Air contamination for predicting wound contamination in clean surgery: A large multicenter study

Area of Science:

• Healthcare-associated infections
• Environmental microbiology
• Surgical safety

Background:

• The optimal method for quantifying operating room (OR) air contamination remains debated, with conflicting study results.
• Assessing the correlation between different air sampling techniques and wound contamination is crucial for surgical site infection prevention.

Purpose of the Study:

• To evaluate the correlation between particle counts and microbiologic air sampling in ORs.
• To identify factors influencing air contamination in surgical environments.
• To determine the relationship between air quality and wound contamination in cardiac and orthopedic surgery.

Main Methods:

• A multicenter observational study involving 13 ORs across 10 healthcare facilities.
• Simultaneous collection of microbiologic air counts, particle counts (0.3, 0.5, 5 µm), and wound cultures before skin closure.
• Data collection on surgical procedures and environmental characteristics.

Main Results:

• Particle counts showed a correlation with microbiologic air counts, with median log10 values for 0.3, 0.5, and 5 µm particles.
• While 28% of air samples were sterile, 50% had 1-10 CFU/m³ and 22% exceeded 10 CFU/m³.
• Turbulent ventilation systems and particle sizes correlated with increased air microbial counts (P < .001) but not with wound contamination (P = .22).

Conclusions:

• Particle counting serves as a reliable surrogate for assessing airborne microbiologic contamination in the OR.
• This finding supports the use of particle counters as a practical tool for monitoring OR air quality.
• Further research may refine the application of particle counting in infection control strategies.