Send to

Choose Destination
See comment in PubMed Commons below
Anaesth Intensive Care. 2003 Feb;31(1):58-62.

Preparing a new generation anaesthetic machine for patients susceptible to malignant hyperthermia.

Author information

  • 1Department of Anaesthesia, Princess Margaret Hospital for Children and Department of Public Health, The University of Western Australia, GPO Box D184, Perth, W.A. 6840.


Anaesthetic machines are prepared for use with patients who are susceptible to malignant hyperpyrexia (MH) by flushing with oxygen at 10 l/min for ten minutes to reduce the anaesthetic concentration to 1 part per million (ppm) or less. Anaesthetic workstations are now often used in place of traditional machines. Workstations have greater internal complexity, and it is not known if they can be made safe for susceptible patients by flushing with oxygen. We used a high sensitivity infrared gas analyser to measure the washout of isoflurane from five Datex-Ohmeda workstations. Measurements were then repeated with a patient breathing circuit. Isoflurane washout occurred in an exponential manner. The time to reach a concentration of 1 ppm at the fresh gas outlet was 17 +/- 7 minutes, and all machines had reached less than 2 ppm by ten minutes. The washout of isoflurane from the machine and patient breathing circuit was much slower than from the machine alone, with a concentration less than 2 ppm reached only after 30 minutes. We conclude that the Datex-Ohmeda workstation can be prepared for use in MH susceptible patients by flushing with oxygen at 10 l/min for ten minutes. Flushing of the patient breathing system is not straightforward, and we recommend using a clean T-piece circuit. If the circle system and ventilator are required for anaesthesia, we suggest using new breathing hoses, rebreathing bag and soda lime cartridge, and ventilating an artificial lung for 30 minutes with a fresh gas flow rate of 10 l/min and tidal volume of 1 litre.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Australian Society of Anaesthetists
    Loading ...
    Write to the Help Desk