[Urinary retention in connection with postoperative pain treatment with epidural opioids]

The incidence of retention of urine in cases of postoperative epidural opioid analgesia varies from 15% to 90%. The extent to which this phenomenon depends upon the dosage employed has not been elucidated. The cause of postoperative retention of urine (PU) is probably a combination of the central and peripheral effect of the opiate involving altered autonomic activity. Increased sympathetic activity resulting from surgery may, similarly, be a pathogenetic factor. The current methods of treatment are prophylactic or symptomatic alpha-receptor blockade, naloxon in refractory doses or catheterization. Inhibition of per- and postoperatively increased sympathetic activity may possibly prevent PU. Carbacholine is not effective in the treatment of postoperative retention of urine. In animal experimental studies, kappa-receptor agonists have an analgesic effect without urodynamic side-effects but no clinical trials on man have hitherto been undertaken. When postoperative retention of urine occurs after epidural opioid treatment, clean intermittent catheterization or introduction of a thin suprapubic catheter are recommended.