Medical Gas Background

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Medical gas systems are an essential part of any hospital as they dispense essential gases and produce vacuum for medical treatments and medical equipment operation.  Medical gas systems can be appreciated as life-support systems as a failure in the system could lead to the death of the patient.

Uses of medical Gases in Patient Care

Some medical gases used in patient care include the following

  • Oxygen: Delivered directly to patients via cannula, blenders, ventilators, and others methods.
  • Medical air: High quality air for patient ventilation and equipment.
  • Nitrous oxide: Administered to patients via anesthesia machines
  • Nitrogen: A gas that powers medical equipment.
  • Vacuum: This function provides the means for suctioning and for anesthesia waste gas evacuation.

System Components

The system consists in a series of devices that produce or control the flow of medical gases through the piping network. See Figure1 below:

Figure1. A simple scheme of a Medical Gas System


  • Master Alarms: These alarms control the main gas lines and source conditions. Master alarms should be tested annually by the suppliers. By hospitals
  • Area Alarms: This alarm is for a specific hospital area.

There are separate alarms for gases and vacuum.

Common Problems
Particulate contamination is a common problem; the following tips can help to detect it:

  • Look for debris in the anesthesia machine(In the filters)
  • Look for debris in the flow meters; look at the needle valve and seal rings.
  • Look for debris after purging outlets at maximum velocity into a white cloth
  • Check inside blenders for presence of debris
  • Examine the 5 micron filters on volume ventilators
  • Disassemble the first outlet in any system and look for debris. Cover the body opening with white cloth. Then open the zone valve for 5 seconds. Hold the cloth firmly. Look for stains. Reassemble the outlet. If debris is found, purge the pipe clean.

Joseph F. Dyro. Clinical Engineering Handbook, Elsevier Inc. 2004
Richard P.Bielen, P.E. Health Care Facilities Handbook, NFDA 2005