The lengthening of daylight time may trigger malfunctions with medical devices and hospital information systems, Health Canada warned Wednesday.

The department disseminated advisories from the U.S. Food and Drug Administration aimed at hospital officials, health-care workers, people reliant on medical devices as well as their caregivers.

The advisories warned that this weekend's early start to daylight time could lead to unpredictable problems with critical medical machinery.

"The extent and seriousness of this problem is unclear," the warning to individuals states. "We do not know if any medical equipment will be affected, how it will be affected or how it may affect patients.

"Although we don't know what specific equipment may fail to work correctly, we are concerned about equipment that consumers or patients use in their homes. We have already notified doctors, nurses and hospitals of our concerns."

Check for software patches

Stand-alone devices used by individuals aren't the only worry. Equipment in hospitals, especially equipment linked to networks, could also be a problem.

"While we do not know which specific devices might be affected, FDA is concerned about medical devices or medical device networks that operate together or interact with other networked devices, e.g., where a synchronization of clocks may be necessary," the U.S. agency warned.

It suggested that a medical device or device network that is adversely affected by the earlier start (and later end) of daylight time could produce patient treatment that is incorrectly prescribed or administered at the wrong time, missed or repeated doses, medications that are given for longer or shorter durations than intended, or erroneous medication records.

"Any of these unpredictable events could harm patients and not be obvious to clinicians responsible for their care," the agency said.

Most of North America commences daylight time three weeks early this year, ending it one week later in the fall.

Devices or technology that predate the law change that mandated the lengthening of daylight time may not be able to update to the new time without new software or a manufacturer's patch.

The advisories suggest devices and software programs should be checked as quickly as possible after 2 a.m. on four dates:

• March 11, the new start of daylight time.
• April 1, the old start date.
• Oct. 28, the old daylight end date.
• Nov. 4, the new end date.

Authorities also suggest that individuals check their medical devices now to see if they use or display time. If they do, individuals should contact the device's manufacturer to see if a patch is needed to update the software.