The Effect of Plasma-air-filtration on the Incidence of Surgical Site Infections in Orthopaedic Surgery

The Effect of Air-filtration Through a Plasma Chamber on the Incidence of Surgical Site Infections in Orthopaedic Surgery: a Double-blind, Randomized, Controlled Trial

The study is a multicenter, double-blind, randomized, controlled trial conducted at six major university and teaching hospitals with a catchment population of approximately 2 million. In the current study it has been hypothesized that a non-invasive air cleaner utilizing a plasma chamber can significantly reduce the incidence of surgical site infections (SSIs).

Despite operating in clean theaters, surface sterilization, and antibiotics, surgical site infections (SSI) after orthopaedic surgery have an estimated incidence of 1-4%. This feared complication is associated with long-term antibiotics, repeated surgeries, prolonged hospital stays, economic burden and a poorer end result for individual patients. It is therefore of great importance to prevent SSI.While skin bacteria and contaminated surfaces have generally been claimed to be the main cause of infections, there are estimates that approximately 20% of hospital-acquired infections are air-transmitted, making this an interesting intervention target. Novaerus is an air-cleaner that sterilizes the air particles through a plasma chamber. Air in the operating theatre is pumped through the chamber (80-380 m3/Hr) and by using a small current it transforms the gas in the vicinity of the electrode into plasmaand eradicates any bacteria that pass through.The small size of the machine allows it to fit into any operating theater without interfering with existing equipment. This technology can reduce the number of colony forming units (CFU) when in hospital settings. In non-randomized settings it has been correlated to reduced respiratory infections, reduced personnel sick-leave, and absence of severe infectious outbreaks. Its effect has not been validated in randomized controlled trials. Both local and national registry data will be used according to availability.

Inclusion Criteria:

• All patients that undergo a 30 minute or longer orthopaedic surgery

Exclusion Criteria:

• The following surgeries will be excluded: already infected surgical site, defined as: ICD-codes indicating infection, Open fractures, Traumatic wounds, Vacuum assisted wound therapy
• Patients that have had antibiotics prescribed 2 weeks or less prior to surgery
• Patients that have actively marked their hospital charts with an added privacy notice