Feature

Hereditary Hemorrhagic Telangiectasia: A Primer for Critical Care NursesKathleen M. Sacco, MSN, ACNP-BC, CCRN, CHPNThomas W. Barkley, Jr, PhD, ACNP-BC

Hereditary hemorrhagic telangiectasia is a rare, autosomal dominant genetic disease that causes abnormal growth of blood vessels and, subsequently, life-threatening arteriovenous malformations in vital organs. Epistaxis may be one of the initial clues that a patient has more serious, generalized arteriovenous malfor-mations. Recommended treatment involves careful evaluation to determine the severity and risk of spon-taneous rupture of the malformations and the management of various signs and symptoms. The disease remains undiagnosed in many patients, and health care providers may miss the diagnosis until catastrophic events happen in multiple family members. Prompt recognition of hereditary hemorrhagic telangiectasia and early intervention can halt the dangerous course of the disease. Critical care nurses can assist with early diagnosis within families with this genetic disease, thus preventing early death and disability. (Critical Care Nurse. 2016;36[3]:36-49)

2016 American Association of Critical-Care Nurses doi: http://dx.doi.org/10.4037/ccn2016270

Mr J, a 19-year-old man, was admitted to the critical care unit of a community hospital with an intracerebral hemorrhage. His mother, father, siblings, and extended family visited often and were attentive and concerned. After initial stabilization of his condition, a ruptured cere-bral arteriovenous malformation (AVM) was diagnosed. Mr J was subsequently intubated and sedated for 12 days before he had a tracheostomy and placement of a feeding tube. During this time, the critical care nurses had a chance to become acquainted with his family. As the family was grieving about this tragic event, the nurses became aware that several other members of the family had experienced the same tragedy at similarly young ages.

This article has been designated for CE contact hour(s). The evaluation tests your knowledge of the following objectives:1. Describe the pathophysiology and known causes of hereditary hemorrhagic telangiectasia (HHT)2. Identify the main physiological complications and treatment strategies of HHT3. Discuss the nursing interventions to support HHT patients across the lifespan

To complete evaluation for CE contact hour(s) for test #C1633, visit www.ccnonline.org and click the CE Articles button. No CE test fee for AACN members. This test expires on June 1, 2019.

The American Association of Critical-Care Nurses is an accredited provider of continuing nursing education by the American Nurses Credentialing Centers Commission on Accreditation. AACN has been approved as a provider of continuing education in nursing by the State Boards of Registered Nursing of California (#01036) and Louisiana (#LSBN12).

CE 1.0 hour

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Authors

Kathleen M. Sacco is the director, Intensive Care Unit and Cardio-pulmonary Services, Simi Valley Hospital, Simi Valley, California.

Thomas W. Barkley, Jr, is president of Barkley and Associates, West Hollywood, California.

Corresponding author: Kathleen Sacco, MSN, ACNP-BC, CCRN, CHPN, 2975 Sycamore Dr, Simi Valley, CA 93065 (e-mail: kathysacco@gmail.com).

To purchase electronic or print reprints, contact the American Association of Critical-Care Nurses, 101 Columbia, Aliso Viejo, CA 92656. Phone, (800) 899-1712 or (949) 362-2050 (ext 532); fax, (949) 362-2049; e-mail, reprints@aacn.org.

Mr J continued to slowly improve. He regained consciousness and was able to have placement of a T-piece and, eventually, a speaking valve. He had residual left-sided hemiparesis, but he readily partnered with his physical and occupational therapists to decrease his deficits. A few days before his transfer to the telemetry unit, a nurse happened to mention to one of Mr Js phy-sicians, a pulmonologist, that the family had knowledge of 6 other family members on the fathers side who had had the same fate, and all when they were less than 29 years old. The physician agreed that the situation was unusual and proceeded to investigate. Later that day, the physician spoke with the family and asked them if anyone in the family had experienced epistaxis that seemed unusually frequent or severe. To everyones amazement, the patients father stated that he had had severe epistaxis since he was an adolescent and that his son also had frequent epistaxis. The father proceeded to explain that 2 of the fathers siblings, several cousins, and his mother and grandmother also had epistaxis. The family mem-bers had assumed it was a family trait, much like their propensity for hypertension; however, no one attributed any significance to the nosebleeds. After hearing this information, the pulmonologist asked Mr Js father if the father or any other family members had noticed any red or pink spots on their mucous membranes or fingers. Again, the father affirmed that he had them, as did the same members who had nosebleeds. The physician exam-ined the father and confirmed the presence of several telangiectasias on the fathers lips and tongue. At that point, the physician spoke with the family and told them that they had sufficient diagnostic criteria consistent with a somewhat rare genetic disorder called hereditary hemorrhagic telangiectasia (HHT).

