney injury in four severely burned patients].

<bObjective:</b To analyze the causes of complication of early acute kidney injury (AKI) in four severely burned patients, and to explore the related treatment methods. <bMethods:</b The clinical data of 4 patients with severe burn complicated with early AKI admitted to Guangzhou Red Cross Hospital Affiliated to Medical College of Jinan University (hereinafter referred to as our hospital) from June 2014 to December 2017 were retrospectively analyzed. All the patients were male, aged 23-33 (30±5) years old, with depth of burns ranged from deep partial-thickness to full-thickness, complicated with myofascial compartment syndrome of extremities and varying degrees of striated muscle injury, and treated in other hospitals before transfer to our hospital. The patients were numbered from small to large according to the total burn area. The total burn area of patients No. 1, 2, 3, and 4 was 10%, 80%, 90%, and 95% total body surface area respectively, their occurrence time of early AKI was 48, 11, 29, and 48 hours after injury respectively, and their time of arriving our hospital was 60, 11, 29, and 144 hours after injury respectively. Hypovolemic shock occurred in patients No. 2 and 3 at admission to our hospital. All the patients received continuous renal replacement therapy (CRRT) after admission to our hospital. Under the support of hemodynamic monitoring and organ function monitoring, the limbs complicated with myofascial compartment syndrome were incised, thorough decompression exploration was performed, and necrotic muscle tissue was removed or amputation was performed. After escharectomy and decompression of limbs, fresh granulation wounds were formed by temporarily covering wounds with Jieya dressing skin or pig skin, multiple debridements, and vacuum sealing drainage. Fresh granulation wounds and other wounds underwent staged eschar excision and shaving were covered with autologous Meek skin graft, particulate skin graft, reticular skin graft and small skin graft respectively. The treatment outcome, CRRT time, operation times, time of recovery of serum creatinine and myoglobin, length of hospital stay, and follow-up were recorded. <bResults:</b All the 4 patients were cured after transfer to our hospital. Among them, totally 5 limbs of patients No. 1 and No. 4 underwent amputation because of complication of myofascial compartment syndrome and a large amount of necrotic muscle which could not be preserved. Patients No. 1, 2, 3, and 4 were treated with CRRT for 19, 35, 14, and 25 days respectively and performed with operation for 5, 6, 10, 8 times respectively. Serum creatinine of patients No. 1, 2, 3, and 4 returned to normal on 22, 35, 37, and 48 days after transfer respectively, and their serum myoglobin returned to normal on 18, 28, 25, and 30 days after transfer respectively. Patients No. 1, 2, 3, and 4 were hospitalized for 52, 105, 148, and 156 days and discharged after basic wound healing. Follow-up for 1 to 36 months showed no abnormal renal function in 4 patients. <bConclusions:</b The early AKI in patients No. 1 and 4 was caused by rhabdomyolysis after severe burn complicated with myofascial compartment syndrome, while that of the other 2 cases were also related to hypovolemic shock and poor renal perfusion. The success rate of early AKI treatment in severely burned patients can be effectively improved by removing the causes of diseases at the same time of CRRT and actively treating burn wounds under the support of organ function and hemodynamic monitoring.

Does the new vascular management of acute limb ischemia have effective results with lower treatment costs.

Aim To compare hospital costs of acute limb ischemia treatment in two periods of time and to show evidence of long-term repercussions on reducing costs during successful treatment. Methods Retrospective analysis of data obtained from 100 patients' medical history in the period 2000-2016 at the Clinic of Vascular Surgery Sarajevo: group A - 60 patients with acute limb ischemia in the period 2005-2016 and group B - 40 patients with acute limb ischemia (ALI) in the period 2000-2005. From 2000 to 2005 conservative treatment method was used, invasive diagnostic and surgical procedures were often delayed for a shorter or longer period of time. During the period from 2005 to 2016, the management model and safe practice included emergency diagnostic procedures, colour-Doppler, arteriography, emergency surgery (embolectomy by Fogharty and if necessary, vascular by-pass). Results Better health service for the patients with acute limb ischemia was offered in the period 2005-2016, which relied on proven medical treatment trends. The largest share of the total costs of each patient included costs of hospital bed with significant difference between the period 2005-2016 and 2000-2005, mean of 1398.71 KM and 2480.45KM, respectively (p<0.0001), indicating rationalization of time that patients spend at the Vascular Clinic. Conclusion This trend of money/fund savings is an example of good practice, effectiveness and efficiency in the treatment of ALI and as such was used in patients with other vascular diseases.

Pediatric upper extremity burns: outcomes of emergency department triage and outpatient management.

Pediatric upper extremity burns are common. Though current American Burn Association guidelines recommend burn unit referral for burns involving the hands or major joints, many minor injuries are treated in the emergency department (ED) or outpatient setting. Despite the large number of burn patients managed by primary care providers, no large studies have been performed to assess effectiveness. A retrospective 5-year review of the epidemiology and outcomes associated with pediatric upper extremity burns treated at an urban ED was performed. Two hundred sixty-nine patients were identified. The mechanism of burn, percentage of total body surface area (%TBSA) affected, plastic surgery consultations (for wound management recommendations and additional treatment), complications, and surgical interventions were examined. Mechanisms of burn included direct contact (47%), scald (29%), flame (12%), electrical (10%), and friction or chemical (1.5%). Fifty percent of patients suffered from burns over less than 1% TBSA; close to 95% had burns on less than 5% TBSA. Seventy-five percent of patients had second-degree burns, 21% had first-degree burns, and 2% had third-degree burns. Forty patients (15%) had a plastic surgery consult. Seven patients (3%) required skin grafting. Complications occurred in five (2%) patients and included two cases of hypertrophic scarring; two patients with flexor contractures, one case of compartment syndrome requiring fasciotomy, and one late infection. These results suggest that although significant burns are usually cared for in specialized burn centers, the majority of childhood burns to the upper extremity are relatively minor and often treated in the primary care setting. Most patients had small areas of injury and healed without complications. Contact burns are an ever-increasing proportion of childhood burns and should be seemingly preventable. Education to parents and primary care physicians should be reemphasized. It appears that minor upper extremity burns treated by our urban ED staff are handled appropriately and result in favorable outcomes.

