Operating room time comparison between spinal and general anesthesia in total knee arthroplasty: an institutional review

Background The type of anesthesia used in total knee arthroplasty is one modifiable factor that could save hospital systems time and money. With spinal and general anesthesia having similar outcomes, more weight can be placed on these anesthesia methods’ time or money-saving aspects. Objective This study aims to determine the differences in time expenditure between spinal and general anesthesia for total knee arthroplasty to optimize OR efficiency and reduce costs. Methods A retrospective analysis of 200 unilateral total knee arthroplasty procedures (CPT Code 27447) was performed from Jan 2017 - July 2019 at one institution. 100 of these received spinal anesthesia, and 100 received general anesthesia. Patient charts were reviewed to obtain demographic, surgical, and anesthetic data. Results Time to prepare the patient for surgery and total preoperative time was significantly decreased in the general anesthesia group (24.4 minutes vs. 18.5 minutes; p=<0.0001 and 25.4 minutes vs. 20.4 minutes; p=0.012). After surgery, the time to remove the patient from the operating room was significantly decreased in the spinal group (4.8 minutes vs. 7.0 minutes; p= <0.0001). Nonoperative total time was not significantly different between the two groups (49.3 minutes vs. 46.6 minutes; p=0.1127). Conclusion While there are significant differences in certain operating room time periods between spinal and general anesthesia, these differences are effectively canceled out when considering total operating room time.