Podcast #396: Oncologic Emergencies

Author: Rachel Brady, MD

Educational Pearls:

Hypercalcemia of malignancy:

  • Hypercalcemia of malignancy can present with lethargy, muscle weakness, hyperreflexia, altered mental status, cardiac dysrhythmias, and even cardiac arrest.
  • Treatment is based both on calcium level and symptoms
  • Intravenous rehydration is first line treatment
  • Other options include steroids, bisphosphonates and calcitonin.

Tumor Lysis Syndrome

  • Occurs due to the breakdown of tumor cells after chemotherapy/radiation
  • Presents as hyperkalemia, hyperuricemia, hyperphosphatemia, and hypocalcemia
  • Treatment is very similar to severe hypercalcemia – hydration with crystalloids
  • Hyperuricemia can be treated using rasburicase or allopurinol

 

References:

Ñamendys-Silva SA, Arredondo-Armenta JM, Plata-Menchaca EP, Guevara-García H, García-Guillén FJ, Rivero-Sigarroa E, Herrera-Gómez A. Tumor lysis syndrome in the emergency department: challenges and solutions. Open Access Emerg Med. 2015 Aug 20;7:39-44. doi: 10.2147/OAEM.S73684. eCollection 2015. Review. PubMed PMID: 27147889; PubMed Central PMCID: PMC4806807.

Zagzag J, Hu MI, Fisher SB, Perrier ND. Hypercalcemia and cancer: Differential diagnosis and treatment. CA Cancer J Clin. 2018 Sep;68(5):377-386. doi: 10.3322/caac.21489. Epub 2018 Sep 21. Review. PubMed PMID: 30240520.

 

Summary by Travis Barlock, MS4  | Edited by Erik Verzemnieks, MD

Podcast # 338: Mononucleosis Predictors

Author: Chris Holmes, MD

Educational Pearls:

  • Symptoms commonly seen with mononucleosis are palatal petechiae, posterior cervical lymphadenopathy, inguinal/axillary lymphadenopathy, splenomegaly, and/or atypical lymphocytes > 10% on CBC.
  • Among these, posterior cervical lymphadenopathy and atypical lymphocytes > 10% were the most sensitive (sensitivities of 0.64 and 0.66 respectively).

References

Welch, JL et al. What Elements Suggest Infectious Mononucleosis? Annals of Emergency Medicine. 2018. 71(4): 521-522. Doi: 10.1016/j.annemergmed.2017.06.014

Podcast # 336: Hypokalemia

Author: Dylan Luyten, MD

Educational Pearls:

  • Most important questions to answer with low potassium are 1. What are their symptoms? 2. Can they take potassium by mouth?
  • Oral repletion is faster, cheaper, and more effective than IV repletion.
  • Give IV potassium when patients have K < 2.5 mmol/L or present with arrhythmias and/or characteristic EKG changes (flattened T waves).
  • Most patients who are hypokalemic are hypomagnesemic and require magnesium supplementation.  Checking a level is unnecessary.

References

Ashurst J, Sergent SR, Wagner BJ, Kim J. Evidence-based management of potassium disorders in the emergency department. Emerg Med Pract. 2016 Nov 22;18(Suppl Points & Pearls):S1-S2

 

Whang R, Flink EB, Dyckner T, et al. Magnesium depletion as a cause of refractory potassium repletion. Arch Intern Med 1985; 145:1686.

Check out this episode!

Podcast # 331: Oral Rehydration Therapy (ORT)

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.

Podcast # 329: Hypokalemic Periodic Paralysis

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.

Podcast # 327: No More Hemoccults

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

Podcast #324: Superwarfarin

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

Podcast #323: Calcium Channel Toxicity

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.

Podcast #322: Methemoglobinemia

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.

Podcast #267: Causes of Very High Lactate

Author: Dylan Luyten, M.D.

Educational Pearls

  • Lactate is a byproduct of anaerobic metabolism, a sign of dying tissue. Dangerous causes of high lactates will not normalize with repeat labs.
  • Crush injuries, seizures, bowel necrosis,  end-stage liver disease, and metformin toxicity are common causes of highly elevated lactate.

References: https://lifeinthefastlane.com/ccc/lactic-acidosis/