Positive end-expiratory pressure setting in adults with acute lung injury and acute respiratory distress syndrome: a randomized controlled trial. A comparison of biologically variable ventilation to recruitment manoeuvres in a porcine model of acute lung injury Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. Lung recruitment in patients with the acute respiratory distress syndrome. Lung recruitment manoeuvres are effective in regaining lung volume and oxygenation after open endotracheal suctioning in acute respiratory distress syndrome Ventilation strategy using low tidal volumes, recruitment maneuvers, and high positive end-expiratory pressure for acute lung injury and acute respiratory distress syndrome: a randomized controlled trial. Effects of periodic lung recruitment maneuvers on gas exchange and respiratory mechanics in mechanically ventilated acute respiratory distress syndrome (ARDS) patients High frequency oscillatory ventilation compared with conventional mechanical ventilation in adult respiratory distress syndrome: a randomized controlled trial [ISRCTN24242669] Beneficial effects of the "open lung approach" with low distending pressures in acute respiratory distress syndrome. A prospective randomized study on mechanical ventilation. Reversibility of lung collapse and hypoxemia in early acute respiratory distress syndrome. Recruitment Maneuvers after a Positive End-expiratory Pressure Trial Do Not Induce Sustained Effects in Early Adult Respiratory Distress Syndrome Effects of recruitment maneuvers in patients with acute lung injury and acute respiratory distress syndrome ventilated with high positive end-expiratory pressure* Higher versus lower positive end-expiratory pressures in patients with the acute respiratory distress syndrome. Reliability of the PEDro scale for rating quality of randomized controlled trials. Effect of a protective-ventilation strategy on mortality in the acute respiratory distress syndrome. An evaluation of a single chest physiotherapy treatment on mechanically ventilated patients with acute lung injury. Comparison of Conventional Mechanical Ventilation and High‐frequency Ventilation: A Prospective, Randomized Trial in Patients with Respiratory Failure Open and Closed-circuit Endotracheal Suctioning in Acute Lung Injury: Efficiency and Effects on Gas Exchange High-frequency oscillatory ventilation for acute respiratory distress syndrome in adults: a randomized, controlled trial.
CONTEXT The need for lung protection is universally accepted , but the optimal level of positive end-expiratory pressure ( PEEP ) in patients with acute lung injury ( ALI ) or acute respiratory distress syndrome remains debated . OBJECTIVE To compare the effect on outcome of a strategy for setting PEEP aim ed at increasing alveolar recruitment while limiting hyperinflation to one aim ed at minimizing alveolar distension in patients with ALI . DESIGN , SETTING , AND PATIENTS A multicenter r and omized controlled trial of 767 adults ( mean [ SD ] age , 59.9 [ 15.4 ] years ) with ALI conducted in 37 intensive care units in France from September 2002 to December 2005 . INTERVENTION Tidal volume was set at 6 mL/kg of predicted body weight in both strategies . Patients were r and omly assigned to a moderate PEEP strategy ( 5 - 9 cm H(2)O ) ( minimal distension strategy ; n = 382 ) or to a level of PEEP set to reach a plateau pressure of 28 to 30 cm H(2)O ( increased recruitment strategy ; n = 385 ) . MAIN OUTCOME MEASURES The primary end point was mortality at 28 days . Secondary end points were hospital mortality at 60 days , ventilator-free days , and organ failure-free days at 28 days . RESULTS The 28-day mortality rate in the minimal distension group was 31.2 % ( n = 119 ) vs 27.8 % ( n = 107 ) in the increased recruitment group ( relative risk , 1.12 [ 95 % confidence interval , 0.90 - 1.40 ] ; P = .31 ) . The hospital mortality rate in the minimal distension group was 39.0 % ( n = 149 ) vs 35.4 % ( n = 136 ) in the increased recruitment group ( relative risk , 1.10 [ 95 % confidence interval , 0.92 - 1.32 ] ; P = .30 ) . The increased recruitment group compared with the minimal distension group had a higher median number of ventilator-free days ( 7 [ interquartile range { IQR } , 0 - 19 ] vs 3 [ IQR , 0 - 17 ] ; P = .04 ) and organ failure-free days ( 6 [ IQR , 0 - 18 ] vs 2 [ IQR , 0 - 16 ] ; P = .04 ) . This strategy also was associated with higher compliance values , better oxygenation , less use of adjunctive therapies , and larger fluid requirements . CONCLUSIONS A strategy for setting PEEP aim ed at increasing alveolar recruitment while limiting hyperinflation did not significantly reduce mortality . However , it did improve lung function and reduced the duration of mechanical ventilation and the duration of organ failure . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00188058 Background Biologically variable ventilation ( return of physiological variability in rate and tidal volume using a computer-controller ) was compared to control mode ventilation with and without a recruitment manoeuvre – 40 cm H2O for 40 sec performed hourly ; in a porcine oleic acid acute lung injury model . Methods We compared gas exchange , respiratory mechanics , and measured bronchoalveolar fluid for inflammatory cytokines , cell counts and surfactant function . Lung injury was scored by light microscopy . Pigs received mechanical ventilation ( FIO2 = 0.3 ; PEEP 5 cm H2O ) in control mode until PaO2 decreased to 60 mm Hg with oleic acid infusion ( PaO2/FIO2 < 200 mm Hg ) . Additional PEEP to 10 cm H2O was added after injury . Animals were r and omized to one of the 3 modes of ventilation and followed for 5 hr after injury . Results PaO2 and respiratory system compliance was significantly greater with biologically variable ventilation compared to the other 2 groups . Mean and mean peak airway pressures were also lower . There were no differences in cell counts in bronchoalveolar fluid by flow cytometry , or interleukin-8 and -10 levels between groups . Lung injury scoring revealed no difference between groups in the regions examined . No differences in surfactant function were seen between groups by capillary surfactometry . Conclusions In this porcine model of acute lung injury , various indices to measure injury or inflammation did not differ between the 3 approaches to ventilation . However , when using a low tidal volume strategy with moderate levels of PEEP , sustained improvements in arterial oxygen tension and respiratory system compliance were only seen with BVV when compared to CMV or CMV with a recruitment manoeuvre BACKGROUND Traditional approaches to mechanical ventilation use tidal volumes of 10 to 15 ml per kilogram of body weight and may cause stretch-induced lung injury in patients with acute lung injury and the acute respiratory distress syndrome . We therefore conducted a trial to determine whether ventilation with lower tidal volumes would improve the clinical outcomes in these patients . METHODS Patients with acute lung injury and the acute respiratory distress syndrome were enrolled in a multicenter , r and omized trial . The trial compared traditional ventilation treatment , which involved an initial tidal volume of 12 ml per kilogram of predicted body weight and an airway pressure measured after a 0.5-second pause at the end of inspiration ( plateau pressure ) of 50 cm of water or less , with ventilation with a lower tidal volume , which involved an initial tidal volume of 6 ml per kilogram of predicted body weight and a plateau pressure of 30 cm of water or less . The primary outcomes were death before a patient was discharged home and was breathing without assistance and the number of days without ventilator use from day 1 to day 28 . RESULTS The trial was stopped after the enrollment of 861 patients because  mortality was lower in the group treated with lower tidal volumes than in the group treated with traditional tidal volumes ( 31.0 percent vs. 39.8 percent , P=0.007 ) , and the number of days without ventilator use during the first 28 days after r and omization was greater in this group ( mean [ + /-SD ] , 12+/-11 vs. 10+/-11 ; P=0.007 ) . The mean tidal volumes on days 1 to 3 were 6.2+/-0.8 and 11.8+/-0.8 ml per kilogram of predicted body weight ( P<0.001 ) , respectively , and the mean plateau pressures were 25+/-6 and 33+/-8 cm of water ( P<0.001 ) , respectively . CONCLUSIONS In patients with acute lung injury and the acute respiratory distress syndrome , mechanical ventilation with a lower tidal volume than is traditionally used results in decreased mortality and increases the number of days without ventilator use BACKGROUND In the acute respiratory distress syndrome ( ARDS ) , positive end-expiratory pressure ( PEEP ) may decrease ventilator-induced lung injury by keeping lung regions open that otherwise would be collapsed . Since the effects of PEEP probably depend on the recruitability of lung tissue , we conducted a study to examine the relationship between the percentage of potentially recruitable lung , as indicated by computed tomography ( CT ) , and the clinical and physiological effects of PEEP . METHODS Sixty-eight patients with acute lung injury or ARDS underwent whole-lung CT during breath-holding sessions at airway pressures of 5 , 15 , and 45 cm of water . The percentage of potentially recruitable lung was defined as the proportion of lung tissue in which aeration was restored at airway pressures between 5 and 45 cm of water . RESULTS The percentage of potentially recruitable lung varied widely in the population , accounting for a mean ( + /-SD ) of 13+/-11 percent of the lung weight , and was highly correlated with the percentage of lung tissue in which aeration was maintained after the application of PEEP ( r2=0.72 , P<0.001 ) . On average , 24 percent of the lung could not be recruited . Patients with a higher percentage of potentially recruitable lung ( greater than the median value of 9 percent ) had greater total lung weights ( P<0.001 ) , poorer oxygenation ( defined as a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen ) ( P<0.001 ) and respiratory-system compliance ( P=0.002 ) , higher levels of dead