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Emergency And Acute Medicine – Priapism
Priapism is a prolonged penile erection involving engorgement of the corpora cavernosa that occurs in the absence of sexual arousal and is often painful. It is classified into low-flow (ischemic) and high-flow (nonischemic) types. Low-flow priapism is the most common and results from impaired venous outflow, leading to stagnant, hypoxic blood within the corpora cavernosa. It is typically painful and constitutes a urologic emergency because ischemia and thrombosis can occur within hours, with subsequent fibrosis and permanent erectile dysfunction as late complications. High-flow priapism is rare and results from arterial laceration, usually following trauma, causing uncontrolled arterial inflow. It is typically painless, presents later, and is less likely to result in ischemia or erectile dysfunction.
The etiology of priapism includes idiopathic causes, medications, hematologic disorders, trauma, and systemic disease. Intracavernosal agents used for erectile dysfunction—such as prostaglandin E1, papaverine, and phentolamine—are common pharmacologic causes. Psychotropic medications including phenothiazines, butyrophenones, trazodone, sedative–hypnotics, and selective serotonin reuptake inhibitors are implicated, as are antihypertensives such as prazosin and hydralazine. Phosphodiesterase inhibitors such as sildenafil, tadalafil, and vardenafil are rarely associated. Recreational drugs including cocaine, marijuana, and ethanol, as well as toxins such as Black Widow or scorpion venom, have also been reported. Hematologic disorders that increase blood viscosity—particularly sickle cell anemia (the most common cause overall and in children), leukemia, multiple myeloma, and polycythemia—predispose to low-flow priapism. Penile or perineal trauma may lead to high-flow priapism, while spinal trauma can disrupt inhibitory adrenergic tone. Rare causes include pelvic tumors, infiltrative diseases, dialysis, and parenteral nutrition containing fat emulsions.
Diagnosis is clinical. Low-flow priapism presents with a painful, rigid erection and often a history of medication use or hematologic disease. High-flow priapism is typically painless and associated with penile trauma. Examination should assess for penile implants, signs of trauma including urethral or rectal injury, and urinary retention. Laboratory and imaging studies should not delay urgent urologic consultation. Laboratory evaluation may include complete blood count, coagulation studies, and sickle cell testing when indicated. Duplex Doppler ultrasound can help identify arterial injury in high-flow priapism, and angiography can localize and treat arterial lacerations. Intracavernosal blood gas analysis differentiates the types: low-flow priapism shows acidosis and hypoxia (pH <7.25, po₂ <30 mm hg), whereas high-flow priapism demonstrates near-normal values.< />pan>
Initial management includes oxygen, analgesia, sedation, and intravenous hydration. Urgent urologic consultation is required. Underlying causes should be addressed concurrently. In sickle cell disease, treatment may include hydration, oxygenation, and packed red blood cell transfusion or exchange transfusion. Leukemia requires oncologic management. High-flow priapism from arterial injury may be managed expectantly or with angiographic embolization.
Low-flow priapism often requires intracavernosal aspiration and sympathomimetic injection. If specialty care is unavailable, the emergency physician may perform the procedure using sterile technique. After local anesthesia or penile nerve block, a 19-gauge butterfly needle is inserted laterally into the corpus cavernosum at the 2- or 10-o’clock position to avoid the urethra and dorsal neurovascular bundle. Blood is aspirated slowly while milking the shaft until brighter arterial blood appears, often requiring removal of 30–50 mL. Saline irrigation may be used. Phenylephrine is the preferred agent for intracavernosal injection due to fewer systemic effects; it should be diluted and administered in small boluses with cardiac and blood pressure monitoring. Injections may be repeated every 5–15 minutes for up to one hour. Epinephrine may be used as a second-line agent. Terbutaline may be administered subcutaneously or orally as adjunctive therapy but is often insufficient alone. Surgical shunting may be required if conservative measures fail.
Admission is indicated for persistent priapism despite initial treatment or for patients with serious underlying conditions such as sickle cell disease or leukemia. Patients may be discharged after complete detumescence and several hours of observation without recurrence, provided urologic consultation has occurred. All patients require short-term urologic follow-up, evaluation of underlying conditions, and discontinuation of offending medications. They should be advised to return immediately if erection recurs.
Timely intervention is critical to reduce the risk of permanent erectile dysfunction. Management of underlying conditions should not delay definitive penile decompression. Intracavernosal vasoactive medications should not be injected during partial tumescence due to risk of systemic absorption and hypertensive complications. Even with prompt treatment, patients must be counseled about the possibility of future erectile dysfunction and this discussion should be documented carefully.
