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Priapism (//) a potentially painful medical condition, in which the erect penis does not return to its flaccid state, despite the absence of both physical and psychological stimulation, within four hours. There are two types of priapism: low-flow and high-flow; 80% to 90% of clinically presented priapisms are low flow disorders. Low-flow involves the blood not adequately returning to the body from the organ. High-flow involves a short-circuit of the vascular system partway along the organ. Treatment is different for each type. Priapism is considered a medical emergency, which should receive proper treatment by a qualified medical practitioner. Early treatment can be beneficial for a functional recovery.
Not all sources give four hours as the guideline for priapism occurring: "The duration time of a normal erection before it is classifiable as priapism is still controversial. Ongoing penile erections for more than 6 hours can be classified as priapism..."
The causative mechanisms are poorly understood but involve complex neurological and vascular factors. Priapism may be associated with haematological disorders, especially sickle-cell disease, sickle-cell trait, and other conditions such as leukemia, thalassemia, and Fabry's disease, and neurologic disorders such as spinal cord lesions and spinal cord trauma (priapism has been reported in hanging victims; see death erection).
Priapism may also be associated with glucose-6-phosphate dehydrogenase deficiency, which leads to decreased NADPH levels. NADPH is a co-factor involved in the formation of nitric oxide, which may result in priapism. Raised levels of adenosine may also contribute to the condition by causing blood vessels to dilate, thus influencing blood flow into the penis.
Sickle cell disease often presents special treatment obstacles. Hyperbaric oxygen therapy has also been used with success in some patients. Priapism is also found to occur in extreme cases of rabies. Priapism can also be caused by reactions to medications. The most common medications that cause priapism are intra-cavernous injections for treatment of erectile dysfunction (papaverine, alprostadil). Other groups reported are antihypertensives, antipsychotics (e.g., chlorpromazine, clozapine), antidepressants (most notably trazodone), anticoagulants, cantharides (Spanish Fly) and recreational drugs (alcohol, heroin and cocaine). Priapism has also been linked to achalasia. Priapism is also known to occur from bites of the Brazilian wandering spider and the black widow spider. PDE-5 inhibitors have been evaluated as preventive treatment for recurrent priapism.
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Potential complications include ischemia, clotting of the blood retained in the penis (thrombosis), and damage to the blood vessels of the penis which may result in an impaired erectile function or impotence. In serious cases, the ischemia may result in gangrene, which could necessitate penis removal.
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Medical advice should be sought immediately for cases of erection beyond four hours. Generally, this is done at an emergency department. In sickle-cell anaemia patients with priapism, the first step in management is a blood exchange transfusion, not a surgical intervention. For other patients, orally administered pseudoephedrine may be effective, pseudoephedrine being an alpha-agonist, agent that exert a constriction effect on smooth muscle of corpora cavernosum, that in turn facilitate venous outflow. Likewise, other sympathomimetic drugs of the amphetamine class have been observed to induce erectile dysfunction, although in a small number of cases they may have the opposite effect. Otherwise, the therapy at this stage is to aspirate blood from the corpus cavernosum under local anaesthetic. If this is still insufficient, then intracavernosal injections of phenylephrine are administered. This should only be performed by a specialist trained in the procedure, with the patient under constant hemodynamic monitoring, as phenylephrine can cause severe hypertension, bradycardia, tachycardia, and arrhythmia.
Terbutaline being a beta-2 agonist causes smooth muscle relaxation; in priapism it probably acts by relaxation of the stretched corporeal smooth muscles, or increasing permeability of erectile cavernous tissue permitting easy flow of fluid from sinusoids into the venous system. In priapism, it was suggested to be administered orally.
Methylene blue is used intracavernously to treat priapism, but it should not be used in treatment of recurrent priapism or fibrosis because it can induce penile necrosis. Temporary blue discoloration of the penis is also of concern.
If aspiration fails and tumescence recurs, surgical shunts are next attempted. These attempt to reverse the priapic state by shunting blood from the rigid corpora cavernosa into the corpus spongiosum (which contains the glans and the urethra). Distal shunts are the first step, followed by more proximal shunts.
