Priapism

Background

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

Types

High-flow (nonischemic)

• AV fistula from trauma (lacerated cavernous artery shunts blood into cavernous bodies)
• Usually not painful
• Ischemia/impotence does not occur

Low-flow (ischemic)

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

Causes

1. Sickle Cell disease
2. Medication induced
3. Leukemia
4. Infection
5. High rate of impotence afterwards if present for > 24hrs

ABG Analysis

• Low-flow priapism is suggested by aspirated blood with a pH of < 7.25, pO2 < 30 mmHg, and pCO2 > 60 mmHg

Clinical Features

• Erect corpus cavernosum
• Flacid glans and spongiosum

Work-Up

1. CBC   (eval leukemia, sickle cell)
2. Type and screen (may need to exchange transfusion)
3. Coags
4. Urinalysis/tox (etoh, marijuana, cocaine can cause priapism)
5. ABG from cavernosa (if hx unclear): Hypoxic, hypercapneic, acidotic → low flow
6. Ultrasound
   1. Can distinguish between high-flow and low-flow

DDx

1. Peyronie's Disease
2. Urethral foreign body
3. Penile surgical implant
4. Erection from sexual arousal
5. Latrodectus envenomation

Treatment

1. Written consent prior to invasive procedure
   1. Regardless of treatment there is a high risk of impotence
2. Pain control
   1. Morphine and/or penile block

Sickle Cell Disease

1. IV hydration
2. O2
3. Transfusion for goal HCT>30% with possible exchange transfusion (HGB-S<30%)
4. Urology consult (especially important with traumatic priapism)

Low Flow Priapism

Penile Block

• Often required prior to injections
• Use 27G needle for penile nerve block at 2 and 10 o'clock position at base of penis (or penile ring block)

Aspiration of corpus cavernosum

• Rarely beneficial after 48hr
• Local anesthesia at puncture
• Aspirate blood from corpus cavernosum (3 or 9 o'clock position of shaft) w/ 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
   1. Dose: 0.25-0.5mg SQ in deltoids OR 5-10mg PO, may repeat in q20min
2. Phenylephrine
   1. Dilute phenylephrine 1mg in 9mL NS for final concentration of 100mcg/mL
   2. Inject base of penis with 29-Ga needle (after blood aspiration to confirm position) 0.5-1mL q3-5min until resolution or one hour (max 1500mcg)
   3. Only one side needs to be injected since there exists a vascular channel between the 2 corpora cavernos
   4. Compress injection area to prevent hematoma formation
   5. Use with caution in cardiovascular disease

Wrap penis in elastic bandage after detumescence is achieved

Disposition

1. Admit if refractory to treatment
2. May dispo home if treatment is successful with close follow-up by urology

Source

• Dubin J, Davis JE. Penile emergencies. Emerg Med Clin North Am. Aug 2011;29(3):485-99
• Roberts JR, Price C, Mazzeo T. Intracavernous epinephrine: a minimally invasive treatment for priapism in the emergency department. J Emerg Med. Apr 2009;36(3):285-9