eMedicine Specialties > Emergency Medicine > Genitourinary

Priapism

Colin M Dougherty, MD, Staff Physician, Department of Emergency Medicine, Tri-City Medical Center; Staff Physician, Department of Emergency Medicine, Kaiser-Permanente, San Diego Medical Center/Kaiser Foundation Hospital
Allison J Richard, MD, Assistant Professor of Emergency Medicine, Keck School of Medicine, University of Southern California; Associate Director, Division of International Medicine; Attending Physician, Los Angeles County-University of Southern California Hospital Emergency Department; Martin J Carey, MD, MB, BCh, MPH, FACEM, FRCS, Program Director, Assistant Professor, Department of Emergency Medicine, University of Arkansas for Medical Sciences

Updated: Nov 17, 2009

Introduction

Background

Priapism is the presence of a persistent, usually painful, erection of the penis unrelated to sexual stimulation or desire. It is a true urologic emergency that may lead to permanent erectile dysfunction and penile necrosis if left untreated. Priapism is frequently idiopathic in etiology but is associated with a number of important medical conditions and pharmacologic agents.

Pathophysiology

Priapism is the result of persistent engorgement of the corpora cavernosa of the penis, originating from a disturbance in the mechanisms that control normal penile detumescence. In most cases, the ventral corpora spongiosum and glans penis remain flaccid.

Priapism. Corporeal relaxation causes external pressure on the emissary veins exiting the tunica albuginea, trapping blood in the penis and causing erection.

Two types of priapism are generally described.¹ Arterial high-flow priapism usually is secondary to a rupture of a cavernous artery and unregulated flow into the lacunar spaces. This rare type of priapism is usually not painful and results from penetrating penile trauma or a blunt perineal injury. Low-flow priapism is usually due to full and unremitting corporeal veno-occlusion where venous stasis and deoxygenated blood pools within the cavernous tissue. Prolonged veno-occlusive priapism results in fibrosis of the penis and a loss of the ability to achieve an erection. Significant changes at the cellular level are noted within 24 hours in veno-occlusive priapism, whereas arterial priapism is not associated with fibrotic change.

Frequency

United States

In one study, 38-42% of adult patients with sickle cell disease reported at least one episode of priapism.

International

The overall incidence of priapism is 1.5 cases per 100,000 person-years, which increases to 2.9 cases per 100,000 person-years for men older than 40 years.^2,1

Mortality/Morbidity

• Deaths have been reported in patients with sickle cell disease presenting with priapism, but the cause of death usually is not related to the priapism per se but to complications from the underlying disease process.
• Morbidity is related to long-term impotence, primarily with veno-occlusive priapism, when diagnosis and therapy have been delayed.

Race

No racial predilection exists. Sickle cell disease, which predisposes to the development of priapism, occurs more frequently in the African American population.

Sex

Priapism is primarily a disease of males. Priapism of the clitoris has been reported but is extremely rare.

Age

• Priapism has been described at nearly all ages, from infancy through old age. A bimodal distribution between 5 and 10 years in children and 20-50 years in adults is noted.¹
• Younger groups are more often associated with sickle cell disease, while older groups tend to be secondary to pharmacologic agents.

Clinical

History

• History of thromboembolic (eg, sickle cell disease) or neoplastic disease
• Drug history, including injectable medications used for erectile dysfunction such as papaverine, phentolamine, and prostaglandin E1; antipsychotic oral medications use (eg, trazodone)
• Recent illicit drug use (Cocaine, ecstasy, and marijuana use have been associated.)
• History of trauma or activities that may result in the formation of an arterial-venous fistula or shunt (eg, bicycle riding)
• Degree of pain may help to differentiate between high and low flow varieties of priapism.
• Arterial high-flow priapism
  • Priapism secondary to arterial causes also may be significantly less painful than venous priapism.
  • Onset of priapism may be delayed after the acute injury. The delay may be due to vessel spasm initially or to the formation of a clot that is gradually reabsorbed over a period of days.
  • Priapism secondary to arterial causes usually is less tumescent when compared with venous priapism.
• Veno-occlusive priapism
  • Patients with veno-occlusive priapism present with a painful erection.
  • Erection may have been present for hours to days.

