Priapism

Clinical definition[1]Bivalacqua TJ, Allen BK, Brock GB, et al. The diagnosis and management of recurrent ischemic priapism, priapism in sickle cell patients, and non-ischemic priapism: an AUA/SMSNA guideline. J Urol. 2022 Jul;208(1):43-52. https://www.auajournals.org/doi/10.1097/JU.0000000000002767 http://www.ncbi.nlm.nih.gov/pubmed/35536142?tool=bestpractice.com

Priapism is defined as a prolonged and persistent penile erection lasting >4 hours, unassociated with sexual interest or stimulation. Stuttering or recurrent priapic episodes may last <4 hours and occur at increasing frequencies.

Pathophysiological criteria[1]Bivalacqua TJ, Allen BK, Brock GB, et al. The diagnosis and management of recurrent ischemic priapism, priapism in sickle cell patients, and non-ischemic priapism: an AUA/SMSNA guideline. J Urol. 2022 Jul;208(1):43-52. https://www.auajournals.org/doi/10.1097/JU.0000000000002767 http://www.ncbi.nlm.nih.gov/pubmed/35536142?tool=bestpractice.com [4]European Association of Urology. Guidelines: sexual and reproductive health. 2022 [internet publication]. https://uroweb.org/guidelines/sexual-and-reproductive-health#9

Ischaemic priapism

• Corpus cavernosum testing: blood is hypoxic and dark in colour

• Blood gases: pO₂ <30 mmHg, pCO₂ >60 mmHg, and pH<7.25

• Colour duplex ultrasonography: minimal or absent blood flow.

Non-ischaemic priapism

• Corpus cavernosum testing: blood is oxygenated and red

• Blood gases: pO₂ >90 mmHg, pCO₂ <40 mmHg, and pH of 7.40 (similar to normal arterial blood)

• Colour duplex ultrasonography: blood flow is normal to high in velocity.

Stuttering (recurrent) priapism

• Corpus cavernosum testing: blood is hypoxic and dark in colour

• Blood gases: pO₂ <30 mmHg, pCO₂ >60 mmHg, and pH<7.25

• May show defective phosphodiesterase-5 regulatory function in the penis, resulting from altered/dysfunctional nitric oxide and cyclic guanosine monophosphate signalling mechanisms that control erectile function.