Extubation outcome after spontaneous breathing trials with T-tube or pressure support ventilation. The Spanish Lung Failure Collaborative Group. Automatic versus manual pressure support reduction in the weaning of post-operative patients: a randomised controlled trial Effect of a nursing-implemented sedation protocol on the duration of mechanical ventilation. Synchronized intermittent mandatory ventilation with and without pressure support ventilation in weaning patients with COPD from mechanical ventilation. Large scale implementation of a respiratory therapist-driven protocol for ventilator weaning. A multicenter randomized trial of computer-driven protocolized weaning from mechanical ventilation. Computer-driven management of prolonged mechanical ventilation and weaning: a pilot study Predicting 3-day and 7-day outcomes of weaning from mechanical ventilation. Preliminary results on nursing workload in a dedicated weaning center Protocol weaning of mechanical ventilation in medical and surgical patients by respiratory care practitioners and nurses: effect on weaning time and incidence of ventilator-associated pneumonia. Automatic control of pressure support for ventilator weaning in surgical intensive care patients. Automatic adjustment of pressure support by a computer-driven knowledge-based system during noninvasive ventilation: a feasibility study A computer-controlled ventilator weaning system. A clinical trial. A randomized, controlled trial of protocol-directed versus physician-directed weaning from mechanical ventilation. Effect of spontaneous breathing trial duration on outcome of attempts to discontinue mechanical ventilation. Spanish Lung Failure Collaborative Group. Computer‐driven automated weaning reduces weaning duration in difficult‐to‐wean patients The attributable morbidity and mortality of ventilator-associated pneumonia in the critically ill patient. The Canadian Critical Trials Group. Incidence of and Risk Factors for Ventilator-Associated Pneumonia in Critically Ill Patients A randomised, controlled trial of conventional versus automated weaning from mechanical ventilation using SmartCare™/PS Protocol-directed weaning from mechanical ventilation: clinical outcome in patients randomized for a 30-min or 120-min trial with pressure support ventilation A prospective comparison of IMV and T-piece weaning from mechanical ventilation. Comparison of three methods of gradual withdrawal from ventilatory support during weaning from mechanical ventilation. Comparison of pressure support ventilation (PSV) and intermittent mandatory ventilation (IMV) during weaning in patients with acute respiratory failure. Weaning children from mechanical ventilation with a computer-driven system (closed-loop protocol): A pilot study* [Comparison of computer-driven weaning and physician-directed weaning from mechanical ventilation: a randomized prospective study]. Characteristics and outcomes in adult patients receiving mechanical ventilation: a 28-day international study. Wean earlier and automatically with new technology (the WEAN study). A multicenter, pilot randomized controlled trial. [Comparison of SmartCare and spontaneous breathing trials for weaning old patients with chronic obstructive pulmonary diseases]. Effect of failed extubation on the outcome of mechanical ventilation.
A 2-h T-tube trial of spontaneous breathing was used in selecting patients ready for extubation and discontinuation of mechanical ventilation . However , some doubt remains as to whether it is the most appropriate method of performing a spontaneous breathing trial . We carried out a prospect i ve , r and omized , multicenter study involving patients who had received mechanical ventilation for more than 48 h and who were considered by their physicians to be ready for weaning according to clinical criteria and st and ard weaning parameters . Patients were r and omly assigned to undergo a 2-h trial of spontaneous breathing in one of two ways : with a T-tube system or with pressure support ventilation of 7 cm H2O . If a patient had signs of poor tolerance at any time during the trial , mechanical ventilation was reinstituted . Patients without these features at the end of the trial were extubated . Of the 246 patients assigned to the T-tube group , 192 successfully completed the trial and were extubated ; 36 of them required reintubation . Of the 238 patients in the group receiving pressure support ventilation  , 205 were extubated and 38 of them required reintubation . The percentage of patients who remained extubated after 48 h was not different between the two groups ( 63 % T-tube , 70 % pressure support ventilation , p = 0.14 ) . The percentage of patients falling the trial was significantly higher when the T-tube was used ( 22 versus 14 % , p = 0.03 ) . Clinical evolution during the trial was not different in patients reintubated and successfully extubated . ICU mortality among reintubated patients was significantly higher than in successfully extubated patients ( 27 versus 2.6 % , p < 0.001 ) . Spontaneous breathing trials with pressure support or T-tube are suitable methods for successful discontinuation of ventilator support in patients without problems to resume spontaneous breathing Introduction Reduction of automatic pressure support based on a target respiratory frequency or m and atory rate ventilation ( MRV ) is available in the Taema-Horus ventilator for the weaning process in the intensive care unit ( ICU ) setting . We hypothesised that MRV is as effective as manual weaning in post-operative ICU patients . Methods There were 106 patients selected in the post-operative period in a prospect i ve , r and omised , controlled protocol . When the patients arrived at the ICU after surgery , they were r and omly assigned to either : traditional weaning , consisting of the manual reduction of pressure support every 30 minutes , keeping the respiratory rate/tidal volume ( RR/TV ) below 80 L until 5 to 7 cmH2O of pressure support ventilation ( PSV ) ; or automatic weaning , referring to MRV set with a respiratory frequency target of 15 breaths per minute ( the ventilator automatically decreased the PSV level by 1 cmH2O every four respiratory cycles , if the patient 's RR was less than 15 per minute ) . The primary endpoint of the study was the duration of the weaning process . Secondary endpoints were levels of pressure support , RR , TV ( mL ) , RR/TV , positive end expiratory pressure levels , FiO2 and SpO2 required during the weaning process , the need for reintubation and the need for non-invasive ventilation in the 48 hours after extubation . Results In the intention to treat analysis there were no statistically significant differences between the 53 patients selected for each group regarding gender ( p = 0.541 ) , age ( p = 0.585 ) and type of surgery ( p = 0.172 ) . Nineteen patients presented complications during the trial ( 4 in the PSV manual group and 15 in the MRV automatic group , p < 0.05 ) . Nine patients in the automatic group did not adapt to the MRV mode . The mean ± sd ( st and ard deviation ) duration of the weaning process was 221 ± 192 for the manual group , and 271 ± 369 minutes for the automatic group ( p = 0.375 ) . PSV levels were significantly higher in MRV compared with that of the PSV manual reduction ( p < 0.05 ) . Reintubation was not required in either group . Non-invasive ventilation was necessary for two patients , in the manual group after cardiac surgery ( p = 0.51 ) . Conclusions The duration of the automatic reduction of pressure support was similar to the manual one in the post-operative period in the ICU , but presented more complications , especially no adaptation to the MRV algorithm . Trial Registration Trial registration number : IS RCT OBJECTIVE To compare a practice of protocol -directed sedation during mechanical ventilation implemented by nurses with traditional non- protocol -directed sedation administration . DESIGN R and omized , controlled clinical trial . SETTING Medical intensive care unit ( 19 beds ) in an urban teaching hospital . PATIENTS Patients requiring mechanical ventilation ( n = 321 ) . INTERVENTIONS Patients were r and omly assigned to receive either protocol -directed sedation ( n = 162 ) or non- protocol -directed sedation ( n = 159 ) . MEASUREMENTS AND MAIN RESULTS The median duration of mechanical ventilation was 55.9 hrs ( 95 % confidence interval , 41.0 - 90.0 hrs ) for patients managed with protocol -directed sedation and 117.0 hrs ( 95 % confidence interval , 96.0 - 155.6 hrs ) for patients receiving non- protocol -directed sedation . Kaplan-Meier analysis demonstrated that patients in the protocol -directed sedation group had statistically shorter duration s of mechanical ventilation than patients in the non- protocol -directed sedation group ( chi-square = 7.00 , p = .008 , log rank test ; chi-square = 8.54 , p = .004 , Wilcoxon 's test ; chi-square = 9.18 , p = .003 , -2 log test ) . Lengths of stay in the intensive care unit ( 5.7+/-5.9 days vs. 7.5+/-6.5 days ; p = .013 ) and hospital ( 14.0+/-17.3 days vs. 19.9+/-24.2 days ; p < .001 ) were also significantly shorter among patients in the protocol -directed sedation group . Among the 132 patients ( 41.1 % ) receiving continuous intravenous sedation , those in the protocol -directed sedation group ( n = 66 ) had a significantly shorter duration of continuous intravenous sedation than those in the non- protocol -directed sedation group ( n = 66 ) ( 3.5+/-4.0 days vs. 5.6+/-6.4 days ; p = .003 ) . Patients in the protocol -directed sedation group also had a significantly lower tracheostomy rate compared with patients in the non- protocol -directed sedation group ( 10 of 162 patients [ 6.2 % ] vs. 21 of 159 patients [ 13.2 % ] , p = .038 ) . CONCLUSIONS The use of protocol -directed sedation can reduce the duration of mechanical ventilation , the intensive care unit and hospital lengths of stay , and the need for tracheostomy among critically ill patients with acute respiratory failure This prospect i ve study compared two weaning modalities in COPD patients requiring mechanical ventilation ( MV ) for acute respiratory failure . Nineteen patients with COPD were studied when their precipitating illness was controlled . Although they satisfied the conventional bedside weaning criteria , they could not tolerate any reduction in the respirator rate below 10 cycles/min . At this time , patients were r and omized into two groups receiving either synchronized intermittent m and atory ventilation ( SIMV ) with pressure support ventilation ( PSV ) ( group 1 ) or SIMV alone ( group 2 ) . The volumetric support of ventilation  ( SIMV rate ) was progressively decreased in both groups according to the patient 's tolerance with a concurrent decrease in the barometric support of ventilation ( PSV levels from 15 cm H2O to 6 cm H2O ) . At each step of SIMV rate , we found no difference between group 1 and group 2 in arterial blood gases , blood pressure , heart rate , airway occlusion pressure , maximal inspiratory pressure , and oxygen cost of breathing ( OCB ) . At each step , however , group 1 patients showed significantly higher spontaneous tidal volume and lower spontaneous breathing frequency than did group 2 patients . We found a slight but not significant tendency to a shorter weaning period with than without PSV , but no difference in the weaning success . We concluded that ( 1 ) conventional weaning criteria might be inaccurate in COPD patients , ( 2 ) SIMV appeared very useful in weaning COPD patients from MV , ( 3 ) PSV marginally reduced the weaning period when added to SIMV , and ( 4 ) the OCB was not significantly improved with PSV We prospect ively investigated the large-scale implementation of a respiratory-therapist-driven protocol ( TDP ) that included 117 respiratory care practitioners ( RCPs ) managing 1,067 patients with respiratory failure over 9,048 patient days of mechanical ventilation . During a 12-mo period , we reintroduced a previously vali date d protocol that included a daily screen ( DS ) coupled with spontaneous breathing trials ( SBTs ) and physician prompt , as a TDP without daily input from a physician or " weaning team . " With grade d , staged educational interventions at 2-mo intervals , RCPs had a 97 % completion rate and a 95 % correct interpretation rate for the DS . The frequency with which patients who passed the DS underwent SBTs increased throughout the implementation process ( p < 0.001 ) . As the year progressed , RCPs more often considered SBTs once patients had passed a DS ( p < 0.001 ) , and physicians ordered more SBTs ( 46 versus 65 % , p = 0.004 ) . Overall , SBTs were ordered more often on the medicine than on the surgical services ( 81 versus 63 % , p = 0.001 ) , likely reflecting medical intensivists ' prior use of this protocol . Important barriers to protocol compliance were identified through a question naire ( 89 respondents , 76 % ) , and included : Physician unfamiliarity with the protocol , RCP inconsistency in seeking an order for an SBT from the physician , specific reasons cited by the physician for not advancing the patient to a SBT , and lack of stationary unit assignments by RCPs performing the protocol . We conclude that implementation of a vali date d weaning strategy is feasible as a TDP without daily supervision from a weaning physician or team . RCPs can appropriately perform and interpret DS data more than 95 % of the time , but significant barriers to SBTs exist . Through a staged implementation process , using periodic reinforcement of all participants in ventilator management , improved compliance with this large-scale weaning protocol can be achieved RATIONALE AND OBJECTIVES Duration of weaning from mechanical ventilation  may be reduced by the use of a systematic approach . We assessed whether a closed-loop knowledge-based algorithm introduced in a ventilator to act as a computer-driven weaning protocol can improve patient outcomes as compared with usual care . METHODS AND MEASUREMENTS We conducted a multicenter r and omized controlled study with concealed allocation to compare usual care for weaning with computer-driven weaning . The computerized protocol included an automatic gradual reduction in pressure support , automatic performance of spontaneous breathing trials ( SBT ) , and generation of an incentive message when an SBT was successfully passed . One hundred forty-four patients were enrolled before weaning initiation . They were r and omly allocated to computer-driven weaning or to physician-controlled weaning according to local guidelines . Weaning duration until successful extubation and total duration of ventilation were the primary endpoints . MAIN RESULTS Weaning duration was reduced in the computer-driven group from a median of 5 to 3 d ( p=0.01 ) and total duration of mechanical ventilation from 12 to 7.5 d ( p=0.003 ) . Reintubation rate did not differ ( 23 vs. 16 % , p=0.40 ) . Computer-driven weaning also decreased median intensive care unit ( ICU ) stay duration from 15.5 to 12 d ( p=0.02 ) and caused no adverse events . The amount of sedation did not differ between groups . In the usual care group , compliance to recommended modes and to SBT was estimated , respectively , at 96 and 51 % . CONCLUSIONS The specific computer-driven system used in this study can reduce mechanical ventilation duration and ICU length of stay , as compared with a physician-controlled weaning process Objective To evaluate the ability of a computer-driven system ( CDS ) to manage pressure-support ventilation over prolonged periods and to predict weaning readiness compared to intensivists . The system continuously adapts pressure support , gradually decreases ventilatory assistance when possible , and indicates weaning readiness . Design and setting A two-center , prospect i ve , open , clinical , pilot study in medical ICUs of two university hospitals . Patients and participants 42 consecutive mechanically ventilated patients ( 60±14 years , SAPS II 39±15 ) , 9 of whom were excluded . Interventions As soon as patients could tolerate pressure support , they were ventilated with the CDS . The times of weaning readiness determined by the intensivists and CDS were compared . Measurements and results Weaning was successful in 25 patients and failed in 7 ; unplanned extubation occurred in 1 patient . Time on CDS ventilation was 3±3 days ( maximum , 12 days ) . The CDS  detected weaning readiness earlier than the intensivists in 17 patients , and intensivists earlier than the CDS in 4 ; in 11 patients detection times coincided . Conclusions A CDS was successful in fully managing pressure-support ventilation over prolonged periods and often proposed weaning readiness earlier than the intensivists did . Use of this CDS may reduce the duration of mechanical ventilation OBJECTIVE To determine the correlation of acute physiology and chronic health evaluation ( APACHE ) II score and various weaning indexes ( WIs ) with 3- and 7-day weaning outcomes . DESIGN Prospect i ve , observational . SETTING The medical ICU of a teaching , urban hospital . METHODS The study included 118 adults referred for weaning from mechanical ventilation ( MV ) .  