title: Air contamination of a closed anesthesia circuit.
abstract: Closed-circuit anesthesia (CCA) has certain advantages such as decreased cost, decreased anesthetic gas pollution, improved inhalational gas humidity and temperature in comparison to conventional inhalational anesthesia using a high fresh gas flow, i.e. more than 2 L x min(-1), with a semi-closed breathing circuit. The main disadvantage of CCA is the possibility of hypoxic anesthetic gas delivery. This potentially lethal situation is caused by an insufficient oxygen flow rate for the body metabolism or by the accumulation of inactive gas, usually nitrogen, within the breathing circuit in spite of a sufficient oxygen concentration in the fresh gas supply to the breathing circuit. In the latter case, the accumulation of inactive gas may also lead an increased risk of awareness because of its dilution effect on the concentrations of inhalational anesthetics. We herein present a case of air contamination of the breathing circuit through a sampling line of an anesthetic gas monitor. The air caused a decrease in the oxygen concentration during closed circuit anesthesia.
authors.affiliation: Department of Anesthesiology, Fukuoka City Hospital, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Mizuno
authors.forename: R
authors.initials: R
authors.lastname: Sumiyoshi
mesh_terms: D000388:Air; D000395:Air Pollutants, Occupational / Q000032:analysis; D016902:Air Pollution, Indoor / Q000032:analysis / Q000517:prevention & control; D000764:Anesthesia, Closed-Circuit / Q000191:economics / Q000295:instrumentation*; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000032:analysis; D001364:Awareness / Q000187:drug effects; D019296:Capnography; D003365:Costs and Cost Analysis; D004734:Energy Metabolism; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D006813:Humidity; D000860:Hypoxia / Q000209:etiology / Q000503:physiopathology; D009584:Nitrogen / Q000008:administration & dosage; D009609:Nitrous Oxide / Q000008:administration & dosage; D010100:Oxygen / Q000008:administration & dosage / Q000097:blood; D012307:Risk Factors; D013696:Temperature
chemical_list: D000395:Air Pollutants, Occupational; D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide; D009584:Nitrogen; D010100:Oxygen