Emergency Medical Minute

Author: Nick Hatch, MD Educational Pearls: The sodium-glucose cotransporter in the gut is essential for rehydration. Oral rehydration therapies require an equimolar concentration of glucose and sodium to be effective. ORT has saved millions of lives globally. Consider using ORT in patients with dehydration. Especially useful in resource limited settings. References: Victora CG, Bryce J, Fontaine O, Monasch R. Reducing deaths from diarrhoea through oral rehydration therapy. Bull World Health Organ. 2000; 78:1246. Santillanes G, Rose E. Evaluation and Management of Dehydration in Children. Emerg Med Clin North Am. 2018. 36(2):259-273. doi: 10.1016/j.emc.2017.12.004.

Author: Nick Hatch, MD Educational Pearls: Behcet Disease is an autoimmune disease that can affect any organ system. Typical symptoms include recurrent oral and genital ulcers, but more concerning features include skin rashes, ocular problems, and strokes. Patients with Behcet disease with hypotension should have low threshold for giving steroids. References: Arlt W, Allolio B. Adrenal insufficiency. Lancet, 2003; 361:1881. Sakane T, Takeno M, Suzuki N, Inaba G. Behçet's disease. New England Journal of Medicine. 1999; 341:1284.

Author: Dylan Luyten , MD Educational Pearls: Rare autosomal dominant condition that is often misdiagnosed as a psychiatric illness. Presents as profound muscle weakness with frank paralysis that is often precipitated by vigorous exercise, high carb diet, high sodium load, or by high temperatures. Supplemental potassium can rapidly reverse symptoms. Important to rule out thyrotoxicosis (get a TSH!). Prevention is key: adhering to a low carb and low sodium diet with supplemental potassium can help prevent episodes. References: Vicart S, Sternberg D, Arzel-Hézode M, et al. Hypokalemic Periodic Paralysis. 2002 Apr 30 [Updated 2014 Jul 31]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2018. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1338/?report=classic Statland JM, Fontaine B, Hanna MG, et al. Review of the Diagnosis and Treatment of Periodic Paralysis. Muscle & Nerve. 2018;57(4):522-530. doi:10.1002/mus.26009.

Author: Sam Killian, MD Educational Pearls: Insufficient sleep and disrupted circadian rhythms are a major health problem today Millions of dollars, thousands of deaths, and millions of injuries are related to sleep deprivation every year 56 billion dollars - 24,000 deaths - 2.5 million disabiling injuries related to a sleep-type deprivation Exxon valdez, challanger, chyrnobel linked to sleep deprivation- at least partially Data has shown that in the Spring (when people lose an hour of sleep) there were 8% more traffic accidents on the Monday immediately after daylight savings. Conversely, in the Fall (when people gain an hour of sleep), there were 8% fewer traffic accidents on the Monday immediately after daylight savings. Studies have also shown an increased risk of myocardial infarction in Spring immediately after daylight savings, and a decreased risk of myocardial infarction in the Fall immediately after daylight savings. References: Corren S. Traffic Accidents and Daylight Saving Time. New England Journal of Medicine. 1996;335(5):355-357. doi:10.1056/nejm199608013350517 Janszky I, Ljung R. Shifts to and from Daylight Saving Time and Incidence of Myocardial Infarction. New England Journal of Medicine. 2008;359(18):1966-1968. doi:10.1056/nejmc0807104.

Author: Don Stader, MD Educational Pearls: The use of fecal occult blood tests is falling out of favor in emergency departments These tests have strong evidence suggesting their efficacy in colon cancer screening but clinical significance in ED is limited They have relatively high false positive and false negative rates Small/microscopic bleeding are often not clinically significant in the ED but can lead to increased costs from over-testing and other harms from fecal occult blood testing References: Gupta A, Tang Z, Agrawal D. Eliminating In-Hospital Fecal Occult Blood Testing: Our Experience with Disinvestment. American Journal of Medicine. (2018). 10.1016/j.amjmed.2018.03.002

Author: Michael Hunt, MD Educational Pearls: Valley fever is a fungal infection known as Coccidiomycosis that can present with vague symptoms like cough, fever, myalgias. A thorough history is critical to the diagnosis. Disease is localized to the Southwestern US (California, New Mexico, Arizona, Nevada, Utah) and parts of Central/South America. Disease is caused by inhaling fungal spores which damage the lung. Rarely, the disease can disseminate and cause infections that require systemic anti fungal therapy. References: Centers for Disease Control and Prevention (CDC). Increase in reported coccidioidomycosis--United States, 1998-2011. MMWR Morb Mortal Wkly Rep 2013; 62:217. Saubolle MA, McKellar PP, Sussland D. (2007). Epidemiologic, clinical, and diagnostic aspects of coccidioidomycosis. Journal of Clinical Microbiology. 45:26. Taylor AB, Briney AK. (1949). Observations on primary coccidioidomycosis. Annals of Internal Medicine. 30:1224.

