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

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).

Study Overview

• Status: Completed
• Conditions: Orthopaedic Surgery (30 Minutes or Longer)
• Intervention / Treatment: Device: Novaerus NV800 on; Device: Novaerus NV800 off; Device: Novaerus NV800 on or off

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 45000
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Sweden
  • Stockholm, Sweden, 182 88
    • Danderyds sjukhus AB

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exposed patients: Plasma-filter on; Those operated with Novaerus NV800 on for at least 2 Days prior to index surgery. This Group will also in the analysis be sub-grouped according to measurements prior to study start into: regular operating theater; ultra-Clean operating theaters	Device: Novaerus NV800 on; The air-cleaner 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 plasma and eradicates any bacteria that pass through. The air-cleaner has to have been turned on for at least 2 days prior to the surgical intervention.
Experimental: Unexposed patients: Plasma-filter off; Those with Novaerus NV800 off for at least 2 Days prior to index surgery	Device: Novaerus NV800 off; The machine decribed above is running but the plasma filter chamber isn't active, i.e. the placebo group.
Experimental: Mixed patients: Plasma-filter on or off; Those receiving multiple surgeries in different theaters with Novaerus NV800 on or off status will belong to a mixed Group.	Device: Novaerus NV800 on or off; Patients with multiple surgeries that have been operated during both periods when the apparatus has been on and off will belong to this mixed group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients with surgical site infection after orthopaedic surgery, defined as any of the following: using antibiotics targeting Staphylococcus aureus, having ICD-codes or surgery codes indicating postoperative infection.	All definitions are merged into one binary outcome measure as "any(No. > 0)"	Within 12 weeks after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patients using any antibiotics after surgery	This is identified either via hospital information system or from the national drug registry. Usage is defined as withdrawal or prescription of a drug with ATC code within the J01 group.	Two treatment days or more during the first 30 postoperative days
Number of days with antibiotics	This is identified either via hospital information system or from the national drug registry. Usage is defined as withdrawal or prescription of a drug with ATC code within the J01 group. Number of days is deduced from the prescribed dosage or if not present the average daily dosage for that particular drug is used.	During the first 30 postoperative days
Patients using any antibiotics after surgery	This is identified either via hospital information system or from the national drug registry. Usage is defined as withdrawal or prescription of a drug with ATC code within the J01 group.	Two treatment days or more during the first 90 postoperative days
Number of days with antibiotics	This is identified either via hospital information system or from the national drug registry. Usage is defined as withdrawal or prescription of a drug with ATC code within the J01 group. Number of days is deduced from the prescribed dosage or if not present the average daily dosage for that particular drug is used.	Two treatment days or more during the first 90 postoperative days
Death	Any cause of death	during the first 2 postoperative years

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Collaborators: The Swedish Research Council
• Investigators: Principal Investigator: Max Gordon, M.D, PhD, Danderyd Hospital, Stockholm, Sweden

Publications and helpful links

General Publications

• Persson A, Atroshi I, Tyszkiewicz T, Hailer N, Lazarinis S, Eisler T, Brismar H, Mukka S, Kernell PJ, Mohaddes M, Skoldenberg O, Gordon M. EPOS trial: the effect of air filtration through a plasma chamber on the incidence of surgical site infection in orthopaedic surgery: a study protocol of a randomised, double-blind, placebo-controlled trial. BMJ Open. 2022 Feb 3;12(2):e047500. doi: 10.1136/bmjopen-2020-047500.

Study record dates

Study Major Dates

• Study Start (Actual): April 10, 2017
• Primary Completion (Actual): December 31, 2021
• Study Completion (Actual): December 31, 2021

Study Registration Dates

• First Submitted: February 9, 2016
• First Submitted That Met QC Criteria: February 24, 2016
• First Posted (Estimate): March 1, 2016

Study Record Updates

• Last Update Posted (Actual): June 24, 2022
• Last Update Submitted That Met QC Criteria: June 23, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Postoperative Complications; Wound Infection; Surgical Wound Infection
• Other Study ID Numbers: EPOS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No