• Prolonged, unwanted erection not associated with sexual stimulation > 4h
  • May lead to erectile dysfunction and penile necrosis if untreated


High-flow (nonischemic)

  • Extremely rare and usually not painful
  • AV fistula from trauma (lacerated cavernous artery shunts blood into cavernous bodies)
  • Ischemia/impotence does not occur
  • Requires less urgent intervention and does not lead to impotence

Low-flow (ischemic)

  • Most common type
  • Veno-occlusion causing pooling of deoxygenated blood in cavernous tissue
  • A urologic emergency


  • Sickle Cell Disease[1]
  • Medication induced (SSRIs, antipsychotics, erectile dysfunction meds)
  • Leukemia
  • Infection
  • High rate of impotence afterwards if present for > 24hrs
  • Cocaine use[2]
  • Cervical injury (C5)

Clinical Features

  • Erect corpus cavernosum
  • Flacid glans and spongiosum

Differential Diagnosis

Non-Traumatic penile diagnoses

Penile trauma


  • CBC (eval leukemia, sickle cell)
  • Type and screen (may need to exchange transfusion)
  • Coags
  • Urinalysis/tox (etoh, marijuana, cocaine can cause priapism)
  • ABG from cavernosa (if history unclear): Hypoxic, hypercapneic, acidotic → low flow
  • Ultrasound
    • Can distinguish between high-flow and low-flow
ABG Analysis
  • Low-flow priapism is suggested by aspirated blood with a pH of < 7.25, pO2 < 30 mmHg, and pCO2 > 60 mmHg


Low Flow Priapism

Aspiration of corpus cavernosum

  • Written consent prior to invasive procedure
    • Regardless of treatment there is a high risk of impotence
  • Rarely beneficial after 48hr
  • Penile nerve block or local anesthesia at puncture site
  • Aspirate blood from corpus cavernosum (3 or 9 o'clock position of shaft) with 16-19ga needle
  • Blood sludging makes aspiration difficult, so to improve flow dynamics use saline irrigation and repeated aspirations
  • After removal of 20-30cc of blood, you may inject and aspirate 10-20cc aliquots

α/β-2 Agonist

  1. Terbutaline[4]
    • Dose: 0.25-0.5mg SQ in deltoids OR 5-10mg PO, may repeat in q20min
  2. Phenylephrine
    • Dilute phenylephrine 1mg in 9mL NS for final concentration of 100mcg/mL
      • For 500 mcg/ml, take 0.5 ml of 10mg/ml phenylephrine, and dilute in 9.5 cc NS
    • Inject base of penis with 29-Ga needle (after blood aspiration to confirm position)
      • 100-500 mcg every 3-5min (max 1000 mcg) until resolution or 1 hour
      • Ensure patient on the monitor, with BP, HR, pulse ox
      • Reflex bradycardia is expected, so consider dosages relative to toleration of drop from baseline HR
      • Only one side needs to be injected since there exists a vascular channel between the 2 corpora cavernos
    • Compress injection area to prevent hematoma formation
    • Use with caution in cardiovascular disease

Wrap penis in elastic bandage after detumescence is achieved

High Flow Priapism

  • Requires urologic consultation for surgical correction or IR guided embolization[5]

Sickle Cell Disease

  • IV hydration
  • O2
  • Transfusion for goal HCT>30% with consultation for partial exchange transfusion (HGB-S<30%)
    • Exchange transfusion is associated with ASPEN syndrome (Association of Sickle cell Priapism, Exchange transfusion & Neurological events)
  • Urology consult


  • Admit if refractory to treatment or need or IR or surgical intervention
  • May discharge home if treatment is successful with close follow-up by urology



  1. Miller ST, Rao SP, Dunn EK, Glassberg KI. Priapism in children with sickle cell disease. J Urol. Aug 1995;154(2 Patient 2):844-7
  2. reen J, Hakim L. Cocaine-induced veno-occlusive priapism: importance of urine toxicology screening in the emergency room setting. Clin Urol. 1999;161
  3. Quan D, Ruha AM. Priapism associated with Latrodectus mactans envenomation. Am J Emerg Med. Jul 2009;27(6):759.e1-2
  4. Lowe FC, Jarow JP. Placebo-controlled study of oral terbutaline and pseudoephedrine in management of prostaglandin E1-induced prolonged erections. Urology. Jul 1993;42(1):51-3
  5. Sandro C. High-flow priapism: treatment and long-term follow-up. 2002. 59(1).110–113 PDF