. Any prothrombotic state Same patient with (D) CTA, coronal MIP reformat; (E) CTA, sagittal MIP reformat; and (F, G) after selective DSA. The Glickman Urological & Kidney Institute offers innovative treatments in urology and kidney medicine, including minimally invasive, scarless options for urologic procedures and medical management of kidney disease. For treatment of an acute major ischemic priapism episode, a 16 or 18 gauge needle is inserted into the corpus cavernosum to aspirate blood, irrigate with saline, and inject sympathomimetics as necessary. Nonischemic priapism, also known as high-flow priapism, is due to an unregulated or disrupted arterial inflow, allowing well-oxygenated blood in the corpora. It is the result of a ruptured artery from an injury to the penis or the perineum (the area between the scrotum and anus), which prevents blood in the penis from circulating normally. Results: Journal of Urology. The mode of presentation, evaluation using a duplex scanner, treatment and ultimate resolution are discussed. Low-Flow/Ischemic/Veno-occlusive Priapism The definitive management of traumatic highflow priapism is by selective embolization with autologous blood clot. This treatment might be repeated until the erection ends. There are two types of priapism, ischemic (low-flow) and nonischemic (high-flow), and treatment varies depending on the type, its severity, and the underlying cause. Venous blood is evident on aspiration of the corpora cavernosa. The bulbar and dorsal penile arteries are less frequently involved. The bulbar and dorsal penile arteries are less frequently involved. Asian J Androl. No etiologic causes were evident in the other patients. B, Schematic drawing depicting different arteries and veins found in penis. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research. The etiology of priapism can broadly be categorized as low flow (ischemic) and high flow (non-ischemic). Color Doppler ultrasonography was repeated 1 day, 1 month, and 6 months after the operation. Low-flow priapism is caused by decreased outflow of blood due to venous thrombosis; thus there results a compartment syndromelike pathophysiology, with the risk of gangrene. Treatment might be needed to prevent further episodes. Erectile Dysfunction If you have used any medication or drugs, legal or illegal. High-Flow Priapism: Long-standing history of the condition. The causes of priapism may be due to drugs for the treatment of erectile dysfunction, substance use (alcohol or drugs) or certain conditions and injuries. It is a result of imbalance of arterial inflow and venous outflow involving the corpora cavernosa. In three of these patients, a second embolization procedure was conclusive. The incidence in the general population is low, between 0.5 and 2.9 per 100,000 person-years, and is higher in patients with sickle cell anemia and in men using intracorporal injections.1,2 and inject sympathomimetics as necessary. Chapter 81 The cookie is used to store the user consent for the cookies in the category "Analytics". This provides a clue to the type of priapism, how long the condition has been present, and how much damage has occurred. High-flow (nonischemic) Rare Associated with trauma or instrumentation Usually painless Increased arterial flow Usually self-resolves and does not require intervention Usually does not cause ischemia or sexual dysfunction Low-flow (ischemic) Most common type Veno-occlusion causing pooling of deoxygenated blood in cavernous tissue Painful Painless in nature. Priapism is a pathologically persisting erection of the penis not associated with sexual stimulation. Your doctor might be able to determine what type of priapism you have based on whether you're experiencing pain and the rigidity of the penis. Combination High Flow Priapism With Low Flow Priapism: CaseReport. The onset is usually delayed after injury, but typically it is clinically evident within 72 hours.9 Aspiration of the cavernosa reveals arterial blood. First-line treatment is aspiration that confirms the diagnosis and at the same time decompresses. Material and methods Between 1995 and 2000, 14 patients affected by high-flow priapism were observed at the Urologic Clinic of the University of Trieste. Embolization Treatment of High-Flow Priapism Priapism is prolonged erection that persists beyond or is unrelated to sexual stimulation. There are two main types of priapism: high flow and low flow. The doctor might suggest that you make a follow-up appointment with a specialist in the urinary tract and male reproductive system, such as a urologist or andrologist. Kuefer R, Bartsch G Jr, Herkommer K, et al. FIGURE e81-1 A, Selective digital subtraction angiography (DSA) (6mL; 3mL/seg) of left internal pudendal artery, with steep oblique view (35 LAO; 10 caudal-cranial angulation) depicting normal anatomy. Penile metastasis can cause either ischemic priapism, by obstructing venous drainage from the corpus cavernosa, or high-flow priapism, by increasing arterial flow to the . 