Clinical Topic: Prewarming, Does it really matter?

Peri-operative hypothermia is a common problem related to the practice of anesthesia.  Numerous studies have documented the negative effects of hypothermia to the extent that SCIP has made patient temperature a marker of quality care.  In an attempt to reduce hypothermia, many anesthesia providers recommend patient pre-warming in the holding area prior to surgery.

An article by Horn EP et al published in Anaesthesia  (The effect of short time periods of pre-operative warming in the prevention of peri-operative hypothermia.,  Anaesthesia. 2012 Jun;67(6):612-7) evaluated the effects of 10, 20 and 30 minutes of forced air pre-warming on surgical patients.  The study found that those who were not pre-warmed experienced a greater temperature drop during surgery regardless of the active measures  used in the operating room to maintain body temperature.  The Authors recommended a minimum of 10 minutes of pre-warming prior to surgery.

Click here for an abstract of the Horn et al study

In a separate study by Wagner, D published in AORN,  the causes and problems related to hypothermia are listed.    According to the author, the following factors place the patient at risk:

  • Cold ambient temperatures
  • Cold beds
  • Reduced Metabolism
  • Anesthesia / pharmacological agents
  • Evaporative heat loss

Patients who become hypothermic experience the following problems:

  • Negative nitrogen balance with reduced kidney perfusion
  • Respiratory distress
  • Reduced metabolism of medications
  • Delayed recovery from anesthesia
  • Impaired platelet function and clotting
  • Impaired wound healing
  • Increased wound infections.

To prevent intraoperative hypothermia, the author recommends forced air pre-warming

Click here to view the author’s article.