Physical

• Presence of priapism should be confirmed by the finding of an erect or semierect penis. The ventral glans and corpus spongiosum are rarely rigid.
• Carefully examine for evidence of trauma or unreported injection sites to the genital region.
• Examine the patient for evidence of an underlying condition that may predispose to priapism.
• Piesis sign - Perineal compression with thumb in young children causes prompt detumescence in high-flow priapism.

Causes

• Medications
  • Only rare case reports of selective cyclic guanosine monophosphate (cGMP) inhibitors such as sildenafil have been associated with priapism. In fact, several case reports suggest sildenafil as a means to treat priapism and may be able to prevent full-blown episodes from occurring in patients with sickle cell disease.
  • Some patients may use injectable medications to induce an erection. In these patients, excessive use may produce priapism. Examples of agents used to induce an erection include papaverine, phentolamine, and prostaglandin E1.
  • Many psychotropic medications such as chlorpromazine, trazodone, quetiapine, and thioridazine have been associated with priapism. The newer agents are not immune to this complication. Priapism has been described with citalopram, a selective serotonin reuptake inhibitor.
  • Rebound hypercoagulable states with anticoagulants such as heparin and warfarin have been associated. Hydralazine, metoclopramide, omeprazole, hydroxyzine, prazosin, tamoxifen, and androstenedione for athletic performance enhancement.
  • Cocaine, marijuana, and ethanol abuse - The complication has been described in patients using ecstasy.³
• Thromboembolic
  • Sickle cell disease and thalassemia
  • Leukemia and multiple myeloma
• Trauma (pelvic, genital, or perineal)
• Neoplastic (may be primary or metastatic)
• Neurologic
  • Spinal cord injury and anesthesia
  • Cauda equina compression syndrome
• Infection
  • Recent infection with Mycoplasma pneumoniae (Mechanism is thought to be a hypercoagulable state induced by the infection.)
  • Malaria
• Other causes
  • Fabry disease (rare association, occasionally noted to be priapism of the high-flow type) and amyloidosis
  • Carbon monoxide poisoning, black widow spider bites,⁴ and vigorous sexual exercise have been implicated.

Differential Diagnoses

Other Problems to Be Considered

Peyronie disease
Urethral foreign body
Penile surgical implant
Erection from sexual arousal

Workup

Laboratory Studies

• In patients with no known predisposing factors, a complete blood count (CBC) is appropriate in order to identify the rare case of priapism associated with leukemia.
• Patients with sickle cell disease should have a CBC and a reticulocyte count. If sickle cell status is unknown, a hemoglobin S determination may be useful
• An ABG of the cavernous is useful in differentiating between high and low flow disease. Values similar to venous blood suggest a low-flow etiology. Values similar to arterial blood suggest high-flow priapism.
• Coagulation profile
• Platelet count
• Urinalysis

Imaging Studies

• Color flow penile Doppler imaging is currently the study of choice to differentiate high-flow from low-flow priapism.
• In patients with high-flow priapism, selective penile angiography may be required in order to identify the site of the fistula.

Procedures

• Aspiration/injection of the corpus cavernosum
  • First perform a penile nerve block, injecting around the entire base of the penile shaft with 1% lidocaine without epinephrine.
  • After anesthesia is ensured, use a 19-gauge needle attached to a large syringe and puncture the corpus cavernosum. This should be performed through the shaft of the penis laterally to avoid the corpus spongiosum and urethra ventrally and the neurovascular bundle dorsally.
  • Aspirate 20-30 mL of blood from either the 2-o'clock or 10-o'clock position while milking the shaft. Because multiple communications exist from one corpus to the other, aspiration usually is required only on one side.
  • If aspiration or injection is successful in producing detumescence, place an elastic bandage around the shaft of the penis to ensure continued emptying of the corpora and to compress the puncture site.
  • Aspiration alone has a success rate of around 30%. If this procedure is not successful, phenylephrine, epinephrine, or methylene blue may be instilled into the corpus cavernosa.

Treatment

Prehospital Care

Any patient who has an erection for longer than 4 hours, especially if he has a predisposing illness (eg, sickle cell disease) probably should receive therapy for priapism. Most cases, if seen early enough in their course, respond to conservative measures.