1. Mostly traumatic However, the longer medical attention is delayed, the greater the risk of permanent erectile dysfunction. Accessibility Unintended consequences: A review of pharmacologically-induced priapism. It gives rise to the following collateral branches, in order: Changing diagnostic and therapeutic concepts in high-flow priapism. The ruptured branch of the cavernous artery was ligated in an open procedure. Non-ischemic or high flow priapism will typically demonstrate reduced rigidity and much less pain than ischemic priapism. 2019 Sep-Oct;52(5):331-336. doi: 10.1590/0100-3984.2018.0035. Priapism is a clinical diagnosis. Low flow priapism is ischemic and a true urologic emergency - a compartment syndrome of the penis, whereas high flow is non-ischemic. Are there activities, such as exercise or sex, that should be avoided? Priapism. If you have sickle cell disease, you might receive additional treatments that are used to treat disease-related episodes. There are two typeslow-flow/ischemic and high-flow/arterialand these are grouped based on the pathophysiology, with implications for subsequent treatment options and outcomes. Doppler studies show normal or high velocities in cavernosal arteries. Bethesda, MD 20894, Web Policies Although erectile function can improve after vascular reconstructive surgery or endovascular angioplasty of the internal pudendal/penile arteries,20-23 there is still very little evidence to recommend vascular imaging studies and therapies for ED in the general population. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. Careers. Ischemic priapism Signs and symptoms include: Erection lasting more than four hours or unrelated to sexual interest or stimulation. What are the causes behind priapism You may also need an Radiology appGet it nowRenovascular InterventionsSplenic Embolization in Nontraumatized PatientsChemical Ablation of Liver LesionsManagement of Male VaricoceleSubintimal AngioplastyCervical Artery DissectionLung AblationInfrapopliteal Revascularization This document was submitted for peer review to 64 urologists and other health care professions. Urol Ann. High flow priapism: Also known as "nonischemic," high flow priapism is rare and . Does priapism increase the risk of developing erectile dysfunction? Idiopathic Diagnostic and therapeutic options for the management of ischemic and nonischemic priapism. During this test, a small needle is placed in the penis, some blood is drawn, and then it is sent to a lab for analysis. Recurrent or Stuttering Priapism This poorly understood condition is uncommon and not confined to men with sickle cell disease. There is unregulated blood flow in an arteriolacunar (not arteriovenous) fistula between one of the terminal branches of the internal pudendal artery (most commonly the cavernosal artery) and lacunar spaces of the corpora cavernosa. The site is secure. These cookies track visitors across websites and collect information to provide customized ads. Pudendal angiography with superselective embolization is the treatment of choice. Asian J Androl. The symptoms of priapism are unrelated to sexual stimulation and in two-thirds of cases it is due to underlying sources, such as sickle cell disease, pelvic infections, pelvic tumors, or prescription medications. Unlike the low-flow/occlusive type, there is no ischemia or pain, and hence it is not an emergency. High-flow or arterial priapism is a fairly rare dysfunction, generally resulting from penile or perineal trauma. 2011 May;41(5):627-32. doi: 10.1007/s00247-010-1912-3. After pain relief, this treatment usually begins with a combination of draining blood from the penis and using medications. sharing sensitive information, make sure youre on a federal Embolization of high-flow priapism: technical aspects and clinical outcome from a single-center experience. Priapism is rare, but it does happen usually occurs in males who are aged 30 to 40. Cleveland Clinic is a non-profit academic medical center. Ice packs to the perineum or compression of the injury may bring down swelling for high-flow priapism. 52; Issue: 4; Pages 298-299. 2019; doi:10.1016/j.sxmr.2018.09.002. Treatment for priapism will depend on the type you have. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Advances in Urology. Priapism: comorbid factors and treatment outcomes in a contemporary series. 2020 Sep 23;91(10-S):e2020010. 8600 Rockville Pike An official website of the United States government. Vascular causes of ED may be arterial and/or venous, and these are the ones amenable to endovascular treatment. Unable to load your collection due to an error, Unable to load your delegates due to an error. 