Optimal positive end-expiratory pressure during robot-assisted laparoscopic radical prostatectomy

Abstract

Background: Increased intra-abdominal pressure during laparoscopic surgery causes cephalad displacement of the diaphragm, resulting in the formation of atelectasis, which can be overcome by positive end-expiratory pressure (PEEP). The aim of this prospective study was to investigate the level of optimal PEEP to maintain adequate arterial oxygenation and hemodynamics during robot-assisted laparoscopic radical prostatectomy (RLRP). Methods: One hundred patients undergoing RLRP were randomly allocated to one of five groups (n = 20) (0, 3, 5, 7 and 10 cmH 2 O of PEEP). Hemodynamic variables and respiratory parameters were measured at baseline with the patient in the supine position; at 30 min, 1, 2, 3 and 4 h during CO 2 insufflation with the patient in the post-Trendelenburg position; and after deflation in the supine position with increasing PEEP. Results: The PaO 2 levels and alveolar-arterial difference in oxygen tension (AaDO 2 ) were improved in patients with PEEPs compared with patients in whom PEEP was not used. The application of PEEP (10 cmH 2 O) resulted in higher PaO 2 levels compared to those with lower PEEP levels, but excessive peak airway pressure (PAP) was sometimes observed. The application of a PEEP of 7 cmH 2 O resulted in similar PaO 2 levels without causing excessive PAP. There was a significant difference in central venous pressure between the groups, but there were no significant differences in heart rate, mean arterial pressure or minute ventilation between the groups. Conclusions: A PEEP of 7 cmH 2 O is associated with the greater improvement of PaO 2 and AaDO 2 without causing excessive PAP during RLRP. (