Reducing operating room ventilation during unoccupied periods may not be associated with poorer postoperative outcomes.
In a retrospective pre-post study, investigators analyzed 127,878 surgical cases across 55 operating rooms (OR) at a single US center prior to and following implementation of automated air change setbacks. Ventilation rates were reduced to four to six air changes per hour when the rooms were unoccupied and returned to the standard level of 21 air changes when occupied. The primary outcome was surgical site infection (SSI), with secondary outcomes including intensive care unit (ICU) admission, mortality, and hospital length of stay.
Compared with outcomes prior to the implementation of air change setbacks, the unadjusted outcomes showed lower rates of superficial SSI (7.8% vs 8.7%) and deep SSI (0.5% vs 0.8%) following implementation, along with small decreases in 30-day mortality (1.5% vs 1.7%) and 90-day mortality (2.9% vs 3.2%). The median length of stay was slightly shorter following the intervention. After adjustment for patient and procedural factors, air change setbacks weren't associated with differences in SSI, ICU admission, or 30-day mortality.
The intervention resulted in signicant reductions in energy use, with annual electricity consumption decreasing by approximately 1.35 million kWh across the operating rooms, corresponding to nearly $135,000 in annual cost savings.
The study was limited by its observational, single-center design, and residual confounding couldn't be excluded. The findings may not be generalizable to other institutions with different ventilation systems or operational workflows.
Overall, the findings suggested that reduced ventilation during unoccupied periods may lower energy use without changes in measured patient outcomes.
"Our findings do not challenge occupied-room standards butsupport optimization within existing guidelines,” wrote lead study author Ali Alipouriani, MD, of the Department of General Surgery, Digestive Disease Institute at the Cleveland Clinic Foundation, and colleagues.
Senior study author Benjamin T. Miller, MD, reported receiving personal fees from BG Medical, Medtronic, and Boston Scientific outside the submitted work. The study authors reported no other conflicts of interest.
Source: JAMA Surgery
