The effect of sterile versus non-sterile tourniquets on microbiological colonisation in lower limb surgery

Surgical tourniquets are commonplace in lower limb surgery. Several studies have shown that tourniquets can be a potential source of microbial contamination but have not compared the use of sterile versus non-sterile tourniquets in the same procedures.

Patients undergoing elective orthopaedic lower limb surgery were randomised prospectively to use of non-sterile pneumatic tourniquet or sterile elastic exsanguination tourniquet (S-MART™, OHK Medical Devices, haifa, Israel). Samples were taken from the ties of the non-sterile tourniquet prior to surgery and from the sterile tourniquets at the end of the operation in a sterile fashion. These were then sealed in universal containers and immediately analysed by the microbiology department on agar plates, cultured and incubated.

Thirty-four non-sterile tourniquets were sampled prior to surgical application, twenty-three of which were contaminated with several different organisms including coagulase-negative Staphylococcus spp, Staphylococcus aureus, Sphingomonas paucimobilis, Bacillus spp, and coliforms. Thirty-six sterile tourniquets were used, with no associated contamination.

There was significant contamination of 68% of orthopaedic surgical tourniquets. These are used regularly in procedures involving the placement of prosthesis and metalwork, and can act as a potential source of infection. We recommend the use of sterile single-use disposable tourniquets where possible. The availability of an alternative should now set the new standard of care and we recommend adopting this as a current NICE guideline for control of surgical site infection.