Abstracto

Ketamine infusion induces urinary retention in patient successfully treated by sacral neuromodulation.

Herve F, Devulder J, Wyndaele M, Everaert K

-Background: Sacral neuromodulation has become an established method for treating lower urinary tract symptoms but the exact mechanisms of action remain unclear. This case report illustrates that the lack of complete knowledge of the mechanisms and (central) effects of sacral neuromodulation may elicit unexpected consequences in treating a patient for chronic pain. Methods: We present a case of transient recurrent urinary and fecal retention after each administration of ketamine for chronic lumbosacral pain in a 57-year-old patient treated with sacral neuromodulation for non-obstructive urinary retention. Each episode of urinary and fecal retention appeared immediately after intravenous administration of ketamine. Spontaneous recovery occurred after a dose-dependent time (between 12 to 48 hours). Results: Sacral neuromodulation may influence the (number of) NMDA-receptors in the spinal cord, thereby altering the physiological micturition and defecation reflex. Conclusion: Sacral neuromodulation has a clear role in the treatment of both urinary retention and overactive bladder syndrome, but not all mechanisms of action have been discovered. We hypothesize a possible influence of sacral neuromodulation on the central presence and function of NMDA-receptors, thereby altering the physiological micturition and defecation reflexes.