Mr J was eventually transferred to the telemetry unit and subsequently entered an acute rehabilitation unit. The family was referred to a local tertiary center that

specialized in HHT. The family members had genetic tests, and the diagnosis was confirmed. Most important, Mr Js 13-year-old sister also tested positive for HHT. Because she had intermittent headaches, she had follow-up imaging, which revealed a small cerebral AVM. The tertiary HHT team, the patient, and the patients family agreed that watchful waiting was the best strategy for treatment. The patient was relieved that she did not need an embolization procedure and thought that the diagnosis of HHT possibly saved her from future disability or premature death. Approximately 6 months later, Mr J, his parents, and his sister visited the critical care unit to thank the nurses. The patients mother was tearful as she hugged the nurses and told them that because of their persistence and the physicians astute diagnostic skills, the family had received the necessary diagnosis and counseling.

This case study underscores the important contribu-tion of nurses in actively listening, recognizing a poten-tially dire circumstance, and acting as patient advocates.

HHT, also known as Osler-Weber-Rendu syndrome, is an uncommon disease, yet it has serious and some-times deadly complications. HHT is easily underdiag-nosed, a situation that places patients at increased risk for serious sequelae such as hemorrhage, brain abscesses, and stroke.1 Even though the diagnosis is infrequent, patients with HHT complications often require care in critical care units, postanesthesia care units, and other general acute care units. Many family physicians may not be aware of the disease, so nurses may be the first health care providers to fit the diagnostic pieces together to help in the diagnosis. Early recognition of the presence of the disease can have major positive effects on an entire familys well-being. The purpose of this article is to inform critical care nurses about HHT, diagnosis, treatment, and nursing considerations in caring for patients with HHT and the patients families.

Background and PathophysiologySir John Legg first described HHT in 1876 as a form

of hemophilia with nevi and frequent epistaxis. Doctors Osler, Weber, and Rendu were physicians in the 1890s who continued Leggs work and realized that HHT was not a clotting disorder but a blood vessel abnormality.2 Osler, Weber, and Rendu later identified a familial

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Telangiectasias, epistaxis, and visceral AVMs are the hallmark signs of HHT.

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association and continued the research.3 HHT is an autosomal dominant condition that causes formation of dysfunctional blood vessels and multiple AVMs in various organs of the body.4 According to estimates,1,5 the incidence of HHT is 1 in 5000 to 1 in 8000. The syn-drome occurs globally and in all races and ethnic groups.6 Males and females are equally affected. The common characteristics of the disease are telangiectasias (small, red lines or dots) on the skin, especially the face, naso- oropharynx, and fingers; visceral AVMs; and epistaxis.7

HHT can be divided into several genetic types. Each type has dominant features, but many features overlap between types. The pathophysiology of HHT includes gene mutations on the endoglin (ENG) gene (type 1), activin A receptorlike kinase (ALK1/ACVRL1) gene (type 2), and sometimes the SMAD4 (similar to mothers against decapentaplegic) family member genes.8 The SMAD4 family of genes has been identified as tumor- suppressing genes. Alterations in these genes not only contribute to HHT and neoplasms of the pancreas, head, and neck but also are associated with a syndrome called juvenile polyposis. Families with juvenile polyposis have a high risk for early colon cancer and HHT. The defec-tive HHT genes code for proteins that mediate signaling pathways in vascular endothelial cells. The alteration in the signaling pathways causes abnormal development of blood vessels, such as dilated venules (eg, telangiecta-sias) and open arteriovenous channels.9 The current understanding is that some unknown vessel injury causes angiogenic stimulation, which results in the vessels inability to mature correctly.

ComplicationsTelangiectasias, epis