Distal shunts, such as the Winter's,[clarification needed] involve puncturing the glans (the distal part of the penis) into one of the cavernosa, where the old, stagnant blood is held. This causes the blood to leave the penis and return to the circulation. This procedure can be performed by a urologist at the bedside. Winter's shunts are often the first invasive technique used, especially in hematologic induced priapism, as it is relatively simple and repeatable over time.
Proximal shunts, such as the Quackel's,[clarification needed] are more involved and entail operative dissection in the perineum to where the corpora meet the spongiosum, making an incision in both, and suturing both openings together.
Shunts created between corpora cavernosa and saphenous vein called Grayhack shunt can be done though rarely.
As the complication of shortened, indurated and non-erectile penis is high in prolonged priapism, early penile prosthesis implantation can be performed. Apart from early resumption of sexual activity, early implantation can avoid the formation of dense fibrosis and hence a shortened penis.
In females 
- OED 2nd edition, 1989 as /'praɪəpɪz(ə)m/.
- Entry "priapism" in Merriam-Webster Online Dictionary.
- PRIAPISM – ETIOLOGY, PATHOPHYSIOLOGY AND MANAGEMENT, C. VAN DER HORST, HENRIK STUEBINGER, CHRISTOPH SEIF, DIETHILD MELCHIOR, F.J. MARTÍNEZ-PORTILLO, K.P. JUENEMANN; http://www.scielo.br/pdf/ibju/v29n5/18554.pdf
- Finley DS (December 2008). "Glucose-6-phosphate dehydrogenase deficiency associated stuttering priapism: report of a case". J Sex Med 5 (12): 2963–6. doi:10.1111/j.1743-6109.2008.01007.x. PMID 18823322.
- Mi T, Abbasi S, Zhang H, Uray K, Chunn JL, Xia LW, Molina JG, Weisbrodt NW, Kellems RE, Blackburn MR, Xia Y (April 2008). "Excess adenosine in murine penile erectile tissues contributes to priapism via A2B adenosine receptor signaling" (PDF). J. Clin. Invest. 118 (4): 1491–501. doi:10.1172/JCI33467. PMC 2267015. PMID 18340377. Lay summary – New Scientist.
- Macaluso JN (1985). "Priapism: Update for the non-urologist". Sexual Medicine Today 9: 11–15.
- Burnett AL, Bivalacqua TJ, Champion HC, Musicki B (May 2006). "Long-term oral phosphodiesterase 5 inhibitor therapy alleviates recurrent priapism". Urology 67 (5): 1043–8. doi:10.1016/j.urology.2005.11.045. PMID 16698365.
- Burnett AL, Bivalacqua TJ, Champion HC, Musicki B (November 2006). "Feasibility of the use of phosphodiesterase type 5 inhibitors in a pharmacologic prevention program for recurrent priapism". J Sex Med 3 (6): 1077–84. doi:10.1111/j.1743-6109.2006.00333.x. PMID 17100941.
- Oral terbutaline in the management of pharmacologically induced prolonged erection, S Priyadarshi, Department of Urology, SMS Medical College & Hospital, Jaipur, India, http://www.nature.com/ijir/journal/v16/n5/pdf/3901180a.pdf
- Macaluso JN, Sullivan JW (1985). "Priapism: A review of 34 cases". Urology 26 (3): 233–236. doi:10.1016/0090-4295(85)90116-5. PMID 4035837.
- Montague DK, Jarow J, Broderick GA, Dmochowski RR, Heaton JP, Lue TF, Nehra A, Sharlip ID (October 2003). "American Urological Association guideline on the management of priapism". J. Urol. 170 (4 Pt 1): 1318–24. doi:10.1097/01.ju.0000087608.07371.ca. PMID 14501756.
Further reading 
- Beers MH, Berkow R (Eds.) (1999). The Merck Manual of Diagnosis and Therapy (17 ed.). Whitehouse Station: Merck Research Laboratories. ISBN 0-911910-10-7
- Therapeutic Guidelines Limited (2001). Therapeutic Guidelines: Endocrinology (2 ed.). North Melbourne: Therapeutic Guidelines Limited. ISSN 1327-9505
- Guidelines on management of priapism - American Urological Association website
- Priapism Primer: Priapism
- Macaluso JN: Priapism (letter). Urology. 25:335, 1985