Priapism is a prolonged penile erection involving engorgement of the corpora cavernosa that occurs in the absence of sexual arousal and is often painful. It is classified into low-flow (ischemic) and high-flow (nonischemic) types. Low-flow priapism is the most common and results from impaired venous outflow, leading to stagnant, hypoxic blood within the corpora cavernosa. It is typically painful and constitutes a urologic emergency because ischemia and thrombosis can occur within hours, with subsequent fibrosis and permanent erectile dysfunction as late complications. High-flow priapism is rare and results from arterial laceration, usually following trauma, causing uncontrolled arterial inflow. It is typically painless, presents later, and is less likely to result in ischemia or erectile dysfunction.
The etiology of priapism includes idiopathic causes, medications, hematologic disorders, trauma, and systemic disease. Intracavernosal agents used for erectile dysfunction—such as prostaglandin E1, papaverine, and phentolamine—are common pharmacologic causes. Psychotropic medications including phenothiazines, butyrophenones, trazodone, sedative–hypnotics, and selective serotonin reuptake inhibitors are implicated, as are antihypertensives such as prazosin and hydralazine. Phosphodiesterase inhibitors such as sildenafil, tadalafil, and vardenafil are rarely associated. Recreational drugs including cocaine, marijuana, and ethanol, as well as toxins such as Black Widow or scorpion venom, have also been reported. Hematologic disorders that increase blood viscosity—particularly sickle cell anemia (the most common cause overall and in children), leukemia, multiple myeloma, and polycythemia—predispose to low-flow priapism. Penile or perineal trauma may lead to high-flow priapism, while spinal trauma can disrupt inhibitory adrenergic tone. Rare causes include pelvic tumors, infiltrative diseases, dialysis, and parenteral nutrition containing fat emulsions.
Diagnosis is clinical. Low-flow priapism presents with a painful, rigid erection and often a history of medication use or hematologic disease. High-flow priapism is typically painless and associated with penile trauma. Examination should assess for penile implants, signs of trauma including urethral or rectal injury, and urinary retention. Laboratory and imaging studies should not delay urgent urologic consultation. Laboratory evaluation may include complete blood count, coagulation studies, and sickle cell testing when indicated. Duplex Doppler ultrasound can help identify arterial injury in high-flow priapism, and angiography can localize and treat arterial lacerations. Intracavernosal blood gas analysis differentiates the types: low-flow priapism shows acidosis and hypoxia (pH <7.25, po₂ <30 mm hg), whereas high-flow priapism demonstrates near-normal values.< />pan>
Initial management includes oxygen, analgesia, sedation, and intravenous hydration. Urgent urologic consultation is required. Underlying causes should be addressed concurrently. In sickle cell disease, treatment may include hydration, oxygenation, and packed red blood cell transfusion or exchange transfusion. Leukemia requires oncologic management. High-flow priapism from arterial injury may be managed expectantly or with angiographic embolization.
Low-flow priapism often requires intracavernosal aspiration and sympathomimetic injection. If specialty care is unavailable, the emergency physician may perform the procedure using sterile technique. After local anesthesia or penile nerve block, a 19-gauge butterfly needle is inserted laterally into the corpus cavernosum at the 2- or 10-o’clock position to avoid the urethra and dorsal neurovascular bundle. Blood is aspirated slowly while milking the shaft until brighter arterial blood appears, often requiring removal of 30–50 mL. Saline irrigation may be used. Phenylephrine is the preferred agent for intracavernosal injection due to fewer systemic effects; it should be diluted and administered in small boluses with cardiac and blood pressure monitoring. Injections may be repeated every 5–15 minutes for up to one hour. Epinephrine may be used as a second-line agent. Terbutaline may be administered subcutaneously or orally as adjunctive therapy but is often insufficient alone. Surgical shunting may be required if conservative measures fail.
Admission is indicated for persistent priapism despite initial treatment or for patients with serious underlying conditions such as sickle cell disease or leukemia. Patients may be discharged after complete detumescence and several hours of observation without recurrence, provided urologic consultation has occurred. All patients require short-term urologic follow-up, evaluation of underlying conditions, and discontinuation of offending medications. They should be advised to return immediately if erection recurs.
Timely intervention is critical to reduce the risk of permanent erectile dysfunction. Management of underlying conditions should not delay definitive penile decompression. Intracavernosal vasoactive medications should not be injected during partial tumescence due to risk of systemic absorption and hypertensive complications. Even with prompt treatment, patients must be counseled about the possibility of future erectile dysfunction and this discussion should be documented carefully.
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