Effect of epidural analgesia with opioids on the prevalence of urinary retention in dogs undergoing surgery for cranial cruciate ligament rupture

Abstract

OBJECTIVE: To determine whether epidural administration of opioids was associated with clinically important urinary retention in dogs undergoing elective orthopedic procedures. DESIGN: Retrospective cohort study. ANIMALS: 179 client-owned dogs undergoing elective surgery for cranial cruciate ligament rupture. PROCEDURES: Medical records of 179 dogs that underwent surgical correction for cranial cruciate rupture between January 2009 and October 2012 were reviewed; 120 received epidural administration of opioids and 59 did not. Signalment, type of procedure, administration of epidural analgesia, time to first postanesthetic urination, and number of urinations during the first 24 hours were evaluated and compared between groups. RESULTS: Administration of preservative-free morphine into the epidural space was not significantly associated with time to first urination following anesthetic recovery or the total number of urinations within the first 24 hours of anesthetic recovery. Administration of a hydromorphone bolus IV following surgery was significantly associated with urinary retention, compared with administration of either morphine boluses or fentanyl constant rate infusions following surgery. No other variables were significantly associated with urinary retention. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of preservative-free morphine into the epidural space was not associated with clinically important urinary retention in dogs undergoing elective orthopedic procedures. Systemic administration of opioids may be associated with urinary retention.