The effect of high-frequency ventilation of the lungs on postbypass oxygenation: A comparison with other ventilation methods applied during cardiopulmonary bypass. Alveolar Recruitment Strategy During Cardiopulmonary Bypass Does Not Improve Postoperative Gas Exchange and Lung Function Effects of alveolar recruitment on arterial oxygenation in patients after cardiac surgery: a prospective, randomized, controlled clinical trial. Pulmonary Effects of Noninvasive Ventilation Combined with the Recruitment Maneuver After Cardiac Surgery Effect of modified ultrafiltration on pulmonary function after cardiopulmonary bypass. The Pulmonary and Hemodynamic Effects of Two Different Recruitment Maneuvers After Cardiac Surgery Effects of three techniques of lung management on pulmonary function during cardiopulmonary bypass. Continuous Positive Airway Pressure at 10 cm H2O During Cardiopulmonary Bypass Improves Postoperative Gas Exchange Ventilation during cardiopulmonary bypass: impact on cytokine response and cardiopulmonary function. CPAP at 10 cm H2O during cardiopulmonary bypass does not improve postoperative gas exchange. Lung perfusion with clarithromycin ameliorates lung function after cardiopulmonary bypass. Both lung recruitment maneuver and PEEP are needed to increase oxygenation and lung volume after cardiac surgery Influence of a vital capacity maneuver on pulmonary gas exchange after cardiopulmonary bypass. Leukocyte depletion during cardiac operation: a new approach through the venous bypass circuit. Intrapulmonary shunt after cardiopulmonary bypass: the use of vital capacity maneuvers versus off-pump coronary artery bypass grafting. Lung management during cardiopulmonary bypass: is continuous positive airways pressure beneficial? A study assessing the potential benefit of continued ventilation during cardiopulmonary bypass. Dexamethasone: benefit and prejudice for patients undergoing on-pump coronary artery bypass grafting: a study on myocardial, pulmonary, renal, intestinal, and hepatic injury. Open lung ventilation improves functional residual capacity after extubation in cardiac surgery* The role of continuous positive airway pressure during weaning from mechanical ventilation in cardiac surgical patients Effects of lung recruitment maneuver and positiveend‐expiratory pressure on lung volume, respiratory mechanics and alveolar gas mixing in patients ventilated after cardiac surgery Lung perfusion during cardiac surgery with cardiopulmonary bypass: is it necessary? Continuous positive airway pressure does not improve lung function after cardiac surgery Lung management during cardiopulmonary bypass: influence on extravascular lung water. Clinical relevance of ventilation during cardiopulmonary bypass in the prevention of postoperative lung dysfunction
OBJECTIVE To compare the effect of high-frequency ventilation versus other ventilation methods applied during cardiopulmonary bypass on postbypass oxygenation . DESIGN Prospect i ve , r and omized study . SETTING University hospital . PARTICIPANTS Seventy-five patients undergoing coronary artery bypass graft surgery . INTERVENTIONS Patients were allocated to 5 equal groups of different ventilation methods during bypass . Groups 1 and 2 received high-frequency , low-volume ventilation with 100 % and 21 % oxygen , respectively . Groups 3 and 4 received 5 cm H(2)O of continuous positive airway pressure ( CPAP ) with either 100 % or 21 % oxygen . Patients from group 5 were disconnected from the ventilator during the bypass period . MEASUREMENTS AND MAIN RESULTS Spirometry data , blood gas analysis , oxygen saturation as measured by pulse oximetry , and end-tidal carbon dioxide were recorded 5 minutes before chest opening , 5 minutes before bypass , 5 minutes after bypass , 5 minutes after chest closure and 6 , 12 , 18 , and 24 hours after surgery . There were no differences in compliance and mean airway pressures . Alveolar-to-arterial oxygen gradients increased , and PaO(2 ) decreased significantly ( p < 0.05 ) in all groups 5 minutes after bypass and this trend continued in the postoperative period . Patients from group 3 had higher PaO(2 ) and lower alveolar-to-arterial oxygen gradients , 5 minutes after weaning from bypass ( p < 0.05 ) . Extubation times were similar in all groups . CONCLUSIONS The alveolar-arterial oxygen gradient was lower , and the PaO(2 ) was higher 5 minutes after bypass in patients receiving CPAP ( 100 % O(2 ) ) as compared with those ventilated with high-frequency ventilation Pulmonary dysfunction with impairment of lung function and oxygenation is one of the most serious problems in the early postoperative period after cardiac surgery . In this study we investigated the effect of alveolar recruitment strategy during cardiopulmonary bypass on postoperative gas exchange and lung function . This prospect i ve r and omized study included 32 patients undergoing elective myocardial revascularization with cardiopulmonary bypass .  In 16 patients 5 cm H2O of positive end-expiratory pressure was applied after intubation and maintained until extubation ( Group I ) . In the other 16 patients ( group II ) a positive end expiratory pressure ( PEEP ) of 5 cm H2O was maintained as well but was increased to 14 cm H2O every 20 min for 2 min during cross clamp . Measurements were taken preoperatively , before skin incision , before and after ( 3 , 24 , 48 h ) cardiopulmonary bypass and before discharge ( 6th postoperative day ) . Postoperative gas exchange , extravascular lung water and lung function showed no significant difference between the groups . Postoperative pulmonary function variables were lower in both groups compared to baseline values . In patients with normal preoperative pulmonary function , application of an alveolar recruitment strategy during cardiopulmonary bypass does not improve postoperative gas exchange and lung function after cardiac surgery OBJECTIVE Pulmonary atelectasis and hypoxemia remain considerable problems after cardiac surgery . The objective of this study was to determine the efficacy of consecutive vital capacity maneuvers ( C-VCMs ) to improve oxygenation in patients after cardiac surgery . STUDY DESIGN R and omized , controlled clinical trial . SETTING Tertiary referral teaching center . PARTICIPANTS Ninety-five patients requiring elective cardiac surgery with cardiopulmonary bypass ( CPB ) .  