Critical care physicians , critical care nurses , and respiratory care practitioners were asked to predict whether it would take < or =3 days , 4 to 7 days , or > or = 8 days to wean each patient from MV . The WIs and APACHE II scores were measured or calculated . The causes of respiratory failure , the duration of MV before initiating weaning assessment , and the 3- and 7-day weaning outcomes were obtained . Significance was set at p<0.05 . RESULTS The most common causes of respiratory failure were pneumonia ( 38 cases ) and acute exacerbation of COPD ( 29 cases ) . Fifty-seven patients ( 48 % ) were successfully weaned from MV within 3 days of weaning assessment , and 67 ( 57 % ) were weaned within 7 days . The percentages of correct prediction of 3-day weaning outcome by critical care physicians , critical care nurses , and respiratory care practitioners were 64 % , 62 % , and 59 % , respectively ; for 7-day weaning outcome , 60 % , 64 % , and 58 % , respectively . The successfully weaned groups had significantly lower APACHE II scores and higher maximal inspiratory pressures than the unsuccessfully weaned ( failure ) groups . There were no significant differences between the two groups for the remaining indexes , including rapid shallow breathing , dynamic compliance , static compliance , spontaneous respiratory rate , and the ratio of PaO2 to the fraction of inspired oxygen . CONCLUSIONS The overall severity of illness as assessed by APACHE II score correlates better with 3- and 7-day weaning outcome than the published WIs Objective : To evaluate the nursing time required for difficult-to-wean patients in a dedicated weaning center ( WC ) and to examine the correlation of the nursing time with nursing workload ( NW ) scores and with clinical severity and dependency.¶ Setting : Four-bed WC of a pulmonary rehabilitation department.¶Intervention : None.¶ Design and measurement : Prospect i ve , observational study of 46 consecutive patients admitted to a long-term WC .  Time required by  items of the Time Oriented Score System ( TOSS )  and other tasks specific to respiratory intermediate intensive care units were evaluated for all the activities performed on each patient in the first 2 days after admission . Patient dependency and level of nursing care at admission were measured using the Dependence Nursing Scale ( DNS ) and the Intermediate Therapeutic Intervention Score System ( TISS-int ) . The Acute Physiology and Chronic Health Evaluation ( APACHE ) II score was also recorded at admission.¶ Results : On the first day each patient needed 45 ± 15 % ( 63 ± 23 % , 45 ± 22 % , and 29 ± 14 % for the three nursing shifts ) of allocated single  nursing time  . On the TOSS on the first day patients required a daily mean 28 ± 10 % of total available nursing time ; on the second day the results did not change . Time of care in the first 24 h was only weakly related to DNS , APACHE II score , and TISS-int ; only DNS was able ( although weakly ; r = 0.45 ) to predict minutes of nursing care.¶ Conclusions : In difficult-to-wean patients from mechanical ventilation  the nursing time in the first 2 days after admission is high . The use of TOSS may underestimate NW by about 38 % . Although only DNS showed the ability to predict minutes of care , the weak relationship limits its value in clinical practice STUDY OBJECTIVES ( 1 ) To determine the effect of a single ventilator management protocol ( VMP ) used in medical and surgical ICUs on the duration of mechanical ventilation . ( 2 ) To determine the effect of a VMP on the incidence of ventilator-associated pneumonia ( VAP ) . DESIGN Prospect i ve , r and omized , controlled study . SETTING : University medical center . PATIENTS Three hundred eighty-five patients receiving mechanical ventilation between June 1997 and May 1998 . INTERVENTIONS A respiratory care practitioner- and registered nurse-driven VMP . RESULTS Intervention and control groups were comparable with respect to age , sex , severity of illness and injury , and duration of respiratory failure at the time of r and omization . The duration of mechanical ventilation for patients was decreased from a median of 124 h for the control group to 68 h in the VMP group ( p = 0.0001 ) . Thirty-one total instances of VAP were noted . Twelve patients in the surgical control group had VAP , compared with 5 in the surgical VMP group ( p = 0.061 ) . The impact of the  VMP  on VAP frequency was less for medical patients . Mortality and ventilator discontinuation failure rates were similar between control and VMP groups . CONCLUSIONS A VMP design ed for multidisciplinary use was effective in reducing duration of mechanical ventilatory support without any adverse effects on patient outcome . The VMP was also associated with a decrease in incidence of VAP in trauma patients . These results , in conjunction with prior studies , suggest that VMPs are highly effective means of improving care , even in university ICUs RATIONALE Despite its ability to reduce overall ventilation time , protocol -guided weaning from mechanical ventilation is not routinely used in daily clinical practice . Clinical implementation of weaning protocol s could be facilitated by integration of knowledge-based , closed-loop controlled protocol s into respirators . OBJECTIVES To determine whether automated weaning decreases overall ventilation time compared with weaning based on a st and ardized written protocol in an unselected surgical patient population . METHODS In this prospect i ve controlled trial patients ventilated for longer than 9 hours were r and omly allocated to receive either weaning with automatic control of pressure support ventilation ( automated-weaning group ) or weaning based on a st and ardized written protocol ( control group ) using the same ventilation mode . The primary end point of the study was overall ventilation time . MEASUREMENTS AND MAIN RESULTS Overall ventilation time ( median [ 25th and 75th percentile ] ) did not significantly differ between the automated-weaning ( 31 [ 19 - 101 ] h ; n = 150 ) and control groups ( 39 [ 20 - 118 ] h ; n = 150 ; P = 0.178 ) . Patients who underwent cardiac surgery ( n = 132 ) exhibited significantly shorter overall ventilation times in the automated-weaning ( 24 [ 18 - 57 ] h ) than in the control group ( 35 [ 20 - 93 ] h ; P = 0.035 ) . The automated-weaning group exhibited shorter ventilation times until the first spontaneous breathing trial ( 1 [ 0 - 15 ] vs. 9 [ 1 - 51 ] h ; P = 0.001 ) and a trend toward fewer tracheostomies ( 17 vs. 28 ; P = 0.075 ) . CONCLUSIONS Overall ventilation times did not significantly differ between weaning using automatic control of pressure support ventilation and weaning based on a st and ardized written protocol . Patients after cardiac surgery may benefit from automated weaning . Implementation of additional control variables besides the level of pressure support may further improve automated-weaning systems . Clinical trial registered with www . clinical trials.gov ( NCT 00445289 ) Objective To evaluate the feasibility of using a knowledge-based system design ed to automatically titrate pressure support ( PS ) to maintain the patient in a “ respiratory comfort zone ” during  noninvasive ventilation ( NIV ) in patients with acute respiratory failure . Design and setting Prospect i ve crossover interventional study in an intensive care unit of a university hospital . Patients Twenty patients . Interventions After initial NIV setting and startup in conventional PS by the chest physiotherapist NIV was continued for 45 min with the automated PS activated . Measurements and results During automated PS minute-volume was maintained constant while respiratory rate decreased significantly from its pre-NIV value ( 20 ± 3 vs. 25 ± 3 bpm ) . There was a trend towards a progressive lowering of dyspnea . In hypercapnic patients PaCO2 decreased significantly from 61 ± 9 to 51 ± 2 mmHg , and pH increased significantly from 7.31 ± 0.05 to 7.35 ± 0.03 . Automated PS was well tolerated . Two system malfunctions occurred prompting physiotherapist intervention . Conclusions The results of this feasibility study suggest that the system can be used during NIV in patients with acute respiratory failure . Further studies should