A279
October 18, 2008
2:00 PM - 4:00 PM
Room Hall E2-Area N
Kelly S. Shinkaruk, M.D., Kevin Nolan, M.D., F.R.C.P.C., Marylou Crossan, B.S.
Anesthesiology, University of Ottawa, Ottawa, ON, Canada
Purpose:
Current guidelines for preparing anesthetic machines for malignant hyperthermia susceptible
patients were outlined based on studies looking at older models. The newer generation Datex-Ohmeda
Aestiva anesthetic machine was studied in order to determine the washout profile of sevoflurane and to
establish new guidelines for its preparation.
Technical Features:
Initially, sevoflurane was run at 2% (MAC) for two hours. After priming, the anesthetic
machine was prepared as per institutional guidelines for a malignant hyperthermia susceptible patient.
Fresh gas flows were increased to 10L/min and circuit and gas analysis tubing was replaced with new
tubing; a MIRan infrared gas analyzer was utilized to determine sevoflurane concentration in ppm every
minute until a concentration below 5ppm was attained. Following this procedure, it was determined that
sevoflurane washout time in an Aestiva anesthetic machine was 52 to 59 minutes with a 95% confidence
interval.
Conclusion:
Given these results, it is concluded that the Aestiva machine must be flushed with a fresh gas
flow of 10L/min for at least 55min in order to achieve a sevoflurane concentration of less than 5ppm.
Anesthesiology 2008; 109 A279