space ( P=0.002 ) , and higher rates of death ( P=0.02 ) than patients with a lower percentage of potentially recruitable lung . The combined physiological variables predicted , with a sensitivity of 71 percent and a specificity of 59 percent , whether a patient 's proportion of potentially recruitable lung was higher or lower than the median . CONCLUSIONS In ARDS , the percentage of potentially recruitable lung is extremely variable and is strongly associated with the response to PEEP Introduction Lung collapse is a contributory factor in the hypoxaemia that is observed after open endotracheal suctioning ( ETS ) in patients with acute lung injury and acute respiratory distress syndrome . Lung recruitment ( LR ) manoeuvres may be effective in rapidly regaining lung volume and improving oxygenation after ETS . Material s and method A prospect i ve , r and omized , controlled study was conducted in a 15-bed general intensive care unit at a university hospital . Eight consecutive mechanically ventilated patients with acute lung injury or acute respiratory distress syndrome were included . One of two suctioning procedures was performed in each patient . In the first procedure , ETS was performed followed by LR manoeuvre and reconnection to the ventilator with positive end-expiratory pressure set at 1 cmH2O above the lower inflexion point , and after 60 min another ETS ( but without LR manoeuvre ) was performed followed by reconnection to the ventilator with similar positive end-expiratory pressure ; the second procedure was the same as the first but conducted in reverse order . Before ( baseline ) and over 25 min following each ETS procedure , partial arterial oxygen tension ( PaO2 ) and end-expiratory lung volume were measured . Results After ETS , PaO2 decreased by 4.3(0.9–9.7)kPa ( median and range ; P < 0.005 ) . After LR manoeuvre , PaO2 recovered to baseline . Without LR manoeuvre , PaO2 was reduced ( P = 0.05 ) until 7 min after ETS . With LR manoeuvre end-expiratory lung volume was unchanged after ETS , whereas without LR manoeuvre end-expiratory lung volume was still reduced ( approximately 10 % ) at 5 and 15 min after ETS ( P = 0.01 ) . Discussion A LR manoeuvre immediately following ETS was , as an adjunct to positive end-expiratory pressure , effective in rapidly counteracting the deterioration in PaO2 and lung volume caused by open ETS in ventilator-treated patients with acute lung injury or acute respiratory distress syndrome CONTEXT Low-tidal-volume ventilation reduces mortality in critically ill patients with acute lung injury and acute respiratory distress syndrome . Instituting additional strategies to open collapsed lung tissue may further reduce mortality . OBJECTIVE To compare an established low-tidal-volume ventilation strategy with an experimental strategy based on the original " open-lung approach , " combining low tidal volume , lung recruitment maneuvers , and high positive-end-expiratory pressure . DESIGN AND SETTING R and omized controlled trial with concealed allocation and blinded data analysis conducted between August 2000 and March 2006 in 30 intensive care units in Canada , Australia , and Saudi Arabia . PATIENTS Nine hundred eighty-three consecutive patients with acute lung injury and a ratio of arterial oxygen tension to inspired oxygen fraction not exceeding 250 . INTERVENTIONS The control strategy included target tidal volumes of 6 mL/kg of predicted body weight , plateau airway pressures not exceeding 30 cm H2O , and conventional levels of positive end-expiratory pressure ( n = 508 ) . The experimental strategy included target tidal volumes of 6 mL/kg of predicted body weight , plateau pressures not exceeding 40 cm H2O , recruitment maneuvers , and higher positive end-expiratory pressures ( n = 475 ) . MAIN OUTCOME MEASURE All-cause hospital mortality . RESULTS Eighty-five percent of the 983 study patients met criteria for acute respiratory distress syndrome at enrollment . Tidal volumes remained similar in the 2 groups , and mean positive end-expiratory pressures were 14.6 ( SD , 3.4 ) cm H2O in the experimental group vs 9.8 ( SD , 2.7 ) cm H2O among controls during the first 72 hours ( P < .001 ) . All-cause hospital mortality rates were 36.4 % and 40.4 % , respectively ( relative risk [ RR ] , 0.90 ; 95 % confidence interval [ CI ] , 0.77 - 1.05 ; P = .19 ) . Barotrauma rates were 11.2 % and 9.1 % ( RR , 1.21 ; 95 % CI , 0.83 - 1.75 ; P = .33 ) . The experimental group had lower rates of refractory hypoxemia ( 4.6 % vs 10.2 % ; RR , 0.54 ; 95 % CI , 0.34 - 0.86 ; P = .01 ) , death with refractory hypoxemia ( 4.2 % vs 8.9 % ; RR , 0.56 ; 95 % CI , 0.34 - 0.93 ; P = .03 ) , and previously defined eligible use of rescue therapies ( 5.1 % vs 9.3 % ; RR , 0.61 ; 95 % CI , 0.38 - 0.99 ; P = .045 ) . CONCLUSIONS For patients with acute lung injury and acute respiratory distress syndrome , a multifaceted protocol ized ventilation strategy design ed to recruit and open the lung result ed in no significant difference in all-cause hospital mortality or barotrauma compared with an established low-tidal-volume protocol ized ventilation strategy . This " open-lung " strategy did appear to improve secondary end points related to hypoxemia and use of rescue therapies . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00182195 Objective : We wished to investigate whether volume recruitment maneuvers ( VRMs ) could improve alveolar recruitment and oxygenation in acute respiratory distress syndrome ( ARDS ) patients , ventilated at relatively low positive end-expiratory pressure ( PEEP ) . Setting : General intensive care unit ( ICU ) located in a teaching hospital . Patients : 15 PEEP responder ARDS patients undergoing continuous positive pressure ventilation ( CPPV ) with sedation and muscle paralysis . Interventions : We identified a low ( 9.4 ± 3 cmH2O ) and a high ( 16.0 ± 2 cmH2O ) level of PEEP associated with target oxygenation values . Using a custom modified mechanical ventilator , we applied in r and om order three steps lasting 30 min : ( 1 ) CPPV at the low PEEP level ( CPPVlo ) ; ( 2 ) CPPV at the high PEEP level ( CPPVhi ) ; ( 3 ) CPPV at low PEEP with the superimposition of periodic VRMs ( CPPVvrm ) . VRMs were performed twice a minute by increasing PEEP to the high level for two breaths . Each brace of two breaths was spaced 30 seconds from the preceding one . Measurements and results : We measured gas exchange , hemodynamics , respiratory mechanics , and the end expiratory lung volume ( EELV ) . Compared to CPPVlo , CPPVvrm result ed in higher PaO2 ( 117.9 ± 40.6 vs 79.4 ± 13.6 mmHg , P < 0.01 ) and EELV ( 1.50 ± 0.62 vs 1.26 ± 0.50 l , P < 0.05 ) , and in lower venous admixture ( Qva/Qt ) ( 0.42 ± 0.07 vs 0.48 ± 0.07 , P < 0.01 ) . During CPPVhi , we observed significantly higher PaO2 ( 139.3 ± 32.5 mmHg ) and lower Qva/Qt ( 0.37 ± 0.08 ) compared to CPPVlo ( P < 0.01 ) and to CPPVvrm ( P < 0.05 ) . Conclusions : VRMs can improve oxygenation and alveolar recruitment during CPPV at relatively low PEEP , but are relatively less effective than a continuous high PEEP level Introduction To compare the safety and efficacy of high frequency oscillatory ventilation ( HFOV ) with conventional mechanical ventilation ( CV ) for early intervention in adult respiratory distress syndrome ( ARDS ) , a multi-centre r and omized trial in four intensive care units was conducted . Methods Patients with ARDS were r and omized to receive either HFOV or CV .  In both treatment arms a priority was given to maintain lung volume while minimizing peak pressures . CV ventilation strategy was aim ed at reducing tidal volumes . In the HFOV group , an open lung strategy was used . Respiratory and circulatory parameters were recorded and clinical outcome was determined at 30 days of follow up . Results The study was prematurely stopped . Thirty-seven patients received HFOV and 24 patients CV  ( average APACHE II score 21 and 20 , oxygenation index 25 and 18 and duration of mechanical ventilation prior to r and omization 2.1 and 1.5 days , respectively ) . There were no statistically significant differences in survival without supplemental oxygen or on ventilator , mortality , therapy failure , or crossover . Adjustment by a priori defined baseline characteristics showed an odds ratio of 0.80 ( 95 % CI 0.22–2.97 ) for survival without oxygen or on ventilator , and an odds ratio for mortality of 1.15 ( 95 % CI 0.43–3.10 ) for HFOV compared with CV . The response of the oxygenation index ( OI ) to treatment did not differentiate between survival and death . In the HFOV group the OI response was significantly higher than in the CV group between the first and the second day . A post hoc analysis suggested that there was a relatively better treatment effect of HFOV compared with CV in patients with a higher baseline OI . Conclusion No significant differences were observed , but this trial only had power to detect major differences in survival without oxygen or on ventilator .  In patients with ARDS and higher baseline OI , however , there might be a treatment benefit of HFOV over CV . More research is needed to establish the efficacy of HFOV in the treatment of ARDS . We suggest that future studies are design ed to allow for informative analysis in patients with higher OI Alveolar overdistention and cyclic reopening of collapsed alveoli have been implicated in the lung damage found in animals su bmi tted to  artificial ventilation  . To test whether these phenomena are impairing the recovery of patients with acute respiratory distress syndrome ( ARDS ) su bmi tted to conventional mechanical ventilation ( MV ) , we evaluated the impact of a new ventilatory strategy directed at minimizing " cyclic parenchymal stretch . " After receiving pre-established levels of hemodynamic , infectious , and general care , 28 patients with early ARDS were r and omly assigned to receive either MV based on a new approach ( NA , consisting of maintenance of end-expiratory pressures above the lower inflection point of the P x V curve , VT < 6 ml/kg , peak pressures < 40 cm H2O , permissive hypercapnia , and stepwise utilization of pressure-limited modes ) or a conventional approach ( C = conventional volume-cycled ventilation , VT = 12 ml/kg , minimum PEEP guided by FIO2 and hemodynamics and normal PaCO2 levels ) . Fifteen patients were selected to receive NA , exhibiting a better evolution of the PaO2/FIO2 ratio ( p < 0.0001 ) and of compliance ( p = 0.0018 ) , requiring shorter periods under FIO2 > 50 % ( p = 0.001 ) and a lower FIO2 at the day of death ( p = 0.0002 ) . After correcting for baseline imbalances in APACHE II , we observed a higher weaning rate in NA ( p = 0.014 ) but not a significantly improved survival ( overall mortality : 5/15 in NA versus 7/13 in C , p = 0.45 ) . We concluded that the NA ventilatory strategy can markedly improve the lung function  in patients with ARDS , increasing the chances of early weaning and lung recovery during mechanical ventilation RATIONALE The hypothesis that lung collapse is detrimental during the acute respiratory distress syndrome is still debatable . One of the difficulties is the lack of an efficient maneuver to minimize it . OBJECTIVES To test if a bedside recruitment strategy , capable of reversing hypoxemia and collapse in > 95 % of lung units , is clinical ly applicable in early acute respiratory distress syndrome . METHODS Prospect i ve assessment of a stepwise maximum-recruitment strategy using multislice computed tomography and continuous blood-gas hemodynamic monitoring . MEASUREMENTS AND MAIN RESULTS Twenty-six patients received sequential increments in inspiratory airway pressures , in 5 cm H(2)O steps , until the detection of Pa(O(2 ) ) + Pa(CO(2 ) ) > or= 400 mm Hg . Whenever this primary target was not met , despite inspiratory pressures reaching 60 cm H(2)O , the maneuver was considered incomplete . If there was hemodynamic deterioration or barotrauma , the maneuver was to be interrupted . Late assessment of recruitment efficacy was performed by computed tomography ( 9 patients ) or by online continuous monitoring in the intensive care unit ( 15 patients ) up to 6 h. It was possible to open the lung and to keep the lung open in the majority ( 24/26 ) of patients , at the expense of transient hemodynamic effects and hypercapnia but without major clinical consequences . No barotrauma directly associated with the maneuver was detected . There was a strong and inverse relationship between arterial oxygenation and percentage of collapsed lung mass ( R = - 0.91 ; p < 0.0001 ) . CONCLUSIONS It is often possible to reverse hypoxemia and fully recruit the lung in early acute respiratory distress syndrome . Due to transient side effects , the required maneuver still awaits further evaluation before routine clinical application Background : Recruitment maneuvers performed in early adult respiratory distress syndrome remain a matter of dispute in patients ventilated with low tidal volumes and high levels of positive end-expiratory pressure ( PEEP ) . In this prospect i ve , r and omized controlled study the authors evaluated the impact of recruitment maneuvers after a PEEP trial on oxygenation and venous admixture ( Qs/Qt ) in patients with early extrapulmonary adult respiratory distress syndrome . Methods : After a PEEP trial 30 consecutive patients ventilated with low tidal volumes and high levels of PEEP were r and omly assigned to either undergo a recruitment maneuver or not . Data were recorded at baseline , 3 min after the recruitment maneuver , and 30 min after baseline . Recruitment maneuvers were performed with a sustained inflation of 50 cm H2O maintained for 30 s. Results : Compared with baseline the ratio of the arterial oxygen partial pressure to the fraction of inspired oxygen ( Pao2/Fio2 ) and Qs/Qt improved significantly at 3 min after the recruitment maneuver ( Pao2/Fio2 , 139 ± 46 mm Hg versus 246 ± 111 mm Hg , P < 0.001 ; Qs/Qt , 30.8 ± 5.8 % versus 21.5 ± 9.7 % , P < 0.005 ) , but baseline values were reached again within 30 min . No significant differences in Pao2/Fio2 and Qs/Qt were detected between the recruitment maneuver group and the control group at baseline and after 30 min ( recruitment maneuver group [ n = 15 ] : Pao2/Fio2 , 139 ± 46 mm Hg versus 138 ± 39 mm Hg ; Qs/Qt , 30.8 ± 5.8 % versus 29.2 ± 7.4 % ; control group : [ n = 15 ] : Pao2/Fio2 , 145 ± 33 mm Hg versus 155 ± 52 mm Hg ; Qs/Qt , 30.2 ± 8.5 % versus 28.1 ± 5.4 % ) . Conclusion : In patients with early extrapulmonary adult respiratory distress syndrome who underwent a PEEP trial , recruitment maneuvers failed to induce a sustained improvement of oxygenation and venous admixture Objective Positive end-expiratory pressure ( PEEP ) and recruitment maneuvers ( RMs ) may partially reverse atelectasis and reduce ventilation-associated lung injury . The purpose s of this study were to assess a ) magnitude and duration of RM effects on arterial oxygenation and on requirements for oxygenation support ( Fio2/PEEP ) in patients with acute lung injury and acute respiratory distress syndrome ( ALI/ARDS ) receiving ventilation with low tidal volumes and high levels of PEEP ; and b ) frequency of adverse respiratory and circulatory events attributable to RMs . Design Prospect i ve , r and omized , crossover study . Setting Thirty-four intensive care units at 19 hospitals . Patients Seventy-two patients with early ALI/ARDS . Baseline PEEP and Fio2 were 13.8 ± 3.0 cm H2O and 0.39 ± 0.10 , respectively ( mean ± sd ) . Interventions We conducted RMs by applying continuous positive airway pressure of 35–40 cm H2O for 30 secs. We conducted sham RMs on alternate days . We monitored oxyhemoglobin saturation by pulse oximetry ( SpO2 ) , Fio2/PEEP , blood pressure , and heart rate for 8 hrs after RMs and sham RMs . We examined chest radiographs for barotrauma . Measurements and Main Results Responses to RMs were variable . Greatest increments from baseline SpO2 within 10 mins after RMs were larger than after sham RMs ( 1.7 ± 0.2 vs. 0.6 ± 0.3 % , mean ± sem , p < .01 ) . Systolic blood pressure decreased more within 10 mins after RMs ( 9.4 ± 1.1 vs. 3.1 ± 1.1 mm Hg , p < .01 ) . Changes in Fio2/PEEP requirements were not significantly different at any time after RMs vs. sham RMs . Barotrauma was apparent on first radiographs after one RM and one sham RM . Conclusions In ALI/ARDS patients receiving mechanical ventilation with low tidal volumes and high PEEP , short-term effects of RMs as conducted in this study are variable . Beneficial effects on gas exchange in responders appear to be of brief duration . More information is needed to determine the role of recruitment maneuvers in the management of ALI/ARDS BACKGROUND Most patients requiring mechanical ventilation for acute lung injury and the acute respiratory distress syndrome ( ARDS ) receive positive end-expiratory pressure ( PEEP ) of 5 to 12 cm of water . Higher PEEP levels may improve oxygenation and reduce ventilator-induced lung injury but may also cause circulatory depression and lung injury from overdistention . We conducted this trial to compare the effects of higher and lower PEEP levels on clinical outcomes in these patients . METHODS We r and omly assigned 549 patients with acute lung injury and ARDS to receive mechanical ventilation with either lower or higher PEEP levels , which were set according to different tables of predetermined combinations of PEEP and fraction of inspired oxygen . RESULTS Mean ( + /-SD ) PEEP values on days 1 through 4 were 8.3+/-3.2 cm of water in the lower-PEEP group and 13.2+/-3.5 cm of water in the higher-PEEP group ( P<0.001 ) . The rates of death before hospital discharge were 24.9 percent and 27.5 percent , respectively ( P=0.48 ; 95 percent confidence interval for the difference between groups , -10.0 to 4.7 percent ) . From day 1 to day 28 , breathing was unassisted for a mean of 14.5+/-10.4 days in the lower-PEEP group and 13.8+/-10.6 days in the higher-PEEP group ( P=0.50 ) . CONCLUSIONS These results suggest that in patients with acute lung injury and ARDS who receive mechanical ventilation with a tidal-volume goal of 6 ml per kilogram of predicted body weight and an end-inspiratory plateau-pressure limit of 30 cm of water , clinical outcomes are similar whether lower or higher PEEP levels are used BACKGROUND AND PURPOSE Assessment of the quality of r and omized controlled trials ( RCTs ) is common practice in systematic review s. However , the reliability of data obtained with most quality assessment scales has not been established . This report describes 2 studies design ed to investigate the reliability of data obtained with the Physiotherapy Evidence Data base ( PEDro ) scale developed to rate the quality of RCTs evaluating physical therapist interventions . METHOD In the first study , 11 raters independently rated 25 RCTs r and omly selected from the PEDro data base . In the second study , 2 raters rated 120 RCTs r and omly selected from the PEDro data base , and disagreements were resolved by a third rater ; this generated a set of individual rater and consensus ratings . The process was repeated by independent raters to create a second set of individual and consensus ratings . Reliability of ratings of PEDro scale items was calculated using multirater kappas , and reliability of the total ( summed ) score was calculated using intraclass correlation coefficients ( ICC [ 1,1 ] ) . RESULTS The kappa value for each of the 11 items ranged from.36 to.80 for individual assessors and from.50 to.79 for consensus ratings generated by groups of 2 or 3 raters . The ICC for the total score was.56 ( 95 % confidence interval=.47-.65 ) for ratings by individuals , and the ICC for consensus ratings was.68 ( 95 % confidence interval=.57-.76 ) . DISCUSSION AND CONCLUSION The reliability of ratings of PEDro scale items varied from " fair " to " substantial , " and the reliability of the total PEDro score was " fair " to " good . BACKGROUND In patients with the acute respiratory distress syndrome , massive alveolar collapse and cyclic lung reopening and overdistention during mechanical ventilation may perpetuate alveolar injury . We determined whether a ventilatory strategy design ed to minimize such lung injuries could reduce not only pulmonary complications but also mortality at 28 days in patients with the acute respiratory distress syndrome . METHODS We r and omly assigned 53 patients with early acute respiratory distress syndrome ( including 28 described previously ) , all of whom were receiving identical hemodynamic and general support , to conventional or protective mechanical ventilation . Conventional ventilation was based on the strategy of maintaining the lowest positive end-expiratory pressure ( PEEP ) for acceptable oxygenation , with a tidal volume of 12 ml per kilogram of body weight and normal arterial carbon dioxide levels ( 35 to 38 mm Hg ) . Protective ventilation involved end-expiratory pressures above the lower inflection point on the static pressure-volume curve , a tidal volume of less than 6 ml per kilogram , driving pressures of less than 20 cm of water above the PEEP value , permissive hypercapnia , and preferential use of pressure-limited ventilatory modes . RESULTS After 28 days , 11 of 29 patients ( 38 percent ) in the protective-ventilation group had died , as compared with 17 of 24 ( 71 percent ) in the conventional-ventilation group ( P<0.001 ) . The rates of weaning from mechanical ventilation were 66 percent in the protective-ventilation group and 29 percent in the conventional-ventilation group ( P=0.005 ) : the rates of clinical barotrauma were 7 percent and 42 percent , respectively ( P=0.02 ) , despite the use of higher PEEP and mean airway pressures in the protective-ventilation group . The difference in survival to hospital discharge was not significant ; 13 of 29 patients ( 45 percent ) in the protective-ventilation group died in the hospital , as compared with 17 of 24 in the conventional-ventilation group ( 71 percent , P=0.37 ) . CONCLUSIONS As compared with conventional ventilation , the protective strategy was associated with improved survival at 28 days , a higher rate of weaning from mechanical ventilation , and a lower rate of barotrauma in patients with the acute respiratory distress syndrome .  Protective ventilation was not associated with a higher rate of survival to hospital discharge BACKGROUND AND PURPOSE Acute lung injury is a lung pathology that presents frequently on the intensive care unit . Chest physiotherapy , in the form of endotracheal suction , alternate side-lying and manual hyperinflation , is usually given to patients with this condition with the intention of removing retained pulmonary secretions and recruiting collapsed distal lung units . Despite this common practice there is insufficient research on the effects of chest physiotherapy in patients with acute lung injury being ventilated mechanically . The aim of the present study was to further underst and ing of the effects of three modes of treatment in chest physiotherapy in an acute lung injury patient group . METHOD This r and omized , controlled trial investigated all mechanically ventilated patients with acute lung injury admitted to the adult intensive care unit at Guy 's and St Thomas ' NHS Trust between August 1996 and July 1997 , who matched the inclusion criteria . Patients were r and omized into one of three treatment groups : Group 1 ( suctioned only ) ; Group 2 ( positioned and suctioned ) ; and Group 3 ( positioned , manually hyperinflated and suctioned ) . Baseline and 10 , 30 and 60 minutes ' post-treatment data were recorded for dynamic pulmonary compliance , arterial blood gases and haemodynamic variables . Results were analysed by use of an SPSS software package with a repeated- measures analysis of variance ( ANOVA ) . RESULTS Eighteen patients fitted the inclusion criteria . Significant changes were observed in both PaCO2 ( p = 0.026 ) and dynamic compliance ( p = 0.019 ) over time for all three groups . The arterial oxygen to fraction of inspired oxygen ratio ( PaO2:FiO2 ) did not alter significantly in any of the groups . With respect to other oxygenation parameters , mixed venous oxygen saturation ( SvO2 ) showed a significant difference between the groups . Heart rate ( HR ) and systemic blood pressure ( BP ) showed statistically significant , but not clinical ly significant differences over time . CONCLUSIONS Patients with acute lung injury are notably complex to nurse and may require protracted physiotherapy intervention , which may take many forms . As de-recruitment was the single most important event that occurred in the present study population , a prescriptive chest physiotherapy approach to treating mechanically ventilated patients with acute lung should be question ed and adapted accordingly Acute respiratory failure ( ARF ) following trauma or sepsis has a mortality rate of 50 % to 85 % . The mainstays of treatment are mechanical ventilation and positive end-expiratory pressure ( PEEP ) . In the past decade , many reports have cl aim ed superiority of high frequency ventilation ( HFV ) in the treatment of ARF . We structured a prospect i ve r and omized trial of HFV versus conventional mechanical ventilation ( CMV ) in the treatment of acute respiratory failure . All patients admitted to the Surgical Intensive Care Unit ( SICU ) were eligible for the study . On admission patients identified for being at risk of developing