What is the minimum air exchanges per hour in a surgical environment, and how many should be fresh air?

What is the minimum air exchanges per hour in a surgical environment, and how many should be fresh air?

• A. At least 10/hr with 2 fresh air exchanges
• B. At least 12/hr with 3 fresh air exchanges
• C. At least 15/hr with 3 fresh air exchanges
• D. At least 20/hr with 5 fresh air exchanges

Answer: (C)

Air changes per hour (ACH) tell you how many times the room’s air is replaced in an hour. In a surgical environment, enough ventilation dilutes and removes contaminants—like airborne particles, smoke, and anesthetic gases—to help protect the sterile field and patient safety. The standard minimum is 15 ACH, with at least 3 of those changes coming from outdoor (fresh) air. This ensures a steady dilution with outdoor air while maintaining proper room pressure to keep contaminants from entering the room from adjacent spaces. So, the best choice is at least 15 air changes per hour with 3 fresh air exchanges. Lower ACH values don’t meet the minimum, while higher values aren’t needed to satisfy the stated standard.

Air changes per hour (ACH) tell you how many times the room’s air is replaced in an hour. In a surgical environment, enough ventilation dilutes and removes contaminants—like airborne particles, smoke, and anesthetic gases—to help protect the sterile field and patient safety. The standard minimum is 15 ACH, with at least 3 of those changes coming from outdoor (fresh) air. This ensures a steady dilution with outdoor air while maintaining proper room pressure to keep contaminants from entering the room from adjacent spaces. So, the best choice is at least 15 air changes per hour with 3 fresh air exchanges. Lower ACH values don’t meet the minimum, while higher values aren’t needed to satisfy the stated standard.