Dorsalis pedis artery

The dorsalis pedis communicates with the plantar blood supply of the foot through the deep plantar artery. Along its course, it is accompanied by a deep vein, the dorsalis pedis vein. Function The dorsalis pedis artery supplies oxygenated blood to the dorsal side of the foot. Clinical significance Pulse The dorsalis pedis artery pulse can be palpated readily lateral to the extensor hallucis longus tendon (or medially to the extensor digitorum longus tendon) on the dorsal surface of the foot, distal to the dorsal most prominence of the navicular bone which serves as a reliable landmark for palpation. It is often examined, by physicians, when assessing whether a given patient has peripheral vascular disease. It is absent, unilaterally or bilaterally, in 2–3% of young healthy individuals. Ultrasound The dorsalis pedis artery may be studied using ultrasound. Doppler ultrasound can be used to investigate blood flow.

Management of acute nontraumatic upper limb ischemia.

A retrospective review of all patients presenting to a tertiary referral center with acute nontraumatic upper limb ischemia between January 1992 and June 1997 was undertaken to examine the role of intraarterial thrombolysis in the management of such cases. Twenty-one patients were identified in the radiology and vascular surgery departments' registers. Twenty (95%) underwent angiography, demonstrating subclavian artery occlusion in four, axillary in two, brachial in 13, and one at the digital level. Intraarterial thrombolysis was attempted in 12 patients. There were three technical failures, all requiring embolectomy. Six had complete lysis and resolution of their symptoms. One patient had partial lysis but experienced no further rest pain. Thrombolysis was unsuccessful in two cases with one subsequently requiring embolectomy and the other surgical bypass. Three patients had surgical intervention as their primary procedure with two favorable outcomes and one ending in above-elbow amputation. Five patients were treated conservatively with heparin, resulting in three partial and two full recoveries. One patient experienced complete resolution of symptoms with an intravenous prostacyclin infusion. Both electrocardiograms (ECG) and echocardiograms (ECHO) were of limited diagnostic aid, and long-term warfarin anticoagulation was prescribed to all patients. There was no recurrence of upper limb ischemia at a median follow up of 18 months. Intraarterial thrombolysis is an effective first line treatment for acute nontraumatic upper limb ischemia in selected cases.

Eschar

Eschar may be allowed to slough off naturally, or it may require surgical removal (debridement) to prevent infection, especially in immunocompromised patients (e.g. if a skin graft is to be conducted). If eschar is on a limb, it is important to assess peripheral pulses of the affected limb to make sure blood and lymphatic circulation is not compromised. If circulation is compromised, an escharotomy, or surgical incision through the eschar, may be indicated.

[Arterial embolisms of the lower extremities].

Embolism is one of the most frequent causes of lower limbs acute arterial occlusion [1]. Of the total number of peripheral embolism 56% of cases involve lower limbs arteries [2]. Inadequate and late treatment of the lower limbs embolism is associated with high morbidity and mortality rate. The aim of this paper was to study the aetiology of lower limbs embolism and to detect factors influencing early and late results after the operative treatment. The study included 204 patients with 224 lower limbs embolism, treated surgically at the Institute of Cardiovascular Diseases of the Clinical Centre of Serbia in Belgrade in the period between 1993 and 1997. There were 107 (52.2%) female and 97 (47.8%) male patients. Thirty two (14.3%) patients were younger than 50 years, 64 (28.6%) were between 51 and 65, 101 (45.1%) between 66-75, while 27 patients (12.1%), were older than 75. Twenty (8.9%) patients were admitted less than 6 hours before the operation, 79 (33.3%) between 6 and 24 hours, and 125 (55.8%) more than 24 hours before the operation (Table 1). One hundred (53.6%) patients had motor and 133 (59.4%) sensor paralysis on admission. Table 2 shows arterial localization of the lower limbs embolism. The popliteal artery was involved in most cases. During the operation transfemoral arterial approach was used in 132 (58.9%) cases, while transpopliteal in 92 (41.1%) cases. Fourteen cases required bypass surgery, 43 fasciotomy, 2 intraoperative streptokinase and 4 intraoperative angiography. All patients were controlled using physical and CW Doppler ultrasonographic examinations immediately after the operation, and then one, six and 12 months, as well as every year. In 173 (84.4%) patients cardiac causes of embolism were found, in 8 (3.9%) noncardiac, while in 8 (3.9%) the cause could not be established. Of all cardiac causes absolute arrhythmia was most frequent. Table 3 and Table 4 show the aetiology of the lower limb embolism. The early amputation rate was 23 (10.3%) cases, while limb salvage was recorded in 174 (77.7%) patients. Of all saved limbs complete recovery was noted in 162 (72.4%) cases and peroneal nerve paresis in 12 (5.3%) cases. The early postoperative mortality rate was 27 (12.0%). Table 5 shows early results of embolectomy. The early results (limb salvage, complete recovery, rethrombosis, early reoperations, amputations rate, morbidity and mortality rate) of embolectomy were statistically significant: worse in cases when the embolus was located in the abdominal aorta and popliteal artery; in cases with a long time interval before the operation as well as in patients with sensor-motoric paralysis on admission (Tables 6-8). Of the total number of patients in 87 (56.5%) cases a late control examination was carried out. Forty nine (31.8%) patients died before the late control, while 18 (11.7%) did not come to control examination. Late recidivation of embolism was found in 3 cases. In these patients the cause could not be found, and they were treated by anticoagulant drugs.

Amputation Following Hand Escharotomy in Patients with Burn Injury.

Hand burns are commonly seen in patients with burn injury. In the past, focus was on lifesaving measures, but with advances in burn care during the last century, the paradigm shifted to digital salvage and eventually to functional digital salvage. Good outcomes are heavily dependent on the care that is rendered during the initial management of the burn. A retrospective medical record review was conducted through the Central Illinois Regional Burn Center Patient Registry. Patients with burn injury treated with upper extremity and hand escharotomy between January 1, 2000, and December 31, 2005, were included in the study. We identified a total of 34 patients with 57 burned hands. Six hands required delayed amputation of digits despite recognition of neurovascular compromise and escharotomy, yielding a 10% amputation rate. No correlation could be drawn with regard to total body surface area, age, or sex. Important principles in the acute phase include early splinting, recognition of the need for escharotomy and complete escharotomy when necessary, early excision and grafting, and involvement of occupational therapy for splinting and to guide both active and passive exercises. Although uncommon, some extremity burns may require subsequent amputation despite prompt attention and optimal treatment. In our case series, the need for amputation after successful escharotomies of salvageable digits was associated with full-thickness and electrical burns.

Acute Iatrogenic Limb Ischaemia, a Report of 2 Late Presentation Cases.

