Evaluating the effect of Novarerus NV800 air purifier units during orthopaedic surgery to reduce bioburden in the air

J Hosp Infect. 2022 Dec;130:108-111. doi: 10.1016/j.jhin.2022.09.005. Epub 2022 Sep 14.


Background: A locally installed air purifier unit (Novaerus Protect 800) has been shown to reduce the air bioburden in an intensive care unit and the incidence of healthcare-associated infections.

Aim: To explore whether this type of air purifying unit could reduce bacterial concentrations in the air of an operating room (OR) during orthopaedic surgery, thereby reducing the risk of surgical site infections.

Methods: In this prospective experimental study, undertaken in 2018, three air purifying units were installed in an OR in a Swedish hospital in 2018. The air was actively sampled during 11 operations by a slit-to-slit agar impactor with the air purifying units either switched on or switched off. Air movements were visualized with the aid of smoke in mock-up studies.

Findings: No significant difference in bacterial concentrations in air was found between the two conditions (air purifying units switched off or on) (P=0.54). Air movements around and above the surgical wound were disordered and resembled those of dilution mixing air.

Conclusion: The three air purifying units installed in the OR did not reduce the airborne bacterial levels in the critical zone during orthopaedic surgery.

Keywords: Air purifier; Operating air bioburden; Operating theatre; Surgical site infection.

MeSH terms

  • Air Filters*
  • Air Microbiology
  • Bacteria
  • Humans
  • Operating Rooms
  • Orthopedic Procedures*
  • Prospective Studies
  • Surgical Wound Infection / prevention & control