INTERVENTION Patients were r and omly allocated to either C-VCM or control groups . In the C-VCM group , lung inflation at pressure of 35 cmH(2)O was sustained for 15 seconds before separation from CPB and at 30 cmH(2)O for 5 seconds after admission to the intensive care unit ( ICU ) . MEASUREMENTS AND MAIN RESULTS The primary outcome was the ratio of arterial oxygen tension to inspired oxygen fraction measured at the following predetermined time intervals : after induction of anesthesia , 15 minutes after separation from CPB , after admission to the ICU , after 3 hours of positive-pressure ventilation , after extubation , and before ICU discharge . C-VCM result ed in better arterial oxygenation extending from the immediate postoperative period to approximately 24 hours after surgery at the time of ICU discharge . There were no significant adverse events related to C-VCM application . CONCLUSION C-VCM is an effective method to reduce hypoxemia associated with the formation of atelectasis after cardiac surgery with CPB BACKGROUND : The aim of our study was to evaluate the pulmonary effects of noninvasive ventilation ( NIV ) with or without recruitment maneuver ( RM ) after open heart surgery . METHODS : One-hundred patients undergoing coronary artery bypass surgery were r and omized into four groups after the operation : 1 ) RM with sustained inflation during mechanical ventilation postoperatively ( RM group , n = 25 ) ; 2 ) RM combined with NIV applied for 1/2-h periods every 6 h in the first postoperative day after tracheal extubation ( RM-NIV group , n = 25 ) ; 3 ) NIV after tracheal extubation ( NIV group , n = 25 ) ; and 4 ) a control group consisting of patients receiving neither RM nor NIV ( control group , n = 25 ) . Pulmonary function tests , oxygenation index , and atelectasis on chest radiograph were evaluated and compared among the groups . RESULTS : RM provided higher arterial oxygen levels during mechanical ventilation and after tracheal extubation compared to other interventions . Oxygenation was better in the RM-NIV and NIV groups than in the control group ( P = 0.02 and P = 0.008 , respectively ) at the end of the study . The postoperative atelectasis score of the control group ( median : 1 ) was higher than those of the RM ( 1 ; P = 0.03 ) , RM-NIV ( 0 ; P < 0.01 ) and NIV ( 0 ; P < 0.01 ) groups . Pulmonary function of the NIV groups on postoperative day 2 was better than in the other groups , whereas the tests were similar among the groups on postoperative day 7 . CONCLUSIONS : NIV associated with RM provided better oxygenation both during and after the mechanical ventilation period . NIV either alone or in combination with RM provided lower atelectasis scores and better early pulmonary function tests compared to the control group , without a significant difference regarding the duration of mechanical ventilation , intensive care unit stay , and the length of hospitalization .  NIV combined with RM is recommended after open heart surgery to prevent postoperative atelectasis and hypoxemia BACKGROUND Pulmonary dysfunction is one of the most common manifestations of inflammatory response after cardiopulmonary bypass ( CPB ) . OBJECTIVE This prospect i ve r and omized study was conducted to evaluate the effect of a modified ultrafiltration ( MUF ) technique on pulmonary function after CPB in children . METHODS Forty patients weighing from 5 to 10 kg with congenital heart disease who required CPB for primary biventricular operative repair were prospect ively r and omized into two groups . The control group received conventional ultrafiltration ( CUF ) during CPB , and the study group received CUF and MUF .  Pulmonary compliance ( static and dynamic ) and gas exchange capacity of the lung expressed as oxygen index , respiratory index , ventilation index , and alveolar-arterial oxygen pressure difference were measured after intubation ( baseline ) , at the termination of CPB , at the end of MUF , on admission to the ICU , and 6 h postoperatively . RESULTS There was no significant difference in lung compliance and gas exchange between the two groups before CPB . CPB produced a significant decrease in static and dynamic lung compliance in both groups . In the control group , static and dynamic lung compliance decreased from 1.0 + /- 0.3 to 0.90 + /- 0.3 mL/cm/kg and 0.87 + /- 0.2 to 0.71 + /- 0.1 mL/cm/kg ( + /- SE ) [ p = 0.0002 and p = 0.002 , respectively ] . In the study group , static and dynamic lung compliance decreased from 1.0 + /- 0.2 to 0.89 + /- 0.03 mL/cm/kg and 0.94 + /- 0.2 to 0.77 + /- 0.1 mL/cm/kg ( p = 0.002 and p = 0.002 , respectively ) . There was no significant difference in the decrease in static ( p = 0.9 ) or dynamic lung compliance ( p = 0.3 ) between the two groups . MUF produced a significant immediate improvement in both static lung compliance ( 0.89 + /- 0.2 to 0.98 + /- 0.2 mL/cm/kg , p = 0.03 ) and dynamic lung compliance ( 0.77 + /- 0.1 to 0.93 + /- 0.2 mL/cm/kg , p = 0.007 ) . The same was observed regarding the gas exchange capacity . CPB produced a significant decrease in lung gas exchange capacity , and MUF produced a significant immediate improvement in lung gas exchange capacity . The effect of MUF on lung compliance and gas exchange capacity was not sustained after admission to the ICU nor 6 h later postoperatively . There was no significant difference in the time of extubation between the two groups ( 12 + /- 3 h and 13 + /- 2 h , p = 0.4 ) , the length of ICU stay , or the total hospital stay postoperatively . CONCLUSIONS The use of MUF after CPB can produce an immediate improvement in lung compliance and gas exchange capacity , which may effectively minimize pulmonary dysfunction postbiventricular repair of congenital heart disease . However , these improvements are not sustained for the first 6 h postoperatively and do not reduce the duration of postoperative intubation , ICU stay , or total hospital stay BACKGROUND : The aim of our study was to evaluate the pulmonary and hemodynamic effects of two different recruitment maneuvers after open heart surgery . METHODS : Sixty patients undergoing coronary artery bypass surgery  were r and omized into three groups after operation : recruitment maneuver with continuous positive airway pressure ( CPAP ) ( CPAP-40 group , n = 20 ) , recruitment by positive end-expiratory pressure ( PEEP ) ( PEEP-20 group , n = 20 ) , and 5 cm H2O PEEP ( PEEP-5 group , n = 20 ) . In the CPAP-40 group , 40 cm H2O peak inspiratory pressure was applied for 30 s , then PEEP was reduced to 20 cm H2O and ventilation was continued with baseline variables with PEEP decreased until the best Pao2 was achieved . In the PEEP-20 group , 20 cm H2O PEEP was set for 2 min , tidal volume was adjusted to achieve a peak inspiratory airway pressure of 40 cm H2O during the maneuver , then PEEP was decreased until the best Pao2 had been achieved . In the PEEP-5 group , 5 cm H2O PEEP was applied postoperatively . RESULTS : The mean arterial blood pressure of the CPAP-40 group was lower than that of the PEEP-20 ( P < 0.01 ) and PEEP-5 groups ( P < 0.01 ) during the interventions . Oxygenation was higher in both recruitment groups than in the PEEP-5 group during the mechanical ventilation period . There was no significant difference among the groups beyond that period . The atelectasis score of the PEEP-5 group ( 1.3 ± 0.9 ) on postoperative day 1 was higher than that of the CPAP-40 ( 0.65 ± 0.6 ; P = 0.01 ) and PEEP-20 ( 0.65 ± 0.5 ; P = 0.01 ) groups . CONCLUSIONS : The recruitment techniques with postmaneuver PEEP increased oxygenation and decreased atelectasis equally , whereas PEEP-20 provided more stable hemodynamic conditions than the CPAP maneuver In this study , 30 patients undergoing elective myocardial revascularization were divided r and omly in three groups ( 10 patients each ) with different management of the lungs during CPB : Group 1 , lungs deflated ; Group 2 , static inflation with PEEP = 5 cmH2O and FIO2 = 1.0 ; Group 3 , static inflation with PEEP = 5 cmH2O and FIO2 = 0.21 . Measurements ( Qs/Qt , P(A-a)O2 , PaO2 , Cstat , Cdyn , PIP , AUTO-PEEP , Rrs , max , Rrs , min and DRrs ) were performed after the induction of anesthesia ( T0 ) , 20 minutes ( T1 ) and 2 hours ( T2 ) after the end of CPB . Respiratory mechanics data were obtained only at T0 and T2 because the sternal retraction . The Group 1 presented a statistically significant increase in Qs/Qt , P(A-a)O2 and Peak Inspiratory Pressure ( PIP ) ; in this group we noticed also a decrease in PaO2 values , static compliance ( Cstat ) and dynamic compliance ( Cdyn ) values comparing basal versus T1 and T2 values . The Group 2 showed a statistically significant increase in Qs/Qt and P(A-a)O2 values ; also in this group we observed a statistically significant decrease in PaO2 and Cdyn values comparing basal versus T1 and T2 values . The Group 3 presented a statistically significant decrease in PaO2 values ( basal versus T1 and T2 ) ; this group also presented an increase in Qs/Qt values , in the immediate postbypass period ( T1 ) , and P(A-a)O2 values significantly increase comparing basal versus T1 and T2 values . In all the three groups the respiratory system resistance and AUTO-PEEP values were unchanged after the end of CPB . The comparison between the groups showed a significant minor impairment of gas exchange ( PaO2 and P(A-a)O2 ) , Qs/Qt and Cstat in the third group of patients . These results show that lungs inflation with air during CPB , effectively preserve respiratory system mechanics : this might be due to a preservation of bronchial perfusion simply due to the mechanic expansion of the lung otherwise compromized when the lungs are completely collapsed . However it is necessary to emphasize that CPB has negative effects on gas-exchange whatever technique of lung management is used Postbypass pulmonary dysfunction including atelectasis and increased shunting is a common problem in the intensive care unit . Negative net fluid balance and continuous positive airway pressure ( CPAP ) have been used to reduce the adverse effects of cardiopulmonary bypass ( CPB ) on the lung . To determine whether CPAP at 10 cm H2O during CPB results in improved postoperative gas exchange in comparison with deflated lungs during CPB , we examined 14 patients scheduled for elective cardiac surgery . Seven patients received CPAP at 10 cm H2O during CPB , and in the other seven patients , the lungs were open to the atmosphere ( control ) . Measurements were taken before and after CPB , after thoracic closure , and 4 h after CPB in the intensive care unit . CPAP at 10 cm H2O result ed in significantly more perfusion of lung areas with a normal ventilation/perfusion distribution ( VA/Q ) and significantly less shunt and low VA/Q perfusion 4 h after CPB in comparison with the control group . Consequently , arterial oxygen partial pressure was significantly higher and alveolar-arterial oxygen partial pressure difference was significantly smaller . We conclude that CPAP at 10 cm H2O during CPB is a simple maneuver that improves postoperative gas exchange . Implication s Inflation of the lungs at a pressure of 10 cm H2O as compared with leaving the lungs deflated during cardiopulmonary bypass was examined . Lung inflation during bypass result ed in significantly improved postoperative gas exchange BACKGROUND A complex inflammatory response associated with the use of cardiopulmonary bypass may ultimately lead to organ dysfunction . We investigate the effect of continuing ventilation during cardiopulmonary bypass on inflammatory reactions and cardiopulmonary function . METHODS Fifty patients undergoing cardiopulmonary bypass were prospect ively r and omized to continuous ventilation and nonventilation groups .  