Newly Published
Perioperative Medicine  |   November 2017
Effects of Forced Air Warming on Airflow around the Operating Table
Author Notes
  • From the Operating Rooms, Kyushu University Hospital, Fukuoka, Japan (K.S., H.S.); the Department of Anesthesiology, Kyushu Medical Center, Fukuoka, Japan (T.K.); Central Uni Co., Ltd., Fukuoka, Japan (N.A.); and the Department of Anesthesiology and Critical Care Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan (S.H.).
  • Authors wish to include the following note at proof: Please be aware of a recent (posted August 30, 2017) communication from the U.S. Food and Drug Administration about the use of forced air thermal regulating systems. See https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm574053.htm.
    Authors wish to include the following note at proof: Please be aware of a recent (posted August 30, 2017) communication from the U.S. Food and Drug Administration about the use of forced air thermal regulating systems. See https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm574053.htm.×
  • Submitted for publication March 26, 2017. Accepted for publication August 24, 2017.
    Submitted for publication March 26, 2017. Accepted for publication August 24, 2017.×
  • Research Support: The authors have been supported by the educational research fund of operating rooms in Kyushu University Hospital, Fukuoka, Japan.
    Research Support: The authors have been supported by the educational research fund of operating rooms in Kyushu University Hospital, Fukuoka, Japan.×
  • Competing Interests: The authors declare no competing interests.
    Competing Interests: The authors declare no competing interests.×
  • Correspondence: Address correspondence to Dr. Shirozu: Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. shiron@kuaccm.med.kyushu-u.ac.jp. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Technology / Equipment / Monitoring
Perioperative Medicine   |   November 2017
Effects of Forced Air Warming on Airflow around the Operating Table
Anesthesiology Newly Published on November 2, 2017. doi:10.1097/ALN.0000000000001929
Anesthesiology Newly Published on November 2, 2017. doi:10.1097/ALN.0000000000001929
Abstract

Background: Forced air warming systems are used to maintain body temperature during surgery. Benefits of forced air warming have been established, but the possibility that it may disturb the operating room environment and contribute to surgical site contamination is debated. The direction and speed of forced air warming airflow and the influence of laminar airflow in the operating room have not been reported.

Methods: In one institutional operating room, we examined changes in airflow speed and direction from a lower-body forced air warming device with sterile drapes mimicking abdominal surgery or total knee arthroplasty, and effects of laminar airflow, using a three-dimensional ultrasonic anemometer. Airflow from forced air warming and effects of laminar airflow were visualized using special smoke and laser light.

Results: Forced air warming caused upward airflow (39 cm/s) in the patient head area and a unidirectional convection flow (9 to 14 cm/s) along the ceiling from head to foot. No convection flows were observed around the sides of the operating table. Downward laminar airflow of approximately 40 cm/s counteracted the upward airflow caused by forced air warming and formed downward airflow at 36 to 45 cm/s. Downward airflows (34 to 56 cm/s) flowing diagonally away from the operating table were detected at operating table height in both sides.

Conclusions: Airflow caused by forced air warming is well counteracted by downward laminar airflow from the ceiling. Thus it would be less likely to cause surgical field contamination in the presence of sufficient laminar airflow.