Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (244 page)

   Nonischemic (high flow, arterial, or congenital) priapism usually results from a fistula between the cavernosal artery and the corpus cavernosum. It commonly follows penile or perineal trauma, or blunt trauma (such as from bicycling). It may also stem from a congenital arterial malformation. In any event, nonischemic priapism is not an emergency condition because the cavernous blood is well oxygenated.

   Recurrent (stuttering) priapism is a form of the ischemic condition (usually occurring in men with sickle cell anemia), which begins with erections of short duration (usually during sleep), then persisting on waking, becoming of longer duration, and increasing frequency until transforming into the classical ischemic form.

   Who Should Be Suspected?

   Patients typically present with an erection of 2–4 hours in the absence of sexual excitation. The duration may be shorter for patients with recurrent priapism.

   Causes can be classified into seven categories:

   Thromboembolic disease (sickle cell disease or trait, polycythemia, pelvic thrombophlebitis)

   Infiltrative diseases (e.g., leukemia, bladder or prostate carcinoma)

   Penile trauma

   CNS infection (e.g., syphilis, TB) or spinal cord injury or anesthesia

   Intracavernous injectables for treatment of erectile dysfunction (papaverine, alprostadil, phentolamine)

   Other medications: Antihypertensives, antipsychotics (e.g., chlorpromazine, clozapine), antidepressants (especially trazodone), anticoagulants, testosterone, heparin, and recreational drugs (alcohol, cocaine, marijuana, cantharides)

   Other causes: Prostatitis and retroperitoneal bleeding. Phosphodiesterase type 5 (PDE5) inhibitors (sildenafil, tadalafil, vardenafil) have only rarely been implicated.

   Laboratory Findings