now determine whether it can improve patient-ventilator interaction and reduce caregiver workload The purpose of this study was to determine if a computer-directed weaning system could wean patients with complex medical problems from mechanical ventilation and appropriately respond to signs of respiratory failure more effectively than traditional physician-directed weaning methods . In a prospect i ve , r and omized , controlled study , we tested the system in 15 patients who had required prolonged mechanical ventilation and met predetermined weaning tests . Patients were r and omly assigned to one of two groups : ( 1 ) automatic , computer-directed weaning or ( 2 ) physician-controlled weaning . The computer-directed system decreased or increased the synchronized intermittent m and atory ventilation rate and pressure support ( PS ) based on predetermined limits of patient respiratory rate ( RR ) and tidal volume ( TV ) . Pulse oximeter oxygen saturation was monitored , and alarms were triggered by an oxygen saturation of < 90 percent . In the physician control group , weaning progressed with SIMV rate and PS reduction , as judged appropriate by the physician . Nine patients were assigned to the computer group ; six patients were assigned to the control group . The average patient age was 64.8 + /- 14.9 years for the computer group , 65.2 + /- 22.7 years for the control group . The average time on mechanical ventilation prior to weaning was 13.4 + /- 7.8 days for the computer group and 14.5 + /- 11.1 days for the control group . Seven of the nine computer group patients weaned within 48 h of the study , with an average time to wean of 18.7 + /- 5.9 h. All seven were breathing spontaneously 48 h after weaning . Two of the six control group patients weaned within 48 h of the study , with an average time of 25.6 + /- 5.6 h. Both patients who weaned were placed back on mechanical ventilation within 30 h. The number of arterial blood gas sample s drawn during the study was 1.4 + /- 0.7 for the computer group , 7.2 + /- 4.3 for the control group . The number of minutes per hour outside acceptable limits of RR > 30 , RR < 8 , or TV < 5 ml/kg was 3.2 + /- 2.8 min for the computer group and 6.6 + /- 4.1 min for the control group . The study suggests that use of the computer-directed weaning system results in fewer arterial blood gas sample s , shorter weaning times , and less time spent outside acceptable RR and TV parameters OBJECTIVE To compare a practice of protocol -directed weaning from mechanical ventilation implemented by nurses and respiratory therapists with traditional physician-directed weaning . DESIGN R and omized , controlled trial . SETTING Medical and surgical intensive care units in two university-affiliated teaching hospitals . PATIENTS Patients requiring mechanical ventilation ( n = 357 ) . INTERVENTIONS Patients were r and omly assigned to receive either protocol -directed ( n = 179 ) or physician-directed ( n = 178 ) weaning from mechanical ventilation . MEASUREMENTS AND MAIN RESULTS The primary outcome measure was the duration of mechanical ventilation from tracheal intubation until discontinuation of mechanical ventilation . Other outcome measures included need for reintubation , length of hospital stay , hospital mortality rate , and hospital costs . The median duration of mechanical ventilation was 35 hrs for the protocol -directed group ( first quartile 15 hrs ; third quartile 114 hrs ) compared with 44 hrs for the physician-directed group ( first quartile 21 hrs ; third quartile 209 hrs ) . Kaplan-Meier analysis demonstrated that patients r and omized to protocol -directed weaning had significantly shorter duration s of mechanical ventilation compared with patients r and omized to physician-directed weaning ( chi 2 = 3.62 , p = .057 , log-rank test ; chi 2 = 5.12 , p = .024 , Wilcoxon test ) . Cox proportional-hazards regression analysis , adjusting for other covariates , showed that the rate of successful weaning was significantly greater for patients receiving protocol -directed weaning compared with patients receiving physician-directed weaning ( risk ratio 1.31 ; 95 % confidence interval 1.15 to 1.50 ; p = .039 ) . The hospital mortality rates for the two treatment groups were similar ( protocol -directed 22.3 % vs. physician-directed 23.6 % ; p = .779 ) . Hospital cost savings for patients in the protocol -directed group were $ 42,960 compared with hospital costs for patients in the physician-directed group . CONCLUSION Protocol -guided weaning of mechanical ventilation , as performed by nurses and respiratory therapists , is safe and led to extubation more rapidly than physician-directed weaning The duration of spontaneous breathing trials before extubation has been set at 2 h in research studies , but the optimal duration is not known . We conducted a prospect i ve , multicenter study involving 526 ventilator-supported patients considered ready for weaning , to compare clinical outcomes for trials of spontaneous breathing with target duration s of 30 and 120 min . Of the 270 and 256 patients in the 30- and 120-min trial groups , respectively , 237 ( 87.8 % ) and 216 ( 84.8 % ) , respectively , completed the trial without distress and were extubated ( p = 0.32 ) ; 32 ( 13.5 % ) and 29 ( 13.4 % ) , respectively , of these patients required reintubation within 48 h. The percentage of patients who remained extubated for 48 h after a spontaneous breathing trial did not differ in the 30- and 120-min trial groups ( 75.9 % versus 73.0 % , respectively , p = 0.43 ) . The 30- and 120-min trial groups had similar within-unit mortality rates ( 13 and 9 % , respectively ) and in-hospital mortality rates ( 19 and 18 % , respectively ) . Reintubation was required in 61 ( 13.5 % ) patients , and these patients had a higher mortality ( 20 of 61 , 32.8 % ) than did patients who tolerated extubation ( 18 of 392 , 4.6 % ) ( p < 0.001 ) . Neither measurements of respiratory frequency , heart rate , systolic blood pressure , and oxygen saturation during the trial , nor other functional measurements before the trial discriminated between patients who required reintubation from those who tolerated extubation . In conclusion , after a first trial of spontaneous breathing , successful extubation was achieved equally effectively with trials targeted to last 30 and 120 min Background Weaning difficulties occur in 31 % of total intubated patients , and result in prolonged weaning duration . A computer‐driven automated weaning system can perform a spontaneous breathing trial ( SBT ) automatically and display a message when the trial is successfully passed . Such a system might have a beneficial effect on difficult‐to‐wean patients . The aim of this study was to examine whether the computer‐driven automated weaning system can accelerate discontinuation of mechanical ventilation and improve outcomes in difficult‐to‐wean patients . Methods This r and omized controlled study included 39 difficult‐to‐wean patients who failed their first spontaneous breathing trial . Before initiating weaning , eligible patients were r and omly allocated to wean by computer‐driven automated weaning system ( CDW group , n=19 ) or a physician‐controlled local protocol ( PW group , n=20 ) . Weaning duration , defined as the time from inclusion until first extubation , was the primary endpoint . Secondary endpoints were total duration of mechanical ventilation , the length of intensive care unit ( ICU ) stay , the number of reintubations , the mortality rate in the ICU , the number of noninvasive ventilations , the number of complications in the ICU , and the number of ventilator‐associated pneumonia cases . Results The weaning duration was reduced with the computer‐driven weaning as compared with the usual protocol ( median 29.0 hours vs. 45.5 hours , P=0.044 ) . Total duration of mechanical ventilation and duration of the ICU stay did not differ between the CDW and PW groups . There was no difference in the number of reintubations between the CDW and PW groups ( 3 and 4 patients , P=0.732 ) . The study groups showed comparable numbers of tracheostomy , selfextubations , ventilator‐associated pneumonia , and non‐invasive ventilation . Mortality in the ICU was similar in the CDW and the PW groups ( 21.1 % vs. 20.0 % , P=0.935 ) . Conclusion The computer‐driven automated weaning system can reduce weaning duration in difficult‐to‐wean patients as compared with a physician‐controlled weaning protocol To evaluate the attributable morbidity and mortality of ventilator-associated pneumonia ( VAP ) in intensive care unit ( ICU ) patients , we conducted a prospect i ve , matched cohort study . Patients expected to be ventilated for > 48 h were prospect ively followed for the development of VAP . To determine the excess ICU stay and mortality attributable to VAP , we matched patients with VAP to patients who did not develop clinical ly suspected pneumonia . We also conducted sensitivity analyses to examine the effect of different population s , onset of pneumonia , diagnostic criteria , causative organisms , and adequacy of empiric treatment on the outcome of VAP . One hundred and seventy-seven patients developed VAP . As compared with matched patients who did not develop VAP , patients with VAP stayed in the ICU for 4.3 d ( 95 % confidence interval [ CI ] : 1.5 to 7 . 