Low-flow priapism is a compartment syndrome of the penis resulting from a failure of detumescence. Ischemia after only 4 to 6 hours can lead to fibrosis and possible permanent erectile dysfunction. It can be due to sickle cell disease, medications, or illicit drugs. High-flow priapism is often due to a traumatic arteriocavernosal fistula and, although alarming, has a low risk for ischemia due to the preservation of oxygenated blood flow to the penis.
Management and Disposition
In low-flow priapism, the penis is at risk for irreversible ischemic damage after only a few hours and should be considered a urologic emergency. Subcutaneous terbutaline can be attempted, but 1st-line therapy is intracavernosal injection of phenylephrine with or without aspiration. Mix 1 mg in 9 mL of normal saline to make 100 µg/mL of solution. Up to 2000 µg may be needed, but small aliquots are recommended. Ensure the patient is on the monitor with blood pressure, heart rate, and pulse oximeter. A urologist should be consulted as operative intervention may be required. For high-flow priapism, consult urology; no emergent intervention is needed by the emergency provider.
Priapism. A painful persistent erection due to pathologic engorgement of the corpora cavernosa is seen in this patient with sickle cell disease. The glans penis and corpus spongiosum are not engorged. (Photo contributor: Kevin J. Knoop, MD, MS.)
Low-flow priapism (think “penile compartment syndrome”) is an emergency, and early therapy and urologic consultation can improve outcomes.
Suspect high-flow priapism in a patient with trauma and painless priapism.
Priapism. Aspiration of the corpora cavernosa is demonstrated. (Photo contributor: David Effron, MD.)
Traumatic Priapism. A persistent erection is seen in this trauma victim who has sustained a cord injury. (Photo contributor: R. Jason Thurman, MD.)
Priapism. Before (A) and after (B) aspiration and irrigation with phenylephrine in a patient with recurrent priapism due to risperidone. The involuntary erection had lasted for 10 hours and required 2000 µg of phenylephrine to achieve detumescence. An artificial right testicle also seen. (Photo contributor: Kevin J. Knoop, MD, MS.)