Articles from the 2004 LLSA Reading List

FigureAuthor Credentials and Financial Disclosure: Daniel K. Mullin, MD, is a Clinical Instructor of Emergency Medicine at Drexel University College of Medicine in Philadelphia. Dr. Mullin has disclosed that he has no financial interests in or relationships with any commercial companies pertaining to this educational activity. Learning Objectives: After reading this article, the physician should be able to: Utilize the NEXUS clinical criteria to rule out cervical spine injury in the blunt trauma patient. Discuss the presentation and treatment of patients with acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. Describe the presentation of immune thrombocytopenic purpura, and explain some of its complications and treatment options. Release Date: October 2006 Validity of a Set of Clinical Criteria to Rule Out Injury to the Cervical Spine in Patients with Blunt Trauma Hoffman JR, et al N Engl J Med 2000;343:94 Physicians in the United States order approximately 800,000 cervical spine radiographs each year to rule out cervical spine injuries in patients with blunt trauma. The purpose of the National Emergency X-Radiography Utilization Study (NEXUS) was to validate a set of previously studied clinical criteria to rule out cervical spine injury in blunt trauma patients and decrease the reliance on x-rays in doing so. The five criteria (decision instrument) set forth by the NEXUS group include: No posterior midline cervical spine tenderness. No focal neurologic deficits. Normal level of alertness. No evidence of intoxication. No clinically apparent painful injury that might distract a patient from the pain of a cervical spine injury. For explicit reasons, none of the criteria was defined and instead were left to clinical judgment. The hypothesis was that patients who meet all five criteria have a low probability of cervical spine injury and are unlikely to need further studies to evaluate the cervical spine. The study was a prospective observational study with the participation of 21 university and community hospitals across the United States and a total study population of 34,069. The standard three-view cervical spine series (cross-table lateral, anteroposterior, and open-mouth) was obtained in all patients unless impractical or impossible, and in those cases, a CT or MRI was performed. There was no age cutoff, and patient ages ranged from under 1 to 101. If a fracture was documented, it was then classified as clinically significant or clinically insignificant. Injuries that were predetermined to be clinically insignificant included spinous-process fractures, simple wedge-compression fractures without loss of 25 percent or more in vertebral-body height, isolated avulsions without associated ligamentous injury, type I odontoid fractures, end-plate fractures, osteophyte fractures, transverse-process fractures, and trabecular bone injuries. Of the 34,069 patients, 818 (2.4%) had documented cervical spine injury on x-ray. The majority of patients with cervical spine injuries were male (64.8%) with a mean age of 40. The decision instrument missed eight of the 818 injuries, but only two were categorized as significant by the predefined criteria. The sensitivity for all patients was determined to be 99.0%, negative predictive value was 99.8%, and specificity was 12.9%. When looking only for patients with clinically significant injuries, the sensitivity was 99.6%, negative predictive value was 99.9%, and specificity was 12.9%. By using this decision instrument, 4,309 patients (12.6%) could have been spared any radiographic evaluation. This is probably an underestimation because many of the study physicians were already aware of this decision instrument because of previous studies, and were utilizing it to some extent during data collection. The true reduction in x-rays ordered may be closer to one-third. Comment: In writing this article, I must mention the other decision rule that many emergency physicians utilize as well: the Canadian C-spine rule (CCR) developed by Stiell et al. (JAMA 2001;286:1841.) In this rule, three questions are asked: Is there any high-risk factor that mandates radiography (i.e., age 65 or older, dangerous mechanism, or paresthesias in the extremities)? Is there any low-risk factor present that allows safe assessment of range of motion (i.e., simple rear-end motor vehicle collision, sitting position in the ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline cervical spine tenderness)? Is the patient able to actively rotate his neck 45 degrees to the left and right? If the answer is yes to the first question, get an x-ray. But if it is no to the first question and yes to the second and third ones, no x-ray is needed. By cross-validation, this rule had a sensitivity of 100% and specificity of 42.5% for identifying clinically