Priapism

Priapism = prolonged, often painful penile erection lasting >4 hours without sexual stimulation. Urological emergency – prolonged ischemia → irreversible erectile dysfunction if untreated. Prompt recognition and rapid management are essential to preserve function.

🔎 Causes

• Haematological: Sickle cell disease, Leukaemia
• Medications: Trazodone, Chlorpromazine, Lithium, recreational drugs (e.g. cannabis, cocaine)
• Intracavernosal injections: Papaverine, Alprostadil (for erectile dysfunction)
• Vascular: Pelvic thrombosis, trauma

⚡ Types

• Ischaemic (low-flow): Most common, painful, rigid. Venous outflow obstruction → hypoxia & acidosis. Emergency.
• Non-ischaemic (high-flow): Often post-trauma. Less painful, partially rigid. Usually not emergency, often resolves spontaneously.

🛠️ Management (Emergency for Ischaemic Priapism)

• Initial Measures:
  • Ice packs ❄️ and compression
  • Mild exercise (climbing stairs) to encourage venous drainage 🏃
  • Analgesia + sedation 💊
• Pharmacological:
  • First-line = Intracavernous phenylephrine (alpha-1 agonist) → vasoconstriction, improves outflow.
  • Other sympathomimetics (epinephrine, etilefrine) if phenylephrine not available.
  • Sickle-cell specific: Hydration 💧, O₂, opioids for pain, ± exchange transfusion.
• Mechanical:
  • Aspiration of stagnant blood from corpora cavernosa using large-bore needle 💉.
  • Irrigation with saline ± direct alpha-agonist infusion.
• Surgical (last resort):
  • Distal or proximal shunt procedures to bypass blocked venous drainage.
  • Penile prosthesis if prolonged refractory cases with necrosis/ED risk.

• Ischaemic priapism = emergency → immediate intervention needed.
• Non-ischaemic priapism = often post-traumatic, less urgent (observe ± embolisation).
• Sickle-cell patients → higher recurrence risk, treat both priapism & underlying crisis.
• Delay >24 hrs = very high risk of permanent erectile dysfunction.

Cases — Priapism

• Case 1 — Sickle Cell Disease (Ischaemic Priapism): A 19-year-old man with known sickle cell anaemia presents with a painful erection lasting >4 hours. He is distressed and reports previous brief episodes that resolved spontaneously. Diagnosis: Ischaemic priapism due to sickle cell vaso-occlusion. Management: Urgent urology referral; aspiration of corpora cavernosa ± intracavernosal phenylephrine. Supportive measures: hydration, oxygen, analgesia, treatment of sickle crisis.
• Case 2 — Drug-Induced Priapism: A 45-year-old man with schizophrenia develops a painful erection lasting 5 hours after starting trazodone. No history of haematological disease. Diagnosis: Drug-induced priapism (ischaemic). Management: Stop offending agent; urological emergency management as above (aspiration/phenylephrine); monitor for recurrence.
• Case 3 — Malignancy-Related (Leukaemia): A 32-year-old man with newly diagnosed acute leukaemia presents with persistent painful erection for 6 hours. FBC: WCC 180 ×10⁹/L. Diagnosis: Priapism due to hyperviscosity from haematological malignancy. Management: Urgent urological management; treat underlying cause with cytoreduction (hydroxyurea/leukapheresis); IV fluids and analgesia.

Teaching Commentary 🍆

Priapism is a prolonged, often painful erection (>4 hours) unrelated to sexual stimulation. Two main types: - Ischaemic (low-flow) — most common; medical emergency; causes include sickle cell disease, drugs (trazodone, antipsychotics, PDE5 inhibitors), haematological malignancy. - Non-ischaemic (high-flow) — usually post-trauma; less painful, semi-rigid penis, not an emergency. Key principle: urgent recognition and urology referral to prevent permanent erectile dysfunction. Initial steps: aspirate blood from corpora cavernosa (dark, hypoxic in ischaemic), irrigate with saline, and inject α-agonist (phenylephrine). Treat the underlying cause (e.g. sickle cell crisis, drug withdrawal, cytoreduction in leukaemia).