Comparison of CO2- and N2O-induced discomfort during peritoneoscopy under local anesthesia.

The most comfortable gas for peritoneoscopy has been the subject of debate. We subjected 46 patients to double-blind comparison of carbon dioxide and nitrous oxide during initial pneumoperitoneum. The discomfort from local anesthesia was similar in both patient groups. The patient's and the physician's assessment of discomfort during gas insufflation showed that carbon dioxide was more uncomfortable as perceived by the patient (p = 0.02), the physician (p = 0.0006), and objectively assessed by degree of abdominal splinting (p = 0.006). The presence of intraabdominal adhesions had no relationship to discomfort. We conclude that nitrous oxide is more comfortable for institution of pneumoperitoneum during peritoneoscopy under local anesthesia.