Tramadol for the Treatment of Catheter-related Bladder Discomfort

A Randomized Controlled Trial

Shuying Li; Liping Song; Yushan Ma; Xuemei Lin


BMC Anesthesiol. 2018;18(194) 

In This Article


This prospective, randomized, controlled, double-blind study was approved by the China Ethics Committee of Registering Clinical Trials and registered in the Chinese Clinical Trial Registry. Written informed consent was abtained from all patients.

Ninety patients with ASA physical status I–II, who underwent elective gynecological operation with 16 French Foley's catheters inserted and spontaneously complained of CRBD in the PACU were enrolled. Ages ranged from 18 to 60 years. Exclusion criteria included overactive bladder, bladder outflow obstruction, neurogenic bladder, chronic analgesic abuse, morbid obesity, severe hepatic or renal disease, and inability to communicate.

Patients who complained of CRBD (moderate or severe) were randomized into three groups of 30 each using a computer-generated randomized number. Group A received normal saline, group B received 1 mg/kg tramadol, and group C received 1.5 mg/kg tramadol. The medication was administered from Murphy's dropper with a slow drip by a PACU nurse who was not involved in the subsequent observation. All patients were monitored by ECG, non-invasive blood pressure, and pulse oximetry. The severity of CRBD, postoperative pain, and adverse effects (nausea, vomiting, dizziness, headache, drowsiness) were then assessed at 0, 0.5, 1, 2 and 6 h by an anesthesiologist who was blinded to the treatment.

The severity of CRBD was recorded as follows: none, did not complain of any CRBD even upon asking; mild, revealed only upon questioning; moderate, reported without questioning but was not accompanied by any behavioral response; and severe, stated on their own and followed by behavioral responses such as a strong verbal response, flailing limbs, and even trying to pull out the urinary catheter.[4–9] Postoperative pain was assessed by the visual analog scale (VAS) score, which varied from 0 to 10, where 0 incicated no pain and 10 the worst imaginable pain.

The sample size was estimated based on a previous study with power analysis α = 0.05 and β = 0.1 to detect differences in the proportion of CRBD in a range of 0.1 to 0.6 between three groups; 24 patients were needed in each group.[17] Considering a 20% dropout rate, 30 patients were ultimately included in each group. The severity of CRBD and adverse effects were analyzed by the chi-squared test. Demographic data were assessed by one-way analysis of variance (ANOVA); postoperative pain was considered the repeated variables and was examined by repeated-measures ANOVA. The data were analyzed using SPSS 17.0, and P < 0.05 was considered significant.