Effect of individualized PEEP guided by EIT vs. conventional fixed PEEP on postoperative pulmonary complications in adult patients with preoperative cardiopulmonary dysfunction undergoing CRS/HIPEC: a randomized clinical trial.

BACKGROUND: In patients with preoperative cardiopulmonary dysfunction undergoing Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), the clinical benefits of individualized positive end-expiratory pressure (PEEP) remain unclear. We aimed to determine whether electrical impedance tomography (EIT)-guided individualized PEEP reduces postoperative pulmonary complications (PPCs) in adult patients with preoperative cardiopulmonary dysfunction undergoing CRS/HIPEC. METHODS: We enrolled 94 patients (18–90 years) with preoperative cardiopulmonary dysfunction undergoing CRS/HIPEC under general anesthesia. Preoperative cardiopulmonary dysfunction was assessed through cardiopulmonary exercise testing (CPET). The primary outcome was the incidence of any PPC within 7 days after surgery (composite defined as pneumonia, atelectasis, and pleural effusion). The secondary outcomes included the incidence of postoperative cardiac complications, postoperative B-type natriuretic peptide (BNP) and cardiac troponin (cTN) levels, length of hospital stay, regional ventilation distribution, respiratory mechanics parameters, hemodynamic variables, and arterial blood gas values. RESULTS: Among the 94 randomized patients, PPCs were observed in 24 patients (52.2%) in the EIT-guided PEEP group and 26 patients (61.9%) in the fixed PEEP group, and there were no statistically significant differences between the 2 groups (χ2 = 0.85, P = 0.36), and the mean (SD) individualized PEEP in the EIT-guided PEEP group was 10.5 (2.1) cmH2O. Compared with the fixed PEEP group, the EIT-guided PEEP group had higher oxygen saturation (SpO2) (P < 0.05), higher dynamic lung compliance (Cdyn) (P < 0.05), and higher arterial oxygen tension/fractional inspired oxygen (PaO2/FiO2) (P < 0.05). CONCLUSIONS: Individualized PEEP guided by EIT compared with fixed PEEP, did not decrease the incidence of PPCs but did improve intraoperative respiratory mechanics and oxygenation for patients with preoperative cardiopulmonary dysfunction undergoing CRS/HIPEC.