Plasma interleukin-8 , interleukin-10 , matrix metalloproteinase-9 , tissue inhibitor metalloproteinase-1 , and thromboxane B2 levels were measured preoperatively , at 1 , 4 , and 6 hours after aortic declamping . Levels of these mediators were also determined in bronchoalveolar lavage preoperatively and four hours after declamping . Seven parameters of cardiopulmonary function , including dynamic compliance and systemic vascular resistance , were recorded during the same time points . RESULTS Plasma interleukin-10 levels were higher at 6 hours and tissue inhibitor metalloproteinase-1 levels were higher at 1 hour after aortic declamping in the continuous ventilation compared with the nonventilation group ( p = 0.04 and 0.002 , respectively ) , while bronchoalveolar lavage levels of tissue inhibitor metalloproteinase-1 were also higher in the continuous ventilation group 4 hours after declamping ( p = 0.02 ) . Plasma interleukin-8 levels were higher at 4 hours after declamping in the nonventilation group ( p = 0.04 ) . Postoperative dynamic compliance was better preserved in continuous ventilation patients than nonventilation patients at 6 hours after declamping ( p = 0.0008 ) . CONCLUSIONS Continued ventilation during cardiopulmonary bypass results in lesser inflammatory and proteolytic responses , and may better preserve pulmonary function than cardiopulmonary bypass without ventilation OBJECTIVE To compare postoperative ( PO ) pulmonary gas exchange indexes in patients su bmi tted to myocardial revascularization ( MR ) with or without the application of continuous positive airway pressure ( CPAP ) during cardiopulmonary bypass ( CPB ) .  METHODS Thirty adult patients su bmi tted to MR with CPB between March and September 2005 were r and omly allocated to two groups : CPAP ( n=15 ) , patients that received CPAP at 10 cm H2O during CPB , and control ( n=15 ) , patients that did n't receive CPAP .  PaO(2)/FiO2 and P(A-a)O2 were analyzed at four moments : Pre ( just before CPB , with FiO2=1.0 ) ; Post ( 30 min post-CPB , with FiO2=1.0 ) ; immediate PO period ( 12h post-surgery , with FiO2=0.4 by using a Venturi(R ) facial mask ) and first PO day ( 24h post-surgery , with FiO2=0.5 by a facial mask ) . RESULTS PaO2/FiO2 and P(A-a)O2 tend to get significantly worst as time elapsed during the postoperative period in both groups , but no differences were observed between them at any moment . When PaO2/FiO2 was subdivided into three categories , a greater prevalence of patients with values between 200 mmHg and 300 mmHg were observed in CPAP group only at moment Post ( 30 min post-CPB ; p = 0.02 ) . CONCLUSION CPAP at 10 cm H2O administered during CPB , although had lightly improved PaO2/FiO2 at 30 minutes post-CPB , had no significant sustained effect on postoperative pulmonary gas exchange . We concluded that in patients su bmi tted to MR , application of 10 cmH2O CPAP does not improve postoperative pulmonary gas exchange BACKGROUND Macrolides antibiotics may affect neutrophil functions that correlate with the inflammation induced by cardiopulmonary bypass . Our study observed the protective effect of clarithromycin on  inflammatory lung injury after cardiopulmonary bypass . METHODS Twelve adult sheep were r and omly divided into two groups . After cardiopulmonary bypass was established , the lung was perfused through the pulmonary artery with either dextran solution ( 30 mL/kg ) in the control group ( n = 6 ) or dextran solution added to clarithromycin ( 10 mg/kg ) in the experimental group ( n = 6 ) . Bypass was withdrawn after 90 minutes . Pulmonary function was determined and inflammatory factors were analyzed . Apoptotic neutrophils in the lung were assayed and lung biopsies were also performed . RESULTS Pulmonary vascular resistance ( 102.2 + /- 14.0 dyne.s.cm(-5 ) ) was lower in the experimental group compared with the control group ( 202.6 + /- 47.3 dyne.s.cm(-5 ) , p < 0.01 ) whereas the oxygen index was higher in the experimental group ( p < 0.05 ) . Plasma myeloperoxidase in the experimental group ( 0.015 + /- 0.006 U/L ) was lower than that in the control group ( 0.029 + /- 0.007 U/L , p < 0.01 ) . Plasma interlukin-8 ( 0.18 + /- 0.04 ug/L ) and tumor necrosis factor ( 1.00 + /- 0.13 ug/L ) in the experimental group were lower than in the control group ( 0.39 + /- 0.09 ug/L , 1.55 + /- 0.35 ug/L , p < 0.01 ) . Histologic analyses showed intra-alveolar hemorrhage and neutrophil accumulation in the control group , whereas there were no significant changes in the experimental group . The apoptosis rate of accumulated neutrophils was significantly lower in the control group ( p < 0.01 ) . CONCLUSIONS Lung perfusion with hypothermic protective solution containing clarithromycin distinctly inhibits inflammatory responses caused by cardiopulmonary bypass and ameliorates lung function Background : Patients ventilated after cardiac surgery commonly have impaired oxygenation , mainly due to lung collapse . We have previously found that PaO2 and end‐expiratory lung volume ( EELV ) were increased by a lung recruitment maneuver ( LRM ) followed by positive end‐expiratory pressure ( PEEP ) . The aim of this study was to evaluate whether only PEEP or only a LRM could give similar effects OBJECTIVE To investigate the effect of a single , vital capacity breath ( vital capacity maneuver [ VCM ] ) , administered at the end of cardiopulmonary bypass ( CPB ) , on pulmonary gas exchange in patients undergoing coronary artery bypass graft surgery . DESIGN Prospect i ve , r and omized , double-blind study . SETTING University-affiliated hospital . PARTICIPANTS Forty patients scheduled for elective coronary artery bypass graft surgery and early tracheal extubation . INTERVENTIONS Patients were r and omized to 1 of 2 groups .  