USMLE Prep - Medical Reference Library

Ischemic Priapism — Aspiration and Phenylephrine

System: Urology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Painful erection lasting more than 4 hours is a urologic emergency; aspirate corporal blood and inject phenylephrine promptly.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Priapism Ischemic Management, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC (Baseline hematology), BMP (Electrolytes/renal). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include Analgesia/Antipyretics. Use validated frameworks (e.g., Key Interventions) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Epidemiology / Risk Factors

  • Risk factors vary by condition and patient profile

Investigations

TestRole / RationaleTypical FindingsNotes
CBCBaseline hematologyAbnormal counts
BMPElectrolytes/renalDerangements

Key Interventions

StepAction
Aspiration18 gauge needle at 3 or 9 o clock
IrrigationWarm normal saline
PhenylephrineSmall aliquots every few minutes with monitoring

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
Phenylephrine (intracavernosal)α1 agonistMinutesIschemic priapism first-lineHypertension, reflex bradycardia
AnalgesiaPain controlMinutesAdjunctSedation

Prognosis / Complications

  • Prognosis depends on severity, comorbidities, and timeliness of care

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

Notes

Treat sickle cell associated priapism with hydration, oxygen, and hematology input. Avoid terbutaline and pseudoephedrine as primary ED therapy.


References

  1. AUA Priapism Guideline — Link
  2. Emergency Urology References — Link