Effects of Operating Room Size on Surgical Site Infection Following Lumbar Fusion Surgery

The Effect of Operating Room Size on Orthopaedic Surgical Site Infection Rates

OBJECTIVE

With many preventable causes of surgical site infections (SSIs) identified, the effect of operating room (OR) size on SSI rates has not been assessed. This study investigated the effect of OR size on incidence of SSIs for orthopaedic procedures.

BACKGROUND

SSIs remain a common complication within the perioperative realm. Responsible for increasing length of hospitalization and costs, SSIs result in a decreased quality of life for patients.

METHODS

A retrospective review of 11,163 patients who underwent orthopaedic surgery-including total knee and hip arthroplasties, laminectomies, and spinal fusions-between January 2018 and January 2020 were reviewed. Total net square footage (NSF) of all ORs was recorded, and incidence of SSIs was calculated. Cases were categorized based on the size of the OR (small: 250 to 399 NSF; medium: 400 to 549 NSF; and large: 550 to 699 NSF). Chi-square analysis compared infection rates between the different OR sizes, and a binary logistic regression model identified other predictors of infection.

RESULTS

Overall, 137 patients (1.2%) developed an SSI. Of these infections, 16 (11.7%) occurred in small ORs, 83 (60.6%) in medium ORs, and 38 (27.7%) in large ORs. The incidence of SSIs was 0.7% in small ORs, 1.3% in medium ORs, and 1.8% in large ORs. Factors found to significantly impact SSI's included medium-sized ORs, younger patients, procedure type (fusions and emergencies/traumas), longer procedures, and higher American Society of Anesthesiologists scores (>3).

CONCLUSION

Our study shows that OR size in addition to various other perioperative parameters plays a role in the rate of SSIs for orthopaedic procedures.

LEVEL OF EVIDENCE

Retrospective Cohort Study; Level III Evidence.

Operating room architecture is not a risk factor for surgical site infections

Surgical site infection (SSI) may cause a substantial burden for patients and healthcare systems. A potential risk of different architectures of the operating room for SSI is yet unknown and was subject of this study. This observational cohort study was performed in a university hospital and evaluated patients, who underwent a broad spectrum of orthopedic surgeries in 2016 (open-plan operating room architecture) versus (vs) 2017 (closed-plan operating room architecture). Patients, who underwent surgery in the transition time period from the open-plan to the closed-plan operating room architecture and those, who were treated e.g. for osteomyelitis as index procedure were excluded. The primary outcome was revision surgery for early SSI within 30 (superficial) or 90 (deep or organ/space) days of surgery. Age, gender, American society of anesthesiologists (ASA) classification, and the body mass index (BMI) were considered as potential interacting factors in a logistic regression analysis. The incidence of revisions for SSI was 0.6 percent (%) (n = 45) in the 7'740 included surgical cases (mean age of 52 (standard deviation (SD) 19) years; n = 3'835 (50%) females). There was no difference in incidences of revision for SSI in the open- vs closed-plan operating room architecture (0.5% vs 0.7%; adjusted odds ratio (OR) = 1.34 (95% confidence interval (CI) 0.72-2.49, P = 0.35)). Age and gender were not a risk factor for revision for SSI. However, ASA classification and BMI were identified as risk factors for the incidence of revision for SSI (OR = 1.92 (95% CI 1.16- 3.18, P = 0.01) and OR = 1.05 (95% CI 1.00-1.11, P = 0.05)). The overall incidence of revisions for early SSI after a broad spectrum of orthopedic surgeries was relatively low (0.6%) and independent from the operating room architecture. An increase in ASA classification and possibly BMI, however, were identified as independent risk factors for revision for SSI.