How hot is too hot for patients?

ECRI reaffirms warmer temp max at 130F

A decade ago, ECRI investigated a series of incidents in which patients were burned — sometimes severely — by blankets that were warmed to a high temperature and placed on body parts that either temporarily or permanently lacked sensation. At the time, there wasn’t even a discussion of what should be a maximum temperature for blanket warming cabinets.

The institute, based in Plymouth Meeting, PA, initially came up with a recommendation that warming cabinets not be set higher than 110 degrees Fahrenheit, explains Chris Lavanchy, the organization’s health devices engineering director. This allowed for uses that included rolling and folding blankets, which stored heat longer. It was in these kinds of instances that some of the previous injuries occurred.

Those initial recommendations, announced in 2005, were questioned by many clinicians, who felt the temperature wasn’t warm enough. The warmers might be far from the bedside and lose significant heat during transport from the cabinets, Lavanchy notes, or they were used spread out, not rolled up, which meant the heat dissipated quickly.

In 2009, ECRI updated the recommendations to a maximum of 130F, and there it has stood, adopted and approved of by many organizations, including the Association of periOperative Registered Nurses (AORN).

"When we first investigated this, we had several investigations of burns, including some blistering ones," Lavanchy says. "Since we made our recommendations, and even after the change in 2009 to 130 degrees, we haven’t heard since of blanket burns. That doesn’t mean it isn’t occurring, but it means it probably isn’t widespread."

What of the reasons that nurses and doctors give for wanting higher temperatures — that their patients still complain of cold, that a blanket at 130 degrees can’t hold heat for long enough to make a difference or loses heat before it gets to the patient? There are other fixes, he says. Move the warming cabinet close to the patients, he says. And remember that what feels warm to an active nurse may be different to a stationary, ill patient.

On the flip side, it takes surprisingly little time to burn a patient badly. At 120 degrees, it can take some minutes to raise skin temperature to dangerous levels. At 130 degrees, it is just one minute. And at 150 degrees, "it is just a few seconds," he says. "It is not a linear equation."

While no provider wants to harm a patient, the hospital environment is busy, and Lavanchy says it would be nearly impossible for every provider to guarantee that he or she would make sure that every time the blanket was hotter than 130 degrees, it wouldn’t be rolled up or placed on a patient who was insensate or incapable of communicating discomfort.

"Engineers say the most effective control is one where you build safety into the design of something," he says. "For this, the appropriate design control is to make 130 degrees the maximum warming cabinet temperature. You might be able to get away with something higher sometimes for some patients, but it is best to design for the cases when you can’t."

ECRI has created a Youtube.com question and answer video on the topic. It can be found at http://www.youtube.com/watch?v=abp-nGiqvMo.

The AORN environment of care standards related to blanket warming cabinets can be found at http://www.aorn.org/Secondary.aspx?id=20975&terms=blanket%20warmer#a.

For more information on this topic, contact Chris Lavanchy, Engineering Director, Health Devices, ECRI, Plymouth Meeting, PA. Telephone: (610) 825-6000.