Emergency Department Management of Priapism (Pharmacology CME)

Table of Contents

 

1. Abstract
2. Case Presentations
3. Introduction
4. Critical Appraisal of the Literature
5. Etiology And Pathophysiology
   1. Ischemic Priapism
   2. Nonischemic Priapism
   3. Recurrent Ischemic Priapism
6. Differential Diagnosis
7. Prehospital Care
8. Emergency Department Evaluation
   1. History
   2. Physical Examination
9. Diagnostic Studies
   1. Corporal Blood Gas Testing
   2. Penile Color Duplex Ultrasonography
   3. Laboratory Analysis
10. Treatment
    1. Surgery
    2. Treatment Of Recurrent Ischemic Priapism
    3. Treatment Of High-Flow Priapism
11. Special Populations
    1. Elderly Patients And Patients With Cardiovascular Disease
    2. Pediatric Patients
    3. Patients With Inflatable Penile Prosthesis
12. Controversies And Cutting Edge
13. Disposition
    1. Resolved Ischemic Priapism
    2. Unresolved Ischemic Priapism
    3. High-Flow And Stuttering Priapism
14. Summary
15. Risk Management Pitfalls For Management Of Priapism
16. Time- And Cost-Effective Strategies
17. Case Conclusions
18. Clinical Pathway For The Management Of Priapism
19. Tables And Figures
    1. Figure 1. Cross-Section Of The Human Penis
    2. Figure 2. Visual Depiction Of Erectile Physiology
    3. Figure 3. Longitudinal Color Duplex Ultrasonography In High-Flow Priapism
    4. Figure 4. Two Approaches To Aspiration Of The Corpus Cavernosum
    5. Figure 5. Schematic Of Inflatable Penile Prosthesis
    6. Table 1. Differential Diagnosis For Priapism
    7. Table 2. Key Distinguishing Features Of Priapism
20. References

Abstract

Priapism is a genitourinary emergency that demands a thorough, time-sensitive evaluation. There are 3 types of priapism: ischemic, nonischemic, and recurrent ischemic priapism; ischemic priapism accounts for 95% of cases. Ischemic priapism must be treated within 4 to 6 hours to minimize morbidity, including impotence. The diagnosis of ischemic priapism relies heavily on the history and physical examination and may be facilitated by penile blood gas analysis and penile ultrasound. This issue reviews current evidence regarding emergency department treatment of ischemic priapism using a stepwise approach that begins with aspiration of cavernosal blood, cold saline irrigation, and penile injection with sympathomimetic agents. Evidence-based management and appropriate urologic follow-up of nonischemic and recurrent ischemic priapism maximizes patient outcomes and resource utilization.

Case Presentations

A 53-year-old man with a history of hemoglobin SS (HbSS) sickle cell disease presents with 5 hours of a persistent, painful erection. This is the third time this has occurred in the past 2 years. Prior to presentation, he took pseudoephedrine tablets that were prescribed by his urologist, with no improvement. He denies fevers, chills, or trauma. He appears to be in a moderate amount of pain and his physical examination is notable for a fully erect penis that is tender to palpation, without lesions or discharge. You wonder: How long does it take for irreversible tissue damage to occur?

As you are deciding on your first course of action, the paramedics bring in a 22-year-old man who was just in a bicycle accident. He had a flat tire that caused him to fall on his bicycle, striking his groin on the handle bars. He was wearing a helmet, did not lose consciousness, and has no neck tenderness. His examination is otherwise normal, apart from superficial abrasions to his extremities and a semirigid phallus that is more embarrassing than painful to him. It persists despite his attempts to apply local pressure. After performing a more detailed physical examination, you note that there is some bruising and swelling to his perineum and the base of his penis. His testicles are mildly tender, but the cremasteric reflex is present bilaterally. You note no blood at the meatus. You have never seen anything like this, and you wonder: What are your priorities for the diagnosis and management of this patient?

Introduction

Genitourinary complaints account for approximately 5% of emergency department (ED) visits in the United States,¹ and one of the most serious of these emergencies is a man presenting with priapism.^1,2 Priapism is defined as a persistent penile erection that continues hours beyond, or is unrelated to, sexual stimulation.^3,4 There are 3 main types of priapism:

• Ischemic (also referred to as “low-flow” priapism)
• Nonischemic (also referred to as “high-flow” priapism)
• Recurrent ischemic priapism (also referred to as “intermittent” or “stuttering” priapism)

Ischemic priapism represents a penile compartment syndrome, thus making it a true emergency requiring rapid intervention. Ischemic changes begin within 12 hours of a maintained erection, beginning with interstitial edema that progresses to denuding of the sinusoidal endothelium and thrombocyte adhesion at 24 hours. After approximately 48 hours, smooth-muscle necrosis occurs, and fibroblast-type cells proliferate.⁵ After 48 hours of ischemic priapism, 100% of patients develop some level of irreversible fibrosis of the corpus cavernosum that negatively affects their erectile function and can lead to permanent impotence.

The incidence of ischemic priapism ranges from 1 to 5 cases in 100,000 men, though it is higher in subsets of the population, particularly in men with sickle cell disease.^6,7 The lifetime risk of ischemic priapism for a man with sickle cell disease is 29% to 42%.⁸

The diagnosis and management of priapism is a core competency of the emergency clinician. This issue of Emergency Medicine Practice provides a review of the literature and best-practice recommendations on how to manage this condition and optimize patient outcomes.

