◊ BACKGROUND:
Spinal local anesthetics interrupt the micturition reflex; bladder function remains impaired until sensory block had regressed to the S3 segment. Intrathecal opioids cause dose-dependent suppression of detrusor contractility. We studied the effects of spinal anesthesia with a combination of lidocaine and sufentanil on lower urinary tract function.
◊ METHODS:
Filling cystometry was performed in 10 healthy young male patients undergoing elective lower limb orthopedic surgery. After baseline recordings, each patient received spinal anesthesia with 100 mg hyperbaric lidocaine combined with 20 microg sufentanil. In the postoperative phase, regressions of sensory and motor block were recorded and urodynamic measurements continued until the patient could void spontaneously without residual volume in the bladder.
◊ RESULTS:
The mean (SD) time to recovery of urge was 240 (37) min after spinal injection, but no patient was able to void at that time. Six patients experienced urge at the previously observed maximum bladder capacity when the sensory block had regressed to the second sacral segment (S2), in four patients to S3. Despite this urge, no detrusor contraction was recorded. The patients were able to completely empty the bladder 332 (52) min after spinal injection. The average time difference between recovery of urge and return of normal bladder emptying was 90 min.
◊ CONCLUSIONS:
Bladder contractility returns much later than recovery of sensory function in sacral dermatomes (S3) when hyperbaric lidocaine combined with sufentanil is used for spinal anesthesia.
◊ Reviewed by P.A. Lönnqvist, MD, PhD
Professor of Paediatric Anesthesiology & Intensive Care, Inst. of Physiology & Pharmacology, Karoliniska Institute, Stockholm, Sweden;
Senior Consultant, Dept. of Paediatric Anaesthesia & Intensive Care, Karolinska University Hospital, Stockholm, Sweden
The study by Kamphuis et al again highlights the effects of local anaesthetics as well as of opioids injected into the intrathecal space. After previously having investigated the effects of each of them alone they now have investigated the effects of the combined use of hyperbaric lidocaine 100 mg plus 20 mcg of sufentanil on urinary bladder function in 10 young men. The clinically important finding of the study is that it takes approximately 5 hours until return of normal bladder emptying, but that the urge to void appears on average 90 minutes earlier.
From a clinical perspective we need to address this finding in our daily practice, especially if spinal anaesthesia with this type of drug combination is performed in outpatients. Based on the study results it appears reasonable to suggest the following:
1. to encourage the patients to empty their bladder immediately before being brought into the operating room.
2. to use bladder scanning in all patients that have not voided spontaneously before leaving the hospital.
3. to provide patients with information that it will take about 5-6 hours before mictuition becomes normal again. If they have not been able to empty their bladder in this time they should alert the medical staff.
One should note that this study was performed in a quite young age group (22-47 yrs) without any significant comorbidity (ASA 1). It can be expected that the times revealed in the current study could be significantly prolonged in elderly patients with prostate hypertrophy, but also in other common patient categories such as diabetic patients. Hopefully, the authors continue research in this field with a focus on these common patient groups to provide further useful information in this setting. |
