Recruitment maneuvers after a positive end-expiratory pressure trial do not induce sustained effects in early adult respiratory distress syndrome

Abstract

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 prospective, randomized 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 randomly 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/ FIO 2) 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 hi 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.