Alteration of Supply and Exhaust Diffusers in a Negative Pressure Operating Room to Prevent Secondary Infection of Surgical Team

Accompanying patient safety, the surgical team needs protection from secondary infection particularly when an infected patient has surgery in a negative pressure room. Even if the room is excessively depressurized, cases of surgical teams acquiring secondary infections have increased. This study aims to analyze the feasibility of altering the supply and exhaust diffusers in negative pressure rooms, in terms of aperture area, diffuser type, and location of exhausts. A CFD pre-analysis was first performed to comprehend the alteration scenarios; field experiments were performed in a real negative pressure room of Myongji Hospital in Korea. This study found that replacing the existing perforated SA diffuser with a register type diffuser directly provided fresher air to a surgical team and significantly reduced the exposure of secondary infection. Additionally, keeping only two exhausts near a patient's feet, rather than four at each corner, secured more apparent air flow patterns within the negative pressure room. The combination of the two alteration scenarios were effective in reducing the spread of infectious particles emitting from a patient while enabling a faster discharge of the presumably infected air.