What type of airflow system is recommended in the operating room to reduce airborne contamination during surgery?

• A. HEPA-filtered positive-pressure ventilation
• B. Negative-pressure ventilation with HEPA filtration
• C. Unfiltered ambient air exchange
• D. Laminar flow without filtration

Answer: (A)

Maintaining clean, filtered air at higher pressure in the operating room is essential to minimize airborne contaminants during surgery. HEPA filtration traps most airborne particles, including bacteria and spores, so the air entering the room is as clean as possible. Positive pressure makes air flow from the inside to the adjacent spaces when doors are opened, helping prevent contaminated air from flowing into the sterile field. Together, HEPA filtration and positive pressure reduce the risk of contamination around the surgical wound.

Negative-pressure systems would draw air from surrounding spaces into the OR, potentially bringing in contaminants. Unfiltered ambient air exchange offers no filtration of particles. Laminar flow without filtration may direct air, but without filtration it does not remove contaminants, making it less effective at protecting the sterile field.