Critical Appraisal Of The Literature

A literature search was performed using PubMed and the Cochrane Database of Systematic Reviews with the search terms priapism, ischemic, high flow, stuttering, impotence, and sickle cell. From the Cochrane library, 69 trials involving priapism were identified. A Cochrane review regarding priapism in which only 1 study met inclusion criteria was found,² and, not surprisingly, no conclusions regarding the benefits and risks of the different treatments for both stuttering and fulminant priapism in males with sickle cell disease could be drawn.⁹

The majority of literature on priapism consists of case reports, case series of well-established therapies, retrospective chart reviews, and position papers. Both the European Association of Urology (EAU)⁴ and the American Urological Association Guidelines Committee³ have published practice guidelines based on a panel of expert opinions. Recently, there have been several review articles summarizing treatment guidelines and practice standards.^10-13 There are ongoing studies describing experimental therapies for recurrent and fulminant priapism.¹⁴ The 2014 EAU guidelines remain the most current and comprehensive literature summary to date; it included 192 review articles, 485 original articles, and 911 case reports.

Risk Management Pitfalls For Management Of Priapism

1. “My patient clearly had high-flow priapism and was comfortable for discharge, so I didn’t run the case by the urologist.”
   Despite the low risk of long-term erectile dysfunction with nonischemic priapism, emergency clinicians should discuss the case with an urologist to establish close follow-up.
    
2. “I had a patient with sickle cell disease and a bedside Doppler ultrasound consistent with ischemic priapism. That’s why I didn’t perform a blood gas analysis.”
   Color Doppler ultrasound is a useful diagnostic adjunct, but should not replace blood gas analysis in ischemic priapism. Note that it is recommended to perform color Doppler ultrasound in cases of penile trauma.
    
3. “My patient with sickle cell disease told me that all he needed for his priapism to resolve was some fluid, oxygen, and pain control. I didn’t want to perform an invasive procedure if he didn’t need it.”
   Definitive therapy for priapism means inserting a needle into the corpus cavernosum. You can supplement your management of ischemic priapism with fluids and oxygen, but these therapies should neither delay nor take the place of aspiration and penile injection.
    
4. “My patient had a clear history of using an intracavernosal vasoactive medication about 5 hours ago. That’s why I went straight to injection with phenylephrine.”
   Despite an accurate history, the exact etiology will not be elucidated until more data are collected. Furthermore, progressing down the algorithm of aspiration and irrigation minimizes the potential systemic side effects of phenylephrine. Cold saline has been shown to be effective in up to 96% of cases of priapism resulting from intracavernosal injection of vasoactive medication.
    
5. “I had a pediatric patient with priapism and I recall phenylephrine being the drug of choice for injection. Do I need to modify the dose?”
   Phenylephrine is the drug of choice in children 11 years and older. Make sure to use a dilute solution of 100 mcg/mL and use 1 mL at a time. Remember that epinephrine is the drug of choice for younger patients. Use dilute epinephrine, 1 mcg/mL, to irrigate the corpora in boys between the ages of 2 and 11 years. Consult a specialist for children younger than 2 years.
    
6. “My patient achieved detumescence after just 1 round of phenylephrine. We were very busy that day, and he was a young patient, so I discharged him expeditiously.”
   Remember that if you inject the corpus cavernosum with a vasoactive agent, it is recommended to observe the patient for at least 1 hour. This also helps assure that your therapy was definitive and priapism does not reoccur.
    
7. “After aspiration of the corpus cavernosum, the patient detumesced. I withdrew the needle and asked the nurse to apply a compressive dressing. The patient developed a hematoma. Why?”
   After you withdraw the needle, apply firm pressure to the aspiration site to prevent hematoma formation. Place the dressing yourself, with ample gauze around the glans. You can place an ice pack over the gauze and use an adult diaper to keep everything in place.
    
8. “I was about to insert the needle, but I realized that the patient had an inflated penile prosthesis.”
   Although abnormal erections secondary to implantable prostheses are usually not painful and patients are usually aware of them, this scenario highlights the importance of performing a through history and physical examination before proceeding with treatment.
    
9. “I had a patient present after having priapism for 48 hours. I still proceeded with the usual treatment algorithm.”
   Patients who present after 36 hours of priapism should have immediate urologic consultation for consideration of placement of a penile prosthesis even if detumescence is achieved in the ED.
    
10. “The patient was in excruciating pain, so I began the aspiration without anesthesia. I was saving him an extra needle stick.”
    Taking the time to properly anesthetize the penis (preferably using ultrasound guidance) before aspiration will save the patient pain and discomfort later, especially if another aspiration approach or surgical shunt is required. If you wish to save the patient an extra needle stick, start with an 18-gauge angiocath and leave the catheter in place while you obtain blood gas samples; aspirate, and irrigate if necessary.

Tables And Figures

References

Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.

To help the reader judge the strength of each reference, pertinent information about the study is included in bold type following the reference, where available. The most informative references cited in this paper, as determined by the authors, are noted by an asterisk (*) next to the number of the reference.

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