8600 Rockville Pike There are two main types of priapism: high flow and low flow. Did the erection occur after using a particular substance, such as alcohol, marijuana, cocaine or other drugs? If you have low-flow priapism, your doctor may use a syringe and needle to remove excess blood from your penis. First-line treatment is aspiration that confirms the diagnosis and at the same time decompresses. You also have the option to opt-out of these cookies. Please enable it to take advantage of the complete set of features! Priapism: current updates in clinical management. Superselective embolization of terminal branches of the male internal pudendal artery is a highly successful procedure in the treatment of high-flow arterial priapism. This procedure is a final treatment option if blocking the artery has failed. Log In or Register to continue Evidence seems to suggest that trazodone exclusively causes low-flow priapism. Possible organic causes: vascular, neurogenic, hormonal, anatomic, drug-induced.12 Policy. Fergus KB, Baradaran N, Tresh A, Conrad MB, Breyer BN. Transfemoral arteriography confirmed the arteriocavernous fistula which was successfully treated by selective embolisation of the internal . The dorsal artery of the penis, the other terminal branch supplying the glans penis and prepuce. High-flow (non-ischemic) priapism: The rarer form of priapism, high-flow priapism, is generally less painful and is caused by injury or trauma to the penis or perineum . The causes of ischemic priapism are numerous and include various hemoglobinopathies, such as sickle cell disease and thalassemia, and any hypercoagulable state. 1998-2023 Mayo Foundation for Medical Education and Research (MFMER). In cases of ischemic priapism, if it is treated early and successfully, erectile function should return to normal. This ensures that behavior in subsequent visits to the same site will be attributed to the same user ID. Ischaemic priapism can result in irreparable damage to the penis from a lack of blood flow, so draining the blood is necessary 3.Medications taken in tablet form may be the first treatment offered, but they are only effective in about 1 in every 3 or 4 cases 2,3.If medication fails, blood can be extracted using a needle and syringe but, on its own, this only works in about . e81-1). Cardiovasc Intervent Radiol 2006; 29:198. Vol. Less common than the low-flow type; in adults, 80% to 90% have a single fistula causing the priapism, but in children, 50% have multiple fistulas. Nine patients underwent selective embolization during arteriography, and in 1 patient, corporotomy and ligature of the cavernous artery were performed. Acute onset of severe pain, rigidity, and other compartment syndrome clinical findings are noted. Cardiovasc Intervent Radiol 2006; 29:198. Ischemic priapism the result of blood not being able to exit the penis is an emergency situation that requires immediate treatment. Shapiro RH, Berger RE. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Tell your doctor: Your doctor will review your medical history and perform a physical examination to help determine the cause of priapism. Vascular imaging and treatment in patients with erectile dysfunction (ED) using cavernosography and internal pudendal artery angiography and angioplasty remains a controversial topic. Elsevier; 2021. https://www.clinicalkey.com. Low flow is far more common, with high flow only making up about 2% of presentations. In some cases, the etiology remains unknown. Vet Sci. Accessibility The data collected including the number visitors, the source where they have come from, and the pages visted in an anonymous form. PMC This type of priapism is usually treated by a consultant urologist. Read more. government site. Cantasdemir M, Gulsen F, Solak S, Numan F. Pediatr Radiol. Accessibility 2014 Dec;6(6):230-44. doi: 10.1177/1756287214542096. Posttraumatic high-flow priapism in children treated with autologous blood clot embolization: long-term results and review of the literature. This cookie is set when the customer first lands on a page with the Hotjar script. High-flow (nonischemic) Extremely rare and usually not painful AV fistula from trauma (lacerated cavernous artery shunts blood into cavernous bodies) Ischemia/impotence does not occur Requires less urgent intervention and does not lead to impotence Low-flow (ischemic) Most common type Careers. If medication is necessary, is there a generic alternative? Don't stop taking any prescription medications without consulting your doctor. If you have high blood flow priapism the initial treatment is to wait and see. Up to 70% of men with ED remain undiagnosed and untreated.15 ED has an effect equal to or greater than the effects of family history of myocardial infarction, cigarette smoking, or