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

Sacral neuromodulation (SNM) is an effective and increasingly used therapeutic option for various conditions such as symptoms of urgency-frequency, refractory urinary urge incontinence, pelvic pain syndrome and fecal incontinence, urinary retention and constipation. The S3 nerve is usually stimulated unilaterally with a standard frequency of 14Hz and an ideal voltage for motoric response below 3V, which is below the activation threshold of somatic muscle. This modulates the pathophysiological control of both bladder and bowel as both organ systems are innervated by the same central + peripheral nerves. However, not only are the exact mechanisms of action of neuromodulation poorly understood, the pathophysiological mechanisms of these disorders of bladder and bowel function remain unclear as well.