With increasing use of percutaneous vascular procedures, access complications that present to a vascular surgeon increase. The most limb-threatening condition is acute limb ischaemia. Acute limb ischaemia is the most common vascular surgical emergency. In spite of recent advances in vascular surgery, it continues to carry a poor prognosis, if not early diagnosed and managed. This is a case-report of 2 patients referenced to a vascular surgery emergency department of a tertiary hospital with late acute limb ischaemia. Patient 1: Male, 42 years, alcoholic, autonomous, presented with pain with elbow active movements in a secondary hospital. Excluded acute orthopaedic injury, doctor recorded signs of acute limb ischaemia and referenced patient to a tertiary hospital, where vascular surgeon diagnosed an acute advanced upper limb ischaemia. Bed-side Eco-Doppler showed an echogenic linear material on a thrombosed umeral artery, surgically confirmed to be a guidewire (Fig.1. Surgical extraction of intra-umeral guidewire). Reviewing patient history, this guidewire should have been missed over 6 months, by the time the patient was hospitalized on an ICU for alcoholic coma. Patient underwent umeral, radial and ulnar thromboembolectomy and had a no-reflow status. However, poor persistent global status, with limited mobilization, pressure forces and prolonged vasotropic support, promoted progression of a cyanotic leg plaque to a necrotic evolving leg ulcer with septic response, despite persistent good perfusion of the foot (Fig.2. Necrotic evolving leg ulcer). Unfortunately, the two reported patients underwent urgent major limb amputation, patient 1 above the elbow, and patient 2 above the knee. Acute limb ischaemia continues to carry a poor limb and life prognosis if not early diagnosed. We should be alert for the increasingly prevalence of iatrogenic acute limb ischaemia, and regularly evaluate perfusion status of limbs after any percutaneous procedure.

Validation of a low-cost simulation strategy for burn escharotomy training.

Escharotomy is the primary effective intervention to relieve constriction and impending vascular compromise in deep, circumferential or near-circumferential burns of the extremities and trunk. Training on escharotomy indications, technique and pitfalls is essential, as escharotomy is both an infrequent and high-risk procedure in civilian and military medical environments, including low-resource settings. Therefore, we aimed to validate an educational strategy that combines video-based instruction with a low-cost, low-fidelity simulation model for teaching burn escharotomy. Pre-hospital and hospital-based medical personnel, with varying degrees of burn care-related experience, participated in a one-hour training session. The first part of the training consisted of video-based instruction that described the indications, preparation, steps, pitfalls and complications associated with escharotomy. The second part of the training consisted of a supervised, hands-on simulation with a previously described low-cost, low-fidelity escharotomy model. Participants were then offered two psychometrically validated instruments to assess their learning experience. 40 participants were grouped according to prior burn care and surgical experience: attending surgeons (6), surgery and emergency medicine residents and fellows (26), medical students (5), and pre-hospital personnel (3). On two psychometrically validated questionnaires, participants at both the attending and trainee levels overwhelmingly confirmed that our educational strategy met best educational practices on the criteria of active learning, collaboration, diverse ways of learning, and high expectations; they also highly rated their satisfaction with and self-confidence under this learning strategy. An educational strategy that combines video-based instruction and a low-cost, low-fidelity escharotomy simulation model was successfully demonstrated with participants across a broad range of prior burn care experience levels. This strategy is easily reproducible and broadly applicable to increase the knowledge and confidence of medical personnel before they are called to perform escharotomy. Important applications include resource-limited environments and deployed military settings.


FiO2 of 1 and hyperventilation with mechanical ventilation, demonstrated by the low PCO2, fail to sufficiently raise PO2, due to a V/Q disturbance, with probable shunt in the area of pulmonary atelectasis, probably acute, since the lung has not been able to create compensatory mechanisms to limit perfusion in the poorly ventilated areas.

FiO2 of 1 and hyperventilation with mechanical ventilation, demonstrated by the low PCO2, [HIDDEN], due to a V/Q disturbance, with probable shunt in the area of pulmonary atelectasis, probably acute, since the lung has not been able to create compensatory mechanisms to limit perfusion in the poorly ventilated areas.

While you are on call in the Emergency Department of your hospital, you have to attend a 64-year-old patient with acute respiratory failure. His clinical condition is critical, with low oxygen saturation and hemodynamic instability. An urgent chest X-ray was performed showing atelectasis of 2/3 of the right lung. Orotracheal intubation and assisted ventilation were performed, with Fi02 of 1.0. Subsequent arterial blood gas analysis showed pH 7.23, Pa02 60 mmHg and PaC02 30 mmHg. What was the cause of the hypoxemia?

Respiratory failure

This type of respiratory failure is caused by conditions that affect oxygenation, such as: Low ambient oxygen (e.g. at high altitude) Ventilation-perfusion mismatch (parts of the lung receive oxygen but not enough blood to absorb it, e.g. pulmonary embolism) Alveolar hypoventilation (decreased minute volume due to reduced respiratory muscle activity, e.g. in acute neuromuscular disease); this form can also cause type 2 respiratory failure if severe. Diffusion problem (oxygen cannot enter the capillaries due to parenchymal disease, e.g. in pneumonia or ARDS) Shunt (oxygenated blood mixes with non-oxygenated blood from the venous system, e.g. right to left shunt) Type 2 Hypoxemia (PaO2 <8kPa or normal) with hypercapnia (PaCO2 >6.0kPa). The basic defect in type 2 respiratory failure is characterized by: {| class="wikitable" |PaO2 || decreased (< )or normal |- | PaCO2 || increased (> ) |- | PA-aO2 || normal |- |pH || <7.35 |}

Tracheal intubation

Intubation may be necessary for a patient with decreased oxygen content and oxygen saturation of the blood caused when their breathing is inadequate (hypoventilation), suspended (apnea), or when the lungs are unable to sufficiently transfer gasses to the blood. Such patients, who may be awake and alert, are typically critically ill with a multisystem disease or multiple severe injuries. Examples of such conditions include cervical spine injury, multiple rib fractures, severe pneumonia, acute respiratory distress syndrome (ARDS), or near-drowning. Specifically, intubation is considered if the arterial partial pressure of oxygen (PaO2) is less than 60 millimeters of mercury (mm Hg) while breathing an inspired O2 concentration (FIO2) of 50% or greater. In patients with elevated arterial carbon dioxide, an arterial partial pressure of CO2 (PaCO2) greater than 45 mm Hg in the setting of acidemia would prompt intubation, especially if a series of measurements demonstrate a worsening

Respiratory failure

Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise in arterial carbon dioxide levels is called hypercapnia. Respiratory failure is classified as either Type 1 or Type 2, based on whether there is a high carbon dioxide level, and can be acute or chronic. In clinical trials, the definition of respiratory failure usually includes increased respiratory rate, abnormal blood gases (hypoxemia, hypercapnia, or both), and evidence of increased work of breathing. Respiratory failure causes an altered mental status due to ischemia in the brain. The typical partial pressure reference values are oxygen Pa O2 more than 80 mmHg (11 kPa) and carbon dioxide Pa CO2 less than 45 mmHg (6.0 kPa). Cause