measures of hyperlipidemia on subsequent cardiovascular events.16 All patients with ED should be considered for screening for undetected cardiovascular disease. e81-1). Tags: Image-Guided Interventions Expert Radiology Series After the final revisions were made based . Sorry, there are no matching doctors in your area, Sorry no questions were found related to this procedure, When Your Prolonged Erection Turns into an Emergency: Signs Your Penis Is In Danger, Do Not Sell or Share My Personal Information. Left untreated, blood vessels in the penis can rupture or the tissue can scar, leading to permanent erectile dysfunction. This neurovascular function must be integrated with sexual perception and desire.12 Other smooth muscle relaxants (e.g., prostaglandin E1 analogs and -adrenergic antagonists) can cause sufficient cavernosal relaxation to result in erection. Otherwise, low flow priapism showed little or no blood flow in the cavernosal arteries. Summary of Current American Urological Association Priapism Treatment Guidelines. Ther Adv Urol. Priapism is a persistent, usually painful, erection that lasts for more than four hours and occurs without sexual stimulation. Management 1. Transl Androl Urol. When left untreated, priapism may result in the following complications: This content does not have an English version. 2003; doi:10.1097/01.ju.0000087608.07371.ca. Al-Qudah et al for Medscape. [Treatment using percutaneous arterial embolization of post-traumatic priapism in children]. An official website of the United States government. Intracavernous vasodilator injections for treatment of ED Priapism tends to resolve of its own accord in about two-thirds of men with this condition. Bookshelf High-flow priapism is a nonsexual, persistent erection caused by unregulated cavernous arterial inflow. Acute onset of severe pain, rigidity, and other compartment syndrome clinical findings are noted. Some authors consider the artery to be called the penile artery from here on, giving rise to: Bulbar artery supplying the bulb of the urethra, posterior corpus cavernosum, and bulbourethral glands (with the normal capillary blush seen within the bulbar spongiosa), Urethral (spongiosal) artery supplying the corpora spongiosa and providing anastomoses with the dorsal artery of the penis at the glans penis, The deep artery of the penis (cavernosal artery), which divides into helicine arteries that enter the lacunar spaces almost at right angles from the cavernosal artery. Copyright 2023 - European Association of Urology - All rights reserved, This information was last updated inMarch 2023. . This cookie is set by doubleclick.net. Keywords: The determination of erectile function at a mean follow-up of 41 months (range 17 to 64) was performed using the International Index of Erectile Function. Generalized penile arterial insufficiency may result from stenotic arterial lesions of the internal pudendal arteries or from microangiopathy of the arteries of the corpora cavernosa. Treatment of High-flow Priapism with Superselective Transcatheter Embolization in 27 Patients: A Multicenter Study - Journal of Vascular and Interventional Radiology Skip to Main Content ED may result from organic causes, psychological causes, or a combination of both. The cookies is used to store the user consent for the cookies in the category "Necessary". We describe 4 cases of high flow arterial priapism, ranging from 1 week to 3 years in duration. . The dorsal artery of the penis, the other terminal branch supplying the glans penis and prepuce. Used by Google DoubleClick and stores information about how the user uses the website and any other advertisement before visiting the website. 2022 Jan 14;9(1):29. doi: 10.3390/vetsci9010029. In high flow priapism's cases, high blood flow velocities were reported in the cavernosal arteries. Possible organic causes: vascular, neurogenic, hormonal, anatomic, drug-induced. This treatment often relieves pain, removes oxygen-poor blood and might stop the erection. Instead, get emergency help as soon as possible. This neurovascular function must be integrated with sexual perception and desire.12 Other smooth muscle relaxants (e.g., prostaglandin E1 analogs and -adrenergic antagonists) can cause sufficient cavernosal relaxation to result in erection. Penile emergencies. diagnosis and treatment of Priapism. Many of the drugs that have been developed to treat ED act at this level.13 official website and that any information you provide is encrypted The cookie is used to calculate visitor, session, campaign data and keep track of site usage for the site's analytics report. The bulbar and dorsal penile arteries are less frequently involved. Korean J Urol. Ferri FF. The management is slightly different but follows the same principles for the sickle cell anemia variant of veno-occlusive priapism.3,4, Less common than the low-flow type; in adults, 80% to 90% have a single fistula causing the priapism, but in children, 50% have multiple fistulas.3-5, Typically a straddle injury to the perineum, Sometimes results from complications of low-flow priapism, Can be idiopathic without a recognizable event, There is unregulated blood flow in an arteriolacunar (not arteriovenous) fistula between one of the terminal branches of the internal pudendal artery (most commonly the cavernosal artery) and lacunar spaces of the corpora cavernosa. Arterial embolization in the treatment of post-traumatic priapism. Please enable it to take advantage of the complete set of features! 