Many factors can lead to hypothermia — anesthetics, air movement, cooler-than-normal temperatures in the surgical suite, evaporation of skin-prep solutions and other reasons. To reduce the risk, perioperative clinicians have implemented a new step in patient care.
“I would say the biggest change in practice comes from the introduction of pre-warming,” said Byron L. Burlingame, MS, RN, CNOR, Senior Perioperative Practice Specialist with the Association of periOperative Registered Nurses (AORN). “Pre-warming should be considered. Though there is conflicting evidence, the majority of the evidence supports pre-warming. In the past, pre-warming was not performed and warming was not begun until the patient reached the OR.”
Al Van Duren, Director of Scientific Affairs and Education for the 3M patient warming business, said intraoperative warming is the least effective way to achieve normothermia in adults. “There are several reasons for this, but the most important one is that the dominant cause of post-induction hypothermia is redistribution, not heat loss,” Van Duren explained. “There is simply no way to heat the adult body by conventional means fast enough to overcome the effect of redistribution. On the other hand, it is possible to store enough energy in the peripheral thermal compartment and virtually eliminate a post-induction decrease in core temperature.”
While evidence shows it works, there’s no definitive answer for how long a patient should be pre-warmed.
“Pre-warming begins in the preoperative setting and continues until the patient is admitted into the operating room,” Burlingame said. “It may begin as soon as possible after admission but no time frame has been established as ideal time for initiation.”
“Recent studies seem to indicate that as few as ten minutes’ exposure provides a substantial benefit,” Van Duren offered. Also, patients face the highest risk of hypothermia during the first hour of surgery indicating that pre-warming is likely to gain greater importance as procedures become shorter in duration. “As surgical times decrease, there simply isn’t time to re-warm patients to normothermia intraoperatively, so there will be considerably more emphasis on pre-warming and ways to make it easier and more efficient,” Van Duren said.
Kent D. Ellis, Principal, Pintler Medical, said patient comfort will also play a role in its adoption. “With patient satisfaction as a CMS survey measurement preoperative warming has another effect that many miss: When a patient is administered anesthesia they have an immediate memory; that memory is the first memory when they are awaking,” Ellis said. “If the patient is feeling warm when going under, then they recall being warm when they awake. The opposite is true with feeling cold. Also, ‘feeling cold’ is the No. 1 complaint of patients. They expect to feel discomfort but not cold.”
Valerie J. Dimond | Managing Editor
Valerie J. Dimond was previously Managing Editor of Healthcare Purchasing News.
