0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:57
1206 Priapism■Signs of fever
■Abdominal or pelvic lymph nodes or masses
tests
■CBC, electrolytes and sickle cell prep or electrophoresis
■Aspiration of penile blood (from corpus cavernosum) for blood gas
determination
■Blood gas values of PO2 <40, PCO2 >60 and pH <7.25 suggest an
ischemic state.
■Blood gas values P02 >65, PC02 <40 and pH >7.3 suggest arterial
priapism.
■Color Doppler ultrasound of penis showing localized pooling of arte-
rial flow
➣Study of choice for arterial priapism
➣If positive, requires angiography to locate and embolize the rup-
tured arterydifferential diagnosis
Priapism should be distinguished from
■Penile carcinoma
■Penile induration
■Severe infection of penis
■Cavernositis
■Penile prosthesis
Causes of priapism
Idiopathic (50%)
■Medications
➣Penile injection with papaverine, phentolamine, alprostadil or
any combination
➣Phosphodiesterase-5 inhibitors (very rare) or intraurethral
alprostadil
➣Antidepressants (trazodone)
➣Antipsychotics (chlorpromazine, phenothiazine, clozapine)
➣Antihypertensives (hydralazine, prazosin, guanethidine)
➣Total parenteral nutrition (high fat content)
➣Drugs of abuse (alcohol, cocaine)
➣Anticoagulants (heparin, coumadin)
■Thrombotic/hyper-viscosity syndromes
■Hematologic conditions
➣Sickle cell disease or trait (up to 35% incidence)
➣Lymphoma
➣Leukemia (esp. CGL)
■Pelvic infections