Emergency Medical Minute Emergency Medical Minute

Contributor: Taylor Lynch MD
Educational Pearls:
Overview: Sympathomimetic drugs mimic the fight or flight response, affecting monoamines such as dopamine, norepinephrine, and epinephrine Limited therapeutic use, often abused. Types: Amphetamines: Methamphetamine, Adderall, Ritalin, Vyvanse MDMA (Ecstasy) Cocaine (Both hydrochloride salt & free based crack cocaine) Theophylline (Asthma treatment) Ephedrine (For low blood pressure) BZP, Oxymetazoline (Afrin), Pseudoephedrine (Sudafed) MAO Inhibitors (treatment-resistant depression) Mechanisms: Act on adrenergic and dopaminergic receptors. Cocaine blocks dopamine and serotonin reuptake. Methamphetamines increase stimulatory neurotransmitter release MAO Inhibitors prevent neurotransmitter breakdown. Symptoms: Agitation, tachycardia, hypertension, hyperactive bowel sounds, diuresis, hyperthermia. Severe cases: Angina, seizures, cardiovascular collapse. Diagnosis: Clinical examination and history. Differentiate from anticholinergic toxidrome by diaphoresis and hyperactive bowel sounds. Tests: EKG, cardiac biomarkers, chest X-ray, blood gas, BMP, CK, coagulation studies, U-tox screen. Treatment: Stabilize ABCs, IV hydration, temperature monitoring, benzodiazepines. Avoid beta-blockers due to unopposed alpha agonism. Whole bowel irrigation for body packers; surgical removal if packets rupture. IV hydration for high CK levels. Observation period often necessary. Recap: Mimic sympathetic nervous system. Key symptoms: Diaphoresis, hyperactive bowel sounds. Treatment: Supportive care, benzodiazepines. Use poison control as a resource. References:
Costa VM, Grazziotin Rossato Grando L, Milandri E, Nardi J, Teixeira P, Mladěnka P, Remião F. Natural Sympathomimetic Drugs: From Pharmacology to Toxicology. Biomolecules. 2022;12(12):1793. doi:10.3390/biom12121793
Kolecki P. Sympathomimetic Toxicity From Emergency Medicine. Medscape. Updated March 11, 2024. https://emedicine.medscape.com/article/818583-overview
Williams RH, Erickson T, Broussard LA. Evaluating Sympathomimetic Intoxication in an Emergency Setting. Lab Med. 2000;31(9):497-508. https://doi.org/10.1309/WVX1-6FPV-E2LC-B6YG
Summarized by Steven Fujaros | Edited by Jorge Chalit, OMSIII
 

Contributor: Travis Barlock MD
Educational Pearls:
Wide-complex tachycardia is defined as a heart rate > 100 BPM with a QRS width > 120 milliseconds
Wide-complex tachycardia of supraventricular origin is known as SVT with aberrancy
Aberrancy is due to bundle branch blocks
Mostly benign
Treated with adenosine or diltiazem
Wide-complex tachycardia of ventricular origin is also known as VTach
Originates from ventricular myocytes, which are poor inherent pacemakers
Dangerous rhythm that can lead to death
Treated with amiodarone or lidocaine
80% of wide-complex tachycardias are VTach
90% likelihood for patients with a history of coronary artery disease
In assessing a wide-complex tachycardia, it is best to treat it as a presumed ventricular tachycardia
Treating SVT with amiodarone or lidocaine does no harm 
However, treating VTach with adenosine or diltiazem may worsen the condition
References
1. Littmann L, Olson EG, Gibbs MA. Initial evaluation and management of wide-complex tachycardia: A simplified and practical approach. Am J Emerg Med. 2019;37(7):1340-1345. doi:https://doi.org/10.1016/j.ajem.2019.04.027
2. Viskin S, Chorin E, Viskin D, Hochstadt A, Schwartz AL, Rosso R. Polymorphic Ventricular Tachycardia: Terminology, Mechanism, Diagnosis, and Emergency Therapy. Circulation. 2021;144(10):823-839. doi:10.1161/CIRCULATIONAHA.121.055783
3. Williams SE, O’Neill M, Kotadia ID. Supraventricular tachycardia: An overview of diagnosis and management. Clin Med J R Coll Physicians London. 2020;20(1):43-47. doi:10.7861/clinmed.cme.20.1.3
Summarized by Jorge Chalit, OMSIII | Edited by Meg Joyce & Jorge Chalit

