Effects of delayed postoperative void and preoperative urologic symptoms on delay in time of discharge for elective lumbar decompression surgery.

Background Context: Almost half of all patients undergoing lumbar spine surgery have preoperative lower urinary tract symptoms (LUTS). These symptoms could affect postoperative voiding and subsequently length of stay.

Purpose: To investigate the association between preoperative LUTS and time to first void and between time to first void and time to discharge among patients undergoing elective lumbar decompression surgery.

Study Design/setting: Retrospective analysis of prospectively collected data among patients at a single academic medical center.

Patient Sample: All patients ≥18 years of age undergoing elective lumbar decompression surgery between July 2017 and March 2020.

Outcome Measures: The physiologic measure of a delayed time to first void was defined as an initial postoperative void of > 4 hours after anesthesia stop time. The outcome of prolonged time to discharge was defined as a stay of >24 hours after anesthesia stop time.

Methods: At their preoperative visit, patients completed the validated International Prostate Symptom Score (IPSS) (range, 0-35 points), which is applicable for LUTS assessment in both sexes. Clinically relevant LUTS are defined as an IPSS score of ≥8. Patients were followed from their preoperative visit to surgery admission discharge. Association of LUTS with time to first void and time to first void with admission discharge were estimated using risk ratios (RR) and 95% confidence intervals (CI) from a multivariable Poisson regression with a robust variance estimate adjusted for potential confounding variables including age, sex, IPSS, and intraoperative Foley catheter use.

Results: The analytic cohort included 170 patients with an average age of 57 years and 103 (61%) were men. Preoperative LUTS prevalence was 45%, and 111 (65%) of patients voided within 4 hours after surgery. For patients with preoperative LUTS, the unadjusted RR for a first void of >4 hours was 1.04 (95% CI: 0.82-1.32) (p=.77). Adjustment for age, sex, intraoperative Foley catheter use, revision surgery, previous spine surgery, single versus multiple levels, and lumbar location did not materially alter the risk: the multivariable RR was 1.04 (95% CI: 0.82-1.31) (p=.74). The unadjusted RR for a discharge of > 24 hours for patients with a time to first void of > 4 hours was 2.17 (95% CI: 1.51-3.10) (p<.001). After adjusting for age, sex, intraoperative Foley catheter use, IPSS, revision surgery, previous spine surgery, single versus multiple levels, and lumbar location, the multivariable RR was 1.72 (95% CI: 1.22-2.41) (p=.002).

Conclusions: Regardless of preoperative LUTS status, an initial first void of >4 hours after surgery is associated with a longer time to discharge among patients undergoing elective lumbar decompression surgery. Future studies are needed to determine if encouraging early postoperative voiding results in timely discharge and shorter length of stay.