![[Pasted image 20240515191714.png]]
**Ischaemic priapism is a urologic emergency**
**causes**
- idiopathic
- medications
- intra-cavernosal injection
- [[Cocaine]]
- anti-psychotics: haloperidol and chlorpromazine, risperidone (alpha blocking)
- phosphodiesterase-5 (PDE5) inhibitors (sildenafil)
- ↑ nitric oxide
- tamsulosin (alpha-1 antagonist)
- adhd meds - methylphenidate and atomoxetine
- anticoagulants - heparin
- alpha antagonists - prazosin
- haematological diseases:
- [[Sickle Cell Anaemia]]
- leukemia
- thalassemia
- multiple myeloma
- [[Thrombotic Thrombocytopaenic purpura|TTP]]
- spinal trauma or local trauma
- [[Redback spider]]
- [[Multiple Sclerosis]]
- gout
- amyloidosis
- high flow → fistula
**complications**
- erectile dysfunction due to fibrosis
- impotence
- ischemic gangrene (rare)
- urinary retention
**Assessment**
- a duration of ==erection for 2-4 hours== in absence of sexual excitation is consistent with diagnosis of pripism
- pain
- ?trauma
- with priapism, the penis reveals engorged corpora cavernosa, but in contrast to normal erections, the corpus spongiosum and glans penis are often flacid
| classification | path | cause | Ix findings |
| ------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
| low-flow priapism | relaxation of smooth muscle of cavernosal tissue → ↑ inflow and ↓ venous outflow → intracorporal pressure increases to MAP → inflow of blood ceases | sildenafil, cocaine, leukemia, etc | - cavernous blood gas shows hypoxia, pH < 7.25, pCO2 > 60<br><br>- minimal / absent cavernosal arterial blood flow |
| high-flow priapism | unregulated cavernosus arterial inflow | needle injury to penis, blunt trauma, spinal injury | - normal blood gas from cavernous / bright red<br><br>- substantial arterial blood flow on doppler |
# Procedure
1. aspiration
1. 19g needle at 2 o'clock or 10 o'clock position
2. aspirate 20-30 mL of blood from one side, up to 100mL can be aspirated
3. usually 1 side is sufficient
2. saline irrigation
1. aspiration alone only has success of 30%
2. saline irrigation and repeated aspirations may improve flow dynamics
3. vasoconstrictor
1. **phenylephrine** → induce contraction of cavernous smooth muscle and permit venous outflow
2. dilute with NaCl to provide final concentration of *100mcg-500mcg* per mL
3. give 1 mL inra-cavernous injection of diluted phenylephrine every 3-5 min until resolution or up until 1 hour
4. use lower concentrations and smaller volumes in children or those with severe cardiovascular disease
5. monitor all patients
4. can use **metaraminal** *0.5mg* as an alternative injected with a butterfly needle Q5 min to max dose of 5mg while carefully monitoring BP Q5 min
5. failing above, refer to urology for surgical shunting
> all suspected high flow non-ischemic cases should be referred directly to urology (eg think they have arterial bleed)
# OSCE
- [ACEM 2024.1 station 6](x-devonthink-item://2B23D5A0-EFAA-4F67-87FD-F514106B2F45)