Priapism

Background

• Prolonged, unwanted erection not a/w sexual stimulation > 4h
  
• May lead to erectile dysfunction and penile necrosis if untreated
• 2 types:
  • 1. High-flow (nonischemic)
    • AV fistula from trauma (lacerated cavernous artery shunts blood into cavernous bodies)
    • Usually not painful
    • Ischemia/impotence does not occur
  • 2. Low-flow (ischemic) - more common
    • Veno-occlusion causing pooling of deoxygenated blood in cavernous tissue
      • Assoc w/ sickle cell, meds, trauma, leukemia, infection, spinal cord injury/cauda equina, hypercoag
    • Painful
    • Fibrotic change leads to impotence

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

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
3. If sickle cell:
   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)
5. α/β-2 Agonists
   1. Terbutaline 0.25-0.5mg SQ in deltoids OR 5-10mg PO, may repeat in q20min
   2. Oral pseudoephedrine 60-120mg PO
6. Injection of phenylephrine
   1. Dilute phenylephrine in normal saline to provide final concentration of 100-500mcg/mL (1amp phenylephrine (1mL:1000mcg) with 9mL NS)
   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 (vascular channel b/w 2 corpora cavernosa)
   4. Compress injection area to prevent hematoma formation
   5. Use with caution in cardiovasc disease
7. Aspiration of corpus cavernosum
   1. Rarely beneficial after 48hr
   2. Local anesthesia at puncture
   3. Occasionally a penile block may be needed
      1. Use 27G needle for penile nerve block at 2 and 10 o'clock position at base of penis (or penile ring block)
   4. Aspirate blood from corpus cavernosum (3 or 9 o'clock position of shaft) w/ 16-19ga needle
      1. Blood sludging makes aspiration difficult, so to improve flow dynamics use saline irrigation and repeated aspirations
   5. After removal of 20-30cc of blood, you may inject and aspirate 10-20cc aliquots (200-500mcg) of a phenylephrine (10mg/500ml NS) or norepi (1mg/500cc NS) containing solution. If neither is available, epi can be used, but use caution due to adverse effects
   6. 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

• Tintinalli
• UpToDate
• emedicine
• Roberts