The effects of low-pressure and standard-pressure pneumoperitoneum on parameters of mechanical ventilation and pain after laparoscopic nephrectomy

Low versus standard pneumoperitoneum in laparoscopic nephrectomy

Abstract

Background and purpose: Pneumoperitoneum (PNP) insufflation during laparoscopic surgery may affect respiratory function and postoperative pain. The aim of the study is to investigate the effects of PNP pressure on artificial respiration and early postoperative pain in patients undergoing transperitoneal laparoscopic nephrectomy.

Materials and methods: In a retrospective study low (8 mmHg, N=16) and standard-pressure PNP (12 mmHg, N=30) were compared. Peripheral oxygen saturation (SpO₂), end-tidal carbon dioxide (ETCO₂) and peak inspiratory pressure (PIP) were recorded at the beginning and 30 minutes after PNP insufflation. The intensity of pain was assessed with a visual analog scale (VAS) up to 4 hours, 4-8 hours, and 9-24 hours postoperatively. Analgesics given were recorded 24 hours postoperatively.

Results: The median age and body mass index (BMI) did not differ between the groups. Duration of the operation (minutes) was significantly shorter in the group with low-pressure PNP (P=0.020). In the standard-pressure PNP group, PIP was significantly higher 30 minutes after PNP insufflation (P=0.003). There was no difference in postoperative pain and postoperative opioid consumption and non-opioid analgesics between groups.

Conclusions: Although the intensity of pain and consumption of analgesics between the groups with low and standard- pressure PNP did not differ significantly, there was a trend towards more favorable outcome on postoperative pain when using low-pressure PNP. In the group with standard-pressure PNP, PIP was significantly higher 30 minutes after PNP insufflation. A prospective study with a larger number of patients could provide better data on the effect of the level of PNP.

Keywords: nephrectomy; laparoscopy; postoperative pain; analgesia; artificial respiration