Effect of recruitment maneuver strategy on early postoperative atelectasis among intermediate- to high-risk patients undergoing abdominal surgery: A multicenter, 2 × 2 factorial, randomized clinical trial.

STUDY

OBJECTIVE

Recruitment maneuver is pivotal for reducing the development of atelectasis but the optimal strategy is far from being established. This study hypothesized that the recruitment maneuver under ultrasound guidance compared with conventional technique, and that stepwise lung inflation compared with sustained inflation would reduce early postoperative atelectasis among intermediate- to high-risk patients undergoing abdominal surgery.

DESIGN

A multicenter, 2 × 2 factorial, randomized clinical trial.

SETTING

Six tertiary hospitals in China.

PATIENTS: Adult patients who had an intermediate to high risk of pulmonary complications scheduled for abdominal surgery with an anticipated duration of 2 h or longer.

INTERVENTIONS: Using a factorial design, patients receiving recruitment maneuver at end of surgery were allocated to ultrasound guidance or conventional technique without ultrasound guidance, combined with one of two lung inflation patterns (stepwise or sustained). All patients received lung-protective ventilation.

MEASUREMENTS: The primary outcome was the incidence of early postoperative atelectasis, as assessed with lung ultrasound at 30 min after tracheal extubation.

MAIN

RESULTS

Between April 2024 and October 2024, 353 patients were enrolled and randomly assigned. The ultrasound guidance group had a significantly lower incidence of early postoperative atelectasis compared with conventional technique group (75 [41.9%] vs 107 [61.5%]; RR 0.67 [95% CI 0.53 to 0.83]; P < 0.001). There were significant differences favoring ultrasound guidance versus conventional technique for 5 prespecified secondary outcomes: early postoperative lung ultrasound score (median difference - 1 [95% CI -2 to 0]), incidence of hypoxemia (RR, 0.72; 95% CI, 0.58 to 0.88), oxygenation index (median difference 21.7 mmHg [95% CI 0.5 to 42.1]), incidence of pulmonary complications within 7 days postoperatively (RR 0.78 [95% CI 0.63 to 0.97]), and hospitalization cost (median difference - 3586 yuan [95% CI -7084 to -313]). For stepwise versus sustained inflation, there were no significant differences in primary and secondary outcomes.

CONCLUSIONS

Among intermediate- to high-risk patients undergoing abdominal surgery, recruitment maneuver under ultrasound guidance significantly reduced early postoperative atelectasis versus conventional technique, while both stepwise and sustained lung inflation can be used alternatively for achieving a recruitment maneuver.