What is the appropriate management for ischemic priapism with significant hypoxemia, hypercapnia, and acidemia as indicated by penile arterial blood gas results?

Management of Ischemic Priapism with Blood Gas Values Confirming Ischemia

The blood gas values (PO2 of 30, PCO2 of 60, pH 7.25) confirm ischemic priapism requiring immediate intervention with corporal aspiration followed by phenylephrine injection to prevent permanent erectile dysfunction. 1, 2

Diagnosis Confirmation

The presented penile blood gas values match the diagnostic criteria for ischemic priapism:

• PO2 ≤30 mmHg (patient value: 30)
• PCO2 ≥60 mmHg (patient value: 60)
• pH <7.25 (patient value: 7.25)

These values indicate hypoxia, hypercapnia, and acidosis, confirming the diagnosis of ischemic priapism, which is a urological emergency requiring immediate treatment. 1, 2

Treatment Algorithm

Step 1: Corporal Aspiration with Irrigation

• Insert a 19-21 gauge butterfly needle into the lateral aspect of the proximal penis
• Aspirate old, dark blood from the corpus cavernosum
• Consider irrigation with normal saline
• This intervention alone resolves 24-36% of cases 2

Step 2: Intracavernosal Phenylephrine Injection

• If aspiration alone fails, proceed to phenylephrine injection
• Use phenylephrine 100-500 μg/mL diluted in normal saline
• Inject 1 mL every 3-5 minutes (maximum 1 mg in one hour)
• Monitor vital signs during administration due to potential cardiovascular effects
• Combined aspiration/irrigation with phenylephrine has 43-81% success rate 2, 3

Step 3: Surgical Shunting (if medical management fails)

• Proceed to distal shunting procedures first:
  • Winter shunt (percutaneous)
  • Ebbehoj shunt (percutaneous)
  • Al-Ghorab shunt (open)
  • T-shunt with tunneling
• If distal shunts fail, consider proximal shunts:
  • Quackels shunt
  • Grayhack shunt 1, 2

Step 4: Penile Prosthesis Placement

• For priapism episodes >48-72 hours
• Consider immediate penile prosthesis insertion to preserve penile length and avoid difficult delayed surgery through fibrotic tissue 2, 4

Treatment Considerations Based on Duration

• <4 hours: Intracavernosal phenylephrine alone may be sufficient
• 4-24 hours: Aspiration/irrigation with phenylephrine injection
• 24-48 hours: Begin with aspiration/irrigation and phenylephrine, but have lower threshold for proceeding to surgical shunting
• >48 hours: Consider more aggressive approaches including T-shunt with tunneling or immediate penile prosthesis placement 2

Important Cautions

• Do not delay penile-directed therapy while addressing potential underlying conditions
• Avoid using epinephrine instead of phenylephrine due to higher risk of cardiovascular side effects
• Monitor vital signs during sympathomimetic administration
• Inform patient that untreated ischemic priapism lasting >36 hours has high likelihood of permanent erectile dysfunction 2
• The longer the duration of priapism, the higher the risk of cavernosal fibrosis and subsequent erectile dysfunction 1, 5

Follow-up Care

• Counsel patient regarding potential need for future erectile dysfunction treatments
• Schedule follow-up to assess erectile function recovery
• Consider evaluation for underlying causes of priapism (medications, hematologic disorders, malignancies) 1, 2