Generalized hypoxia

Causes Restricted oxygen flow to the body's tissue that leads to hypoxia can be caused by a variety of situations or other underlying conditions. High altitude (above 3048 metres/10,000 feet) Hypoventilation – failure of respiratory pump due to any cause (fatigue, barbiturate poisoning, pneumothorax, etc.) Ventilation perfusion mismatch Obstructed airway Drowning Abnormal pulmonary function Chronic obstructive pulmonary diseases (COPD) Neuromuscular diseases or interstitial lung disease Constrained blood flow to a tissue (such as atherosclerosis or vasoconstriction) Blockage in blood flow like a sickle cell crisis Low or no blood flow caused by bleeding or heart attack Malformed vascular system such as an anomalous coronary artery Limited oxygen transportation due to anemia While respiring in the open air at high altitudes, the human body experiences altitude sickness and hypoxemia due to a low partial pressure of oxygen, decreasing the carriage of oxygen by hemoglobin.

Alveolar–arterial gradient

Because A–a gradient is approximated as: (150 − 5/4(P)) – at sea level and on room air (0.21x(760-47) = 149.7 mmHg for the alveolar oxygen partial pressure, after accounting for the water vapor), the direct mathematical cause of a large value is that the blood has a low , a low Pa, or both. is very easily exchanged in the lungs and low Pa directly correlates with high minute ventilation; therefore a low arterial Pa indicates that extra respiratory effort is being used to oxygenate the blood. A low indicates that the patient's current minute ventilation (whether high or normal) is not enough to allow adequate oxygen diffusion into the blood. Therefore, the A–a gradient essentially demonstrates a high respiratory effort (low arterial Pa) relative to the achieved level of oxygenation (arterial ). A high A–a gradient could indicate a patient breathing hard to achieve normal oxygenation, a patient breathing normally and attaining low oxygenation, or a patient breathing hard and still

Emergency department

Asthma and COPD Acute exacerbations of chronic respiratory diseases, mainly asthma and chronic obstructive pulmonary disease (COPD), are assessed as emergencies and treated with oxygen therapy, bronchodilators, steroids or theophylline, have an urgent chest X-ray and arterial blood gases and are referred for intensive care if necessary. Noninvasive ventilation in the ED has reduced the requirement for tracheal intubation in many cases of severe exacerbations of COPD. Special facilities, training, and equipment An ED requires different equipment and different approaches than most other hospital divisions. Patients frequently arrive with unstable conditions, and so must be treated quickly. They may be unconscious, and information such as their medical history, allergies, and blood type may be unavailable. ED staff are trained to work quickly and effectively even with minimal information.

Mechanical ventilation

When 100% oxygen (1.00 Fi) is used initially for an adult, it is easy to calculate the next Fi to be used, and easy to estimate the shunt fraction. The estimated shunt fraction refers to the amount of oxygen not being absorbed into the circulation. In normal physiology, gas exchange of oxygen and carbon dioxide occurs at the level of the alveoli in the lungs. The existence of a shunt refers to any process that hinders this gas exchange, leading to wasted oxygen inspired and the flow of un-oxygenated blood back to the left heart, which ultimately supplies the rest of the body with de-oxygenated blood. When using 100% oxygen, the degree of shunting is estimated as 700 mmHg - measured Pa. For each difference of 100 mmHg, the shunt is 5%. A shunt of more than 25% should prompt a search for the cause of this hypoxemia, such as mainstem intubation or pneumothorax, and should be treated accordingly. If such complications are not present, other causes must be sought after, and positive

Diffuse alveolar damage

Berlin Criteria: as stated on UpToDate (2020) Timing: onset of respiratory symptoms within one week of a injury/insult. Chest Imaging: either chest x-ray or CT scan, must show bilateral opacities that cannot be fully explained by other conditions such as effusion, lung/lobar collapse, or lung nodules. Origin of Edema: respiratory failure that cannot be fully explained by cardiac failure or fluid overload, this needs objective assessment such as an echocardiogram. Impaired Oxygenation: this can be determined by looking at the ratio of arterial oxygen tension to fraction of inspired oxygen (PaO2/FiO2) that can be obtained based on an arterial blood gas test. Note: all PaO2/FiO2 ratios used in the determination of the severity of ARDS require that the patient be on a ventilator at a setting that includes 5 cm H2O or more of positive end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP).

Respiratory failure

The typical partial pressure reference values are oxygen Pa O2 more than 80 mmHg (11 kPa) and carbon dioxide Pa CO2 less than 45 mmHg (6.0 kPa). Cause Several types of conditions can potentially result in respiratory failure: Conditions that reduce the flow of air into and out of the lungs, including physical obstruction by foreign bodies or masses and reduced breathing due to drugs or changes to the chest. Conditions that impair the lungs' blood supply. These include thromboembolic conditions and conditions that reduce the output of the right heart, such as right heart failure and some myocardial infarctions. Conditions that limit the ability of the lung tissue to exchange oxygen and carbon dioxide between the blood and the air within the lungs. Any disease which can damage the lung tissue can fit into this category. The most common causes are (in no particular order) infections, interstitial lung disease, and pulmonary oedema. Diagnosis

Intermittent positive pressure breathing (IPPB) is a respiratory therapy treatment for people who are hypoventilating. While not a preferred method due to cost, IPPB is used to expand the lungs, deliver aerosol medications, and in some circumstances ventilate the patient. Indications IPPB may be indicated for patients who are at risk for developing atelectasis and who are unable or unwilling to breathe deeply without assistance. In patients with severe lung hyperinflation, IPPB may decrease dyspnea and discomfort during nebulized therapy. Contraindications Most contraindications are relative, such as nausea, hemodynamic instability, tracheal fistula, singulation and hemoptysis. Untreated tension pneumothorax is an absolute contraindication. IMPLEMENTATION When treating atelectasis - Therapy should be volume-oriented 2. Tidal volumes(VT) must be measured 3. VT goals must be set 4. VT goal of 10-15mL/kg ofbody weight

[A case of emergency admission for CO2 narcosis in a patient with amyotrophic lateral sclerosis].