• Examples of immediate treatment that can be suggested prior to arrival at the hospital may include the use of ice packs to the perineum and penis or asking the patient to walk up stairs.
  • The mechanism for the latter strategy is thought to be an arterial steal phenomenon.
  • External perineal compression may also be a useful temporizing measure in the ED or prehospital setting.
  • If these measures fail to produce rapid detumescence, patients should not delay transfer to the hospital.

Emergency Department Care

Attempt to treat the underlying etiology whenever possible. Treatment for priapism secondary to sickle cell disease includes hydration, alkalization, analgesia, and oxygenation to prevent further sickling. Hypertransfusion and/or exchange transfusions may be required to increase hemoglobin concentration to higher than 10% and decrease hemoglobin S to less than 30% have a high rate of success but may produce serious neurologic side effects.
 
Clinical practice guidelines on treatment of priapism are available from the American Urological Association.⁵

• Low-flow (vaso-occlusive) priapism
  • Some studies suggest that the use of terbutaline orally, at a dose of 5-10 mg, followed by another 5-10 mg 15 minutes later, if required, produces resolution in about one third of patients. This may be a reasonable treatment option when preparing the infusion. If no resolution occurs within 30 minutes, injection therapy is required.
  • Oral pseudoephedrine, 60-120 mg orally has also been suggested as a potential therapy due to its alpha-agonist effect. The exact efficacy of this medication orally is unknown.
  • If oral therapy fails, aspiration of the corpus cavernosum and intracavernous injection of alpha-adrenergic agents or methylene blue is the next line of therapy.
  • If this procedure is not successful, phenylephrine, epinephrine,⁶ or methylene blue may be instilled into the corpus cavernosa.
  • If initial aspiration of the corpus cavernosum reveals bright red blood rather than the dark venous blood, consider an arterial cause for priapism and institute the steps noted below.
• High-flow (arterial) priapism
  • Observation alone may be sufficient as erectile function is usually unimpaired.¹ Compression therapy may be successful in certain cases, especially children.
  • Selective angiography with subsequent embolization of the offending vessel has been shown to be effective with few long-term complications in some studies. Patients who do not respond to more conservative measures may benefit from this approach.
  • Surgical ligation of the fistula may be required. However, potential complications of this procedure include long-term impotence.

Consultations

Early consultation with a urologist is recommended, especially when less-invasive measures in the ED fail to resolve priapism or high-flow condition is suspected.

Medication

Phenylephrine, an alpha-agonist, is very effective in the management of priapism, especially priapism due to iatrogenic injection. Terbutaline is also effective in some cases. The exact mechanism is not clear.

Alpha-adrenergic agonists

These agents have been used successfully in the treatment of priapism, possibly due to their sympathomimetic vasopressor activity.

Phenylephrine (Neo-Synephrine)

A strong postsynaptic alpha-receptor stimulant with little beta-adrenergic activity that produces vasoconstriction of arterioles in the body. Increases peripheral venous return. The drug is best administered in a dilute solution; add 10 mg (usually 1 mL) of phenylephrine to 499 mL of saline 0.9%, yielding a solution with 20 mcg/mL.
Primary benefit in treatment of priapism is vasoconstrictive properties.

Dosing

Adult

100-500 mcg/dose, up to 10 doses; use 10-20 mL of 20 mcg/mL solution via intracavernous injection q5-10min
Alternatively, mix 1000 mcg phenylephrine in 100 mL of isotonic sodium chloride solution (10 mcg/mL) and infuse 10-20 mL at a time; if unable to infuse, inject phenylephrine directly in 200- to 500-mcg aliquots; not to exceed 1500 mcg

Pediatric

Administer as in adults

Interactions

Bretylium may potentiate action of vasopressors on adrenergic receptors, possibly resulting in arrhythmias; MAOIs may significantly enhance adrenergic effects of phenylephrine, and pressor response may be increased 2- to 3-fold;
Guanethidine may increase pressor response of direct-acting vasopressors, possibly resulting in severe hypertension

Contraindications

Documented hypersensitivity; severe hypertension or ventricular tachycardia

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in elderly patients, hyperthyroidism, myocardial disease, bradycardia, partial heart block or severe arteriosclerosis; in hypovolemia, use is not a substitute for replacement of blood, fluids and electrolytes, and plasma (these should be restored promptly when loss has occurred)

Pseudoephedrine (Sudafed)

Stimulates vasoconstriction by directly stimulating alpha-adrenergic receptors.

