Characterizing Intraoperative Vasopressor Use in Total Knee Arthroplasty: A Retrospective Cohort Study

Preoperative optimization and protocols for joint replacement care pathways have led to decreased length of stay (LOS)and narcotic use, and are increasingly important in delivering quality, cost savings, and shifting appropriate cases to an outpatient setting. The intraoperative use of vasopressors is independently associated with increased LOS and risk of adverse postoperative events including death, and in total hip arthroplasty, there is an increased risk for intensive care unit (ICU) admission. Our aim is to characterize the patient characteristics associated with vasopressor use specifically in total knee arthroplasty (TKA). We retrospectively reviewed the electronic medical records of a cohort of patients who underwent inpatient primary TKA at a single academic hospital from January 1, 2017 to December 31, 2018. Demographics, comorbidities, perioperative factors, and intraoperative medication administration were compared with multivariate regression to identify patients who may require intraoperative vasopressors. Out of these, 748 patients underwent TKA, 439 patients required intraoperative vasopressors, while 307 did not. Significant independent predictors of vasopressor use were older age (odds ratio [OR]=1.06, 95% confidence interval [CI]: 1.03-1.08) and history of a prior cerebrovascular accident (CVA; OR=11.80, CI: 1.48-93.81). While not significant, male sex (OR=0.72, CI: 0.50-1.04) and regional anesthesia (OR=0.64, CI: 0.40-1.05) were nearing significance as negative independent predictors of vasopressor use. In a secondary analysis, we did not observe an increase in complications attributable to vasopressor administration intraoperatively. In conclusion, nearly 59% of patients undergoing TKA received intraoperative vasopressor support. History of stroke and older age were significantly associated with increased intraoperative vasopressor use. As the first study to examine vasopressor usage in a TKA patient population, we believe that understanding the association between patient characteristics and intraoperative vasopressor support will help orthopaedic surgeons select the appropriate surgical setting during preoperative optimization.