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. Etiology If the priapism is ischemic in nature, there are a number of treatment options, including aspiration, medication, and surgery. Epub 2013 Dec 10. Use of angioembolization in urology: a review. The dorsal artery of the penis, the other terminal branch supplying the glans penis and prepuce. The 16 G needle was first inserted into the central part of the abscess to aspirate 10 mL of yellow pus. Accessed April 20, 2021. However, only your doctor can distinguish between high- and low-flow priapism. Up to 70% of men with ED remain undiagnosed and untreated. MeSH There are two typeslow-flow/ischemic and high-flow/arterialand these are grouped based on the pathophysiology, with implications for subsequent treatment options and outcomes. Venous outflow is not restricted, because there is no compression of subtunical veins, normally produced by neural stimulation; hence, there is a constant state of inflow/outflow without pooling of blood. When the desired result is not achieved, negative ways of thinking about the best course of action result . When nonsurgical treatment options are ineffective, or when damage has resulted, surgery may be required. Urology. Antihypertensives (i.e., hydralazine, guanethidine and propranolol). Transl Androl Urol. This cookie is set by Hotjar. Urethral (spongiosal) artery supplying the corpora spongiosa and providing anastomoses with the dorsal artery of the penis at the glans penis Medications. The mode of presentation, evaluation using a duplex scanner, treatment and ultimate resolution are discussed. Inferior rectal (or inferior hemorrhoidal) branches at the level of the ischial tuberosity, Perineal-scrotal artery, supplying the perineal muscles, structures between anus and scrotum, skin and dartos tunic of the scrotum, Some authors consider the artery to be called the, Bulbar artery supplying the bulb of the urethra, posterior corpus cavernosum, and bulbourethral glands (with the normal capillary blush seen within the bulbar spongiosa), Urethral (spongiosal) artery supplying the corpora spongiosa and providing anastomoses with the dorsal artery of the penis at the glans penis, The deep artery of the penis (cavernosal artery), which divides into helicine arteries that enter the lacunar spaces almost at right angles from the cavernosal artery. Pathophysiology Since this type of priapism can resolve spontaneously after weeks of healing, physicians will often take a watch-and-wait approach. MeSH Elsevier; 2021. https://www.clinicalkey.com. e81-1). The actual site of the arteriolacunar fistula can usually be accurately determined.3,4. Sometimes results from complications of low-flow priapism Int J Impot Res 2005; 17:109. We describe 4 cases of high flow arterial priapism, ranging from 1 week to 3 years in duration. Accepted for publication Jun 14, 2012. Venous outflow is not restricted, because there is no compression of subtunical veins, normally produced by neural stimulation; hence, there is a constant state of inflow/outflow without pooling of blood. Relevant Anatomy The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Evolving concepts in the diagnosis and treatment of arterial high flow priapism. We report on the management and long-term follow-up of patients treated for high-flow priapism in our clinic between 1995 and 1998. Only gold members can continue reading. If these treatments are insufficient, we may need to use other techniques to normalize blood circulation in the penis. Bookshelf . Epub 2018 Dec 3. Patients may be followed by blood flow measurement by repeated PDU . All rights reserved. doi: 10.23750/abm.v91i10-S.10233. Postembolization or surgery for venous leak For ischemic priapism, surgical treatment may include: For nonischemic priapism, surgical options are: Prognosis depends on the type of priapism and its severity. Ischemic . Tiago Bilhim, Joo M. Pisco, Max Kupershmidt and Kenneth R. Thomson This cookie is installed by Google Analytics. This website uses cookies to improve your experience. Duplex sonography with pulsed Doppler analysis (with and without dynamic erection studies with vasoactive substances) and nocturnal penile tumescence (NPT) are usually performed as first-line studies. Epub 2010 Dec 3. 