Orthopaedic Surgery (30 Minutes or Longer)EPOSNCT02695368
The Effect of Plasma-air-filtration on the Incidence of Surgical Site Infections in Orthopaedic Surgery
A study testing Novaerus NV800 on, Novaerus NV800 off and Novaerus NV800 on or off in people with Orthopaedic Surgery (30 Minutes or Longer), run by Karolinska Institutet at 1 site in Sweden.
Trial summary
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. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Orthopaedic Surgery (30 Minutes or Longer)
- What is being tested?
- Novaerus NV800 on, Novaerus NV800 off and Novaerus NV800 on or off
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45,000 participants
- Where
- 1 siteSweden
- Study dates
- 10 Apr 2017to 31 Dec 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- All patients that undergo a 30 minute or longer orthopaedic surgery
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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).
Read the 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.
- Being tested
- Novaerus NV800 on, Novaerus NV800 off, Novaerus NV800 on or off
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Novaerus NV800 onDevice
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.
Novaerus NV800 offDevice
The machine decribed above is running but the plasma filter chamber isn't active, i.e. the placebo group.
Novaerus NV800 on or offDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| Exposed patients: Plasma-filter on | Experimental | 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 Receives: Device: Novaerus NV800 on |
| Unexposed patients: Plasma-filter off | Experimental | Those with Novaerus NV800 off for at least 2 Days prior to index surgery Receives: Device: Novaerus NV800 off |
| Mixed patients: Plasma-filter on or off | Experimental | Those receiving multiple surgeries in different theaters with Novaerus NV800 on or off status will belong to a mixed Group. Receives: Device: Novaerus NV800 on or off |
What is being measured
The primary outcome is the main question the study is designed to answer.
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)"
Measured: Within 12 weeks after surgery
Secondary outcomes (5)
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Two treatment days or more during the first 90 postoperative days
Death
Any cause of death
Measured: during the first 2 postoperative years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2016 (estimated)
- Study start10 Apr 2017
- Primary completion31 Dec 2021
- Study completion31 Dec 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Orthopaedic Surgery (30 Minutes or Longer)Studies of the same condition, open and under way.
- More trials run by Karolinska InstitutetThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 45,000 participants (actual)
Sponsor and investigators
- Lead sponsor
- Karolinska Institutet
- Sponsor type
- University, hospital or other
- Collaborators
- The Swedish Research Council
- Responsible party
- Principal investigator, Max Gordon, Karolinska Institutet
- Investigators
- Max Gordon, M.D, PhD, Principal investigator, Danderyd Hospital, Stockholm, Sweden
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02695368
- Sponsor's protocol ID
- EPOS
- Acronym
- EPOS
- Status last verified
- Jun 2022
- First submitted
- 9 Feb 2016
- Last updated
- 24 Jun 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Persson A, Atroshi I, Tyszkiewicz T, Hailer NP, Lazarinis S, Eisler T, Brismar H, Mukka S, Kernell PJ, Mohaddes M, Skoldenberg O, Gordon M. Effect of Plasma Air Purifiers on Infection Rates in Orthopedic Surgery. NEJM Evid. 2025 Apr;4(4):EVIDoa2400289. doi: 10.1056/EVIDoa2400289. Epub 2025 Mar 25.
PubMed 40130977Persson 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.
PubMed 35115346
Study at a glance
From the registry record, last updated by the sponsor on 24 Jun 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT02695368
- Acronym / sponsor ID
- EPOS / EPOS
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 45,000 participants (actual)
- Lead sponsor
- Karolinska InstitutetUniversity, hospital or other
- Collaborators
- The Swedish Research Council
- Study start
- 10 Apr 2017 (actual)
- Primary completion
- 31 Dec 2021 (actual)
- Study completion
- 31 Dec 2021 (actual)
- First posted
- 1 Mar 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
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 design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Exposed patients: Plasma-filter on | Experimental | Device: Novaerus NV800 onThose 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 |
| Unexposed patients: Plasma-filter off | Experimental | Device: Novaerus NV800 offThose with Novaerus NV800 off for at least 2 Days prior to index surgery |
| Mixed patients: Plasma-filter on or off | Experimental | Device: Novaerus NV800 on or offThose receiving multiple surgeries in different theaters with Novaerus NV800 on or off status will belong to a mixed Group. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- All patients that undergo a 30 minute or longer orthopaedic surgery
Key exclusion criteria (3 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Novaerus NV800 onThe 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. | Device | Exposed patients: Plasma-filter on |
| Novaerus NV800 offThe machine decribed above is running but the plasma filter chamber isn't active, i.e. the placebo group. | Device | Unexposed patients: Plasma-filter off |
| Novaerus NV800 on or offPatients with multiple surgeries that have been operated during both periods when the apparatus has been on and off will belong to this mixed group. | Device | Mixed patients: Plasma-filter on or off |
Primary outcome
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.
Time frame: Within 12 weeks after surgery
All definitions are merged into one binary outcome measure as "any(No. > 0)"
5 secondary outcomes
Patients using any antibiotics after surgery
Time frame: Two treatment days or more during the first 30 postoperative days
Number of days with antibiotics
Time frame: During the first 30 postoperative days
Patients using any antibiotics after surgery
Time frame: Two treatment days or more during the first 90 postoperative days
Number of days with antibiotics
Time frame: Two treatment days or more during the first 90 postoperative days
Death
Time frame: during the first 2 postoperative years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Jun 2022.
- Derived from this study: PubMed 40130977Persson A, Atroshi I, Tyszkiewicz T, Hailer NP, Lazarinis S, Eisler T, Brismar H, Mukka S, Kernell PJ, Mohaddes M, Skoldenberg O, Gordon M. Effect of Plasma Air Purifiers on Infection Rates in Orthopedic Surgery. NEJM Evid. 2025 Apr;4(4):EVIDoa2400289. doi: 10.1056/EVIDoa2400289. Epub 2025 Mar 25.
- Derived from this study: PubMed 35115346Persson 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Max Gordon, M.D, PhD principal investigator
Danderyd Hospital, Stockholm, Sweden
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Novaerus NV800 on, Novaerus NV800 off and Novaerus NV800 on or off in people with Orthopaedic Surgery (30 Minutes or Longer), run by Karolinska Institutet at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Jun 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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. (time frame: Within 12 weeks after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02695368, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jun 2022.