Production and systemic absorption of toxic byproducts of tissue combustion during laparoscopic surgery.

Background: Among the potential hazards of laparoscopic surgery using electrocautery is the intraperitoneal release and subsequent absorption of byproducts of tissue combustion. In a porcine model of laparoscopic surgery with smoke production, our aims were to assess (1) the relationship between levels of intraperitoneal carbon monoxide (CO) and systemic carboxyhemoglobin (COHb) and methemoglobin (MetHb), and (2) intraperitoneal concentrations of other noxious gases, including hydrogen cyanide (HCN), acrylonitrile (Acr), and benzene (Bzn).

Methods: Seven pigs underwent laparoscopic resection of three hepatic wedges using monopolar electrocautery in a CO2 pneumoperitoneum. Sequential arterial samples were drawn to measure [COHb] and [MetHb] perioperatively, while gaseous intraabdominal [CO], [HCN], [Acr], and [Bzn] were assayed intraoperatively.

Results: The mean +/- SEM duration of operation was 90 +/- 2 min, and electrocautery was used for 68 +/- 4 min. Intraabdominal [CO] rose from 0 to 814 +/- 200 ppm (p < 0.01) while [COHb] increased from 2.9 +/- 0.1% to 3.5 +/- 0.1% (p < 0.001). Systemic [MetHb] remained unchanged intra- and postoperatively, ranging from 0.3 to 0.7%. Intraperitoneal [HCN] rose from 0 to 5.7 +/- 0.7 ppm (p < 0.001). [Acr], however, did not change significantly from preoperative values, ranging from 0 to 1.6 +/- 1. 0 ppm, and [Bzn] was undetectable.

Conclusions: Laparoscopic tissue combustion increases intraabdominal [CO] to "hazardous" levels leading to minimal, yet significant, elevations of [COHb]. Systemic [MetHb] and intraabdominal [HCN], [Acr], and [Bzn] are not elevated to toxic levels. Production of intraperitoneal smoke during laparoscopic electrosurgery therefore may not pose a significant threat to the patient.