0 d ) longer and had a trend toward an increase in risk of death ( absolute risk increase : 5.8 % ; 95 % CI : -2.4 to 14.0 d ; relative risk ( RR ) increase : 32.3 % ; 95 % CI : -20.6 to 85.1 % ) . The attributable ICU length of stay was longer for medical than for surgical patients ( 6 . 5 versus 0.7 d , p < 0.004 ) , and for patients infected with " high risk " organisms as compared with " low risk " organisms ( 9.1 d versus 2.9 d ) . The attributable mortality was higher for medical patients than for surgical patients ( RR increase of 65 % versus -27.3 % , p = 0 . 04 ) . Results were similar for three different VAP diagnostic criteria . We conclude that VAP prolongs ICU length of stay and may increase the risk of death in critically ill patients . The attributable risk of VAP appears to vary with patient population and infecting organism A recent international prevalence study involving more than 1000 intensive care units indicated that pneumonia is responsible for almost half of the infections in critically ill patients in Europe [ 1 ] . Ventilator-associated pneumonia accounts for approximately 90 % of infections in patients requiring assisted ventilation [ 2 , 3 ] . An independent contribution to mortality conferred by ventilator-associated pneumonia was recently suggested [ 4 , 5 ] . Although debate persists about the mortality attributable to ventilator-associated pneumonia among other causes of death in critically ill patients [ 1 , 4 - 7 ] , there is little doubt that ventilator-associated pneumonia causes substantial morbidity by increasing the duration of mechanical ventilation and intensive care unit stay [ 4 , 5 ] . It is therefore important to underst and the factors that are predictive of ventilator-associated pneumonia , to identify patients at highest risk , and to target these patients for the most effective preventive strategies as determined by r and omized trials [ 8 , 9 ] . Risk factors for nosocomial pneumonia have been evaluated in hospitalized elderly persons [ 10 ] , heterogeneous groups of hospitalized patients breathing spontaneously or requiring assisted ventilation [ 11 ] , and similar mixed population s admitted to the intensive care unit [ 2 , 12 - 15 ] . Investigations in ventilated critically ill patients only are needed to identify independent predictors of ventilator-associated pneumonia . Most studies of risk factors for ventilator-associated pneumonia have been conducted at single institutions , and different predictors have been examined . In cohort studies using multivariable analyses [ 16 - 21 ] , only reintubation [ 17 , 19 , 21 ] and antibiotic use [ 18 , 20 ] were identified as risk factors in more than one report . However , a direct relation between antibiotics and pneumonia was found in one study [ 18 ] , whereas an inverse relation was found in another [ 20 ] . We examined factors associated with ventilator-associated pneumonia . We explored baseline and time-dependent characteristics , including measures of illness severity , factors relating to mechanical ventilation , variables in the gastropulmonary route of infection , and drug exposure . Methods Patients We used a multicenter national data base of 1200 patients who received mechanical ventilation for 48 hours or more and were enrolled from October 1992 to May 1996 in a double-blind , concealed , r and omized trial of sucralfate compared with ranitidine to determine rates of ventilator-associated pneumonia and gastrointestinal bleeding [ 22 ] . Patients were followed until death , discharge , or clinical suspicion of ventilator-associated pneumonia as determined by the attending intensivist . Bronchoalveolar lavage or protected specimen brush was indicated for patients with a clinical suspicion of ventilator-associated pneumonia . A diagnosis of ventilator-associated pneumonia was considered only in patients who were receiving mechanical ventilation or who stopped receiving ventilation for less than 48 hours . In the absence of a reference st and ard for diagnosing pneumonia in critically ill patients [ 23 , 24 ] , each patient 's clinical , laboratory , and radiographic data were independently review ed by one of four pairs of adjudicators blinded to treatment group . The readers in each adjudication pair decided on the presence or absence of ventilator-associated pneumonia , resolving any disagreement through discussion . Consensus was achieved on all cases . The adjudicated outcome was used for the primary analysis [ 177 cases ] . However , each case of pneumonia was classified according to four additional definitions : 1 ) the bedside clinician 's diagnosis [ 233 cases ] ; 2 ) the modified Centers for Disease Control and Prevention criteria [ 25 ] , which require a new radiographic infiltrate persistent for 48 hours or more plus a body temperature greater than 38.5 C or less than 35.0 C , a leukocyte count of more than 10 cells 109/L or less than 3 cells 109/L , purulent sputum or change in character of sputum , or isolation of pathogenic bacteria from an endotracheal aspirate [ 211 cases ] ; 3 ) a Clinical Pulmonary Infection score of 7 or more [ 26 ] [ 194 cases ] ; or 4 ) a positive culture from bronchoalveolar lavage ( > 104 colony-forming units/mL ) or protected specimen brush ( < 103 colony-forming units/mL ) ( 97 cases ) . Statistical Analysis We expressed continuous variables as the mean ( SD ) or as the median and interquartile range if their distribution was skewed . We used the Student t-test to compare continuous variables and the chi-square test to compare proportions . All statistical tests were two-tailed . We performed a forward stepwise Cox proportional-hazards regression analysis to evaluate potential risk factors for ventilator-associated pneumonia . The Cox model assesses the effect of each risk factor on the hazard rate of ventilator-associated pneumonia over time , adjusted for other factors in the model and allowing for censoring because of death or discharge . The hazard function in the Cox model can be used to estimate the event rate per day over the duration of stay in the intensive care unit . Independent variables recorded at baseline included age ; sex ; primary diagnosis ; medical or surgical status ; hospital admission in the fall or winter compared with spring or summer ; location before admission to the intensive care unit ; treatment center ; Acute Physiology and Chronic Health Evaluation II score ; Acute Physiology score ; Multiple Organ Dysfunction score [ 27 ] ; Glasgow Coma Scale score ; and chronic comorbid conditions , such as alcoholism , a smoking history of 10 or more pack-years , asthma , bronchiectasis , pulmonary fibrosis , cancer , and HIV infection ; organ transplantation ; and recent  corticosteroid therapy  or chemotherapy . Additional independent variables evaluated daily throughout the intensive care unit stay were classified as illness severity measures ( daily Multiple Organ Dysfunction score and change in Multiple Organ Dysfunction score from baseline ) , ventilation variables  ( mechanical ventilation , change or reinsertion of endotracheal tube , discontinuation and reinstitution of mechanical ventilation , and tracheostomy ) , nutritional variables ( nasoenteral nutrition , gastrostomy feeding , jejunostomy feeding , enteral nutrition through any route  ,  central parenteral nutrition , peripheral parenteral nutrition , and insulin requirement of more than 15 U/d ) , witnessed  aspiration , and  drug exposure ( stress-ulcer prophylaxis with ranitidine or sucralfate , paralytic agents , and antibiotics ) . The Multiple Organ Dysfunction Score combines measures of physiologic