Dosing

Adult

60-120 mg PO may be given in cases of priapism of short duration (2-4 h)
Primary benefit in treatment of priapism is vasoconstrictive properties

Pediatric

Not established

Interactions

Propranolol, MAO inhibitors and sympathomimetic agents may increase toxicity of pseudoephedrine; methyldopa and reserpine may reduce effects of pseudoephedrine

Contraindications

Documented hypersensitivity; severe anemia, postural hypertension or hypotension, closed angle glaucoma, head trauma, or cerebral hemorrhage

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in cardiovascular disease, diabetes mellitus, prostatic hypertrophy and increased intraocular pressure

Beta-adrenergic agonists

Agent has been shown to be effective, but the reason is not yet fully elucidated.

Terbutaline (Brethaire, Bricanyl)

Selective beta2-adrenergic agonist used successfully in the treatment of priapism.

Dosing

Adult

5 mg PO, repeated after 15 min; 0.25-0.5 mg SC

Pediatric

<12 years: Not established
>12 years: Administer as in adults

Interactions

Concomitant use with beta-blockers may inhibit bronchodilating, cardiac, and vasodilating effects of beta agonists; concomitant administration of MAOIs with beta-sympathomimetics may result in a hypertensive crisis; concurrent administration of oxytocic drugs such as ergonovine with terbutaline may result in severe hypotension

Contraindications

Documented hypersensitivity; tachycardia resulting from cardiac arrhythmias

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Through intracellular shunting, terbutaline may decrease serum potassium levels, which can produce adverse cardiovascular effects; decrease is usually transient and may not require supplementation

Guanylate cyclase inhibitors

Have second messenger inhibitory effect, affecting muscle relaxation.

Methylene blue (Urolene Blue)

Inhibits smooth muscle relaxation.

Dosing

Adult

1-2 mg/kg IV slowly over 5 min

Pediatric

Not established

Interactions

None reported

Contraindications

Documented hypersensitivity; renal insufficiency

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

In G-6-PD deficiency, can cause profound anemia; do not inject into the CNS

Follow-up

Further Inpatient Care

• Patients with refractory priapism should be admitted to the hospital under the care of a urologist.

Further Outpatient Care

• Ensure adequate follow-up care with a urologist if therapy in the emergency department is successful.
• Some patients may have recurrent priapism. These patients may have a home supply of terbutaline. Instruct these patients on how to self-administer this medication either as a 5-mg tablet or a 0.25-0.5 mg SC prior to presentation. A small study by Abern and Levine describes successful use of ketoconazole and prednisone for treatment of recurrent priapism.⁷

Transfer

• If a urologist is not available at the presenting institution, transfer patients with priapism who do not respond to ED maneuvers to an appropriate tertiary care center where a urologist is available.

Complications

• A major complication of priapism is long-term impotence. Warn all patients of this possible complication. The fact that this warning was given should be recorded in the chart and clearly written on the discharge instruction sheet. In general, vaso-occlusive priapism has a higher risk of impotence than high-flow arterial priapism.

Prognosis

• Most patients respond to therapeutic measures.
• In high-flow priapism, patients may require surgical intervention to correct the problem.
• Deaths in patients with priapism are usually related to complications from the underlying problem (eg, leukemia, sickle cell disease).

Patient Education

• Warn patients with a predisposing condition for priapism of the symptoms and signs of the condition. Instruct them to report to the nearest ED should priapism develop.

Miscellaneous

Medicolegal Pitfalls

• Intervention for vaso-occlusive erections lasting greater than 4 hours duration should be initiated as soon as possible.
• Failure to warn patients of the long-term incidence of impotence is a major concern.
• Careful monitoring of patients at risk of complications due to the use of vasoactive medications should be instituted. Alpha-agonists may cause significant systemic hypertension.