Author: Sam Killian, MD Educational Pearls: Being exposed to E-cigarette vapor may increase risk of pneumonia. Recent study has shown e-cigarette vapor increases quantities of Platelet-activating-receptor factor in epithelial cells, which may aid pneumococcal bacteria in entering pneumocytes. References: Miyashita L, et al. (2018). E-cigarette vapour enhances pneumococcal adherence to airway epithelial cells. The European Respiratory Journal. 7;51(2).

Author: Rachel Beham, PharmD Educational Pearls: Some synthetic cannabinoids have been contaminated with Brodifacoum. Brodifacoum is a Vitamin K antagonist and can present with a severe coagulopathy. Brodifacoum is commonly known as "superwarfarin" and has a very long half life of 120+ days. Check PT/INR in patients with a bleeding diathesis in setting of synthetic cannabinoid use. Treatment is activated charcoal and large doses of Vitamin K (10mg Q6H for months). References: Lipton R.A.; Klass E.M. (1984). "Human ingestion of a 'superwarfarin' rodenticide resulting in a prolonged anticoagulant effect". JAMA. 252: 3004–3005. La Rosa F; Clarke S; Lefkowitz J. B. (1997). "Brodifacoum intoxication with marijuana smoking". Archives of Pathology & Laboratory Medicine. 121: 67–69

Author: Jared Scott, M.D. Educational Pearls: Cardiac myocytes and vascular smooth muscle are dependent on an intracellular calcium influx for contraction. Pancreatic beta cells rely on calcium to release insulin. Calcium channel blockers will decrease cardiac contractility and heart rate, but will also cause vascular smooth muscle relaxation with a subsequent decrease in systemic vascular resistance. Resultant cardiac depression and hypotension. Pancreatic beta cells also use calcium to release insulin, so calcium channel blockade can cause hyperglycemia. Treatment for calcium channel toxicity include: fluid resuscitation, calcium gluconate, vasopressors, and high dose insulin. Dosing for insulin therapy is usually 1-5 Units/kg/hr. Make sure to add dextrose! References: Boyer EW, Shannon M. (2001).Treatment of calcium-channel-blocker intoxication with insulin infusion. New England Journal of Medicine. 344:1721. Proano L, Chiang WK, Wang RY. (1995).Calcium channel blocker overdose. American Journal of Emergency Medicine. 13:444. St-Onge M, Dubé PA, Gosselin S, et al. (2014). Treatment for calcium channel blocker poisoning: a systematic review. Clinical Toxicology. 52:926.

Author: Nick Hatch, M.D. Educational Pearls: Methemoglobinemia is when the iron in hemoglobin is in the Fe3+ (ferric) state rather than the normal Fe2+ (ferrous) state. Methemoglobin cannot release oxygen at the tissues. Symptoms include cyanosis, headache, tachycardia, dyspnea, and lethargy. Suspect in setting of hypoxia that does not improve with oxygenation, and clinical cyanosis with a normal PaO2 on ABG. Treatment is methylene blue which reduces the iron back to the ferrous state. Causes can be Dapsone, Lidocaine, Benzocaine. References: Agarwal N, Nagel RL, Prchal JT. Dyshemoglobinemias. In: Disorders of Hemoglobin: Genetics, Pathophysiology, and Clinical Management, 2nd ed, Steinberg M (Ed), 2009. P.607 Cortazzo JA, Lichtman AD. (2014). Methemoglobinemia: a review and recommendations for management. Journal of Cardiothoracic and Vascular Anesthesia. 28:1043. Darling R, Roughton F. (1942). The effect of methemoglobin on the equilibrium between oxygen and hemoglobin. American Journal of Physiology. 137:56.