Investigation of electrochemical carbon monoxide sensor monitoring of anesthetic gas mixtures.

AN electrochemical sensor has previously been reported to provide useful detection of carbon monoxide while exposed to one minimum alveolar concentration of volatile anesthetics. My independent laboratory study yields further evidence supporting the possible utility of electrochemical carbon monoxide sensor measurements in anesthetic gas mixtures. Several scientific investigations have elucidated the chemistry of base-catalyzed volatile anesthetic degradation into by-products, including carbon monoxide. Multiple case reports corroborate the laboratory studies with clinical documentation of significantly elevated intraoperative carboxyhemoglobin levels as a consequence of anesthetic circuit carbon monoxide contamination. Only a single case report exists of the suspected correlation between intraoperative carbon monoxide exposure and actual patient morbidity. However, veterinary anesthetic practice may also utilize volatile anesthetic agents in the presence of alkaline carbon dioxide absorbents. Voluntary reporting via the United States Pharmacopeial Convention Veterinary Practitioners Reporting Program recorded a signal clustering (three dogs) of perioperative animal deaths with routine anesthetics/surgeries associated with intraoperative carbon monoxide exposure involving isoflurane and soda lime/Baralyme® (Chemetron Medical Division, Allied Healthcare Products, St. Louis, MO). Current anesthesia monitors provide only indirect evidence of carbon monoxide production in anesthesia circuits. Early specific carbon monoxide identification in anesthetic gases could avert patient exposure to that toxic by-product. My in vitro investigation assesses the capability of an electrochemical carbon monoxide sensor in various anesthetic atmospheres with maximal volatile anesthetic concentrations.