VCM  patients received a VCM at the conclusion of CPB . Control patients received no VCM . MEASUREMENTS AND MAIN RESULTS Intrapulmonary shunt ( Q(S)/Q(T ) ) , arterial oxygenation ( PaO2 ) , and alveolar-arterial oxygen gradients ( P(A-a)O2 ) were measured after induction of anesthesia , CPB , intensive care unit ( ICU ) arrival , and extubation . The duration of postoperative intubation was recorded for each group . Q(S)/Q(T ) increased significantly 30 minutes after CPB in the control group ( 15.7 + /- 1.8 % to 27.4 + /- 2.6 % ; p = 0.01 ) . In the VCM group , a small decrease in Q(S)/Q(T ) occurred ( 16.1 + /- 2.0 % to 14.9 + /- 2.0 % ) . After ICU arrival and extubation , no significant difference in Q(S)/Q(T ) existed between the 2 groups . With the exception of a higher P(A-a)O2 in the control group at induction of anesthesia , no differences in PaO2 or P(A-a)O2 were present between the 2 groups at any measurement interval . Patients who received a VCM were extubated earlier than the control group ( 6.5 + /- 2.1 hours v 9.4 + /- 4.2 hours ; p = 0.01 ) . CONCLUSION The use of a VCM prevented an increase in Q(S)/Q(T ) from occurring in the operating room . Although a VCM did not influence pulmonary gas exchange in the ICU , its application in the operating room appears to exert a beneficial effect on tracheal extubation times after cardiac surgery BACKGROUND Leukocyte depletion recently has been introduced for cardiac surgical patients to attenuate leukocyte-mediated inflammation and organ reperfusion injury . We evaluated the feasibility of a new leukocyte depletion method in which systemic leukocyte depletion is achieved through the venous side of the cardiopulmonary bypass circuit under low blood flow . METHODS Forty cardiac surgical patients undergoing cardiopulmonary bypass were allocated r and omly to a leukocyte depletion group ( n = 20 ) and a control group ( n = 20 ) . In the depletion group , leukocyte filtration was achieved with two filter sets located between the venous drainage and the venous reservoir . Leukocyte filtration was commenced after the start of rewarming but before the release of the aortic cross-clamp , and it was driven by a spare roller pump of the heart-lung machine . RESULTS All the episodes of filtration went smoothly within a period of 10 minutes and with a blood flow rate of 400 mL/min . The mean leukocyte removal rate calculated at the end of filtration was 69 % . Circulating leukocytes were reduced by 38 % in the depletion group compared with the control group at the moment of cross-clamp release ( 4.3x10(9)/L versus 6.8x10(9)/L , p<0.05 ) . The postoperative inflammatory response also was reduced as indicated by less production of interleukin-8 ( p<0.05 ) . Clinical ly , there was no significant difference between the two groups in postoperative PaO2 or pulmonary hemodynamics . CONCLUSIONS It is technically feasible to deplete circulating leukocytes through the venous side of the cardiopulmonary bypass circuit with a low blood flow rate . Future studies should focus on the duration and timing of leukocyte depletion to optimize the methodology of leukocyte depletion for cardiac surgical patients OBJECTIVES It has been proved in human subjects and animals that atelectasis is a major cause of intrapulmonary shunting and hypoxemia after cardiopulmonary bypass . Animal studies suggest that shunting can be prevented entirely by a total vital capacity maneuver performed before termination of bypass . This study aim ed to test this theory in human subjects and to evaluate possible advantages of off-pump coronary artery bypass grafting . METHODS Twenty-four patients scheduled for coronary artery bypass grafting were r and omly assigned to receive no total vital capacity maneuver ( control group , n = 12 ) or st and ard total vital capacity maneuvers ( TVCM group , n = 12 ) . Additionally , 12 consecutive patients undergoing off-pump coronary artery bypass grafting ( off-pump group ) were studied . Systemic and central hemodynamics , the pattern of breathing , and ventilatory mechanics were evaluated after induction of anesthesia , after sternotomy , after cardiopulmonary bypass and skin closure , and 4 hours after extubation . RESULTS The use of total vital capacity maneuvers reduced ( P < .05 ) intrapulmonary shunting after termination of cardiopulmonary bypass . However , shunting increased ( P < .05 ) in all groups ( control group , 8.2 % + /- 3.3 % vs 25.6 % + /- 8.1 % ; TVCM group , 8.7 % + /- 3.4 % vs 24.4 % + /- 8.5 % ; and off-pump group , 7.8 % + /- 2.8 % vs 14.0 % + /- 5.3 % ) after extubation , but the increase was significantly ( P < .05 ) less pronounced in the off-pump group . Furthermore , pulmonary compliance decreased ( P < .05 ) in all groups except the off-pump group after extubation . Duration of hospital and intensive care unit stay was significantly shorter ( P < .05 ) in the off-pump group than in the other groups . CONCLUSION The development of intrapulmonary shunting and hypoxemia after coronary artery bypass grafting can be substantially reduced by performance of total vital capacity maneuvers while patients are mechanically ventilated . However , off-pump coronary artery bypass surgery is superior in preventing shunting and hypoxemia after bypass grafting in the immediate and early postoperative periods , probably leading to substantially shorter intensive care unit and hospital stays It is not clear if the use of continuous positive airway pressure ( CPAP ) during cardiopulmonary bypass ( CPB ) improves lung function after cardiac surgery . We have measured alveolar-arterial oxygen partial pressure difference ( PAO2-PaO2 ) in 61 patients undergoing elective coronary artery bypass surgery .  