Priapism

Background

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

Types

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

Causes

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

Clinical Features

• Erect corpus cavernosum
• Flacid glans and spongiosum

Differential Diagnosis

• Peyronie's Disease
• Urethral foreign body
• Penile surgical implant
• Erection from sexual arousal
• Latrodectus envenomation (Black widow)

Non-Traumatic penile diagnoses

• Phimosis
• Balanoposthitis
• Paraphimosis
• Priapism
• STDs

Penile trauma types

• Penile amputation
• Penile contusion
• Penile fracture
• Traumatic epididymitis
• Zipper injury to penis

Evaluation

• 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

Management

• Pain control: Morphine and/or penile nerve block

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
   • 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
3. Epinephrine
   • In pediatric population , intracavernosal injection of epinephrine instead of phenylephrine as it has been shown to be more successful in achieving detumescence in priapism.

Wrap penis in elastic bandage after detumescence is achieved

High Flow Priapism

• Requires urologic consultation for surgical correction or IR guided embolization

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

Disposition

• 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

Video

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