Blankets Have Patient Warming Considerations Covered

There is a growing awareness that inadvertent hypothermia during surgical procedures can cause excessive bleeding, wound infections, reduced medication metabolism and potentially fatal arrhythmias. The entire surgical team (i.e., surgeons, preoperative nurses, circulating nurses, scrub persons and PACU nurses) needs to be aware of effective methods of pre, intra, and postoperative patient warming that reduce the threat of hypothermia.

Preoperative Warming Considerations

Patient warming in the preoperative holding area is a positive first step in maintaining patient normothermia. The majority of heat loss in a patient occurs from exposed body surfaces. The application of a single heated cotton blanket is known to reduce heat loss by 33 percent. Increased skin temperatures from warmed blankets help with pre-surgical vasodilation, which aids in easier IV access.

The heat-transfer process begins immediately when the blanket is removed from the warmer as the warmed blanket loses heat to the ambient air. Because the warmed blanket will cool before it reaches the patient, the blanket should be as warm as possible in the warmer. A blanket heated to only 43˚ C (110˚ F) will likely be only 37˚ C (98˚ F) or lower when it reaches the patient, so no heat transfer to the patient can occur. For this reason, Enthermics Medical Systems, Inc. warmers have separate chambers for blankets and fluids with independent heating systems for each, offering a better, higher, and perfectly safe maximum temperature of 93˚ C (200˚ F) for blankets, 37-43˚ C (98-110˚ F) for intravenous fluids or between 37-66˚ C (98-150˚ F) for irrigation fluids.

Intraoperative Warming Considerations

The greatest contributing factors to inadvertent hypothermia during surgical procedures is exposure to cooler temperatures within the OR environment and the application of anesthesia that compromises the body’s ability to generate heat. The American Society of PeriAnesthesia Nurses (ASPAN) recommends skin exposure be limited with the use of warm blankets, socks and head coverings and ambient room temperatures should be increased to between 20 and 23˚ C (68 and 73˚ F). Several studies using warmed intravenous fluids at 42˚ C (108˚ F) have been shown to maintain the patient’s core temperature throughout the procedure.¹

The Association of periOperative Registered Nurses (AORN) and the Centers for Disease Control and Prevention (CDC) agree that systemic warming has a significant effect on reducing the rate of wound infections.² Fluid warming is a low-maintenance, no-risk intervention that should be considered for all patients.

Postoperative Warming Considerations

Continuing blanket warming and intravenous fluid warming methods into recovery and PACU increase positive patient outcomes.

References:

1. Metro Health Anesthesia Abstract: Convective and IV Fluid Warming Reduces Hypothermia and Shivering in Adults Undergoing Outpatient Surgery. Accessed at: http://metrohealthanesthesia.com/research/abstracts/fluidWarming.html

2. AORN Journal. Vol. 78, No. 1. July 2003.