We studied three groups of patients : in group 1 the lungs were disconnected from the breathing system ( no CPAP ) during CPB ; in group 2 , 5 cm H2O CPAP with air was applied to the lungs ; in group 3 , 5 cm H2O of CPAP was applied with 100 % oxygen .  ( PAO2-PaO2 ) was measured before CPB and then at 30 min , 4 h and 8 h after CPB . Compared with group 1 ( no CPAP ) , ( PAO2-PaO2 ) was significantly smaller in groups 2 and 3 at 30 min ( P = 0.036 ) , but not at 4 h and 8 h after CPB ( P = 0.32 , P = 0.96 ) . The time to extubation ( P = 0.42 ) and early extubation ( P = 0.87 ) were not affected by the use of CPAP . The results of this study do not support the use of CPAP during CPB as a mechanism of improving lung function after cardiac surgery It has been suggested that maintaining ventilation during bypass might reduce lung injury , which is a common complication of cardiac surgery . In order to assess this , a study is being undertaken to examine the effect upon a number of parameters that may be indicative of lung injury , of continued ventilation compared with discontinued ventilation whilst on bypass . The following parameters have been assessed : extravascular lung water , static and dynamic compliance , ratio of left atrial/right atrial white blood count , alveolar arterial oxygen gradient and the respiratory index together with clinical end points . Provisional results are reported . Twenty-three elective patients for coronary artery surgery have to date been r and omised to either ventilation ( VB ) ( n=12 ) or non-ventilation on bypass ( NVB ) ( n=11 ) . The post-bypass extravascular lung water was significantly smaller in the VB group compared to the NVB group ( 530+/-50 ml vs. 672+/-32 ml ; P=0.028 ) . Extubation time was also significantly shorter in the VB group ( 3.6+/-0.3 h vs. 4.8+/-0.4 h ; P=0.038 ) . The provisional results of this work in progress are suggestive that continued ventilation during bypass may reduce lung injury STUDY OBJECTIVES Cardiac surgery with cardiopulmonary bypass ( CPB ) results in perioperative organ damage caused by the systemic inflammatory response syndrome ( SIRS ) and ischemia/reperfusion injury . Administration of corticosteroids before CPB has been demonstrated to inhibit the activation of the systemic inflammatory response . However , the clinical benefits of corticosteroid therapy are controversial . This study was design ed to document the effects of dexamethasone on cytokine release and perioperative myocardial , pulmonary , renal , intestinal , and hepatic damage , as assessed by specific and sensitive biomarkers . DESIGN AND PATIENTS A prospect i ve , double-blind , placebo-controlled , r and omized trial for dexamethasone was conducted in 20 patients receiving either dexamethasone ( 1 mg/kg before anesthesia induction and 0.5 mg/kg after 8 h ; n = 10 ) or placebo ( n = 10 ) . Different markers were used to assess the SIRS : interleukin (IL)-6 , IL-8 , IL-10 , C-reactive protein ( CRP ) , and tryptase ; and organ damage : heart ( plasma heart-type fatty acid binding protein , cardiac troponin I [ cTnI ] , creatine kinase-MB ) , kidneys ( N-acetyl-glucosaminidase [ NAG ] , microalbuminuria ) , intestine ( intestinal-type fatty acid binding protein [I-FABP]/liver-type fatty acid binding protein [ L-FABP ] ) , and liver ( alpha-glutathione S-transferase ) . RESULTS Dexamethasone modulated the SIRS with lower proinflammatory ( IL-6 , IL-8 ) and higher antiinflammatory ( IL-10 ) IL levels . CRP and tryptase were lower in the dexamethasone group . cTnI values were lower in the dexamethasone group at 6 h in the ICU ( p = 0.009 ) . Patients in the dexamethasone group had a longer time to tracheal extubation ( 18.86 + /- 1.13 h vs 15.01 + /- 0.99 h , p = 0.02 [ mean + /- SEM ] ) , with a lower oxygenation index at that time : Pa(O2)/fraction of inspired oxygen ratio , 37.17 + /- 1.8 kPa vs 29.95 + /- 2.1 kPa ( p = 0.009 ) . The postoperative glucose level ( 10.7 + /- 0.6 mmol/L vs 7.4 + /- 0.5 mmol/L , p = 0.005 ) was higher in the dexamethasone group . Serum glucose was independently associated with intestinal injury ( urine I-FABP peak , R2 = 42.5 % , beta = 114.4 + /- 31.4 , significant at p = 0.002 ; urine L-FABP peak , R2 = 47.3 % , beta = 7,714.1 + /- 1,920.9 , significant at p = 0.001 ) and renal injury ( urine NAG , R2 = 32.1 % , beta = 0.21 + /- 0.07 , significant at p = 0.009 ) . Tryptase peaks correlated negatively with peaks of intestinal and renal injury biomarkers . CONCLUSION Even while inhibiting SIRS , dexamethasone treatment offered no protection against transient , sub clinical , perioperative abdominal organ damage . Tryptase release could have a preconditioning effect , offering protection against perioperative intestinal and renal damage . Dexamethasone treatment result ed in more pronounced postoperative pulmonary dysfunction , prolonged time to tracheal extubation , and initiated postoperative hyperglycemia in patients undergoing elective on-pump coronary artery bypass graft surgery Objective : After cardiac surgery , functional residual capacity ( FRC ) after extubation is reduced significantly . We hypothesized that ventilation according to the open lung concept ( OLC ) attenuates FRC reduction after extubation . Design : A prospect i ve , single-center , r and omized , controlled clinical study . Setting : Cardiothoracic operating room and intensive care unit of a university hospital . Patients : Sixty-nine patients scheduled for elective coronary artery bypass graft and /or valve surgery with cardiopulmonary bypass . Interventions : Before surgery , patients were r and omly assigned to three groups : ( 1 ) conventional ventilation ( CV ) ; ( 2 ) OLC , started after arrival in