Contributor: Aaron Lessen MD
Educational Pearls:
The case:
A gentleman came in from a nursing home with symptoms concerning for sepsis. He was hypotensive, hypoxic, febrile, and mentally altered.
His past medical history included previous strokes which had left him with deficits for which he required a feeding tube.
Initial workup included some point of care labs which revealed a sodium of 165 mEq/L (normal range 135-145)
Hypernatremia
What causes it?
Dehydration, from insufficient fluid intake. This might happen in individuals who cannot drink water independently, such as infants, elderly, or disabled people, as was the case for this patient.
Other causes of dehydration/hypernatremia include excessive sweating; diabetes insipidus; diuretic use; kidney dysfunction; and severe burns which can lead to fluid loss through the damaged skin.
How do you correct it?
Need to correct slowly, not more than 10 to 12 meq/L in 24 hours
Can do normal saline (0.9%) or half saline (0.45%) and D5, at 150-200 mL per hour.
Check the sodium frequently (every 2-3 hours)
Will likely need ICU-level monitoring
What happens if you correct it too quickly?
Cerebral edema
Seizures
Bonus fact: Correction of hyponatremia too quickly causes osmotic demyelination syndrome (ODS).
References
Chauhan, K., Pattharanitima, P., Patel, N., Duffy, A., Saha, A., Chaudhary, K., Debnath, N., Van Vleck, T., Chan, L., Nadkarni, G. N., & Coca, S. G. (2019). Rate of Correction of Hypernatremia and Health Outcomes in Critically Ill Patients. Clinical journal of the American Society of Nephrology : CJASN, 14(5), 656–663. https://doi.org/10.2215/CJN.10640918
Lindner, G., & Funk, G. C. (2013). Hypernatremia in critically ill patients. Journal of critical care, 28(2), 216.e11–216.e2.16E20. https://doi.org/10.1016/j.jcrc.2012.05.001
Muhsin, S. A., & Mount, D. B. (2016). Diagnosis and treatment of hypernatremia. Best practice & research. Clinical endocrinology & metabolism, 30(2), 189–203. https://doi.org/10.1016/j.beem.2016.02.014
Summarized by Jeffrey Olson MS2 | Edited by Meg Joyce & Jorge Chalit, OMSIII

Contributor: Aaron Lessem MD
Educational Pearls: 
Oseltamivir (Tamiflu) is an antiviral medication used commonly to treat influenza
Trials show that the medication reduces the duration of illness by less than 1 day (~16 hours in one systematic review)
Benefit only occurs if taken within 48 hours of symptom onset
Must be taken for 5 days
A 2024 meta-analysis reviewed 15 randomized-controlled trials for the risk of hospitalization
No reduction in hospitalizations with oseltamivir in patients over the age of 12
No difference in high-risk patients over the age of 65 or those with comorbidities
The authors note that the confidence interval in these populations is wide, indicating a need for subsequent studies in high-risk populations
Oseltamivir is associated with adverse effects including nausea, vomiting, and neurologic symptoms
The risk of adverse effects may outweigh the benefits of a small reduction in the duration of illness
References
1. Hanula R, Bortolussi-Courval É, Mendel A, Ward BJ, Lee TC, McDonald EG. Evaluation of Oseltamivir Used to Prevent Hospitalization in Outpatients with Influenza: A Systematic Review and Meta-Analysis. JAMA Intern Med. 2024;184(1):18-27. doi:10.1001/jamainternmed.2023.0699
2. Jefferson T, Jones M, Doshi P, Spencer EA, Onakpoya I, Heneghan CJ. Oseltamivir for influenza in adults and children: Systematic review of clinical study reports and summary of regulatory comments. BMJ. 2014;348(April):1-18. doi:10.1136/bmj.g2545
Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit
 

