Effect of Recruitment Maneuvers and PEEP on Respiratory Failure After Cardiothoracic Surgery in Obese Subjects: A Randomized Controlled Trial.

Background: Obesity may increase the risk of respiratory failure after cardiothoracic surgery. A recruitment maneuver followed by PEEP might decrease the risk of respiratory failure in obese subjects. We hypothesized that the routine use after heart surgery of a recruitment maneuver followed by high or low PEEP level would decrease the frequency of respiratory failure in obese subjects.

Methods: In a pragmatic, randomized controlled trial, we assigned obese subjects (ie, with body mass index [BMI] 30 kg/m) in the immediate postoperative period of cardiothoracic surgery to either volume control ventilation with 5 cm HO of PEEP (control group) or a recruitment maneuver followed by 5 or 10 cm HO of PEEP in the intervention arms (RM5 and RM10 groups, respectively). The primary outcome was the proportion of subjects with postextubation respiratory failure, defined as the need for re-intubation, bi-level positive airway pressure, or high-flow nasal cannula within the first 48 h.

Results: The study included 192 subjects: 65 in the control group (BMI 33.5 ± 3.2 kg/m), 66 in the RM5 group (BMI 34.5 ± 3.2 kg/m, and 61 in RM10 group (BMI 33.8 ± 4.8 kg/m). Postextubation respiratory failure occurred in 14 subjects in the control group (21.5% [95% CI 13.3-35.3]), 21 subjects in the RM5 group (31.8% [95% CI 21.2-44.6]), and 9 subjects in the RM10 group (14.7% [95% CI 7.4-26.7]) ( = .07). The recruitment maneuver was stopped prematurely due to severe hypotension in 8 (12.1%) RM5 subjects and in 4 (6.6%) RM10 subjects ( = .28). There were no significant differences between the 3 groups for the frequencies of atelectasis, pneumonia, and death in the ICU.

Conclusions: The routine use after heart surgery of a recruitment maneuver followed by 5 or 10 cm HO of PEEP did not decrease the frequency of respiratory failure in obese subjects. A recruitment maneuver followed by 5 cm HO of PEEP is inappropriate.