dysfunction in six domains : the cardiovascular system ( heart rate x right atrial pressure/mean arterial pressure ) , pulmonary system ( Pao 2:Fio 2 ratio ) , the renal system ( serum creatinine concentration ) , the hepatic system ( serum bilirubin level ) , the hematologic system ( platelet count ) , and the central nervous system ( Glasgow Coma Scale score ) [ 25 ] . These continuous variables are constructed in 5 categories so that 0 represents normal function and 4 reflects marked physiologic derangement and is associated with a mortality rate greater than 50 % . Composite scores provide a quantitative measure of global physiologic dysfunction at a discrete point in the intensive care unit stay . For individual domains , either the raw data or their score provides a measure of dysfunction in the system of interest . Variables that were associated with ventilator-associated pneumonia in the univariable analysis and had a P value less than 0.10 were entered into a multivariable regression analysis . Factors were considered significant if the P value was less than 0.05 in the multivariable analysis . We calculated risk ratios and 95 % CIs for all significant predictors of ventilator-associated pneumonia in the multivariable analysis using all five definitions . We tested for all pairwise interactions between significant risk factors in the multivariable model . We also tested for interactions between predictors in the multivariable model and factors that were significant in the univariable analysis . Finally , we investigated the possibility that the effects of risk factors may vary over the duration of stay in the intensive care unit ; this was done by using a nonproportional Cox model testing the interaction of each variable in the final model with time . For example , we hypothesized that the influence of antibiotics on ventilator-associated pneumonia may vary over time . Time was considered both a continuous variable and a discretized variable by using 3-day and 5-day intervals . We did not consider antibiotics administered 24 hours before the diagnosis of ventilator-associated pneumonia , so that drugs prescribed in response to early ventilator-associated pneumonia would be excluded [ 28 ] . Role of Study Sponsor Our funding sources had no role in the acquisition , analysis , or interpretation of data or in the su bmi ssion of this report . Results Of the 1200 patients enrolled in this study , 186 were excluded ( 85 were discharged , 71 died , and 30 had pneumonia in the first 48 hours ) , leaving 1014 patients ventilated for 48 hours or more who were free of pneumonia at admission to the intensive care unit . Of these patients , 177 ( 17.5 % ) developed ventilator-associated pneumonia 9.0 5.9 days after admission ( median , 7 days [ interquartile range , 5 to 10 days ] ) . The characteristics of patients with and without ventilator-associated pneumonia are shown in Table 1 . The total duration of mechanical ventilation among patients with ventilator-associated pneumonia was 19.3 16.0 days ( median , 15 days [ interquartile range , 9 to 23 days ] ) compared with 10.2 10.5 days ( median , 7 days [ interquartile range , 4 to 11 days ] ) in other patients ( P < 0.001 ) . Among the 177 patients with ventilator-associated pneumonia , 131 ( 74.0 % ) had bronchoscopic testing with bronchoalveolar lavage or protected specimen brush . Patients in the following admitting diagnostic Objective Preliminary assessment of an automated weaning system ( SmartCare ™ /PS ) compared to usual management of weaning from mechanical ventilation performed in the absence of formal protocol s. Design and setting A r and omised , controlled pilot study in one Australian intensive care unit . Patients A total of 102 patients were equally divided between SmartCare/PS and Control . Interventions The automated system titrated pressure support , conducted a spontaneous breathing trial and provided notification of success ( “ separation potential ” ) . Measurements and results The median time from the first identified point of suitability for weaning commencement to the state of “ separation potential ” using SmartCare/PS was 20 h ( interquartile range , IQR , 2–40 ) compared to 8 h ( IQR 2–43 ) with Control ( log-rank P = 0.3 ) . The median time to successful extubation was 43 h ( IQR 6–169 ) using SmartCare/PS and 40 ( 14–87 ) with Control ( log-rank P = 0.6 ) . Unadjusted , the estimated probability of reaching “ separation potential ” was 21 % lower ( 95 % CI , 48 % lower to 20 % greater ) with SmartCare/PS compared to Control . Adjusted for other covariates ( age , gender , APACHE II , SOFAmax , neuromuscular blockade , corticosteroids , coma and elevated blood glucose ) , these estimates were 31 % lower ( 95 % CI , 56 % lower to 9 % greater ) with SmartCare/PS . The study groups showed comparable rates of reintubation , non-invasive ventilation post-extubation , tracheostomy , sedation , neuromuscular blockade and use of corticosteroids . Conclusions Substantial reductions in weaning duration previously demonstrated were not confirmed when the SmartCare/PS system was compared to weaning managed by experienced critical care specialty nurses , using a 1:1 nurse-to-patient ratio . The effect of SmartCare/PS may be influenced by the local clinical organisational context .Descriptor28 . Mechanical ventilation : weaning Abstract Abstract Objective . To investigate the possibility of successful extubation performing a spontaneous breathing trial ( SBT ) in pressure support ventilation ( PSV ) with target duration s of 30 and 120 min . Design and setting . Prospect i ve and r and omized study in two medical-surgical adult intensive care units . Patients and participants . 98 adult patients supported by mechanical ventilation for at least 48 h and considered ready for a weaning trial . Interventions . An SBT conducted in PSV with 7 cmH2O and patients r and omly assigned to two groups with target duration s of 30- and 120-min . Measurements and results . In the 30-min group 43 patients ( 93 % ) tolerated the SBT and were extubated while 4 ( 9 % ) needed reintubation within 48 h ; in the 120-min group 46 patients ( 88 % ) successfully completed the trial and were extubated while 2 ( 4 % ) were reintubated . ICU mortality in the groups with short and long periods was 6 % and 4 % , and in-hospital mortality 20 % and 17 % , respectively . Those successful in the 30- and 120-min groups had similar length of ICU stay ( 6 and 7 days , respectively ) and in-hospital length of stay ( 20 and 25 days , respectively ) . Compared to the successfully extubated , the reintubated patients had significantly higher length of ICU stay and mortality ( 17 vs. 6 days and 33 vs. 3.6 % , respectively ) . Conclusions . An SBT with PSV of 7 cmH2O lasting 30 min is equally effective in recognizing the successfully extubated patients as a 120-min trial Two hundred ( 200 ) consecutive medical and surgical patients requiring mechanical ventilation were entered into a prospect i ve r and omized trial of weaning by either intermittent m and atory ventilation ( IMV ) or T-piece . Patients in these groups were of similar age and sex and had the same total ventilation time ( TVT ) . The study design provided equal time for each weaning mode after specific criteria for oxygenation and ventilation were satisfied ( PaO2 greater than 55 mm Hg on FIO2 less than 0.5 ; VE less than 12 L/min and two of the following four parameters : MVV greater than 2 VE , VT greater than 5 ml/kg , FVC greater than 10 ml/kg , NIF less than or equal to -20 cm H2O ) . Of the original 200 patients 165 were entered into the weaning phase ; 35 patients were withdrawn prior to weaning due to the discretion of the attending physician or protocol error .  