important cervical spine injuries. A head-to-head study of NEXUS versus the CCR done by the authors of the CCR (N Engl J Med 2003;349:2510) found that the CCR was more sensitive (99.4% vs. 90.7%) and more specific (45.1% vs. 36.8%) for injury. Questions have arisen from this later study because 16 important injuries were missed by using the NEXUS criteria in only 8,283 patients, while in the validation study by the NEXUS group itself, only two important injuries were missed in 34,069 patients. High-Altitude Illness Hackett PH, Roach RC N Engl J Med 2001;345:107 This review paper describes the presentation, pathophysiology, treatment, and prevention of acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. These syndromes develop in the unacclimatized person shortly after ascent to high altitude. Rate of ascent, the altitude reached, the altitude where sleeping occurs, and individual physiology determine whether a high-altitude illness will occur. Risk factors include a history of high-altitude illness, residence at an altitude of less than 900 meters, exertion, and certain predisposing illnesses. Acute mountain sickness is defined as the presence of a headache after ascent to above 2500 meters plus one of the following: gastrointestinal symptoms (anorexia, nausea, or vomiting), insomnia, dizziness, and lassitude or fatigue. These symptoms typically develop within six to 10 hours of ascent. High-altitude cerebral edema is defined as onset of ataxia or altered consciousness in someone with acute mountain sickness or high-altitude pulmonary edema. Physical exam findings in someone with high-altitude cerebral edema may include papilledema, retinal hemorrhage, and occasionally cranial nerve palsies. If not treated appropriately, high-altitude cerebral edema progresses over hours to days and may cause death via brain herniation. The management of acute mountain sickness or high-altitude cerebral edema follows three main axioms. Further ascent should be avoided until symptoms have resolved, patients with no response to medical treatment should descend to a lower altitude, and at the first sign of high-altitude cerebral edema (i.e., ataxia), patients should descend to a lower altitude. Descent and supplemental oxygen are always the treatment of choice for severe illness. For mild to moderate acute mountain illness, acetazolamide and dexamethasone are effective and equivalent. Ibuprofen also is effective treatment for the headache. For cerebral edema, treat with immediate descent (portable hyperbaric chamber if descent is not possible), oxygen and dexamethasone, and acetazolamide if descent is delayed. Prior to travel to high altitudes, patients should be consulted on preventative techniques including ascending at a slow rate, spending a night at an intermediate altitude, and avoiding overexertion. Consideration should be given to prophylactic treatment with acetazolamide and/or dexamethasone. Ginkgo biloba and aspirin also appear to be of some benefit. High-altitude pulmonary edema is the most common cause of death from high-altitude illnesses. It is a noncardiogenic pulmonary edema associated with pulmonary hypertension and elevated capillary pressures. Early diagnosis is critical, and the syndrome should be suspected after recent ascent (commonly on the second night), generalized weakness, and a dry cough. Later symptoms include cough productive of pinkish sputum and shortness of breath, while physical examination usually reveals tachycardia, tachypnea, and rales. It also is common for patients with high-altitude pulmonary edema to have signs and symptoms of acute mountain sickness or high-altitude cerebral edema. The treatment of choice is supplemental oxygen and descent. Oxygen alone reduces pulmonary artery pressure 30 percent to 50 percent. Descent, oxygen, or both are nearly always successful. Medication (nifedipine) is necessary only when supplemental oxygen is unavailable or descent is impossible. For prevention, ascend at a slow rate and avoid overexertion, and patients with repeated episodes of high-altitude pulmonary edema should consider taking nifedipine prophylactically. Immune Thrombocytopenic Purpura Cines DB, Blanchette VS N Engl J Med 2002;346:995 Immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by a low platelet count and mucocutaneous bleeding. ITP is classified as either primary or secondary to an underlying disorder, either acute (less than six months in duration) or chronic. The disease presentation and progression are different depending on whether the disorder is childhood-onset or adult-onset. Adult-onset ITP is generally chronic, with a gradual onset. Meanwhile childhood onset ITP is more often acute, but the eventual outcome is better, considering that more than 70 percent have symptom resolution within six months. Affected children are young (peak age, 5 