PSU16 EVALUATION OF THE ASSOCIATION BETWEEN 30-DAY POST-OPERATIVE INFECTION AND CHANGE IN OPERATION ROOM TIME BY SPINAL ANATOMY

Abstract

The association between operation room time (ORT) and post-operative infections among patients undergoing spinal fusion surgery has been evaluated, with higher risks for infection paralleling increases in ORT. This study sought to further understand the incidence of 30-day post-operative infections and incremental changes in ORT in the thoracic vs. lumbar spine. Through data partnership with Mercy Technology Services, adult patients who underwent multi-level fusions of the thoracic and/or lumbar anatomic regions of the spine were extracted from 2011-2018 Mercy electronic health records. To evaluate incidence of 30-day post-operative infections by 10-minute changes in ORT, a binary logistic regression model was fitted. To evaluate the association between any infection type and 10-minute changes in ORT, a multinomial logistic regression model was fitted; the outcome variable was presence of superficial, deep, general or no infection. Models included an interaction term between ORT+anatomic region and covariates included patient characteristics. A total of 556 patients were evaluated. The incidence of any 30-day infection was 16.8%(66/392) and 17.7%(29/164) for patients that had “thoracic or lumbar” and “thoracolumbar” fusions, respectively. When compared to patients without infection(no infection–infection), the mean difference in ORT was -35.1(94.5)minutes, “thoracic or lumbar”, and -43.1(110.0) minutes, “thoracolumbar”. With a 10-minute increase in ORT, the odds for any infection increased similarly for both anatomy categories: “thoracic or lumbar”, 3.0% (adjusted Odds ratio(aOR),1.03,95% Confidence Interval (CI),1.00-1.06), and “thoracolumbar”, 2.5%(aOR,1.02,95%CI,0.99-1.06) compared to no infection. The odds differed by infection type and anatomy; with a 10-minute increase in ORT, the odds for “thoracic or lumbar” were 5.2%, 2.1%, and 2.0%, and for “thoracolumbar”, 1.2%, 4.8%, and 2.5%, superficial, deep and general, respectively, compared to no infection. The risk of post-operative infection type and increase in ORT may differ due to regional spinal anatomy. Evaluation of these trends with a larger sample size is needed.