Circulation 60,475 • Volume 13, No. 2 • Summer 1998

Y2K Computer Glitch May Affect Anesthesia Equipment Functions

Robert C. Morell, MD; Richard C. Prielipp, MD

Will anesthesia machines and monitors that happen to be in use at the stroke of midnight ushering in the year 2000 fail or alter their function? Anesthesia providers and departments are beginning to ask this and other millennial questions.

The coming turn of the century presents physicians, administrators, and health care providers with a new challenge. Software and hardware intrinsic to many medical devices and systems are subject to malfunction or failure when the clock strikes midnight on December 31, 1999. This problem results from older programming designs that rely on two digits to specify a year, such as “98,” rather than four-digit years, such as “1998.” Computer systems generally require a positive integer to indicate a date and “00” is thus not recognized. This overall problem that applies to all computers using two-digit year fields has been referred to as the Year 2000 problem, the “Y2K problem,” or the “millennium bug.”


The magnitude of the problem is essentially unknown. Desktop and laptop computers can be relatively easily identified and checked for susceptibility to the Y2K problem. What is less obvious is the fact that over 3.5 billion programmable chip microcontrollers were shipped in 1995, and more than 7 billion were shipped in 1997. Many of these programmable chips and additional millions of older ones are embedded in devices and equipment and, if date sensitive, may not be compliant with the year 2000 issue. It has been suggested that the presence of non-compliant embedded chips may cause medical devices and support systems to malfunction or completely fail. Intravenous infusion pumps, defibrillators, pacemakers, MRI’s, CT and PET scanners, laboratory and diagnostic equipment, as well as elevators and environmental controls could all be affected due to malfunction of date-sensitive embedded microchips. In addition, software may also be at risk and could affect the interpretation of telemetry data, EEG or EKG analysis, as well as image processing. For example, on February 29, 1996, at one institution, a multimillion-dollar CT scanner failed to function because the device was incapable of recognizing a leap year.

Each Device Needs Testing

It is difficult, if not impossible, to determine accurately all the devices that could conceivably cease ongoing operation, fail to start up, or malfunction on or shortly after January 1, 2000. Even identical devices may perform differently if their embedded chips originated from different manufacturers, or even came from different lots from the same manufacturer. Such potential variability would seem to necessitate assessment and/or testing of individual devices, rather than just of representative models or classes of devices.

Assessment and Planning

Hospitals and health care institutions should institute a systematic process to inventory and identify possible Y2K problems in the following functional categories: personal computers, network servers, operating system software, clinical software, infusion pumps, defibrillators, monitors, ventilators, pacemakers, radiology imaging equipment, laboratory equipment, dialysis machines and also environmental, alarm, and safety equipment. It is advisable that detailed plans be developed for the replacement or upgrading of equipment found to be Y2K non-compliant. The economic impact of such efforts must also be considered. Institutions, particularly those without sophisticated in-house information technology departments, may desire to employ or contract with external consultants to accomplish this process. Contingency plans for critical patient care and business operations should be developed and tested. The FDA database and/or individual manufacturers can be contacted regarding the status of and projections for specific devices.

Multidisciplinary Effort

The process of assessment, testing and planning should be a multidisciplinary effort involving biomedical engineers, clinicians, risk management staff and hospital administration. It is important to note that specific dates may be problematic, and testing should address dates that extend beyond the year 2000, leap year dates, the end of the first month in the year 2000, and special values that occur even sooner, such as 9/9/99 (which may be an error code in some computer systems).

FDA Plays Role

The FDA also has specific recommendations for manufacturers. Manufacturers must insure that future medical devices can perform date operations correctly and will be unaffected by the change to the year 2000. The FDA further recommends that currently manufactured medical devices be analyzed to determine if device performance will be affected by the Y2K. Appropriate corrective measures should be taken to correct any problems that are identified. Furthermore, the FDA has stipulated that manufacturers do not need to submit a new 510K (premarket notification) for Y2K modifications to an existing device, provided that the changes do not affect the safety or efficacy of the device. A manufacturer’s efforts to correct problems with year 2000 compliance are not considered a recall, if the actions are completed before January 1, 2000, and are voluntary. The Department of Health and Human Services issued a letter to manufacturers of biomedical equipment on January 21, 1998. This letter gives manufacturers the opportunity to identify devices that will be affected. The full text of the regulatory responsibilities and manufacturers’ guidelines is available on the FDA website.

Drs. Morell and Prielipp are faculty members in the Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, NC. In addition, Dr. Morell is Associate Editor of this Newsletter and Dr. Prielipp is an APSF research grant recipient.

Resources and References

An FDA website is available to share related information. This website is located at

Other resources are available, including the following:

1. Center for Disease Control –

2. Rx 2000 Solutions Institute –

3. Food and Drug Administration –

4. Society of Information Management Year 2000 Working Group

5. Metro Detroit Healthcare y2k user group –

6. CNA Health Partners -Provider Relations, P.O Box 3707, Little Rock, AR 72203

7. Veteran’s Health Administration –