the intensive care unit ( late open lung ) ; and ( 3 ) OLC , started directly after intubation ( early open lung ) . In both OLC groups , recruitment maneuvers were applied until Pao2/Fio2 was > 375 Torr ( 50 kPa ) . No recruitment maneuvers were applied in the CV group . Measurements and Main Results : FRC was measured preoperatively and 1 , 3 , and 5 days after extubation . Peripheral hemoglobin saturation ( Spo2 ) was measured daily till the third day after extubation while the patient was breathing room air . Hypoxemia was defined by an Spo2 value ≤90 % . Averaged over the 5 postoperative days , FRC was significantly higher in the early open lung group and tended to be higher in the late open lung group , in comparison with the CV group ( mean ± sem : CV , 1.8 ± 0.1 ; late open lung,1.9 ± 0.1 ; and early open lung , 2.2 ± 0.1l ) . In the CV group , 37 % of the patients were hypoxic on the third day after extubation , compared with none of the patients in both OLC groups . Conclusions : After cardiac surgery , earlier application of OLC result ed in a significantly higher FRC and fewer episodes of hypoxemia than with CV after extubation We investigated the effects of providing patients with continuous positive airway pressure during a short weaning period from mechanical ventilation to extubation . Following elective primary aortocoronary bypass surgery employing cardiopulmonary bypass , 80 patients received intermittent positive pressure ventilation for 5 h. At the end of this time patients were r and omly allocated to one of the following three groups for a 2 h period of spontaneous respiration prior to extubation : group CPAP0 = T‐piece circuit ( n = 27 ) ; group CPAP5 = 5cmH2O of continuous positive airway pressure ( n = 27 ) ; group CPAP10 = 10cmH2O of continuous positive airway pressure ( n = 26 ) . Following extubation , pulmonary gas exchange was assessed after 1,2,4 , and 24 h. All patients had good pre‐operative lung function . There was a significant increase in the median alveolar‐arterial oxygen partial pressure difference and a decrease in the oxygenation index in all three groups during the period of added inspired oxygen which persisted until 24 h post‐extubation , but there were no differences between the groups . In patients with good pre‐operative lung function requiring primary aortocoronary bypass surgery , the use of continuous positive airway pressure confers no advantage over a simple T‐piece attachment during the short period of weaning from mechanical ventilation to extubation Background : It is unclear whether positive end‐expiratory pressure ( PEEP ) is needed to maintain the improved oxygenation and lung volume achieved after a lung recruitment maneuver in patients ventilated after cardiac surgery performed in the cardiopulmonary bypass ( CPB ) Thirty-two pigs were r and omized into group I ( aortic cross clamping , ante grade cardioplegia , moderate hypothermia ) and group II ( normothermia , beating empty heart ) . Groups were subdivided into subgroups A , B and C , receiving no lung perfusion , perfusion with arterial blood and perfusion with venous blood . Swan-Ganz catheter was used to take mean pulmonary artery pressure which would be used as lung perfusion pressure . Cardiopulmonary bypass ( CPB ) was established through cannulating aorta and double venae cavae , mechanical ventilation was interrupted and lung perfusion was carried out for 30 min . Blood sample s and pulmonary specimens were withdrawn pre- and postoperatively for gasometrical , histological and genic analyses . Postoperative comparison revealed that pulmonary vascular resistance was lower in IC than IA ( P=0.01 ) and it was lower in IIC than IIA ( P=0.005 ) . Subgroup IIB had increasing venous oxygen tension ( P=0.01 ) as well as arterial and venous oxygen saturation ( P=0.01 ) compared to IIA . Arterial oxygen saturation was decreased in IIC vs. IIA ( P=0.006 ) . Histological differences were observed between subgroups A and B as well as A and C ( P=0.003 ) . Lung perfusion during CPB may improve pulmonary hemodynamic performance , optimize gas exchange and maintain cellular integrity Purpose Despite the well-documented impairment of pulmonary function after cardiopulmonary bypass , effective pre caution s and ideal management strategies for this problem are still under debate . This study aim ed to evaluate the effects of continuous positive airway pressure ( CPAP ) applied during cardiopulmonary bypass on respiratory and hemodynamic variables . Methods In this r and omized , prospect i ve , controlled trial , 120 male patients , aged 45 to 70 yr undergoing first-time elective bypass surgery , were r and omly assigned to receive either 10 cm H2O of CPAP ( Group I ; n = 60 ) during cardiopulmonary bypass , or serve as control ( Group II ; n = 60 ) , where the patient ’s lungs were vented to atmosphere during the bypass period . Results Alveolar-arterial oxygen partial pressure difference and shunt fraction were significantly higher in the control group compared with the CPAP group after cardiopulmonary bypass ( T2 ) and after closure of sternum ( T3 ) , ( P < 0.05 ) . No differences between groups with respect to hemodynamic variables were observed at any time . Postoperative pulmonary function variables were lower in both groups compared to baseline values . Conclusions Continuous positive airway pressure administered during cardiopulmonary bypass decreased shunt fraction and alveolar-arterial oxygen partial pressure difference during surgery , but had no sustained effect on either variable postoperatively . We conclude that , in patients with normal preoperative pulmonary function , application of 10 cm H2O CPAP does not improve lung function after cardiac surgery . RésuméObjectifMalgré les connaissances acquises sur l’atteinte de la fonction pulmonaire après la circulation extracorporelle , les pré caution s