A recent randomized bench study investigated the effectiveness of disinfectants on polyethylene (PE) liners accidentally dropped onto operating room (OR) floors. Published in Infection Control & Hospital Epidemiology, the study evaluated immersion in sterile chlorhexidine-alcohol (CHG) or povidone-iodine (PI) against ethanol immersion or no intervention.
The Unseen Threat: Implant Contamination in the OR
Accidental implant drops in the OR are a recognized clinical risk. Such incidents result in measurable microbial contamination, challenging the notion that brief contact with the floor is harmless. Currently, no standardized guidelines exist for managing a dropped implant during surgery.
OR floors are known to harbor harmful pathogens, making any floor contact by surgical implants a contamination risk. Previous research indicated that orthopedic surgeons generally prefer replacing contaminated implants, though some consider antiseptic soaking or using provisional implants.
"Accidental implant drops in the OR are a recognized clinical risk. Such incidents result in measurable microbial contamination, challenging the notion that brief contact with the floor is harmless."
Rigorous Investigation: How the Study Was Conducted
The study was conducted across four orthopedic ORs at Duke University Medical Center. Researchers simulated real-world conditions by placing PE liners, from hip or knee arthroplasty cases, on the OR floor for 10 seconds. Each liner's surface was divided, with one half swabbed pre-intervention and the other post-intervention.
Liners were randomized into control, CHG, PI, or 70% ethanol (EtOH) groups. Floor sponge samples were also collected to establish baseline microbial burden. Colony-forming units (CFUs) were quantified, and organisms were identified.
The primary outcome was post-intervention total CFU count. A secondary outcome was the proportion of liners contaminated with clinically important pathogens, such as Staphylococcus aureus, Enterococcus species, and Gram-negative bacteria.
Decisive Results: Disinfectant Efficacy Unveiled
The study analyzed 213 PE liners. Nineteen floor sponge samples revealed a heavily contaminated OR environment, with a median total CFU count of 2,958. Pathogens such as MRSA/MSSA, Enterococcus spp., and Gram-negative species were identified in a significant percentage of samples.
Significant Bioburden Reduction
Pre-intervention analysis showed a median bioburden of 10 CFU on implant surfaces. Post-intervention, the overall median bioburden impressively decreased to 0 CFU, indicating a significant reduction. This highlights the potential of interventions to mitigate contamination.
CHG and PI Outperform Ethanol
CHG and PI demonstrated comparable efficacy, achieving statistically significant reductions in CFU compared to the untreated control. Ethanol, however, did not show a statistically significant reduction compared to control and was less effective than CHG and PI.
"CHG and PI demonstrated comparable efficacy, achieving statistically significant reductions in CFU compared to the untreated control."
Tackling Clinically Important Pathogens
Clinically important pathogens were recovered from 34.3% of PE liners before disinfection, reducing to 19.2% post-intervention. Both CHG and PI significantly reduced the recovery of these pathogens compared to the control. Ethanol's effectiveness was limited in this regard, especially compared to CHG. Specific pathogen prevalence for S. aureus, Enterococcus spp., and Gram-negative bacteria also decreased post-disinfection, with CHG generally showing strong performance.
Guiding Practice: Recommendations for Patient Safety
The study concluded that OR floors are a significant source of microbial contamination for PE liners. While CHG and PI effectively reduced bacterial burden, neither reliably achieved complete sterility, indicating a persistent residual risk.
Given these findings, replacement of a dropped PE liner remains the recommended course of action. If replacement is not feasible, immersion in CHG or PI is considered the most defensible rescue strategy. Patients should be informed of such events and monitored for signs of infection.
"Replacement of a dropped PE liner remains the recommended course of action. If replacement is not feasible, immersion in CHG or PI is considered the most defensible rescue strategy."
The findings highlight the need for standardized intraoperative rescue protocols to enhance patient safety. The researchers noted that these findings are based on a bench study and do not directly demonstrate clinical infection outcomes.