Continuous Hydrogen Sulfide Gas Monitoring using the PortaSens II Portable Gas Leak Detector Model C16 during Laparoscopic or Robotic Surgery Cannot Be Used Intraoperatively to Detect Bowel Injury

Abstract

Study objective: To determine the feasibility of measuring hydrogen sulfide (H₂S) gas in the insufflated abdomen during laparoscopic surgery after transmural bowel injury as a marker of unrecognized bowel injuries.

Design: This is a feasibility study performed on swine models during a robotic training course. We aimed to determine baseline H₂S levels and subsequent elevations in H₂S levels after enterotomy of the large and small intestines.

Setting: University-based robotic training lab.

Participants: Three swine participants.

Interventions: During initial insufflation of the swine abdominal cavity, baseline H₂S levels were recorded over 15-second intervals for 10 minutes using the PortaSens II Portable Gas Leak Detector Model C16 (Analytical Technology, Inc., Collegeville, PA). The same values were recorded in separate studies after transmural transection of the small intestine and the large intestine using laparoscopic shears with and without monopolar electrosurgery.

Measurements and main results: Baseline H₂S level over the initial 10 minutes of insufflation was 0 parts per million (ppm). The device is calibrated to detect levels of H₂S of 0 ppm to 200 ppm. H₂S levels after small and large bowel enterotomies without monopolar electrosurgery initially showed a rise to 1 ppm to 2 ppm. However, repeat confirmatory testing failed to show any elevation in H₂S levels. H₂S levels after small and large bowel enterotomies with monopolar electrosurgery both showed increases to 108 ppm and 74 ppm with a duration of elevation measuring 4 minutes and 4 minutes 15 seconds, respectively. Although our study did show elevations in H₂S after transection with monopolar electrosurgery, this was later determined to be the result of cross contamination with carbon monoxide, which was a confounding factor.

Conclusion: Our study demonstrated that using the methodology and detection methods described, H₂S cannot be used to detect unrecognized bowel injury during laparoscopic surgery. Our results were due to cross contamination with other gases created with the use of electrosurgery, and we were unable to reproduce initial testing results, which did show slight rises in H₂S levels after enterotomies without monopolar electrosurgery. Further testing of other gases produced by the gastrointestinal tract or the use of alternative detection methods may provide more clinically relevant results.

Keywords: Minimally invasive; Robotics; Surgical complications; Unrecognized.