Do forced air patient-warming devices disrupt unidirectional downward airflow?

J Bone Joint Surg Br. 2012 Feb;94(2):254-6. doi: 10.1302/0301-620X.94B2.27562.


Patient warming significantly decreases the risk of surgical site infection. Recently there have been concerns that forced air warming may interfere with unidirectional airflow, potentially posing an increased risk of infection. Our null hypothesis was that forced air and radiant warming devices do not increase the temperature and the number of particles over the surgical site when compared with no warming device. A forced air warming device was compared with a radiant warming device and no warming device as a control. The temperature and number of particles were measured over the surgical site. The theatre was prepared as for a routine lower-limb arthroplasty operation, and the same volunteer was used throughout the study. Forced air warming resulted in a significant mean increase in the temperature (1.1°C vs 0.4°C, p < 0.0001) and number of particles (1038.2 vs 274.8, p = 0.0087) over the surgical site when compared with radiant warming, which raises concern as bacteria are known to require particles for transport.

Publication types

  • Comparative Study

MeSH terms

  • Air Microbiology
  • Air Movements*
  • Arthroplasty, Replacement / methods*
  • Heating / adverse effects
  • Heating / instrumentation
  • Heating / methods*
  • Humans
  • Intraoperative Care / adverse effects
  • Intraoperative Care / methods*
  • Joint Prosthesis / adverse effects
  • Operating Rooms
  • Particulate Matter / analysis
  • Prosthesis-Related Infections / etiology*
  • Prosthesis-Related Infections / prevention & control
  • Temperature


  • Particulate Matter