A 68-year-old man with severe dyspnea was admitted as an emergency case. He had no past history of any respiratory or neuromuscular diseases. Immediately after insufflation of oxygen, respiratory arrest occurred. The blood gas analysis showed hypoxemia and severe hypercapnia (PaO2; 32 mmHg, PaCO2; 127 mmHg). We diagnosed as CO2 narcosis, and he was treated with a respirator in the ICU. He showed nonflaccid bilateral diaphragmatic paralysis and muscle atrophy of the upper extremities. As the EMG showed giant spikes of neurogenic pattern, he was diagnosed as ALS. Weaning from the respirator failed because of his respiratory muscle fatigue. He was given rehabilitation during the day time and ventilatory support with the respirator during the night. We conclude that if we meet with an emergency patient with CO2 narcosis without any pulmonary disorder, we have to suspect neuromuscular diseases, e.q. ALS. In some of such cases, mechanical ventilation supports social rehabilitation.

[A case of postural hypoxemia with a final diagnosis of myasthenia gravis].

We present a case of postural hypoxemia with a final diagnosis of myasthenia gravis (MG). A 62-year-old man experienced double vision in his left eye from December 2008 and received a diagnosis of diabetic neuropathy. From mid-December he began to experience breathing difficulties at night when in a supine position and was admitted to our hospital. Bilateral diaphragmatic elevation was observed on a chest X-ray film, and lower lung atelectasis and an anterior mediastinal tumor were observed on chest CT. However, his breathing difficulties only occurred when he was in a supine position. Therefore, we performed blood gas analysis in supine and sitting positions. Hypoxemia, hypercapnia and an increase in A-aDO2 were observed in the supine position, leading to a diagnosis of postural hypoxemia. Due to the exacerbation of his double vision, the patient was referred to the ophthalmology and neurology departments where he tested positive for anti-acetylcholine receptor antibodies and also on a tensilon test, resulting in a final diagnosis of MG. During the tensilon test, the patient's breathing difficulties in the supine position improved, and therefore his postural hypoxemia was thought to have resulted from diaphragmatic muscle weakness as a result of MG. MG respiratory failure is typically of the acute fulminating type and is considered to be a critical condition. However, it should be noted that there are cases, such as the present one, in which MG presents as postural hypoxemia.

[Ipsilateral pneumothorax in one-lung respiration. A rare, recently diagnosed and atypical complication of a double lumen tube].

The authors report a rare, recently diagnosed and atypical mishap during one-lung ventilation (OLV) via a double lumen tube (DLT) and left-sided thoracotomy: an ipsilateral pneumothorax during ventilation of the right lung. This occurred in a 63-year-old patient with chronic obstructive airway disease who was scheduled for urgent repair of a descending thoracic aortic aneurysm. Anaesthesia and surgery were uneventful until aortic cross-clamping release. The common presentation of increased intrathoracic extrapleural pressure owing to a pneumothorax in patients with mechanically ventilated lungs is a rapid decrease in oxygen saturation, followed or paralleled by haemodynamic deterioration. Although the above presentation could be seen in this case, the diagnosis of a tension pneumothorax was delayed twice. First, symptoms were initially obscured by haemodynamic changes resulting from a head-down tilt and aortic declamping. Second, since the lack of consolidation after aortic declamping focused attention on the airway problems, complications resulting from the use of a DLT were primarily considered. In particular, since breathing sounds were detectable initially, malposition or torsion of the DLT had to be excluded by fibre-optic bronchoscopy, which involved a further delay. Finally, two observations led to the diagnosis of a right-sided tension pneumothorax: (1) bullae of the contralateral lung, detected during thoracotomy; (2) the finding that ventilation of both lungs and the left lung subsequently increased arterial (SaO2) and mixed venous oxygen saturation (SvO2) and the circulatory status, but ventilation of the right lung caused a deterioration. Chest radiography and insertion of a chest tube with drainage of air, thereafter, validated our hypothesis. The time course of oxygen desaturation during OLV and tension pneumothorax was as severe as expected; the time course of haemodynamic deterioration, however, appeared quicker and had more impact than expected. Assuming that mediastinal deviation was not hindered by contralateral intrathoracic pressure during thoracotomy, we believed that circulation should be depressed later or to a lesser extent in patients with an intraoperative pneumothorax. Yet, during thoracotomy, decrease in cardiac filling and output during tension pneumothorax in OLV obviously results primarily from the immovability of the mediastinum owing to mediastinal fixation and is at least as decisive as the contralateral intrathoracic pressure in closed-chest patients. In summary, a tension pneumothorax during one-lung ventilation and thoracotomy is a rare, but disastrous complication during the use of a DLT, which has not, to our knowledge, been reported previously. We recommend that tension pneumothorax be added to the list of complications and problems during OLV by the use of a DLT, especially in patients with structural lung diseases.

Respiratory compromise

Respiratory compromise describes a deterioration in respiratory function with a high likelihood of rapid progression to respiratory failure and death. Respiratory failure occurs when inadequate gas exchange by the respiratory system occurs, with a low oxygen level or a high carbon dioxide level. Causes Patients in acute care hospitals, particularly those with respiratory conditions, are at risk for developing respiratory compromise. Respiratory failure requiring emergency mechanical ventilation occurs in over 40,000 patients per year in the United States. In postoperative patients in the United States, the National Surgical Quality Improvement Program reports that 1.03% of all surgical patients require an unplanned intubation postoperatively.

InternalMed_Harrison

General principles of respiratory evaluation in patients with PNS involvement, regardless of cause, include assessment of pulmonary mechanics, such as maximal inspiratory force (MIF) and vital capacity (VC), and evaluation of strength of bulbar muscles. Regardless of the cause of weakness, endotracheal intubation should be considered when the MIF falls to <–25 cmH2O or the VC is <1 L. Also, patients with severe palatal weakness may require endotracheal intubation in order to prevent acute upper airway obstruction or recurrent aspiration. Arterial blood gases and oxygen saturation from pulse oximetry are used to follow patients with potential respiratory compromise from PNS dysfunction. However, intubation and mechanical ventilation should be undertaken based on clinical assessment rather than waiting until oxygen saturation drops or CO2 retention develops from hypoventilation. Noninvasive mechanical ventilation may be considered initially in lieu of endotracheal intubation but is

Acute respiratory distress syndrome

If Pa:Fi < 300 mmHg (40 kPa), then the definitions recommended a classification as "acute lung injury" (ALI). Note that according to these criteria, arterial blood gas analysis and chest X-ray were required for formal diagnosis. Limitations of these definitions include lack of precise definition of acuity, nonspecific imaging criteria, lack of precise definition of hypoxemia with regards to PEEP (affects arterial oxygen partial pressure), arbitrary Pa thresholds without systematic data.

