REDUCTION IN THE INCIDENCE OF CARBON-MONOXIDE EXPOSURES IN HUMANS UNDERGOING GENERAL-ANESTHESIA

Background: Carbon monoxide forms via reaction of Isoflurane, enfluran e, and desflurane with dried CO2 absorbents. The authors hypothesize t hat interventions by nonphysician support personnel to decrease absorb ent drying will decrease rile exposure rate of patients to carbon mono xide from anesthetic breakdown, Methods: In the control group, all ane sthetizing personnel were made aware of the factors enabling CO genera tion from anesthetic breakdown, and prevention techniques were left to the anesthetizing personnel, After data collection was complete, the following interventions were initiated to reduce absorbent drying: Ane sthesia technicians and housekeeping personnel were instructed to turn off all anesthesia machines after the last case of the day in each ro om, and the CO2 absorbent was changed each morning if fresh gas was fo und flowing. Baralyme(R) was used in all phases of this study. Results : Five cases of intraoperative carbon monoxide exposure occurred among 1,085 (0.46%) first cases in the control group. Postintervention, pat ient carbon monoxide exposures decreased (P < 0.05), with one exposure among 1,961 (0.051%) first cases in the main operating room. Two expo sures among 68 (2.9%) first cases occurred in remote locations (P < 0. 001) versus main operating room. Predisposing factors for absorbent dr ying include the prolonged use of anesthesia machines for monitored an esthesia case, inappropriate drying techniques for expiratory flowmete rs, understaffing of support personnel, and anesthesia in remote locat ions. Conclusions: These interventions reduced patient exposure to car bon monoxide. Monitoring for carbon monoxide exposures during general anesthesia may be necessary to recognize and end patient exposures tha t occur despite preventative measures.