Positive end-expiratory pressure in pressure-controlled ventilation improves ventilatory and oxygenation parameters during laparoscopic cholecystectomy

During laparoscopy, pneumoperitoneum may result in intraoperative atelectasis, which impairs normal gas exchange. This study investigated whether positive end-expiratory pressure (PEEP) of 5 cmH(2)O in pressure-controlled ventilation (PCV) mode can improve ventilatory and oxygenation parameters during pneumoperitoneum. Thirty patients, aged 18-65 years, undergoing laparoscopic cholecystectomy were randomly allocated to the ZEEP (PEEP = 0 cmH(2)O) or PEEP (PEEP = 5 cmH(2)O) group. PCV was started after induction of anesthesia. Apart from PEEP level, all other ventilator settings were identical for both groups. Peak airway pressure was set at induction and reset after pneumoperitoneum to deliver tidal volume of 8 ml/kg in both groups. Hemodynamic, ventilatory, and oxygenation parameters were measured after induction of anesthesia (T1) and 30 min after pneumoperitoneum (T2). Oxygenation index (PaO(2)/FiO(2)) was significantly higher in the PEEP group than in the ZEEP group at T2 (P = 0.031). In both groups, dynamic compliance significantly decreased over 40 min from T1 to T2. There were no significant differences in hemodynamics between the two groups during the study period. Application of PEEP of 5 cmH(2)O should be considered in PCV during laparoscopic surgeries to decrease intraoperative atelectasis caused by pneumoperitoneum to improve gas exchange and oxygenation.