Weaning time was not different between the IMV ( 5.3 + /- 1.2 h , mean + /- SEM ) and T-piece groups ( 5.9 + /- 1.4 h , p = NS ) . Of the 165 patients , 155 ( 93 percent ) were weaned successfully by protocol , 79 in the IMV and 76 in the T-piece group . Of 155 patients , 136 ( 88 percent ) were weaned on the first attempt by protocol . Of the 19 who were not weaned , 11 were weaned successfully on the second and five on the third trial ; three patients required three-day weans . We conclude that clinical ly stable patients who require short-term mechanical ventilation and meet st and ard bedside weaning criteria can be weaned efficiently by protocol using either IMV or T-piece techniques Several modalities of ventilatory support have been proposed to gradually withdraw patients from mechanical ventilation , but their respective effects on the outcome of weaning from mechanical ventilation are not known . We conducted a r and omized trial in three intensive care units in mechanically ventilated patients who met st and ard weaning criteria . Those who could not sustain 2 h of spontaneous breathing were r and omly assigned to be weaned with T-piece trials , with synchronized intermittent m and atory ventilation ( SIMV ) , or with pressure support ventilation ( PSV ) . Specific criteria for performing tracheal extubation were defined for each modality . The number of patients who could not be separated from the ventilator at 21 d ( i.e. , who failed to wean ) was compared between the groups . Patients in whom tracheal intubation was required in a 48-h period following extubation were also classified as failures . Among 456 mechanically ventilated patients who met weaning criteria , 109 entered into the study ( 35 with T piece , 43 with SIMV , and 31 with PSV )  . The three groups were comparable in terms of etiology of disease or characteristics at entry in the study . When all causes for weaning failure were considered , a lower number of failures was found with PSV than with the other two modes , with the difference just reaching the level of significance ( 23 % for PSV , 43 % for T piece , 42 % for SIMV ; p = 0.05 ) . After excluding patients whose weaning was terminated for complications unrelated to the weaning process , the difference became highly significant ( 8 % for PSV versus 33 % and 39 % , p < 0.025 ) . ( ABSTRACT TRUNCATED AT 250 WORDS Certain groups of mechanically ventilated patients with acute respiratory failure are difficult to wean from prolonged ventilation despite advanced respiratory support techniques . The common modes for providing support during weaning are intermittent m and atory ventilation ( IMV ) , and spontaneous ventilatory trial ( SVT ) techniques ; such as continuous positive airway pressure ( CPAP ) and T-piece . Weaning is often initiated with IMV , and a series of SVTs are introduced as the patient tolerates decreasing rates of IMV . However , there is some concern that this strategy of weaning may not be optimal for patient comfort , and muscle reconditioning [ 1 ] Objective : To evaluate the applicability , tolerance , and efficacy of a closed-loop protocol to wean children from mechanical ventilation . Design : Prospect i ve single-center pilot study . Setting : Tertiary care university hospital . Patients : Twenty mechanically ventilated children aged between 1 and 17 yrs , with a body weight ≥10 kg , no inotropes , and no heavy sedation . Interventions : Patients were weaned in pressure support mode by a closed-loop computerized protocol ( closed-loop protocol ) that interprets clinical data in real time and controls pressure support levels . Measurements and Main Results : The closed-loop protocol applicability and tolerance were evaluated . The efficacy of this protocol was evaluated by comparing the duration of mechanical ventilation with a historical group of 20 patients weaned with a clinician-decision protocol . The closed-loop protocol successfully decreased pressure support ventilation in 16 children , recommended separation from the ventilator in 14 children , and did not cause any serious adverse events . Mechanical ventilation duration was 5.1 ± 4.2 days in the closed-loop group and 6.7 ± 11.5 days ( mean ± sd ) in the clinician-decision group ( p = .33 ) with no difference in the need for reintubation or noninvasive mechanical ventilation ( one of 20 and four of 20 , respectively ; p = .20 ) . Conclusions : A closed-loop protocol was successfully used to wean children from mechanical ventilation . Further studies are required to assess the impact of this novel therapeutic strategy on the length of mechanical ventilation OBJECTIVE To evaluate if the computer-driven weaning ( CDW ) with a closed-loop knowledge-based system introduced in a ventilator is superior to physician-directed weaning ( PDW ) in difficult-to-wean patients in the intensive care unit ( ICU ) . METHODS Sixty-two difficult-to-wean patients were r and omized into 2 groups : weaning with Smart Care/PS ( SC group , n = 32 ) or with synchronize intermittent m and atory ventilation add positive support ventilation ( SP group , n = 30 ) . In the SC group , the automated system titrated pressure support , conducted a spontaneous breathing trial and provided notification of success ( separation potential ) . In the SP group , weaning from ventilators was carried out by gradually decreasing respiratory support . The length of mechanical ventilation and stay in ICU , the rate of ventilator-associated pneumonia ( VAP ) , the retubing rate in 48 h , manual ventilator setting changes before extubation were compared between the 2 groups . RESULTS In the SC group , the weaning time was ( 49 + /- 13 ) h , ( 67 + /- 37 ) h , and ( 254 + /- 96 ) h , respectively in patients with neuromuscular diseases , for post-operative respiratory support and patients with respiratory diseases ; while in the SP group , the weaning time was ( 223 + /- 38 ) h , ( 106 + /- 34 ) h and ( 502 + /- 91 ) h , respectively ; the difference between the 2 groups being statistically significant ( chi(2 ) = 8.33 , 4.77 , 4.43 , all P < 0.05 ) . The time of stay in ICU was ( 9.0 + /- 1.7 ) d and ( 7.3 + /- 1.9 ) d in the SC group for patients with neuromuscular diseases and patients with post-operative respiratory support , respectively , while that was ( 20.8 + /- 5.1 ) d and ( 14.6 + /- 1.7 ) d in the SP group , respectively . Time of stay in ICU was significantly shorter in the SC group ( chi2 = 6.74 , 7.68 , both P < 0.05 ) . The number of manual ventilator setting changes was ( 5 + /- 1 ) times in the SC group , significantly less than that of the SP group ( 13 + /- 3 , t = 2.73 , P < 0.05 ) . There were no significant differences between the SC and the SP groups in the rate of re-intubation , the rate of tracheotomy , the incidence of pneumothorax , the incidence of VAP and the incidence of subcutaneous emphysema . CONCLUSION The CDW method used in patients with difficult weaning from ventilators was shown to shorten the weaning time , reduce stay in ICU , and decrease the need for manual adjustment of ventilators CONTEXT The outcome of patients receiving mechanical ventilation for particular indications has been studied , but the outcome in a large number of unselected , heterogeneous patients has not been reported . OBJECTIVE To determine the survival of patients receiving mechanical ventilation  and the relative importance of factors influencing survival . DESIGN , SETTING , AND SUBJECTS Prospect i ve cohort of consecutive adult patients admitted to 361 intensive care units who received mechanical ventilation for more than 12 hours between March 1 , 1998 , and March 31 , 1998 . Data were collected on each patient at initiation of mechanical ventilation and daily throughout the course of mechanical ventilation for up to 28 days . MAIN OUTCOME MEASURE All-cause mortality during intensive care unit stay . RESULTS Of the 15 757 patients admitted , a total of 5183 ( 33 % ) received mechanical ventilation  for a mean ( SD ) duration of 5.9 ( 7.2 ) days . The mean ( SD ) length of stay in the intensive care unit was 11.2 ( 13.7 ) days . Overall mortality rate in the intensive care unit was 30.7 % ( 1590 patients ) for the entire population , 52 % ( 120 ) in patients who received ventilation because of acute respiratory distress syndrome , and 22 % ( 115 ) in patients who received ventilation for an exacerbation of chronic obstructive pulmonary disease . Survival of unselected patients receiving mechanical ventilation for more than 12 hours was 69 % . The main conditions independently associated with increased mortality were ( 1 ) factors present at the start of mechanical ventilation ( odds ratio [ OR ] , 2.98 ; 95 % confidence interval [ CI ] , 2.44 - 3.63 ; P<.001 for coma ) , ( 2 ) factors related to patient management ( OR , 3.67 ; 95 % CI , 2.02 - 6.66 ; P<.001 for plateau airway pressure > 35 cm H(2)O ) , and ( 3 ) developments occurring over the course of mechanical ventilation ( OR , 8.71 ; 95 % CI , 5.44 - 13.94 ; P<.001 for ratio of PaO(2 ) to fraction of inspired oxygen < 100 ) . CONCLUSION Survival among mechanically ventilated patients depends not only on the factors present at the start of mechanical ventilation , but also on the development of complications and patient management in the intensive care unit RATIONALE Automated weaning has not been compared with a paper-based weaning protocol in North America . OBJECTIVES We conducted a pilot r and omized trial comparing automated weaning with protocol ized weaning in critically ill adults to evaluate clinician compliance and acceptance of the weaning and sedation protocol s , recruitment , and impact on outcomes . METHODS From August 2007 to October 2009 , we enrolled critically ill adults requiring more than 24 hours of mechanical ventilation and at least partial reversal of the condition precipitating respiratory failure at nine Canadian intensive care units . We r and omized patients who tolerated at least 30 minutes of pressure support and either failed or were not yet ready to undergo a spontaneous breathing trial to automated or protocol ized weaning .  