acute respiratory failure were r and omized to receive either HFV or CMV . Patients were treated to the same therapeutic endpoint ( pH greater than 7.35 , PaCO2 35 to 45 torr , PaO2/FIO2 greater than 225 ) . Daily ventilatory support , fluid and drug requirements , and cardiopulmonary variables were recorded . One hundred thirteen patients were entered into the study . Of these , 100 completed the study ( HFV n = 52 , CMV n = 48 ) and 60 developed acute respiratory failure  ( HFV n = 32 , CMV n = 28 ) . Patients on HFV reached the therapeutic endpoint at a lower level of continuous positive airway pressure and mean airway pressure ; however there were no differences in mortality , SICU days , hospital days , incidence of barotrauma , number of blood gases , or cardiovascular interventions . This report suggests that HFV offers no concrete advantages over CMV when applied in a prospect i ve fashion for the treatment of acute respiratory failure Background : Closed-circuit endotracheal suctioning ( CES ) is advocated for preventing hypoxemia caused by the loss of lung volume result ing from open endotracheal suctioning ( OES ) . However , the efficiency of CES and OES on tracheal secretion removal has never been compared in patients with acute lung injury . The authors design ed a two-part study aim ed at comparing gas exchange and efficiency between OES and CES performed at two levels of negative pressure . Methods : Among 18 patients with acute lung injury , 9 underwent CES and OES at 3-h intervals in a r and om order using a negative pressure of −200 mmHg . Nine other patients underwent CES twice using two levels of negative pressure ( −200 and −400 mmHg ) applied in a r and om order . After each CES , a recruitment maneuver was performed using 20 consecutive hyperinflations . Tracheal aspirates were weighed after each suctioning procedure . Arterial blood gases were continuously recorded using an intravascular sensor . Results : Open endotracheal suctioning induced a significant 18 % decrease in arterial oxygen tension ( Pao2 ) ( range , + 13 to −71 % ) and an 8 % increase in arterial carbon dioxide tension ( Paco2 ) ( range , −2 to + 16 % ) that persisted 15 min after the end of the procedure . CES using −200 cm H2O did not change Pao2 , but tracheal aspirate mass was lower compared with OES ( 0.6 ± 1.0 vs. 3.2 ± 5.1 g ; P = 0.03 ) . Increasing negative pressure to −400 cm H2O during CES did not change Pao2 but increased the tracheal aspirate mass ( 1.7 ± 1.6 vs. 1.0 ± 1.3 g ; P = 0.02 ) . Conclusions : Closed-circuit endotracheal suctioning followed by a recruitment maneuver prevents hypoxemia result ing from OES but decreases secretion removal . Increasing suctioning pressure enhances suctioning efficiency without impairing gas exchange Observational studies of high-frequency oscillatory ventilation in adults with the acute respiratory distress syndrome have demonstrated improvements in oxygenation . We design ed a multicenter , r and omized , controlled trial comparing the safety and effectiveness of high-frequency oscillatory ventilation with conventional ventilation in adults with acute respiratory distress syndrome ; 148 adults with acute respiratory distress syndrome ( Pa(O2)/fraction of inspired oxygen < or= 200 mm Hg on 10 or more cm H2O positive end-expiratory pressure ) were r and omized to high-frequency oscillatory ventilation  ( n = 75 ) or conventional ventilation ( n = 73 ) . Applied mean airway pressure was significantly higher in the high-frequency oscillation group compared with the conventional ventilation group throughout the first 72 hours ( p = 0.0001 ) . The high-frequency oscillation group showed early ( less than 16 hours ) improvement in Pa(O2)/fraction of inspired oxygen compared with the conventional ventilation group ( p = 0.008 ) ; however , this difference did not persist beyond 24 hours . Oxygenation index decreased similarly over the first 72 hours in both groups . Thirty-day mortality was 37 % in the high-frequency oscillation group and was 52 % in the conventional ventilation group ( p = 0.102 ) . The percentage of patients alive without mechanical ventilation at Day 30 was 36 % and 31 % in the high-frequency oscillation and conventional ventilation groups , respectively ( p = 0.686 ) . There were no significant differences in hemodynamic variables , oxygenation failure , ventilation failure , barotraumas , or mucus plugging between treatment groups . We conclude that high-frequency oscillation is a safe and effective mode of ventilation for the treatment of acute respiratory distress syndrome in adults
BACKGROUND Recruitment manoeuvres are often used to treat patients with acute lung injury ( ALI ) or acute respiratory distress syndrome ( ARDS ) but the effect of this treatment on clinical outcomes has not been well established .
OBJECTIVES The objective of this review was to examine recruitment manoeuvres compared to st and ard care as therapy for adults with acute lung injury in order to quantify the effects on patient outcomes ( mortality , length of ventilation , and other relevant outcomes ) .