When is the best time to remove epidurals and urinary catheters?

Removal of an epidural catheter before a urethral catheter after abdominal surgery reduces incidence of postoperative urinary retention (POUR), according to results of a Japanese retrospective cohort study published in Digestive Surgery. POUR is a frequent complication of epidural anesthesia, occurring in 5% to 70% of cases. Both timing of epidural catheter removal and older age were found to be risk factors for POUR. 

The researchers analyzed medical records from September to December 2014 at Wakayama Medical University for 120 patients who had major abdominal surgery. Thirty-eight of the patients had open surgery and 82 had laparoscopic surgery. The surgical sites ranged from the gastrointestinal (GI) tract (N=37), to liver/biliary ducts/pancreas (N=42) to colon and rectum (N=41). Forty (33.3%) of the 120 patients developed POUR. Patients in the POUR group were slightly older (median age 70.5 years, range 46 to 84 years) than those who did not develop POUR (median age 67 years, range 28 to 86 years, P= 0.03). The patient groups were similar in regard to sex, height, weight, body mass index, and patient history. No differences were identified between the two group in terms of surgical field or approach, operative time, or intraoperative blood loss. There was also no statistical difference in epidural opioid use (fentanyl, morphine) (P= 0.67). 

In the POUR group, the epidural catheter was removed a median of 4 days postoperatively (range 2 to 5 days) versus 3.5 days (range 1 to 6 days) in the non-POUR group (P = 0.04). Removal of the urethral catheter occurred a median of 2 days postoperatively in both groups (range 1 to 5 days in the POUR group and 1 to 7 days in the non-POUR group, P= 0.15). 

Some patients had their catheters removed in an atypical order, according to the researchers, with the urethral catheter removed before the epidural catheter. In these cases, incidence of POUR was found to be greater (P< 0.001) than when the epidural catheter was removed first. 

No urinary tract infections (UTIs) occurred in either group, which the researchers attributed to relatively early removal of urethral catheters in this cohort. This finding confirms that of other trials in which urethral catheters were removed early in patients with epidural catheters. In the previous studies, however, early removal led to more postvoid residual volume, which was not observed in this study. 

Benefits and risks of epidural anesthesia

There are numerous benefits of continuous epidural mid-thoracic anesthesia/analgesia for major abdominal surgery, according to the enhanced recovery after anesthesia (ERAS) protocol. Epidural anesthesia can reduce the risk of cardiac episodes, venous thrombosis, and pulmonary events. On the other hand, it can cause pruritus, POUR, hematoma, abscess, meningitis, motor blockade, and direct traumatic spinal cord injury. It is believed that epidural anesthesia increases risk of POUR by affecting detrusor function, blocking the transmission of afferent and efferent nerve impulses entering and leaving the bladder. 

Study takeaway

The authors concluded that older age, which has been reported by other groups to be a risk factor for POUR, and removal of the urethral catheter before the epidural catheter were risk factors for POUR. “Our results might provide a suggestion of simultaneous removal of urethral and epidural catheter[s after abdominal surgery],” they wrote.