Naloxone Reversal of Urinary Retention After Epidural Morphine

Effects of thoracic epidural analgesia on lower urinary tract function in women

“…4 The effect of spinal and lumbar epidural morphine administration on the lower urinary tract is a direct action on the sacral nociceptive neurons and autonomic fibers. 17 Long acting local anesthetics such as bupivacaine administrated intrathecally rapidly block the micturition reflex. Detrusor contraction is again restored approximately 7--8 hr after spinal injection of bupivacaine.…”

Postoperative Urinary Retention

“…Administration of opioids in the lumbar epidural space is associated with higher rate of urinary retention compared to thoracic. 97 Detrusor strength starts to decrease within 5-15 min after 4 mg of epidural morphine, its maximum effect reached between 30 and 120 min and lasting 10-15 h. 69,98 A supraspinal effect due to the rostral spread of opioids in the cerebrospinal fluid toward the pontine micturition center, where opioids receptors are placed, could poorly contribute to the development of POUR, as the onset of analgesia corresponds to the beginning of bladder relaxation and to the loss of detrusor strength. 69,71 Naloxone per se has no effect on normal bladder function; however, it has been shown to reverse the urodynamic effects associated with epidural opioids.…”

Detrusor Activity Is Impaired during Thoracic Epidural Analgesia after Open Renal Surgery

“…7 Lumbar epidural and spinal morphine administration influence lower urinary tract function by direct spinal action on the sacral nociceptive neurons and autonomic fibers. 26 Long-acting local anesthetics such as bupivacaine administrated intrathecally rapidly block the micturition reflex. Detrusor contraction is restored approximately 7-8 h after spinal injection of bupivacaine.…”