Paravertebral blocks reduce the risk of postoperative urinary retention in inguinal hernia repair.

Abstract

Inguinal hernia repair and general anesthesia (GA) are known risk factors for urinary retention. Paravertebral blocks (PVBs) have been utilized to facilitate enhanced recovery after surgery. We evaluate the benefit of incorporating PVBs into our anesthetic technique in a large cohort of ambulatory patients undergoing inguinal hernia repair. Records of 619 adults scheduled for ambulatory inguinal hernia repair between 2010 and 2015 were reviewed and categorized based on anesthetic and surgical approach [GA and open (GAO), GA and laparoscopic (GAL), PVB and open (PVBO), and GA/PVB and open (GA/PVBO)]. Patients were excluded for missing data, self-catheterization, chronic opioid tolerance, and additional surgical procedures coinciding with hernia repair. Risk factors associated with the primary outcome of urinary retention were examined using logistic regression. PVBO (n = 136) had significantly lower odds than GAO of experiencing urinary retention (odds ratio 0.16; 95% CI 0.05-0.51); overall (P < .01), with 4.4% (n = 6) of the patients in the PVBO group having urinary retention versus 22.6% (n = 7) with GAO. Expressed as intravenous morphine equivalences, the PVBO group had the lowest median opioid use (5mg), followed by GA, PVB, and open (7.5mg); GAO 25mg; and GAL 25mg. Also, 30% (n = 41) of the PVBO group required no opioid analgesia in the postanesthesia care unit. PVBs as the primary anesthetic or an adjunct to GA is the preferred anesthetic technique for open inguinal hernia repair as it facilitates enhanced recovery after surgery by decreasing risk of urinary retention, opioid requirements, and length of stay.