Special Concerns

• Priapism in females is extremely rare but has been described.
• No single therapy has been shown to be effective. Consider terbutaline in the first instance and consultation with a urologist.
• Congenital neonatal priapism may result from birth trauma or other conditions at birth.
• Stuttering or recurrent priapism may occur in patients with sickle cell trait or disease. Usually self-limiting in nature, over time episodes may lead to erectile dysfunction.

Multimedia

Media file 1: Priapism. Corporeal relaxation causes external pressure on the emissary veins exiting the tunica albuginea, trapping blood in the penis and causing erection.

References

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2. Eland IA, van der Lei J, Stricker BH, Sturkenboom MJ. Incidence of priapism in the general population. Urology. May 2001;57(5):970-2. [Medline].

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6. 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. [Medline].

7. Abern MR, Levine LA. Ketoconazole and prednisone to prevent recurrent ischemic priapism. J Urol. Oct 2009;182(4):1401-6. [Medline].

8. Bastuba MD, Saenz de Tejada I, Dinlenc CZ, et al. Arterial priapism: diagnosis, treatment and long-term followup. J Urol. May 1994;151(5):1231-7. [Medline].

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14. Ilkay AK, Levine LA. Conservative management of high-flow priapism. Urology. Sep 1995;46(3):419-24. [Medline].

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16. Lee M, Cannon B, Sharifi R. Chart for preparation of dilutions of alpha-adrenergic agonists for intracavernous use in treatment of priapism. J Urol. Apr 1995;153(4):1182-3. [Medline].

17. Lowe FC, Jarow JP. Placebo-controlled study of oral terbutaline and pseudoephedrine in management of prostaglandin E1-induced prolonged erections. Urology. Jul 1993;42(1):51-3; discussion 53-4. [Medline].

18. Lue TF. Physiology of penile erection and pathophysiology of erectile dysfunction and priapism. In: Walsh PC, et al, eds. Campbell's Urology. 7^th ed. Philadelphia, Pa: WB Saunders Co; 1997:1157-79.

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Keywords

priapism, priapism causes, priapism treatment, painful erection, erectile dysfunction, intracavernous injection, arterial high-flow priapism, veno-occlusive priapism, painful erection of the penis, sickle cell disease, impotence

Contributor Information and Disclosures

Author

Colin M Dougherty, MD, Staff Physician, Department of Emergency Medicine, Tri-City Medical Center; Staff Physician, Department of Emergency Medicine, Kaiser-Permanente, San Diego Medical Center/Kaiser Foundation Hospital
Colin M Dougherty, MD is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.

Coauthor(s)

Allison J Richard, MD, Assistant Professor of Emergency Medicine, Keck School of Medicine, University of Southern California; Associate Director, Division of International Medicine; Attending Physician, Los Angeles County-University of Southern California Hospital Emergency Department
Disclosure: Nothing to disclose.

Martin J Carey, MD, MB, BCh, MPH, FACEM, FRCS, Program Director, Assistant Professor, Department of Emergency Medicine, University of Arkansas for Medical Sciences
Martin J Carey, MD, MB, BCh, MPH, FACEM, FRCS is a member of the following medical societies: American College of Emergency Physicians, American Medical Association, British Medical Association, and Fellowship of the Australasian College for Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Lance W Kreplick, MD, MMM, FAAEM, FACEP, Medical Director of Hyperbaric Medicine, Fawcett Wound Management and Hyperbaric Medicine; Consulting Staff in Occupational Health and Rehabilitation, Company Care Occupational Health Services; President and Chief Executive Officer, QED Medical Solutions, LLC
Lance W Kreplick, MD, MMM, FAAEM, FACEP is a member of the following medical societies: American Academy of Emergency Medicine and American College of Physician Executives
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Richard H Sinert, DO, Associate Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, Research Director, State University of New York College of Medicine; Consulting Staff, Department of Emergency Medicine, Kings County Hospital Center
Richard H Sinert, DO is a member of the following medical societies: American College of Physicians and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Robert E O'Connor, MD, MPH, Professor and Chair, Department of Emergency Medicine, University of Virginia Health System
Robert E O'Connor, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Physician Executives, American Heart Association, American Medical Association, Medical Society of Delaware, National Association of EMS Physicians, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

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