Contributor: Aaron Lessen MD
Educational Pearls:
Epinephrine is essential in the treatment of anaphylaxis, but is epinephrine dangerous from a cardiovascular perspective?
A 2024 study in the Journal of the American College of Emergency Physicians Open sought to answer this question.
Methods:
Retrospective observational study at a Tennessee quaternary care academic ED that analyzed ED visits from 2017 to 2021 involving anaphylaxis treated with IM epinephrine.
The primary outcome was cardiotoxicity
Results:
Out of 338 patients, 16 (4.7%) experienced cardiotoxicity. Events included ischemic EKG changes (2.4%), elevated troponin (1.8%), atrial arrhythmias (1.5%), ventricular arrhythmia (0.3%), and depressed ejection fraction (0.3%).
Affected patients were older, had more comorbidities, and often received multiple epinephrine doses.
Bottom line:
All adults presenting with anaphylaxis should be rapidly treated with epinephrine but monitored closely for cardiotoxicity, especially in patients with a history of hypertension and those who receive multiple doses.
These results are supported by a 2017 study that found that 9% (4/44) of older patients who received epinephrine for anaphylaxis had cardiovascular complications.
References
Kawano, T., Scheuermeyer, F. X., Stenstrom, R., Rowe, B. H., Grafstein, E., & Grunau, B. (2017). Epinephrine use in older patients with anaphylaxis: Clinical outcomes and cardiovascular complications. Resuscitation, 112, 53–58. https://doi.org/10.1016/j.resuscitation.2016.12.020
Pauw, E. K., Stubblefield, W. B., Wrenn, J. O., Brown, S. K., Cosse, M. S., Curry, Z. S., Darcy, T. P., James, T. E., Koetter, P. E., Nicholson, C. E., Parisi, F. N., Shepherd, L. G., Soppet, S. L., Stocker, M. D., Walston, B. M., Self, W. H., Han, J. H., & Ward, M. J. (2024). Frequency of cardiotoxicity following intramuscular administration of epinephrine in emergency department patients with anaphylaxis. Journal of the American College of Emergency Physicians open, 5(1), e13095. https://doi.org/10.1002/emp2.13095
Summarized by Jeffrey Olson MS2 | Edited by Meg Joyce & Jorge Chalit OMS II

Contributor: Aaron Lessen MD
Educational Pearls:
Opioid overdoses that are reversed with naloxone (Narcan), a mu-opioid antagonist, can precipitate acute withdrawal in some patients
Treatment of opioid use disorder with buprenorphine can also precipitate withdrawal
Opioid withdrawal symptoms include nausea, vomiting, diarrhea, and agitation
Buprenorphine works as a partial agonist at mu-opioid receptors, which may alleviate withdrawal symptoms
The preferred dose of buprenorphine is 16 mg
Treatment of buprenorphine-induced opioid withdrawal is additional buprenorphine
Adjunctive treatments may be used for other opioid withdrawal symptoms
Nausea with ondansetron
Diarrhea with loperamide
Agitation with hydroxyzine
References
1. Quattlebaum THN, Kiyokawa M, Murata KA. A case of buprenorphine-precipitated withdrawal managed with high-dose buprenorphine. Fam Pract. 2022;39(2):292-294. doi:10.1093/fampra/cmab073
2. Spadaro A, Long B, Koyfman A, Perrone J. Buprenorphine precipitated opioid withdrawal: Prevention and management in the ED setting. Am J Emerg Med. 2022;58:22-26. doi:10.1016/j.ajem.2022.05.013
Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit