Written by: Aaron Quarles, MD (EM Resident Physician, PGY-3, NUEM), Emmanuel Ogele, MS4, Northwestern University Feinberg School of Medicine ; Edited by: Meghan Quigley, MD (NEUM 2017 Graduate); Expert Commentary by: Nelson Bennett, Jr., MD
An otherwise healthy 36 year old man presents to the emergency department late on a Saturday night. You enter the exam room to find a man who appears anxious and cannot seem to get comfortable. He immediately informs you that he is in the adult film industry and they were doing a shoot earlier in the day. He states that he took Viagra, but was unable to achieve an erection as rapidly as needed. So he injected an intracavernosal prostaglandin E1 with rapid and resolute effect.
Despite the popular refrain to “seek immediate medical help for erections lasting more than 4 hours,” your patient waited until hour 9 before presenting. He was thorough, however, in his attempt to detumesce; employing such strategies as repeated masturbation, warm baths, alcohol, and even cocaine (the latter two may actually cause priapism!).
Physical exam revealed an extremely firm, fully erect penis that was painful to touch. The glans was soft and not discolored. At this point, all the patient can say is, “Please doc, you have to help me.”
A Bit About Priapism
Priapism is most commonly defined as an erection lasting longer than 4 hours and is unrelated to sexual stimulation. Between 2006 and 2009, somewhere between 5 and 8 visits per 100,000 male subjects to the emergency department (ED) in the United States were due to priapism. In adult males, erectile dysfunction drugs are the usual culprit, accounting for up to 25% of presentations. There is also a notable increase in incidence during the summer months and in patients with sickle cell disease, leukemia, pelvic tumors, & trauma [1,2,3].
What is the pathophysiology behind this condition?
Ischemic priapism occurs secondary to obstruction of venous outflow. The nitric oxide-phosphodiesterase-5 (NO-PDE5) pathway has been implicated in the pathogenesis of ischemic priapism. Dysregulation of this pathway leads to failure to control vasodilation, which in turn leads to prolonged arterial inflow and subsequent obstruction of venous outflow. This causes prolonged erection and ischemia in the penis [3,4].
Non ischemic priapism is not caused by obstruction but rather is due to extravasation of blood into the corpus cavernosum from an arterial fistula. This is less common than the ischemic variant and often happens in the setting of trauma to the perineum (think bicycle seats and other straddle injuries).
A third type of priapism, known as stuttering priapism, represents unwanted intermittent erections usually lasting 3 hours and confined mostly to the sickle cell population. Given its veno-occlusive pathophysiology, stuttering priapism is akin to a self-limited ischemic priapism. These patients are sometimes managed with self-injection of sympathomimetic agents.
How can I distinguish between the types of priapism and why is it important to do so?
It is important to distinguish ischemic from non-ischemic priapism because ischemic priapism is a urologic emergency. This is the first step in management. In ischemic priapism, microscopic changes begin to occur at 4 hours of persistent erection and irreversible fibrotic damage occurs after 24 hours. 90% of cases lasting over 24 hours develop erectile dysfunction with severe impairment in sexual function, which is why early intervention along with counseling the patient on likely outcomes is critical.
Is a physical exam necessary for patient presenting with priapism?
Although presentation is usually self-evident, a fast, focused physical examination of the genitals, perineum and abdomen are warranted. Ischemic priapism will usually present with a painful, tender and a fully rigid phallus. Non-ischemic is usually less rigid and less painful. Abdominal and perineal inspection are helpful to rule out any other traumatic injuries.
Management in the ED
Once the diagnosis of ischemic priapism has been made, intervention is required to prevent long term dysfunction. Underlying conditions such as sickle cell, should be considered and treated as appropriate (hydration, O2 etc), but they should not delay treatment of priapism. A general approach to management of ischemic priapism is demonstrated below:
Analgesia → Systemic Vasodilators → Direct Vasoconstrictor → Aspiration/Irrigation → Urologic surgery
Provide oral or parenteral analgesia as appropriate. You may consider systemic vasodilators such as terbutaline (Roberts and Hedges recommends 0.25 to 0.5 mg subQ q15minutes; or 5mg PO once). However, the AUA guidelines suggest no indication for oral systemic vasodilators given limited efficacy. And let’s be honest, the next steps provide significantly more bang for your buck.
Both the European and American Urological Associations recommend cavernosal aspiration and intracavernosal sympathomimetic injection as the treatment of choice. When sympathomimetic injection was added to aspiration and irrigation there was a significant associated increase in resolving priapism .
But first, provide local anesthesia. A dorsal penile nerve block can be achieved using a 27-gauge needle and 1% lidocaine (without epinephrine). Raise a skin wheal at the 10 and 2 o’clock positions of the penis as close to the base as possible. Inject through the wheals in a medial direction, being careful to avoid cavernous artery injury. Alternatively a subcutaneous ring block over the dorsal aspect of the penis is effective. Or simply anesthetize the skin on either side of the mid penile shaft where you anticipate entering for aspiration. Be careful to avoid superficial veins.
Next, sterilely attach a 19 or 21 gauge butterfly needle to a syringe or tubing irrigation system of your choice (a useful video demonstrating a convenient way to set up aspiration and irrigation tubing by Dr. Larry Melick ).
Direct the butterfly needle into the now anesthetized 10 or 2 o’clock position of your choice and begin to aspirate. Advance carefully until you get return of dark venous blood. The corpora communicate, so in most cases, only one side needs to be aspirated. If one side isn’t working, try the other. After about 30-60 cc’s of blood are removed, if priapism persists, irrigation with 10-20 ml aliquots of saline or a diluted phenylephrine solution may be attempted. Continue with this approach until the dark venous blood becomes bright red or until flaccidity is achieved.
Alternatively, direct injections of phenylephrine diluted to a concentration of 100-500 mcg/mL dosed in 1 mL injections can be performed every 3-5 minutes. Treatment failure is considered after one hour of these injections. Patients should be placed on a cardiac monitor while administering these medications given the risk of systemic effects (severe hypertension, dysrhythmia). Proceed with caution in those patients with such underlying conditions.
If these methods fail, urgent urological consultation is required for possible placement of a corpus cavernosum-spongiosum shunt.
Pearl: Phenylephrine is less capable of binding its receptor in acidotic conditions. Thus in patients presenting with 2-3 days of sustained erection, although one should try Phenylephrine as first line, keep in mind this patient will most likely need surgery and should be moved to the OR faster.
Pearl: For patients with a positive history of sickle cell disease, ischemic priapism is managed in the same way it is when caused by other etiologies. In addition, narcotic analgesia, IV hydration, supplemental oxygen, and alkalization is indicated.
Non – ischemic Priapism
Non-ischemic priapism is not an emergency. Management consists of observation with the expectation that it will resolve spontaneously.
Pitfall: Injection of sympathomimetics is not recommended as arterial flow will distribute the drug promptly into systemic circulation. In the setting of trauma, other injuries should be managed accordingly. If non – ischemic priapism does not resolve spontaneously, it can be treated by embolization of the fistula in the IR suite .
Following successful aspiration, observation is recommended. The patient may be sent home with urology follow up.
Pearls and Pitfalls:
- A good history can often distinguish between ischemic and nonischemic priapism
- Time is functional penis
- Providing proper analgesia is critical, dorsal penile nerve block makes you and your patient’s life easier
- Intracorporeal injection = intravenous injection (patients should be placed on a monitor when administering vasoactive agents & caution should be taken in severe hypertension, dysrhythmias, etc)
- Be mindful that this can be embarrassing and traumatic for patients so care should be taken in addressing the patient as a whole
Definition and Etiology
Priapism, a prolonged erection lasting more than 4 hours in the absence of sexual stimulation, is a urologic emergency that can result in ischemia, corporal fibrosis, and erectile dysfunction. The duration of corporal ischemia results in variable reversible and irreversible smooth muscle and endothelial injury with histologic changes seen by 12 hours. After 48 hours of ischemia, there is permanent smooth muscle cell death and erectile dysfunction[16-18]. Incidence of all-cause priapism has been reported between 0.3 per 100,000 person-years up to 2.9 per 100,000 person-years.
Although the etiology of priapism is not completely understood, it is believed to be a failure of detumescence. Many disease states have been associated with priapism, including hematologic disorders, malignancy, neurologic disorders, trauma, infection, medications, recreational drugs (see Table 1)[15, 17]. Evaluation should include a complete history, physical exam, CBC with differential, hemoglobin electrophoresis, and urine toxicology screen.
For the proper management of priapism, it is important to distinguish between ischemic and non-ischemic subtypes. Ischemic priapism is comparable to a compartment syndrome causing hypoxia of the corpora cavernosa that is typically painful and requires emergent intervention to preserve erectile function. Non-ischemic priapism is a high-flow state that is typically not painful and resolves spontaneously. Non-ischemic priapism is more often associated with trauma. A cavernous blood gas can be performed to differentiate the two. Patients with ischemic priapism will have hypoxia with pH <7.25, pCO2 >60 mmHg, and pO2 >30 mmHg. Blood gas results for patients with non-ischemic priapism will be consistent with normal arterial blood gases. The blood gas on a detumesced penis would be consistent with a mixed venous blood gas.
The practical aspects of priapism treatment deserve special comment. Understand that the patient will be embarrassed, anxious, and in pain. Do everything needed to ensure patient comfort and privacy.
- Prior to performing any treatment, obtain informed consent for treatment of priapism.
- Place patient on a cardiac and BP monitor.
- Administer a dorsal penile nerve block with 1-2% lidocaine using a 25-27G needle.
- Insert the needle at the base of the penis at the 10 o’clock position. Advance the needle towards the opposite side of the shaft (2 o’clock). Make sure that you have not entered the corpora by gently aspirated.
- Deposit 10 mL of lidocaine into the penile shaft. Note the distention of Buck’s fascia when injecting the lidocaine. Allow approximately 10 minutes for the local anesthesia to reach full effect.
- Insert a 16 or 18 gauge needle into the penile shaft and aspirate 20 to 30 mL of blood. Irrigation with a saline solution is not routinely recommended as it rarely results in faster detumescence.
- Next, inject 1 mL of a diluted phenylephrine concentration (100-500 mcg/ml). This phenylephrine solution may be injected in 1 mL aliquots - no less than every five minutes
- Pay special attention to the cardiac and BP monitor as phenylephrine may cause reflex bradycardia and hypertension
There is no upper limit in the amount of phenylephrine that can be injected. However, practically it may take 10 to 15 mL to achieve detumescence or to decide that surgical intervention is needed.
- Once the penis is detumesced, it should be wrapped loosely with gauze and non-adhesive dressing (Coban).
- The patient should be monitored in the emergency department for at least another hour to ensure continued penile detumescence.
Nelson Bennett, Jr, MD
Associate Professor, Department of Urology, Northwestern University, Feinberg School of Medicine
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How to Cite this Blog Post
[Peer-Reviewed, Web Publication] Quarles A, Ogele E, Quigley M(2017, July 4). Priapism: The ED Focused Appropach. [NUEM Blog. Expert Commentary By Bennett N]. Retrieved from http://www.nuemblog.com/blog/priapism
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