Microbial Colonization of Pneumatic Tourniquets in the Orthopedic Operating Room

Background The rate of surgical site infections following orthopedic procedures is approximately 2% globally. Potential sources of contamination in the operating room include pneumatic tourniquets, blood pressure cuffs, and stethoscopes, among others. Our study aims to investigate microbial colonization on reusable pneumatic tourniquets stored and used in the orthopedic department of our institution and evaluate the efficacy of the cleaning protocols employed. Methods Over a course of two weeks, 26 samples were obtained. A total of 14 pneumatic tourniquets were sampled preoperatively on Monday morning following the weekly cleaning protocol of soaking the tourniquets in sodium hypochlorite for 30 minutes while 12 tourniquets were cultured immediately following the postoperative cleaning protocol of wiping the tourniquet clean with a cloth soaked in sodium hypochlorite. Samples were cultured on MacConkey and sheep blood agar and incubated at 37-degrees centigrade for a total of 48 hours. Organisms were identified and colony count was documented. The analysis was performed using the Fisher Exact test on SPSS v23 (IBM Corp., Armonk, NY, US). Results All 14 samples obtained after being soaked in sodium hypochlorite for 30 minutes cultured negative. However, four out of 12 (33%) samples obtained after simply wiping the pneumatic tourniquet with a cloth soaked in sodium hypochlorite cultured coagulase-negative Staphylococci. The difference between the two was significant (p=0.002). Conclusion Postoperative tourniquets, wiped with a cloth soaked in sodium hypochlorite and ready to be used on the next patient, were found to be contaminated with coagulase-negative Staphylococcus. This species is notorious for causing surgical site infections following implant-related surgeries potentially through direct inoculation and cross-infections intraoperatively and in storage. Efforts to identify the relationship with postoperative surgical site infections need to be made to suggest more aggressive cleaning protocols.