Production and systemic absorption of toxic byproducts of tissue combustion during laparoscopic cholecystectomy

Abstract

Among the potential hazards of laparoscopic surgery using electrocautery is the release of chemical byproducts of incomplete tissue combustion into the pneumoperitoneum with subsequent transperitoneal absorption into the bloodstream and/or release into the operating room. The purpose of this study of patients undergoing laparoscopic cholecystectomy (LC) was twofold: (1) to assess the relationship between intraperitoneal concentration of carbon monoxide (CO) and blood levels of carboxyhemoglobin (COHb) and methemoglobin (MetHb), and (2) to assess the surgeon's inhalation of CO resulting from ambient smoke exposure. During LC with monopolar electrocautery, 21 patients were evaluated intraoperatively for intraperitoneal [CO] by sampling gas from a trocar, whereas arterial [COHb] and [MetHb] were determined perioperatively. The surgeon's venous blood was drawn pre- and postoperatively to assay [COHb] and [MetHb]. Patients completed visual analogue questionnaires 6 hours and 24 hours postoperatively to assess for adverse symptoms. Mean (± SEM) patient age and weight were 45 ± 3 years and 84 ± 4 kg, respectively. Mean duration of the operation was 69 ± 5 minutes, and electrocautery was used for 3.0 ± 0.3 minutes. Intraperitoneal [CO] rose to peak levels of 209 ± 19 ppm at 50 minutes, whereas systemic [COHb] and [MetHb] were unchanged. The surgeon's systemic [COHb] and [MetHb] did not increase postoperatively. Nausea, abdominal pain, and fatigue scores decreased significantly between 6 and 24 hours postoperatively; however, there were no correlations between these symptoms and peak intraperitoneal [CO]. Although LC using electrocautery increases intraperitoneal [CO] to “hazardous” levels, systemic [COHb] and [MetHb] are not elevated by generation of intraperitoneal smoke. The surgeon's exposure to CO by the evacuation of smoke through laparoscopic ports is negligible. Production of smoke during LC using monopolar electrocautery, therefore, does not appear to pose a threat to either the patient or the surgeon.