A comparison between two different alveolar recruitment maneuvers in patients with acute respiratory distress syndrome

BACKGROUND: Alveolar recruitment is a physiological process that denotes the reopening of previously gasless lung units exposed to positive pressure ventilation. The current study was aimed to compare two recruitment maneuvers, a high continuous positive airway pressure (CPAP), and an extended sigh in patients with ARDS. MATERIALS AND METHODS: Forty patients with acute respiratory distress syndrome were randomly divided into two groups, 20 patients each. Group I received a CPAP of 40 cm H(2)O for 40 seconds and group II received extended sigh (providing a sufficient recruiting pressure × time). In our study, we assessed the effects of both recruitment maneuvers on respiratory mechanics, gas exchange, and hemodynamics. These data were analyzed using two-way analysis of variance (ANOVA) followed by a Student--Newman--Keuls post hoc comparison test. P < 0.05 was considered statistically significant. RESULTS: Both methods improved the compliance, increased arterial oxygenation (PaO(2)), increased the PaO(2)/FiO(2) ratio, and reduced the pulmonary shunt fraction (Q(s)/Q(t)). However, the extended sigh improved both PaO(2) and PaO(2)/FiO(2) ratios more than continuous positive airway pressure. Also the hemodynamic parameters were better maintained during the extended sigh. CONCLUSION: Alveolar recruitment maneuvers are effective in management of mechanically ventilated ARDS patients. We conclude that extended sigh is more effective than continuous positive airway pressure as a recruitment maneuver.