Comparative study of three recruitment maneuvers in acute respiratory distress syndrome caused by extrapulmonary disease

Objective To evaluate the effects and side effects of three different recruitment maneuvers (RM) in acute respiratory distress syndrome (ARDS) caused by extrapulmonary disease.Methods Forty-four patients of extrapulmonary ARDS, according to crossover design methods, were undergone three RM in different periods, including sustained inflation (SI), increase progressively positive end expiratory pressure (IP), pressure control ventilation (PCV). Heart rate (HR), mean arterial blood pressure (MAP), central venous pressure (CVP), oxygenation index, lung compliance were recorded before and after RM, and were analyzed for statistical analysis. Results Oxygenation index and lung compliance were increased obviously in a short time after RM, improvement of IP method were better more obviously than the other two methods [1 h oxygenation index after RM:227 ± 42 vs 190 ± 19,186 ± 21; lung compliance:(59.4±12.5 ) ml/cm H2O(1 cm H2O = 0.098 kPa) vs (50.1 ± 9.3 ), (49.7 ± 10.6) ml/cm H2O;P＜ 0.05], 2h after RM,there were no statistical difference among the three methods (P＞0.05). After RM,HR and CVPwere increased, MAP was decreased in a short time, changes of SI method were smaller than the other two inethods [10 min HR after RM: (94.0±10.3 ) beats/min vs (116.0 ± 14.8 ), ( 107.0 ± 5.7 ) beats/min; CVP:(13.7±3.1 )cm H2O vs ( 18.4 ± 6.7 ), ( 15.4 ± 2.7 )cm H2O; MAP: ( 87.0 ± 12.1 ) mm Hg( 1 mm Hg = 0.133 kPa) vs (73.0 ± 4.8), (81.0 ± 6.6) mm Hg;P＜ 0.05), 20 min after RM, there were no statistical difference among the three methods (P＞ 0.05). Conclusion When extrapulmonary ARDS undergo RM ,IP method is the most effective on increasing oxygenation index and lung compliance, SI method has the smallest side effect on hemodynamics. Key words: Respiratory distress syndrome, adult;  Recruitment maneuvers;  Sustained inflation;  Increase progressively positive end expiratory pressure;  Pressure control ventilation