Neurology_Adams

are usually necessary (see further on). However, a fairly severe impairment of ventilation may occur before the first sign of dyspnea appears and before there is elevation of arterial carbon dioxide content. Incipient respiratory failure may be evident by tachypnea and a decrease in arterial oxygen tension (Po2 less than 85 mm Hg) reflecting pulmonary atelectasis. When respiratory failure arises gradually as the patient weakens over days, there is slight tachycardia, diaphoresis, restlessness, and tachypnea. Attempts to forestall intubation and positive-pressure ventilation by using negative-pressure cuirass-type devices have been unsatisfactory in our experience. Patients with oropharyngeal weakness require intubation even earlier so as to prevent aspiration, but full mechanical ventilation is not always necessary at the same time. Patients in these circumstances should obviously be admitted to an intensive care unit staffed by personnel skilled in maintaining ventilation and airway

A successful management after preterm delivery in a patient with severe sepsis during third-trimester pregnancy.

A 33-year-old woman visited the emergency department presenting with fever and dyspnea. She was pregnant with gestational age of 31 weeks and 6 days. She had dysuria for 7 days, and fever and dyspnea for 1 day. The vital signs were as follows: blood pressure 110/70 mmHg, heart rate 118 beats/minute, respiratory rate 28/minute, body temperature 38.7℃, and oxygen saturation by pulse oximetry 84% during inhalation of 5 liters of oxygen by nasal prongs. Crackles were heard over both lung fields. There were no signs of uterine contractions. Chest X-ray and chest computed tomography scan showed multiple consolidations and air bronchograms in both lungs. According to urinalysis, there was pyuria and microscopic hematuria. She was diagnosed with community-acquired pneumonia and urinary tract infection (UTI) that progressed to severe sepsis and acute respiratory failure. We found extended-spectrum beta-lactamase producing <iEscherichia coli</i in the blood culture and methicillin-resistant Staphylococcus aureus in the sputum culture. The patient was transferred to the intensive care unit with administration of antibiotics and supplementation of high-flow oxygen. On hospital day 2, hypoxemia was aggravated. She underwent endotracheal intubation and mechanical ventilation. After 3 hours, fetal distress was suspected. Under 100% fraction of inspired oxygen, her oxygen partial pressure was 87 mmHg in the arterial blood. She developed acute kidney injury and thrombocytopenia. We diagnosed her with multi-organ failure due to severe sepsis. After an emergent cesarean section, pneumonia, UTI, and other organ failures gradually recovered. The patient and baby were discharged soon thereafter.

[Mechanical ventilation in neuromuscular diseases: do not start too early, but certainly not too late].

Three patients had chronic respiratory disorders: a 42-year-old man with glycogenosis type II was tired, had headaches, poor pulmonary function values and, according to the arterial blood gas values, hypercapnia; a man aged 24 with Duchenne's muscular dystrophy had variable moderate dyspnoea with hypoxia and hypercapnia, and a man aged 64 years with an mitochondrial myopathy complained of dyspnoea and headache but had good blood gas values. The symptoms and abnormalities of the first patient were suppressed by nocturnal ventilatory support through a nasal mask system, the second preferred to refrain from ventilatory support and died a few weeks later and the symptoms of the third patient decreased without ventilatory support. Assessing a ventilatory disorder in patients with a neuromuscular disease is not always simple. Symptoms suggestive of nocturnal hypoventilation may occur in patients without respiratory insufficiency. It is also possible for patients with chronic respiratory insufficiency to be free of symptoms. Determinations of the arterial blood gas values are the most reliable method. Since normal daytime values do not exclude a nocturnal respiratory insufficiency, it is advisable in case of suspicion of nocturnal hypoventilation to measure the arterial blood gas values at night, as well. Nocturnal pulse oximetry does not always adequately reflect the degree of hypoventilation. In view of the positive effects of assisted respiration, adequate diagnostic examinations and early referral to a centre for home mechanical ventilation are advisable.

InternalMed_Harrison

Whichever mode of MV is used in acute respiratory failure, the evidence from several important controlled trials indicates that a protective ventilation approach guided by the following principles (and summarized in Fig. 323-1) is safe and offers the best chance of a good outcome: (1) Set a target tidal volume close to 6 mL/kg of ideal body weight. (2) Prevent plateau pressure (static pressure in the airway at the end of inspiration) exceeding 30 cm H2O. (3) Use the lowest possible fraction of inspired oxygen (Fio2) to keep the Sao2 at ≥90%. (4) Adjust the PEEP to maintain alveolar patency while preventing overdistention and closure/reopening. With the application of these techniques, the mortality rate among patients with acute hypoxemic respiratory failure has decreased to ~30% from close to 50% a decade ago.

[Non-invasive ventilation of the lungs in neuromuscular diseases].

To describe a clinical case and to analyze our own practice of using NIVL in a myasthenia (MG) gravis patient. Since 2018 in the Republican Research and Clinical Center of Neurology and Neurosurgery NIVL has been performed in 29 patients (21 amyotrophic lateral sclerosis patients and 8 MG patients). The research was carried out using the portable polysomnograph Polymate YH-1000C (BMC, China) and in the Sleep Laboratory of the Republican Clinical Medical Center of the Presidential Administration of the Republic of Belarus using SOMNOlab V 2.19 (Weinmann, Germany). Respiratory support was provided by the Ventimotion 2 device (Weinmann, Germany). The article presents our own experience of using NIVL in MG patient and profound description of the diagnostic and therapeutic complex. The development of chronic respiratory failure in NMD is based on a violation of the ventilation-perfusion ratio in the alveoli as a result of the development of hypoventilation due to restrictive disorders (namely, due to weakness of the respiratory muscles). Compensatory mechanisms eventually lead to an increase in the work on the affected respiratory muscles that leads to the formation of a vicious circle. The use of NIVL provides adequate ventilation of the lungs providing rest for the respiratory muscles. Like any other medical intervention NIVL has indications and contraindications, advantages and disadvantages that are described in this article. The use of NIVL helps to reduce the risk and frequency of respiratory complications, the number and duration of hospitalizations that significantly affects the prognosis and course of NMD as well as improves the quality of life and the level of adaptation of patients.

Possible silent hypoxemia in a COVID-19 patient: A case report.

