Priapism
A painful erection lasting over 4 hours is a compartment syndrome of the penis. Decide whether it is ischaemic (painful, rigid, dark blood) or non-ischaemic (painless, often after trauma). Ischaemic priapism needs urgent urology: aspiration, then intracavernosal sympathomimetic, then surgery. Built for revision, not live patient decisions.
Settle them, and check the basics
ischaemic?Red flags — what each should make you think
Erectile function starts to be lost after about 24 hours of ischaemic priapism, and the chance of recovery falls steeply with time. Treat it like a compartment syndrome and call urology early.
Ischaemic priapism — first actions
- ☎Urology now
- 💊Analgesia
- 🩸Corporal blood gas
- 💉Aspiration ± irrigation
- PhIntracavernosal phenylephrine
- 🔪Surgical shunt
Understand the patient
ischaemic vs non-ischaemicTwo types
- Ischaemic (low-flow) — painful, rigid corpora, soft glans; blood gas: pO₂ low, pCO₂ high, pH low. Emergency
- Non-ischaemic (high-flow) — painless, partially rigid, often after perineal/penile trauma (arterial fistula); bright red, well-oxygenated blood. Not an emergency; Doppler, often resolves, embolisation if persistent
- Stuttering — recurrent painful episodes (often sickle cell); needs prevention plan
Causes
- Intracavernosal injections (alprostadil), PDE5 inhibitors
- Antipsychotics, trazodone, alpha-blockers, cocaine
- Sickle cell disease (most common cause in children)
- Leukaemia, malignancy infiltration, spinal cord injury
Work A–E — assess and act as you go
The diagnoses you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
Painful rigid erection over 4 hours.
Corporal blood gas.
Aspiration, intracavernosal phenylephrine, shunt surgery; early urology.
Known sickle cell disease, may be part of a wider crisis.
FBC, reticulocytes, corporal gas.
Urology treatment as above without delay, plus haematology input (hydration, analgesia, oxygen, consider exchange transfusion).
Investigate — what to order, when, and what it tells you
test with a question in mindCorporal blood gas
Bloods
Doppler USS
How the plan comes together
disposition · handoverhome
Resolved ischaemic priapism with detumescence maintained, or non-ischaemic: urology follow-up, review drugs, return if recurs.
admit / theatre
Failed aspiration/phenylephrine, sickle cell, prolonged duration.
Hand over: duration, gas result, treatment given and doses, monitoring.
Painful and rigid is ischaemic until a gas says otherwise. Call urology early, because erectile function depends on how quickly it's treated. Nicely done getting here.
Clerking template
copy or downloadPriapism — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.
Test yourself
active recallCover the answer, say it out loud, then reveal. Retrieval beats re-reading.
0 / 8 knownFrequently asked questions
quick answersWhat are the red flags for priapism?
- Painful, fully rigid, over 4 h — think ischaemic priapism — emergency
- Sickle cell disease — think ischaemic — urology + haematology
- Intracavernosal injection / PDE5 inhibitor — think drug-induced ischaemic
- Painless, partially rigid, after perineal trauma — think non-ischaemic (high-flow)
- Antipsychotics / trazodone — think drug-induced
- Leukaemia — think hyperviscosity
What is the initial management of priapism?
- Urology now — —
- Analgesia — consider a penile (dorsal) nerve block
- Corporal blood gas — dark blood; low O₂, high CO₂, acidotic = ischaemic
- Aspiration ± irrigation — by urology (or trained ED clinician)
- Intracavernosal phenylephrine — per protocol, with cardiovascular monitoring
- Surgical shunt — if aspiration and phenylephrine fail
Always alongside senior support and your local guideline.
What diagnoses must you not miss in priapism?
- Ischaemic priapism — time-critical
- Sickle cell priapism — sickle crisis
Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.
What investigations should a junior doctor order for priapism?
- Corporal blood gas — Dark blood, pO₂ below about 4 kPa, pCO₂ above about 8 kPa, pH below 7.25.
- Bloods — FBC (leukaemia, sickle), reticulocytes, clotting, drug screen if relevant.
- Doppler USS — Confirms high-flow fistula; supports diagnosis.
Admit or discharge: how is the plan decided for priapism?
- Home — Resolved ischaemic priapism with detumescence maintained, or non-ischaemic: urology follow-up, review drugs, return if recurs.
- Admit / theatre — Failed aspiration/phenylephrine, sickle cell, prolonged duration.
Is there a clerking template for priapism?
Yes — there is a clerking template for priapism on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.
Keep going
one more?More from Urology