efficaces et le traitement idéal touchant ce problème font toujours l’objet de débats . Nous voulions évaluer les effets d’une ventilation en pression positive continue ( CPAP pour « continuous positive airway pressure » ) pendant la circulation extracorporelle sur les variables respiratoires et hémodynamiques . MéthodeDans notre étude r and omisée , prospect i ve et contrôlée , 120 hommes de 45 à 70 ans devant subir un premier pontage électif , ont reçu soit 10 cm H2O de CPAP ( Groupe I ; n = 60 ) pendant la circulation extracorporelle , soit ont servi de témoins ( Groupe II ; n = 60 ) et les poumons ont été ventilés à la pression atmosphérique pendant le pontage . RésultatsLa différence alvéolaire-artérielle de pression partielle en oxygène et la fraction de shunt ont été significativement plus élevées chez les témoins que chez les patients sous CPAP après la circulation extracorporelle ( T2 ) et après la fermeture du sternum ( T3 ) , ( P < 0,05 ) . Les variables hémodynamiques ont toujours été similaires dans les deux groupes . Dans les deux groupes aussi , les variables de la fonction pulmonaire postopératoire étaient plus basses que les valeurs de départ . Conclusion La ventilation à pression positive continue pendant la circulation extracorporelle a réduit la fraction de shunt et la différence alvéolaire-artérielle de pression partielle en oxygène pendant l’opération , mais n’a pas eu d’effet postopératoire prolongé sur chacune des variables . Donc , chez les patients do nt la fonction pulmonaire préopératoire est normale , une CPAP de 10 cm H2O n’améliore pas la fonction pulmonaire après la cardiochirurgie Progressive respiratory insufficiency secondary to cardiopulmonary bypass ( CPB ) is still a hazard after cardiac surgery . Pathophysiologically , impaired capillary endothelial integrity seems to be the fundamental lesion , followed by increased interstitial fluid accumulation . The reasons for this pulmonary damage are controversial ; however , management of the nonperfused lungs during CPB has been widely neglected and may be partly responsible . In this study , 90 patients undergoing coronary artery bypass grafting were r and omly divided into six groups ( 15 patients each ) with different management of the lungs during CPB : group 1 , lungs collapsed ( 0/0 ) ; group 2 , static inflation with + 5 cm H2O and F1O2 1.0 ( + 5/1.0 ) ; group 3 , static inflation with + 5 cm H2O and F1O2 0.21 ( + 5/0.21 ) ; group 4 , static inflation with + 15 cm H2O and F1O2 1.0 ( + 15/1.0 ) ; group 5 , static inflation with + 15 cm H2O and F1O2 0.21 ( + 15/0.21 ) ; and group 6 , controlled mechanical ventilation as before start of CPB ( positive end-expiratory pressure [ PEEP ] + 5 cm H2O ; F1O2 1.0 ) ( ventilation ) . In addition to hemodynamic monitoring , extravascular lung water ( EVLW ) was measured by means of a double-indicator dilution technique with heat and indocyanine green . Measurements were performed after induction of anesthesia , before onset of CPB , and immediately after weaning from bypass , as well as 60 minutes and 5 hours after termination of CPB . Pulmonary gas exchange ( PaO2 ) and intrapulmonary shunting ( Qs/Qt ) were also measured . Starting from comparable , normal baseline values , EVLW was increased in all groups after weaning from CPB , with the most pronounced increase in group 4 ( maximum , + 35 % ) and group 5 ( + 40 % ) . ( ABSTRACT TRUNCATED AT 250 WORDS The current clinical study is the continuity of previous experimental findings in which ventilation during cardiopulmonary bypass ( CPB ) prevented reperfusion injury of the pulmonary arterial tree as demonstrated by preservation of vasorelaxation to acetylcholine ( ACh ) in swine . The aim of this prospect i ve r and omized study is to determine : 1 ) if ventilation during CPB prevents the selective endothelium-mediated lung dysfunction in humans and , 2 ) the clinical relevance of ventilation during CPB . Forty patients scheduled for primary coronary artery bypass grafting ( CABG ) were r and omized into two groups : Group 1 : Usual care ( defined as no ventilation during CPB ) and Group 2 : CPB with low tidal volume ventilation ( 3 ml.kg-1 ) without positive end expiratory pressure ( PEEP ) . To evaluate endothelial function , ACh was injected into the pulmonary artery and the changes in pulmonary vascular resistance index ( PVRI ) were measured at : ( 1 ) induction of anesthesia prior to surgery , ( 2 ) immediately after weaning from CPB and ( 3 ) 1 hour after CPB . In addition , secondary endpoints , such as PaO2/FiO2 ratio , mean pulmonary artery pressure ( MPAP ) , postoperative length of stay ( LOS ) and postoperative pulmonary complications were measured to evaluate the effect of ventilation during CPB . To assess pulmonary complications , a chest x-ray was taken on the first and third postoperative days . There were no statistically significant changes in PVRI , PaO2 /FiO2 ratio , MPAP , postoperative LOS and postoperative pulmonary complications when comparing the non-ventilated and the ventilated groups during CPB . The ventilated group appears to obtain a greater vasorelaxation to ACh , as shown by the more pronounced change in PVRI when compared to the non-ventilated group . However , the difference in PVRI between the two groups was not statistically significant after weaning ( p= 0.32 ) and 1hr after CPB ( p= 0.28 ) . Contrary to our hypothesis and due to larger than expected variability in the data , the hemodynamic and clinical changes seen were not statistically significant
OBJECTIVES A variety of lung-protective techniques , including continuous positive airway pressure and vital capacity maneuvers , have been suggested as beneficial when applied during  cardiopulmonary bypass ( CPB ) .
To better define the efficacy of these techniques , a systematic review of different ventilation strategies during and after CPB was performed .