2018 Aug;7(4):535-544. doi: 10.21037/tau.2018.05.12. The cookies store information anonymously and assign a randomly generated number to identify unique visitors. The emergency room doctor will determine whether you have ischemic priapism or nonischemic priapism. Interventional radiology management of high flow priapism: review of the literature. official website and that any information you provide is encrypted Priapism is prolonged erection that persists beyond or is unrelated to sexual stimulation. The AUA recommends that the initial evaluation of ED include a complete medical, sexual, and psychosocial history. Clipboard, Search History, and several other advanced features are temporarily unavailable. Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. Chick JFB, J Bundy J, Gemmete JJ, Srinivasa RN, Dauw C, Srinivasa RN. In rare cases, priapism may be related to cancers that can affect the penis and prevent the outflow of blood. Before Priapism: pathophysiology and the role of the radiologist. . e81-1). The https:// ensures that you are connecting to the Being ready to answer them might allow time later to cover other points you want to address. PurposeTo present three cases of arterial high flow priapism (HFP) and propose a management algorithm for this condition.Materials and methodsWe studied three children with post-traumatic arterial HFP (two patients with perineal trauma and one with penis trauma).ResultsSpontaneous resolution was observed in all the patients. Bethesda, MD 20894, Web Policies There are two terminal branches: It is used by Recording filters to identify new user sessions. Advances in the understanding of priapism. 12th ed. When a ruptured artery causes priapism, your doctor will perform an operation to tie it off (surgical ligation). Shearing forces on the endothelium cause release of increased levels of nitric oxide and activation of the cyclic guanosine monophosphate pathway, resulting in relaxation of smooth muscle. Gottsch H, Berger R, & Yang C. (2012). Priapism is an often painful penile erection that lasts four hours or more. Journal of Postgraduate Medicine. Accessed April 20, 2021. Do you have brochures, or can you suggest websites that explain more about priapism? Clinical Presentation The cookie is used to store the user consent for the cookies in the category "Other. Note: High-flow (non-ischemic) priapism will present with different signs/symptoms than low-flow priapism. Priapism develops when blood in the penis becomes trapped and unable to drain. ED may result from organic causes, psychological causes, or a combination of both. This site needs JavaScript to work properly. Advertising revenue supports our not-for-profit mission. Treatment of "high-flow" priapism with superselective transcatheter embolization: a useful alternative to surgery. This is followed by irrigation with a sympathomimetic pharmaceutical agent and, if necessary, a surgical shunt. Treatment of "high-flow" priapism with superselective transcatheter embolization: a useful alternative to surgery. Priapism is one of the most common urologic emergencies. Epub 2018 Jul 29. There are three types of high-flow priapism: traumatic, neurogenic and post-shunting. Vascular imaging and treatment in patients with erectile dysfunction (ED) using cavernosography and internal pudendal artery angiography and angioplasty remains a controversial topic. Failure of the veins to close completely during an erection (veno-occlusive dysfunction) may occur in men with large venous channels that drain the corpora cavernosa, and may be studied by cavernosography.13 Evidence is accumulating in favor of ED as a vascular disorder in the majority of patients.14. This is the most common type. Last reviewed by a Cleveland Clinic medical professional on 10/14/2019. Clinical Presentation Vascular causes of ED may be arterial and/or venous, and these are the ones amenable to endovascular treatment. The .gov means its official. It is used to persist the random user ID, unique to that site on the browser. "Stuttering" priapism is a term frequently used to . Non-ischemic priapism is a high-flow state that is typically not painful and resolves spontaneously. Would you like email updates of new search results? Pathophysiology Repeat penile corporal blood gas analysis reaffirmed the priapism to be non-ischemic in nature, and it was decided to manage the patient conservatively. Disclaimer. If damage has occurred, surgery can repair the ruptures and allow erectile function to return to normal. Priapism Treatment. Unlike the low-flow/occlusive type, there is no ischemia or pain, and hence it is not an emergency. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS).