Definition for priapism: persistent penile erection that is unrelated to sexual stimulation or which persists for hours beyond any stimulation. Typically only the corpora cavernosa is affected.
For the AUA guidelines, the erection must persist for > 4 hours.
Types:
(1) ischemic
(2) nonischemic
Features of ischemic priapism:
(1) no or little cavernous blood flow
(2) the blood is both hypoxic and acidotic
(3) usually the penis is fully rigid
(4) usually the penis is painful and tender to palpation
(5) upon completion of the episode the penis may return to a completely flaccid state, or it may be show persistent edema, ecchymosis or partial rigidity
(6) may be idiopathic or may be associated with:
(6a) oral or injectable therapy for impotence
(6b) psychotropic prescription drugs like trazadone or chlorpromazine
(6c) alcohol or cocaine
(6d) sickle cell disease
(6e) leukemia or genitourinary neoplasm
(7) does require emergent therapy
Stuttering or intermittent priapism is a subtype of ischemic priapism in which episodes occur repeatedly with intervening periods of detumescence.
Features of nonischemic priapism:
(1) high cavernous blood flow with unregulated cavernous arterial inflow
(2) the blood is neither hypoxic nor acidotic
(3) usually the penis is not fully rigid
(4) usually the penis is not painful
(5) upon completion of the episode the penis returns to a completely flaccid state
(6) may be idiopathic or may following penile trauma
(7) does not require emergent therapy