It has been hypothesized that silent hypoxemia is the cause of rapid progressive respiratory failure with severe hypoxia that occurs in some COVID-19 patients without warning. A 60-year-old male presented cough without any breathing difficulty. Vital signs showed blood pressure 130/75 mmHg, pulse 84x/minute, respiratory rate (RR) 21x/minute, body temperature 36.5C, and oxygen saturation (SpO2) 75% on room air. RT-PCR for COVID-19 were positive. On third day, he complained of worsening of breath shortness, but his RR was still normal (22x/minute) with SpO2 of 98% on 3 L/minute oxygen via nasal cannula. On fifth day, he experienced severe shortness of breath with RR 38x/minute. He was then intubated using a synchronized intermittent mandatory ventilation. Blood gas analysis showed pH 7.54, PaO2 58.9 mmHg, PaCO2 31.1 mmHg, HCO3 26.9mEq/L, SaO2 94.7%, FiO2 30%, and P/F ratio 196 mmHg. On eighth day, his condition deteriorated with blood pressure 80/40 mmHg with norepinephrine support, pulse 109x/minute, and SpO2 72% with ventilator. He experienced cardiac arrest and underwent basic life support, then resumed strained breathing with return of spontaneous circulation. Blood gas analysis showed pH 7.07, PaO2 58.1 mmHg, PaCO2 108.9 mmHg, HCO3 32.1mEq/L, SaO2 78.7%, FiO2 90%, and P/F ratio 65 mmHg. Three hours later, he suffered cardiac arrest again and eventually died. Possible mechanisms of silent hypoxemia are V/Q mismatch, intrapulmonary shunting, and intravascular microthrombi. Silent hypoxemia might be considered as an early sign of deterioration of COVID-19 patients, thus, physician may be able to intervene early and decrease its morbidity and mortality.

Acute non-invasive ventilation - getting it right on the acute medical take.

Non-invasive ventilation (NIV) given to the right patient, in the right setting, in the right way and at the right time improves outcomes. However, national audits reveal poor practice in patient selection, clinical judgement, treatment initiation and availability of trained staff. NIV is indicated for persistent acute hypercapnic respiratory failure (AHRF) with acidosis after usual medical management in chronic obstructive pulmonary disease (COPD) exacerbation and even without acidosis in neuromuscular disorders or other restrictive conditions eg obesity hypoventilation or kyphoscoliosis. Having trained staff in a suitable environment with adequate equipment are keys to its success, along with close monitoring. A plan should be put in place at the time of initiating NIV about the ceiling of care, eg escalation to intubation or palliation, if the patient is not improving with NIV. Early NIV failure is most likely due to technical issues, such as inadequate pressures or mask leak, while late failure is usually the consequence of advanced disease. Any presentation with AHRF is a poor prognostic indicator and outpatient respiratory follow-up is indicated following discharge. For selected patients with COPD who remain hypercapnic 2 weeks after an exacerbation, domiciliary NIV can reduce admissions and improve survival. For patients with neuromuscular disorders or kyphoscoliosis a presentation with AHRF almost always indicates the need for domiciliary NIV.

Ventilator Management -- Issues of Concern -- Airway Pressure Release Ventilation (APRV)

Minute ventilation, then, will depend on T low and the patient's tidal volumes during T high. Indications for the use of APRV: ARDS that is difficult to oxygenate with AC Acute lung injury Postoperative atelectasis. Advantages of APRV: APRV is a good mode for lung protection ventilation. The ability to set the P high means that the operator has control over the plateau pressure which can significantly lower the incidence of barotrauma Because the patient initiates his respiratory efforts, there is better gas distribution secondary to improved V/Q matching. Constant high pressure means more recruitment (open lung strategy) APRV may improve oxygenation in ARDS patients who are difficult to oxygenate on AC APRV may reduce the need for sedation and neuromuscular blocking agents as the patient may be more comfortable than with other modes. Disadvantages and contraindications:

[Successful extracorporeal membrane oxygenation (ECMO) treatment in Legionella pneumonia].

The mortality of severe ARDS is almost 60%. Ventilation-associated lung-injury can be avoided by low-pressure, low-volume ventilation. Potential use of ECMO in case of refractory hypoxemia beside modern ventilatory therapy can be considered. Increasing numbers of respiratory ECMO runs are seen worldwide, though the efficacy remains controversial. The authors present the first successful venovenous-ECMO treatment in severe ARDS in our Institute. We report the case of a 67-year-old male who was admitted with community-acquired pneumonia caused by Legionella. Despite empirical and later targeted antibiotic therapy, severe ARDS with sepsis evolved. Neither ventilation nor prone position resulted in permanent improvement in oxygenation. The patient was referred to our Institute for extracorporeal life support (ECLS) therapy. On admission, blood gas showed severe hypoxemia with mild hypercapnia (PaO<sub2</sub/FiO<sub2</sub: 60, pCO<sub2</sub: 53 mmHg at PEEP: 14 mmHg, PIP: 45 mmHg). X-ray showed bilateral patchy infiltrates while cardiac impairment (EF: 45%) and dilated right ventricle were seen on echocardiography. Elevated pulmonary artery pressure (mPAP: 41 mmHg) was measured. After implantation of femoral-jugular VV ECMO, oxygen saturation was appropriate with lung protective ventilation (FiO<sub2</sub: 0.5, TV: 3-4 ml/kg). Improving lung function enabled us to stop ECMO after 8 days and further 5 days later the patient was weaned off ventilation. After 21 days of intensive care we discharged him to the referral hospital. By reporting this case we emphasise the potential role of respiratory ECMO. Consideration should be given to increase the contingent of this modality in the Hungarian intensive care in accordance with international practice. Orv Hetil. 2019; 160(6): 235-240.

An 84-Year-Old Woman with Shortness of Breath and Low Oxygen Saturation: "Think Outside the Box".

An 84-year-old woman, who had been admitted to the emergency department (ED) several times because of dyspnoea, was treated for acute exacerbation of chronic respiratory failure without satisfactory clinical improvement. According to her medical history, 8 years earlier, she underwent a complicated cardiosurgical procedure that required tracheostomy and mechanical ventilation in the post-operative period for 45 days. Traditional X-Ray did not show any abnormal findings; however, high resolution thorax computed tomography (HRCT) scan revealed a severe tracheal stenosis, which was confirmed with bronchoscopy, and required immediate tracheostomy. Tracheal stenosis is a rare but severe complication that should be suspected when a patient with previous tracheostomy presents to the ED with dyspnoea even if tracheostomy had been closed many years before, because adaptive mechanism results in asymptomatic life for a long period.

InternalMed_Harrison

The most common cause of respiratory hypoxia is ventilation-perfusion mismatch resulting from perfusion of poorly ventilated alveoli. Respiratory hypoxemia may also be caused by hypoventilation, in which case it is associated with an elevation of Paco2 (Chap. 306e). These two forms of respiratory hypoxia are usually correctable by 248 inspiring 100% O2 for several minutes. A third cause of respiratory hypoxia is shunting of blood across the lung from the pulmonary arterial to the venous bed (intrapulmonary right-to-left shunting) by perfusion of nonventilated portions of the lung, as in pulmonary atelectasis or through pulmonary arteriovenous connections. The low Pao2 in this situation is only partially corrected by an Fio2 of 100%.

