Author: Chase Doyle
Age may be just a number, as the saying goes, but when it comes to patients undergoing open thoracic lobectomy, the higher the number the greater the risk for postoperative urinary retention.
In a retrospective review of 38 patients undergoing open lobectomy using patient-, anesthesia- and surgery-specific variables, age was found to be the only significant risk factor for postoperative urinary retention, although benign prostatic hyperplasia (BPH) was nearly significant, the authors reported.
“Risk stratification and prevention of postoperative urinary retention for thoracic surgery are important parts of an enhanced recovery after surgery program,” said Aurelie Merlo, MD, a resident physician in the Department of Cardiothoracic Surgery at the University of North Carolina at Chapel Hill School of Medicine. “Based on these initial results, analgesic type does not appear to play a role in the development of this complication, but age was found to be a significant risk factor.”
“Thoracic surgeons were noticing a lot of complications related with post-op urinary retention, and have a tendency to blame the epidural,” Dr. Merlo said. “Anesthesiologists, on the other hand, have presented data suggesting that the epidural is not the cause. We decided we wanted to get to the bottom of it.”
As postoperative urinary retention may be a multifactorial problem, Dr. Merlo and her colleagues sought to evaluate these risk factors in a multidisciplinary quality improvement effort at their institution. The goals of this effort, said Dr. Merlo, are to determine the incidence of postoperative urinary retention within open lobectomy patients and to optimize perioperative management to minimize the risk for this complication.
Consecutive patients who underwent open lobectomy between June 2016 and October 2017 were eligible for inclusion in this review, and all patients followed the institution’s catheterization removal protocol. Researchers analyzed the following risk factors: age, race, history of BPH, surgical and anesthetic duration, fluid and pressor administration, incidence of intraoperative hypotension, and analgesics (including epidural, intercostal block and opioid use). Postoperative urinary retention was defined as requiring recatheterization (by either in-and-out or Foley catheter). The study has a target accrual of 255 patients.
Epidural Not to Blame
At the 2018 annual meeting of the Society of Cardiovascular Anesthesiologists (abstract 216), Dr. Merlo reported findings for the first 38 patients with complete data. According to initial findings, the incidence of postoperative urinary retention was 26%, and age was found to be a significant risk factor. Patients who had postoperative urinary retention were significantly older than those who did not acquire this complication (median age, 74 vs. 65 years; P<0.05). Although age was the only significant risk factor, said Dr. Merlo, BPH neared statistical significance (43% vs. 0%; P=0.0515). Moreover, among men (n=17), patients with postoperative urinary retention appeared to be more likely to have BPH compared with those without the complication (43% vs. 0%; P=0.05).
Finally, the authors reported no significant difference in fluids, documented hypotension, pressor use, analgesic technique, opioid consumption or postoperative characteristics between the two groups. Specifically, secondary analysis showed no association with use of epidural analgesia.
“Surgery teams are often convinced that the epidural causes post-op urinary retention, and they’ll keep the Foley catheter in until the epidural is removed,” Dr. Merlo said. “However, a secondary analysis with 74 patients showed that the epidural was not associated with post-op urinary retention.”
According to Dr. Merlo, this is just a first look at the data. A larger sample size is needed to clearly elucidate these risk factors, and the review is ongoing. Ultimately, however, researchers intend to expand the study beyond open lobectomy to find significant risk factors for postoperative urinary retention in all patients undergoing lung resection, including video-assisted thoracic surgery and robotics.
“We’re hoping that by adding more patients and getting a larger base, we’ll be able to find more significant findings,” said Dr. Merlo, who emphasized that addressing postoperative complications in a multidisciplinary fashion is necessary to evaluate perioperative risk factors. “We have a really great collaboration between the anesthesiologists and the thoracic surgery department. I think this study demonstrates that when you have that type of collaboration, you can achieve high-quality research and really answer a question the right way.”
Senior author of the study, Lavinia Kolarczyk, MD, an associate professor, the chief of cardiothoracic anesthesiology and the director of the Enhanced Recovery Program at the University of North Carolina at Chapel Hill, noted that this project was part of the university’s Enhanced Recovery After Surgery (ERAS) Thoracic Program.
“The ERAS Thoracic Program was started in September 2015 as a multidisciplinary collaboration to improve perioperative care,” Dr. Kolarczyk said. “As part of our ongoing quality improvement process, we look at complications—such as urinary retention—with a multidisciplinary lens.”