Physiologic effects of simultaneous carbon dioxide insufflation by laparoscopy and colonoscopy: prospective evaluation

Abstract

Background

The use of intraoperative carbon dioxide (CO₂) colonoscopy during a laparoscopic colon operation is becoming more common. Simultaneous intracolonic and intraabdominal CO₂ insufflation may result in significant physiologic changes, but in-depth physiologic effects have not been studied to date. This study aimed to evaluate the physiologic changes and the overall safety of simultaneous CO₂ laparoscopy and colonoscopy.

Methods

A prospective pilot study was performed with 26 subjects (17 men and 9 women) undergoing laparoscopic surgical treatment for colorectal conditions adjunctively managed with CO₂ intraoperative colonoscopy. Surgery proceeded with CO₂ insufflation to a maximum pressure of 12 mmHg by laparoscopy and with a maximum CO₂ flow of 5 l/min via colonoscopy. Serial intra- and postoperative arterial blood gases, end-tidal CO₂, and minute ventilation were recorded during predetermined periods: during initial laparoscopy, during simultaneous colonoscopy and laparoscopy, during laparoscopy after colonoscopy, and after desufflation.

Results

No significant morbidity resulted from simultaneous CO₂ insufflation. Three patients had a CO₂ partial pressure (PaCO₂) greater than 50, and one patient with a body mass index (BMI) higher than 42 kg/m² had a PaCO₂ greater than 50 for more than 30 min and was compensated by increasing minute ventilation. The mean pH was 7.36 in the recovery room. Postoperatively, no patient had a pH lower than 7.3, prolonged intubation, or reintubation.

Conclusion

Simultaneous CO₂ colonoscopy and laparoscopy lead only to transient alterations in respiratory parameters that can be compensated. Based on these findings, simultaneous insufflation of CO₂ into the peritoneal cavity and the large bowel lumen during complex endoscopic procedures may be considered safe for most patients.