InternalMed_Harrison

Arterial blood gas testing is often helpful in assessing respiratory 1663 disease. Hypoxemia, while usually apparent with pulse oximetry, can be further evaluated with the measurement of arterial PO2 and the calculation of an alveolar gas and arterial blood oxygen tension difference ([A–a]DO2). Patients with diseases that cause ventilation-perfusion mismatch or shunt physiology have an increased (A–a) DO2 at rest. Arterial blood gas testing also allows the measurement of arterial PCO2. Hypercarbia can accompany severe airway obstruction (e.g., COPD) or progressive restrictive physiology, as in patients with neuromuscular weakness.

Alveolar–arterial gradient

For example, consider hypoventilation. Patients can exhibit hypoventilation for a variety of reasons; some include CNS depression, neuromuscular diseases such as myasthenia gravis, poor chest elasticity as seen in kyphoscoliosis or patients with vertebral fractures, and many others. Patients with poor ventilation lack oxygen tension throughout their arterial system in addition to the respiratory system. Thus, the river will have decreased flow throughout both parts. Since both the "A" and the "a" decrease in concert, the gradient between the two will remain in normal limits (even though both values will decrease). Thus patients with hypoxemia due to hypoventilation will have an A-a gradient within normal limits.

[Clinical value of noninvasive positive-pressure ventilation in chronic obstruction pulmonary disease combined with type II respiratory failure: a 4-year retrospective study].

To evaluate the value of noninvasive positive-pressure ventilation (NIPPV) in treatment of patients with chronic obstruction pulmonary disease (COPD) combined with type II respiratory failure (RF). From June 15th, 2002 to June 15th, 2006, there were 351 inpatients with COPD combined with type II RF. Those treated with NIPPV were categorized as treatment group; those who were not treated by NIPPV served as control group. All patients were divided into four subgroups according to results of blood gas analysis as follows. Mild RF group: 50 mm Hg < or = arterial partial pressure of carbon dioxide (PaCO2) < or = 65 mm Hg, 1 mm Hg=0.133 kPa; medium RF group: 66 mm Hg < or = PaCO2 < or = 80 mmHg; severe RF group: 81 mm Hg < or = PaCO2 < or = 95 mm Hg; extremely severe RF group: > or = 96 mm Hg. NIPPV was used in treatment group on top of conventional treatment. Values of blood gas analysis, length of stay, cost of hospitalization, rate of cannulation and fatality rate were observed in all groups before treatment and after treatment. After being treated with NIPPV, all patients with COPD combined with type II RF in different degrees, arterial partial pressure of oxygen (PaO2) were raised in different degrees, and PaCO2 were all lowered in different degrees. Blood pH, PaO2 and PaCO2 showed statistically significant difference between treatment group and control group in severe and extremely severe RF patients (all P < 0.05). The length of stay of patients with RF in different degrees, was shortened obviously, also the cost of hospitalization, rate of cannulation and fatality rate were all significantly reduced in treatment group. In contrast to mild, medium RF patients, rate of cannulation and fatality rate were increased in extremely severe RF group (all P < 0.05). NIPPV is beneficial to COPD combined with type II RF in different degrees.

Acute respiratory failure induced by mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH2O.

The effects of high pressure mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH(2)O were studied on the lungs of healthy newborn pigs (14-21 days after birth). Forty percent oxygen in nitrogen was used for ventilation to prevent oxygen intoxication. The control group (6 pigs) was ventilated for 48 hours at a peak inspiratory pressure less than 18 cmH(2)O and a PEEP of 3-5 cmH(2)O with a normal tidal volume, and a respiratory rate of 20 times/min. The control group showed few deleterious changes in the lungs for 48 hours. Eleven newborn pigs were ventilated at a peak inspiratory pressure of 40 cmH(2)O with a PEEP of 3-5 cmH(2)O and a respiratory rate of 20 times/min. To avoid respiratory alkalosis, a dead space was placed in the respiratory circuit, and normocarbia was maintained by adjusting dead space volume. In all cases in the latter group, severe pulmonary impairments, such as abnormal chest roentgenograms, hypoxemia, decreased total static lung compliance, high incidence of pneumothorax, congestive atelectasis, and increased lung weight were found within 48 hours of ventilation. When the pulmonary impairments became manifest, 6 of the 11 newborn pigs were switched to the conventional medical and ventilatory therapies for 3-6 days. However, all of them became ventilator dependent, and severe lung pathology was found at autopsy. These pulmonary insults by high pressure mechanical pulmonary ventilation could be occurring not infrequently in the respiratory management of patients with respiratory failure.

The addition of a membrane oxygenator to a ventricular assist device in a patient with acute respiratory distress syndrome.

A 12-year-old boy with Marfan's syndrome required a biventricular assist device (VAD) after an aortic root replacement. The patient developed acute respiratory distress syndrome and required escalating ventilator support. We hypothesized that the addition of a membrane oxygenator in series with the assist device would improve gas exchange and allow for a more lung-protective ventilator approach. A membrane oxygenator was placed in series with the right VAD resulting in a blood path of right atrium to VAD to oxygenator to pulmonary artery. Circuit function was gauged by monitoring flow and oxygenator pressures and periodic circuit inspections and oxygenator blood gases. Heparin was titrated to maintain unfractionated antifactor Xa levels of .3-.7 IU/mL and partial thromboplastin time of 60-80 seconds. The initial sweep gas supplying the oxygenator was 5 L/min at an F1O2 of 1.0, which achieved a pH > 7.40 and a PF ratio > 250. The pre- and post-oxygenator pressures were 55-60 mmHg and 45-50 mmHg, respectively, and the measured flow at the oxygenator outlet was 2.0-2.2 L/min. The patient was changed from high-frequency oscillatory ventilation to pressure-controlled synchronized intermittent ventilation with pH maintained at 7.35-7.40 and PF ratio > 250. Paralytics were discontinued and the patient's neurologic condition was deemed intact. The patient hemorrhaged after a sternal closure and required transfusions and antifibrinolytics that led to thrombus in the membrane and membrane circuitry, which were replaced without incident. The patient's respiratory status remained stable; however, his overall condition worsened as a result of additional organ dysfunction and septicemia, and he did not survive. The addition of a membrane oxygenator to a VAD is feasible and supplements gas exchange permitting the use of more lung protective ventilation.