years) and previously healthy, and they typically present with sudden onset of petechiae or purpura several days after an infectious illness. The diagnosis of ITP is one of exclusion, usually by a hematologist, because there are many causes of thrombocytopenia and many causes of secondary ITP including HIV, hepatitis C, and systemic lupus erythematosus. Apart from thrombocytopenia, the blood count should be normal in ITP, except in cases where the hemoglobin is low due to heavy bleeding. In adults, petechiae or ecchymoses develop spontaneously when platelet counts are between 10,000/mm3 and 30,000/mm3. Below 10,000/mm3 and patients are at risk of spontaneous internal bleeding. In children, the most serious complication of ITP is intracranial hemorrhage, seen in 0.2 percent to one percent of patients. Almost all intracranial hemorrhages occur at platelet counts below 20,000/mm3 and generally below 10,000/mm3. For patients with neurologic symptoms secondary to intracranial hemorrhages, internal bleeding, or emergency surgery, treatment should begin immediately in consultation with a hematologist. Urgent treatment of this nature includes methylprednisolone (30 mg/kg/day, max 1000 mg × 2–3 days), with intravenous immune globulin (1 g/kg/day × 2–3 days), and an infusion of platelets that is two to three times the usual amount infused. Antifibrinolytic therapy (i.e., aminocaproic acid) and recombinant factor VIIa should be considered. For the majority of patients with ITP, treatment is not urgent (not to be started by the emergency physician), and should be left up to hematologists. There are several treatment options which include but are not limited to glucocorticoids, intravenous immune globulin, and anti-D immune globulin. Chronic ITP in adults and children becomes even more challenging, but the most definitive treatment involves splenectomy. The rate of complete remission (from chronic ITP) after splenectomy is approximately 70 percent to 80 percent in children and 60 percent to 70 percent in adults. About the LLSA As part of its continuous certification program, the American Board of Emergency Medicine has developed the Lifelong Learning and Self-Assessment (LLSA) program to promote continuous education of diplomates. Each year, beginning in 2004, 16 to 20 articles are chosen based on the Emergency Medicine Model. A list of these articles can be found on the ABEM web site, www.abem.org. After reading the articles, ABEM diplomates are required to take a web-based examination of 32 to 40 multiple-choice questions. Each test remains online for three years, based on the date of publication. (The deadline for the 2004 articles, for instance, is March 31, 2007). Once registered for an LLSA test, diplomates may access the test as often as needed with no time limit. A passing score is achieved by answering 90 percent of the items correctly. Each physician has three opportunities to pass. Diplomates are required to take and pass a specific number of LLSA tests to take the Continuous Certification (ConCert) examination. This number depends on what year the ConCert exam will be taken. (Physicians whose certificates expire after 2012 are required to complete eight LLSA tests to be eligible to take the ConCert examination.) Up to 40 percent of the ConCert exam will be based on content from the preceding nine LLSA reading lists. ABEM is not authorized to confer CME credit for the successful completion of the LLSA test, but it has no objection to physicians participating in such activities. EMN's CME activity, Learning to Live with the LLSA, is not affiliated with ABEM's LLSA program, and reading this article and completing the quiz does not count toward ABEM certification. Rather, participants may earn 1 CME credit from the Lippincott Continuing Medical Education Institute, Inc., for each completed EMN quiz. CME Participation Instructions To earn CME credit, you must read the article in Emergency Medicine News, and complete the quiz, answering at least 80 percent of the questions correctly. Mail the completed quiz with your check for $10 payable to the Lippincott Continuing Medical Education Institute, Inc., 770 Township Line Road, Suite 300, Yardley, PA 19067. Only the first entry will be considered for credit, and must be received by Lippincott Continuing Medical Education Institute, Inc., by Oct. 31, 2007. Acknowledgement will be sent to you within six to eight weeks of participation. Lippincott Continuing Medical Education Institute, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide medical education to physicians. Lippincott Continuing Medical Education Institute, Inc., designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit.™ Physicians should only claim credit commensurate with the extent of their participation in the activities.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.