What is priapism and how is it treated?

Priapism: What It Is and How It's Treated

Priapism is a medical emergency defined as a persistent penile erection lasting more than 4 hours that is unrelated to sexual stimulation and requires immediate medical attention to prevent permanent erectile dysfunction. 1, 2

Types of Priapism

There are three main types of priapism:

1. Ischemic (low-flow) priapism:

   • Most common type (95% of cases)
   • Painful, rigid erection
   • Blood trapped in penis becomes hypoxic, hypercarbic, and acidotic
   • TRUE EMERGENCY requiring immediate treatment
   • Characterized by PO₂ <30 mmHg, PCO₂ >60 mmHg, and pH <7.25 2

2. Non-ischemic (high-flow) priapism:

   • Usually caused by trauma
   • Not fully rigid or painful
   • Not an emergency
   • Normal blood gas values 1

3. Stuttering (intermittent) priapism:

   • Recurrent episodes of painful erections
   • Often seen in patients with sickle cell disease
   • Requires prevention strategies 1

Why Immediate Treatment is Critical

Time is critical with ischemic priapism:

• Smooth muscle edema and atrophy begin as early as 6 hours
• After 18 hours, significant risk of permanent erectile dysfunction
• After 36 hours, extremely low likelihood of erectile function recovery 2

Diagnosis

To determine the type of priapism:

1. History: Duration of erection, presence of pain, previous episodes, medication use, trauma history, and underlying conditions like sickle cell disease 2

2. Physical examination: Assess rigidity of corpora cavernosa and whether corpus spongiosum and glans penis are involved 2

3. Corporal blood gas analysis: Essential to differentiate ischemic from non-ischemic priapism 2

Treatment of Ischemic Priapism

Treatment follows a stepwise approach:

1. First-line treatment:

   • Aspiration of blood from the corpora cavernosa using a 19-21 gauge butterfly needle
   • May include irrigation with normal saline
   • Intracavernosal injection of phenylephrine (100-500 μg diluted in saline)
   • This combined approach has a resolution rate of 43-81% 2

2. Second-line treatment (if first-line fails):

   • Surgical shunting procedures
   • Distal shunts (66-74% success rate)
   • Al-Ghorab procedure (excision of both tips of corpora cavernosa) is considered most effective 2

3. Third-line treatment:

   • Proximal shunting (76-77% success rate) if distal shunting fails 2

Special Considerations

Sickle Cell Disease

• Standard urologic management should not be delayed for disease-specific interventions
• Treat priapism first with standard approaches (phenylephrine injection, aspiration)
• Consider simple transfusion to raise hemoglobin to 9-10 g/dL if surgical shunting is needed 2

Medication-Induced Priapism

• PDE5 inhibitors like sildenafil and tadalafil can rarely cause priapism
• Patients taking these medications should seek emergency medical attention for erections lasting more than 4 hours 3, 4

Treatment of Non-Ischemic Priapism

• Not an emergency
• Initial management is observation
• Selective arterial embolization (74% success rate) if treatment is requested 2, 5

Follow-up and Counseling

• Patients must be informed about the high risk of erectile dysfunction with prolonged priapism
• Follow-up evaluation for erectile function recovery
• Assessment for underlying causes (medications, hematologic disorders, malignancies) 2

Monitoring During Treatment

• During phenylephrine administration, monitor for hypertension, bradycardia, tachycardia, and arrhythmias
• More careful monitoring needed in patients with cardiovascular disease 2

Key Warning Signs for Patients

If you experience an erection lasting longer than 4 hours:

• Seek immediate medical attention
• Do not wait, as delay increases risk of permanent erectile dysfunction
• This is especially important for patients taking medications for erectile dysfunction 3, 4

Remember that priapism is a true urological emergency that requires prompt evaluation and treatment to preserve future erectile function.