Priapism Flashcards
what is it?
Priapism is a persistent penile erection, typically defined as lasting longer than 4 hours and is not associated with sexual stimulation
how is it categorised?
ishcaemia
non-ischaemic
cause of ischaemic priapism?
impaired vasorelaxation and therefore reduced vascular outflow resulting in congestion and trapping of de-oxygenated blood within the corpus cavernosa.
cause of non-ishcaemic priapism?
high arterial inflow, typically due to fistula formation often either as the result of congenital or traumatic mechanisms.
epidemiology
Age at presentation has a bimodal distribution, with peaks between 5-10 years and 20-50 years of age
causes
Idiopathic
Sickle cell disease or other haemoglobinopathies
Erectile dysfunction medication (e.g. Sildenafil and other PDE-5 inhibitors), this also includes intracavernosal injected therapies.
Other drugs both prescribed (anti-hypertensives, anticoagulants, antidepressants etc) and recreational (specifically cocaine, cannabis and ecstasy).
Trauma
presentation
A persistent erection lasting over 4 hours
Pain localised to the penis
Often a history of either known haemoglobinopathy or use of medications listed above
Patients may, more rarely, present with either a non-painful erection or an erection that is not fully rigid: these are both suggestive of non-ischaemic priapism.
History of trauma to the genital or perineal region: also suggestive of non-ischaemic priapism.
ix
Cavernosal blood gas analysis to differentiate between ischaemic and non-ischaemic: in ischaemic priapism pO2 and pH would be reduced whilst pCO2 would be increased.
Doppler or duplex ultrasonography: this can be used as an alternative to blood gas analysis to assess for blood flow within the penis.
A full blood count and toxicology screen can be used to assess for an underlying cause of the priapism.
Diagnosis of priapism is largely clinical, with investigations helping to categorise into ischaemic and non-ischaemic as well as assessing for the underlying cause.
mx of ischaemic priapism
Ischaemic priapism is a medical emergency and delayed treatment can lead to permanent tissue damage and long-term erectile dysfunction.
If the priapism has lasted longer than 4 hours,
the first-line treatment is aspiration of blood from the cavernosa, this is often combined with injection of a saline flush to help clear viscous blood that has pooled.
If aspiration and injection fails, then intracavernosal injection of a vasoconstrictive agent such as phenylephrine is used and repeated at 5 minute intervals.
If medical therapy fails then surgical options can be considered.
mx of non-ischaemic priapism
is not a medical emergency and is normally suitable for observation as a first-line option.
mx of non-ischaemic priapism
is not a medical emergency and is normally suitable for observation as a first-line option.
