title: Closed-system anaesthesia for laparoscopic surgery: is there a risk for carbon monoxide intoxication?
abstract: OBJECTIVE
  One of the complications of laparoscopic surgery is carbon monoxide production during electrocautery. The aim of our study was to ascertain the relationship between intraperitoneal and alveolar concentrations of carbon monoxide and systemic carboxyhaemoglobin in patients undergoing laparoscopic cholecystectomy and anaesthetized with a closed system, where the carbon monoxide excreted through the lungs is accumulated in the circuit and thus re-inhaled.
  
  
  METHODS
  Nine consecutive patients undergoing laparoscopic cholecystectomy were studied. Patients' lungs were ventilated with a closed anaesthesia breathing system (Physioflex). Measurements were taken after establishing pneumoperitoneum (baseline) and at 5, 15 and 30 min after starting electrocautery.
  
  
  RESULTS
  Mean duration of pneumoperitoneum was 42 +/- 13 min with cumulative electrocautery time of 2.4 +/- 1.8 min. Intraperitoneal carbon monoxide concentrations increased significantly at 5, 15 and 30 min reaching peak values of 481 +/- 151 ppm at 15 min. No significant differences were found in alveolar carbon monoxide and carboxyhaemoglobin concentrations with respect to baseline.
  
  
  CONCLUSIONS
  No significant increase in carboxyhaemoglobin is produced during laparoscopic surgery, even under closed-system anaesthesia without pulmonary carbon monoxide elimination. This is most likely due to a low peritoneal absorption of carbon monoxide. We conclude that in adult patients, no carbon monoxide intoxication is caused if reasonable periods of electrocautery are used and the intraperitoneal gas is regularly renewed.
authors.affiliation: Hospital Clínico Universitario, Department of Anesthesiology and Postsurgical Intensive Care, Valencia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Soro
authors.forename: M L
authors.initials: ML
authors.lastname: García-Pérez
authors.forename: R
authors.initials: R
authors.lastname: Ferrandis
authors.forename: G
authors.initials: G
authors.lastname: Aguilar
authors.forename: E J
authors.initials: EJ
authors.lastname: Belda
mesh_terms: D000368:Aged; D000764:Anesthesia, Closed-Circuit / Q000009:adverse effects*; D002248:Carbon Monoxide / Q000032:analysis; D002249:Carbon Monoxide Poisoning / Q000209:etiology*; D002263:Carboxyhemoglobin / Q000032:analysis; D017081:Cholecystectomy, Laparoscopic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010529:Peritoneal Cavity; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects; D011650:Pulmonary Alveoli / Q000737:chemistry
chemical_list: D002248:Carbon Monoxide; D002263:Carboxyhemoglobin