Practitioners' Reporting News

Medical Gas Errors

Issued June 19, 2001

The USP Medication Errors Reporting (MER) Program received a report from a community hospital concerning medical gas tanks that were mislabeled. According to the report, the hospital received four yellow air tanks with air tank fittings (valves) from its supplier that were mislabeled as nitrogen. A respiratory therapist was alerted to the error by the distinctive air valve on the tank.

Although this error did not result in patient harm, the Food and Drug Administration (FDA) received four reports in the last four years in which medical gas mix-ups have resulted in a total of 7 deaths and 15 serious injuries. The most recent incident occurred in December 2000 at a nursing home in Ohio. In all cases the patients were thought to be receiving medical grade oxygen, but instead were receiving industrial grade nitrogen, or industrial grade argon, or carbon dioxide, which had been incorrectly connected to the oxygen supply system.

There were several striking similarities among the FDA reports:

  • The person connecting the medical gas tank to the oxygen system lacked proper training.
  • When connecting the tank, the untrained employee failed to examine the labels carefully and as a result, selected the wrong cryogenic vessel.
  • The employee was unable to connect the incorrect cryogenic vessel to the oxygen system because of the distinctive valve fittings, so the employee removed the fitting from the incorrect cryogenic vessel and replaced it with an oxygen fitting from an empty oxygen tank. The employee failed to realize that the incompatibility is a built-in safeguard, i.e., that connectors for the oxygen vessels are specially fitted so they are only compatible with oxygen delivery systems.

To alert hospitals, nursing homes and other health care facilities of the hazards of medical gas mix-ups the FDA has issued a public health advisory. The advisory recommends implementing the following:

  1. If your facility receives medical gas deliveries, you should store medical grade products separately from industrial grade products. The storage area for medical grade products should be well defined with one area for receiving full cryogenic vessels and another area for storing empty vessels.
  2. All personnel who will be handling medical gases should be trained to recognize the various medical gas labels. Personnel should be trained to examine all labels carefully.
  3. If your supplier uses 360-degree wrap-around labels to designate medical oxygen, personnel should be specifically trained to make sure each vessel they connect to the oxygen system bears such a label.
  4. Make sure that all personnel in your facility who are responsible for changing or installing cryogenic vessels are trained to connect medical gas vessels properly. Personnel should understand how vessels are connected to the oxygen supply system and be alerted to the serious consequences of changing connections.
  5. You should emphasize repeatedly that the fittings on these vessels should not be changed under any circumstances. If a cryogenic vessel fitting does not seem to connect to the oxygen supply system fitting, the supplier should be contacted immediately. The vessel should be returned to the supplier to determine the fitting or connection problem.
  6. Once a cryogenic vessel is connected to the oxygen supply system, but prior to introducing the product into the system, a knowledgeable person should ensure that the correct vessel has been connected properly.

The complete FDA "Guidance for Hospitals, Nursing Homes, and Other Health Care Facilities" can be accessed at http://www.fda.gov/cder/guidance/4341fnl.htm.

Hospitals, nursing homes, and other health care facilities should submit reports to CDER (301-594-0095) or directly to FDA's voluntary reporting program, MedWatch, by phone (800) FDA-1088, by facsimile (800) FDA-0178, or by mail to MedWatch, Food and Drug Administration (HFA-2), 5600 Fishers Lane, Rockville, Maryland, MD, 20857-9787.


Readers are advised that official USP cautions and warnings for drugs appear in the USP–NF or USP DI. Unless otherwise indicated, any advice or opinions expressed herein reflect solely the judgment of USP staff. Such statements are intended for further consideration and evaluation and may or may not be applicable to a particular practice. The USP Medication Errors Reporting Program is presented in cooperation with the Institute for Safe Medication Practices.