Both groups used pressure support , included spontaneous breathing trials , used a common positive end-expiratory pressure-FI(O(2 ) ) chart , sedation protocol , and criteria for extubation , reintubation , and noninvasive ventilation . MEASUREMENTS AND MAIN RESULTS We recruited 92 patients ( 49 automated , 43 protocol ized ) over 26 months .  Adherence to assigned weaning protocol s and extreme sedation scale scores fell within prespecified thresholds . Combined physician-respiratory therapist and nurse acceptance scores of the study weaning and sedation protocol s , respectively , were not significantly different . Automated weaning patients had significantly shorter median times to first successful spontaneous breathing trial ( 1.0 vs. 4.0 d ; P < 0.0001 ) , extubation ( 3.0 vs. 4.0 d ; P = 0.02 ) , and successful extubation ( 4.0 vs. 5.0 d ; P = 0.01 ) , and underwent fewer tracheostomies and episodes of protracted ventilation . CONCLUSIONS Compared with a st and ardized protocol , automated weaning was associated with promising outcomes that warrant further investigation . Minor protocol modifications may increase compliance , facilitate recruitment , and enhance feasibility . Clinical trial registered with www.controlled-trials.com ( IS RCT N43760151 ) OBJECTIVE To compare the outcome of the SmartCare and spontaneous breathing trials ( SBT ) for weaning old patients with chronic obstructive pulmonary diseases ( COPD ) . METHODS Thirty-eight COPD patients were enrolled in Department of Respiratory Medicine on the South Building , General Hospital of People 's Liberation Army from January , 2003 to April , 2005 . They mechanically ventilated for at least 3 d ( age : 70 - 91 year , average : 83.3 + /- 4.3 ) , r and omly assigned to receive SmartCare ( SC group , n = 13 ) or  SBT ( SBT group , n = 25 ) . All patients were considered clinical ly and biologically stable , and therefore ready to be weaned from mechanical ventilation . In SC group , patients were ventilated with an inspiratory pressure ( IPAP ) support adjusted to achieve pH value > or = 7.35 , saturation of oxygen in arterial blood ( SaO2 ) > or = 90 % , respiratory frequency ( RR ) > or = 10 and < or = 30 breaths/min , and fraction of inspired oxygen ( FiO2 ) < or = 45 % . In SBT group , the patients were placed in a weaning protocol utilizing increasing duration of spontaneous breathing . The following data were recorded at weaning : the acute physiology and chronic health evaluation II ( APACHE II ) score , arterial blood gases under mechanical ventilation , serum calcium , magnesium , and phosphorus , the days of ventilation before weaning and the duration of weaning . The patients of both groups were considered as successfully weaned when they were able to tolerate at least 48 consecutive hours of spontaneous breathing . Failure was defined in a patient who died during the weaning process or who still needed mechanical ventilation after at least 40 consecutive days of weaning . RESULTS No significant differences were found between the groups at the onset of weaning from mechanical ventilation regarding APACHE II , serum albumin , calcium , magnesium , phosphorus , partial pressure of carbon dioxide in arterial blood ( PaCO2 ) , and the days of mechanical ventilation ( t = 0.834 , 0.696 , 1.384 , 0.682 , 0.467 , 0.816 , 0.384 , all P > 0.05 ) . The pH value of the SBT group ( 7.45 + /- 0.05 ) was higher than the SC group ( 7.40 + /- 0.04 , t = 3.263 , P < 0.05 ) . Although patients in the SC group spent less time in weaning than those in the SBT group , the difference was not significant [ ( 8.54 + /- 2.09 ) , ( 13.32 + /- 2.19 ) d for the SC and SBT groups , respectively , t = 1.320 , P = 0.251 ] . The 7-d weaning success rate was greater in the SC group than the SBT group ( 77 % , 40 % , chi(2 ) = 4.677 , P = 0.031 ) . No significant difference was found in 14-d weaning success rate ( 77 % , 64 % in the SC and SBT groups , chi(2 ) = 0.661 , P = 0.416 ) . Fewer arterial blood analyses were performed in the SC group ( 3.5 + /- 3.1 , 6.6 + /- 3.7 , t = 2.710 , P = 0.011 ) . CONCLUSION The SmartCare is better than SBT in weaning patients with COPD within 7 days OBJECTIVE To examine medical outcomes associated with reintubation for extubation failure after discontinuation of mechanical ventilation . DESIGN Prospect i ve cohort study of consecutive intubated medical ICU patients who underwent a trial of extubation at a tertiary-care teaching hospital . The failed extubation group consisted of all patients reintubated within 72 h or within 7 days ( if continuous ICU care had been required ) of extubation . All others were considered to be successfully extubated . Study end points included hospital death vs survival , the number of days spent in the ICU and in the hospital after the onset of mechanical ventilation , the likelihood of requiring > or = 7 or > or = 14 days of ICU care after extubation , and the need for transfer to either a long-term care or rehabilitation facility among the survivors . RESULTS Of 289 intubated patients , 247 ( 85 % ) were successfully extubated , and 42 ( 15 % ) required reintubation for failed extubation ( time to reintubation 1.5+/-0.2 days ) . Reintubation for extubation failure result ed in 12 additional days of mechanical ventilation . When compared with successfully extubated patients , reintubated patients were more likely to die in the hospital ( 43 % vs 12 % ; p<0.0001 ) , spend more time in the ICU ( 21.2+/-2.8 days vs 4.5+/-0.6 days ; p<0.001 ) and in the hospital ( 30.5+/-3.3 days vs 16.3+/-1.2 days ; p<0.001 ) after extubation , and require transfer to a long-term care or rehabilitation facility ( 38 % vs 21 % ; p<0.05 ) . Using multiple logistic regression , extubation failure was an independent predictor for death and the need for transfer to a long-term care facility . Compared with those successfully extubated , patients who failed extubation were seven times ( p<0.0001 ) more likely to die , 31 times ( p<0.0001 ) more likely to spend > or = 14 days in the ICU after extubation , and six times ( p<0.001 ) more likely to need transfer to a long-term care or rehabilitation facility if they survived . CONCLUSION After adjusting for severity of illness and comorbid conditions , extubation failure had a significant independent association with increased risk for death , prolonged ICU stay , and transfer to a long-term care or rehabilitation facility . Extubation failure may serve as an additional independent marker of severity of illness . Alternatively , poor outcomes may be etiologically related to extubation failure . If the latter proves to be the case , identifying patients at risk for poor outcomes from extubation failure and instituting alternative care practice s may reduce mortality , duration of ICU stay , and need for transfer to a long-term care facility
BACKGROUND Automated systems use closed-loop control to enable ventilators to perform basic and advanced functions while supporting respiration .
SmartCare ™ is a unique automated weaning system that measures selected respiratory variables , adapts ventilator output to individual patient needs by operationalizing predetermined algorithms and automatically conducts spontaneous breathing trials ( SBTs ) when predetermined thresholds are met .
OBJECTIVES The primary objective of this review was to compare weaning time ( time from r and omization to extubation as defined by study authors ) between invasively ventilated critically ill adults weaned by automated weaning and SBT systems  versus  non-automated weaning strategies .