Priapism was first described in the English literature in an 1824 case report by Callaway.1,2 Priapism is defined as a prolonged engorgement or erection of the penis or clitoris that lasts over 4 hours, occurs beyond sexual stimulation or arousal, or occurs apart from sexual stimulation or arousal.3 The term “priapism” derives its origin from the name of a minor Greek god of fertility and growth named Priapus.4 He was prenatally cursed by Hera with “out of proportion genitals, ugliness, lewdness, and impotence.” A famous Pompeiian fresco graphically illustrates Priapus’ plight as he weighs his massive phallus with a hanging scale.4 His humiliated and demoralized demeanor in ancient mythology seems to parallel that of many present-day afflicted patients.5
Priapism affects an estimated 5.34 cases per 100,000 person-years in the general US male population.6 It was present in 2.3% of Emergency Department visits by male sickle cell patients from 2006 to 2010.7 There is a predilection for presentation during the summer months.6 The most common form of priapism is often excruciatingly painful and is frequently embarrassing to the patient. This can result in delays seeking medical attention. Priapism can sometimes lead to permanent erectile dysfunction without swift and expert intervention.
Priapism is classified into the major subtypes of ischemic, nonischemic, and stuttering priapism (Table 178-1).8-11 Stuttering priapism is often associated with sickle cell anemia. It is critical that the Emergency Physician determines which subtype the patient has because emergent management and prognosis differ considerably.
TABLE 178-1The Clinical, Penile Blood Characteristics, and Color Doppler Flow Differences Between Ischemic and Nonischemic Priapism |Favorite Table|Download (.pdf) TABLE 178-1The Clinical, Penile Blood Characteristics, and Color Doppler Flow Differences Between Ischemic and Nonischemic Priapism
| ||Ischemic priapism ||Nonischemic priapism |
|Clinical characteristics || |
Less tense penis
|Penile blood characteristics || |
PaCO2 > 60 mmHg
PaO2 < 30 mmHg
pH < 7.25
Bright red appearance
PaCO2 < 60 mmHg
PaO2 > 30 mmHg
pH > 7.25
|Color Doppler flow pattern || |
Low arterial inflow
Low/no venous outflow
High arterial inflow
The presenting subtype is ischemic (i.e., low flow or vaso-occlusive) in 95% of priapism cases and poses the greatest risk of permanent penile dysfunction. This type of priapism is of the greatest concern to the Emergency Physician. It is generally thought to result from an impediment to blood emptying from the penis regardless of the etiology (Table 178-2).
TABLE 178-2Some Etiologies of Ischemic Priapism |Favorite Table|Download (.pdf) TABLE 178-2Some Etiologies of Ischemic Priapism
Erectile dysfunction agents