Wound Contamination During Orthopaedic Surgery

Study Overview
=================
Brief Summary
-----------------
In the present study we will compare bacteriological findings and the incidence of SSI in relation to laminar airflow (LAF) ventilated ORs, conventional (also called displacement or mixed) ventilated ORs and conventional ventilated ORs with the addition of tables equipped with units providing a local LAF over the surgical instruments. The hypothesis is that there exist a correlation between number and types of airborne bacteria and bacteria in the surgical wound and on surgical instruments at the time of wound closure.

Detailed Description
-----------------
The scientific literature on the relationship between airborne bacteria and wound contamination during different conditions is scares. A study from 1982 (Whyet et al.), demonstrated that the most important and consistent source of contamination of the wound during clean surgery (in this case hip implant surgery) was via air. The study concluded that approximately one third of bacteria in the wound were caused by direct air contamination whereas the remaining number of bacteria were transferred to the wound by indirect routes such as via contaminated instruments. The present study includes patients undergoing hemiarthroplastic surgery due to hip fracture. During the surgery active air sampling, for microbial analysis, will be done within 30 cm from the wound. Passive sampling of instrument tables, to measure number of depositing bacteria on the surface during the procedure, will be performed by placing sterile filters on the table surfaces before initiating the surgical procedure and collecting them at the end. Skin and wound sampling will be performed with sterile flocked nylon swabs. The method for skin and wound sampling was decided based on a literature review and discussions with the department of Clinical microbiology at Sahlgrenska University hospital. Both aerobe and anaerobe bacteria will be analyzed. The wound will be measured and number of personnel, door openings and clothing, at each procedure will be recorded. Patients included in the study will be interviewed after 6 weeks and 1 year, to evaluate incidence rate of SSI.

Official Title
-----------------
Assessment of Relationships Between Airborne Microorganisms and Wound Contamination During Orthopaedic Surgery - a Trial Within the Clean Care Project

Conditions
-----------------
Surgical Site Infection, Hip Fractures, Orthopedic Disorder, Implant Infection

Intervention / Treatment
-----------------
* Device: Conventional ventilation + instrumental tables with integrated laminar airflow
* Device: Conventional ventilation + standard instrumental tables
* Device: Laminar airflow ventilation + standard instrumental tables


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients undergoing hip fracture surgery treated with hemiarthroplasty implant and that are subsequently cared for at participating ortho-geriatric unit Exclusion Criteria: Patients that will not give their informed consent. Patient that, at the time of surgery, have an infection in any part of the body, hospital or community acquired. Patients receiving fracture fixation with pins only

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hemiarthroplasty<br>Hip fracture patients operated with hemiarthroplasty | Device: Conventional ventilation + instrumental tables with integrated laminar airflow<br>* Surgical instruments protected from contamination by local laminar airflow<br>Device: Conventional ventilation + standard instrumental tables<br>* Control<br>Device: Laminar airflow ventilation + standard instrumental tables<br>* Control<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Live bacterial Count (colony forming units, CFU) per meter3 air during surgery; in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | Active airsampling within 30cm from the surgical wound will be performed during surgery and number of collected aerobe and anaerobe bacteria analyzed. | 2019-2021 | 
| Number of CFU in the surgical wound before closure; after surgery in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | The entire wound is swabed before closure, aerobe and anaerobe bacteria analyzed. | 2019-2021 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CFU/dm2 on the patients skin Before directly prior to incission, before surgery in surgery in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | Swab sample is taken of the skin directly prior to incission, aerobe and anaerobe bacteria analyzed. | 2019-2022 | 
| CFU/dm2 on the instrument tables during surgery in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | Passive sampling of bacteria falling down on the instrument tables during the duration of each surgical procedure will be analyzed. Aerobe and anaerobe bacteria analyzed. | 2019-2022 | 
| Bacterial species in air collected during surgery in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | The bacterial species in collected samples are identified with MALDI-TOF | 2019-2022 | 
| Bacterial species in wound samples collected during surgery in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | The bacterial species in collected samples are identified with MALDI-TOF | 2019-2022 | 
| Number and sort of SSI in patients operated in ORs with LAF ventilation, Conventional ventilation or Conventional ventilation + local LAF above instrument tables | Patients are contacted 6 weeks and 1 year after surgery and incidense and severrensess of infection recorded | 2019-2022 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
LAF, UDF, SSI, Wound contamination, Infection control, Airborne contamination, Operating room