Definitions
• Priapism is defined as a prolonged erection lasting generally >4 h in the absence of sexual stimulation
• Ischemic (low-flow) priapism is the most common subtype & is due to painful engorgement of the corpora cavernosa. This can lead to intracavernosal acidosis, sludging of blood, thrombosis of cavernal arteries, & impotence
• Nonischemia (high-flow) priapism is rare, painless, & is caused by increased arterial inflow to the penis as a result of traumatic arterial–cavernosal fistulas
History
• Painful, persistent erection lasting >4 h, not relieved by ejaculation
• RFs: SCD, leukemia, urogenital malignancies (prostate, bladder), CVA, spinal cord injury antihypertensives (hydralazine, prazosin, doxazosin), antidepressants (trazodone, fluoxetine, sertraline), antipsychotics (phenothiazines & atypicals), phosphodiesterase inhibitors, cocaine, toxins (scorpion, black widow, CO)
Physical Exam
• Obvious erection, generally involving only the corporal cavernosa & flaccid corpora spongiosum
Evaluation
• Labs: Preoperative labs if contemplating OR
• May send a blood gas from penile aspirate
Treatment
• Pain control
• To reduce flow/vasoconstriction:
• Oral/IM: Terbutaline 5 mg PO × 1; terbutaline 0.25–0.5 mg IM × 1 (unclear benefit)
• Intracavernosal phenylephrine injection: Using a 25- or 27-gauge needle (or tuberculin syringe), inject 0.2–0.5 mg of phenylephrine into corporus q10–15min (maximum 4–5 doses) 2 cm distal to origin of shaft on dorsal penis at 2- or 10-o’clock position
Note: Must dilute phenylephrine solution. Take phenylephrine 1% solution (10 mg/mL) & extract 1 mL (10 mg) from solution. Add this 1 mL to 9 mL of saline, which will give you 1 mg/mL of phenylephrine solution. You can then extract 0.2–0.5 mL (0.2–0.5 mg) of this for intracavernosal injection.
• If unsuccessful, aspiration/irrigation technique:
• Perform penile nerve block: On the dorsal aspect of the penis in the 2- & 10- o’clock positions, deposit 1% lidocaine; subsequently complete a ring block by depositing anesthetic circumferentially around the proximal shaft
• Prep & drape penis in sterile fashion
• At 2- or 10-o’clock position insert a 16–18 g needle (also consider 18-gauge dialysis butterfly access needle), & using a 10–30 mL syringe, slowly aspirate while milking corporus w/ other hand until return if bright red blood & detumescence occurs
• If this fails, you can attempt to irrigate by injecting 20–30 mL of phenylephrine & NS solution (10 mg phenylephrine in 500 mL NS) as exchange for 20–30 mL aspirate
• W/ sickle cell crisis: IVFs, O2, pain control, consider exchange transfusion
• Consult urology for refractory priapism (may necessitate surgical decompression)
Disposition
• Recommended to observe for at least 2 h to assess for recurrence
• Home: Once detumescence achieved. Recommended to d/c w/ 3-d course of oral α-adrenergic agent (pseudoephedrine)
• Admit: If priapism not responsive to ED tx
Pearls
• >12 h of priapism a/w onset of tissue demise w/ >24 h a/w permanent impotence
• Cx: Hematoma, infection, systemic absorption of vasoactive agents (severe HTN), recurrence, impotence (this risk should be discussed w/ pt & is a possibility despite efforts & timeliness of therapy)