Effect of electrical impedance tomography-guided positive end-expiratory pressure optimisation on postoperative pulmonary complications in laparoscopic colorectal surgery: a randomised controlled trial.

BACKGROUND

Pneumoperitoneum and steep Trendelenburg positioning during laparoscopic colorectal surgery promote atelectasis and increase the risk of postoperative pulmonary complications (PPCs). Electrical impedance tomography (EIT) enables individualised PEEP titration by visualising regional lung collapse, facilitating lung-protective ventilation. However, evidence of its effect on clinical PPCs remains limited.

METHODS

In this single-centre, parallel-group RCT, adults with intermediate to high risk for PPCs (ARISCAT score ≥26) who underwent laparoscopic colorectal surgery were randomly assigned to receive intraoperative PEEP titration guided by EIT or a conventional fixed PEEP of 5 cm H2O. The primary outcome was PPCs incidence within 30 days, as determined by a multidisciplinary adjudication team using standardised criteria.

RESULTS

Among the 117 randomised participants (mean [range] age: 62 [37-80] yr; 37% female), EIT-guided PEEP (n=59) resulted in lower driving pressure (16 [15-18] cm H2O) compared with fixed PEEP (n=58; 19 [17-22] cm H2O; P<0.0001). The incidence of 30 day PPCs was lower among participants randomised to EIT-guided PEEP (29/59 [49.2%]) than those in the fixed-PEEP group (42/58 [72.4%]; hazard ratio: 0.53; 95% CI, 0.33-0.85; P=0.009). PPCs including atelectasis and pneumonia occurred less frequently among participants randomised to EIT-guided PEEP.

CONCLUSIONS

Compared with conventional fixed PEEP of 5 cm H2O, EIT-guided PEEP was associated with a lower incidence of PPCs among patients at intermediate to high PPCs risk undergoing laparoscopic colorectal surgery, suggesting a role for EIT in intraoperative lung protection.

CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2300076677.