Podcast # 371: EKG changes of Hyperkalemia

Author:  Jared Scott, MD

Educational Pearls:

  • EKG changes do not necessarily correlate to degree of hyperkalemia
  • Traditional progression through peaked T-waves, flattened p-waves, QRS widening, and then sine-waves before asystole

References

Mattu A, Brady WJ, Robinson DA. Electrocardiographic manifestations of hyperkalemia. Am J Emerg Med. 2000;18:721–729.

Podcast # 346: Pediatric DKA

Author: Chris Holmes, MD

Educational Pearls:

  • There is a risk of cerebral edema in pediatrics with DKA if over resuscitated.
  • Recent study comparing normal saline vs. ½ normal saline showed no difference in rates of cerebral edema regardless of rate of infusion.
  • Recommend sticking with a fluid resuscitation protocol you are familiar with (i.e., 2 rounds of 10cc/kg bolus of NS).

 

References

Glaser, N. S., Ghetti, S., Casper, T. C., Dean, J. M., & Kuppermann, N. (2013). Pediatric Diabetic Ketoacidosis, Fluid Therapy and Cerebral Injury: The Design of a Factorial Randomized Controlled Trial. Pediatric Diabetes, 14(6), 435?446. http://doi.org/10.1111/pedi.12027

Podcast #310: Bicarb in DKA

Author: Gretchen Hinson, M.D.

Educational Pearls:

  • Controversial topic.
  • Pathophysiology – acidosis leads to an extracellular potassium shift. Patients in DKA will be intracellularly potassium deplete, but will have a falsely normal/elevated serum potassium.
  • 3 risk of giving bicarb in DKA – alkalosis will drive potassium intracellularly but can overshoot (hypokalemia) and  increase risk of arrhythmias; bicarb slows clearance of ketones and will transiently increase their precursors; bicarb can cause elevated CSF acidosis.
  • 3 instances when appropriate to give bicarb in DKA: DKA in arrest; hyperkalemic in DKA with arrhythmia; fluid and vasopressor refractory hypotension.

References:

Bratton, S. L., & Krane, E. J. (1992). Diabetic Ketoacidosis: Pathophysiology, Management and Complications. Journal of Intensive Care Medicine, 7(4), 199-211. doi:10.1177/088506669200700407

Chua, H., Schneider, A., & Bellomo, R. (2011). Bicarbonate in diabetic ketoacidosis – a systematic review. Annals of Intensive Care, 1(1), 23. doi:10.1186/2110-5820-1-23

Podcast #292: Hypercalcemia

Author: John Winkler, M.D. 

Educational Pearls

  • Normally, the parathyroid is the master regulator of serum Ca levels. It secretes PTH, which stimulates calcium uptake from the bone and gut.
  • Causes of hypercalcemia include: parathyroid tumor, lytic bone lesions (multiple myeloma), breast cancer, renal injury, and some lung cancers.
  • Hypercalcemia can lead to poor bone quality and pathological fractures. It can also cause heart arrhythmias.
  • It is important to order an ionized calcium to quantify the level of hypercalcemia, since calcium binds to albumin.
  • Treatment for hypercalcemia includes fluids and loop diuretics.

References:  https://emedicine.medscape.com/article/766373-treatment

Podcast #290: The Biochemistry of DKA

Author: Dave Rosenberg, M.D.

Educational Pearls

  • DKA commonly causes hyperkalemia, leading to peaked T-waves on ECG. However, DKA causes hypokalemia at the same time.
  • In DKA, glucose cannot be taken into the cells. This signals the body to create and use acidic ketones for energy. This leads to acidosis. To compensate for increased acid, H ions are pumped into cells. To maintain electroneutrality, K is pumped out of the cell. At the kidney, K is lost in the urine.
  • Overall, while serum K is high in DKA, total body K is low. The derangement in K can lead to life-threatening arrhythmias.
  • Treatment for DKA can induce hypokalemia, as the K will shift back into the cells with insulin administration. Therefore, treatment for DKA needs to include K.

References:  http://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/diabetes-mellitus-and-disorders-of-carbohydrate-metabolism/diabetic-ketoacidosis-dka

Podcast #186: IV Contrast

Run Time: 2 minutes

Author: Aaron Lessen M.D.

Educational Pearls:

  • Regularly a patient’s creatinine level is an important factor in determining whether a patient will receive IV contrast with a CT because it is thought that contrast can harm the kidneys and could worsen underlying kidney disease.
  • A recent retrospective study compared the rates of worsening kidney problems between patients who received a CT scan with contrast, a CT without contrast, and no CT.
  • The study even included patients with creatinines of up to 4 before excluding patients.
  • The study suggested that there is no difference in the rate of worsening kidney problems between the three groups.

References: http://www.annemergmed.com/article/S0196-0644(16)31388-9/fulltext

Podcast #181: Electrolyte Emergency

Run Time: 5 minutes

Author: Peter Bakes, MD

Educational Pearls:

  • Calcium is ubiquitous ion in the body necessary for bone, muscle, and nerve function
  • Hypocalcemia is associated with tetany (elicit Chvostek’s sign and Trousseau’s sign) and irritability
  • Hypocalcemia can progress to seizures and prolonged QT which can cause cardiac arrest
  • Hypocalcemia can be caused by vitamin D deficiency
  • Patients with malabsorption are at risk of vitamin deficiencies

Link to Podcast: http://medicalminute.madewithopinion.com/electrolyte-emergency/

References: http://emedicine.medscape.com/article/241893-overview

http://www.mayoclinic.org/diseases-conditions/short-bowel-syndrome/basics/definition/con-20037215

Podcast #178: Lupus Myocarditis

3c26d8f8-0b3c-4930-9051-44c6a0804477Run Time:  3 minutes

Author: Gretchen Hinson M.D.

Educational Pearls:

  • Case presentation: a 44 year-old male after a syncope was found to have a heart rate of 261 wide complex tachycardia and a SBP in the 80s for EMS in the field. The patient was given adenosine on arrival to the ED, but with no resolution of the tachycardia, but after electrocardioversion the patient’s heart rate converted to 100 but still in a wide complex tachycardia.
  • The missing piece of history for this patient is a diagnosis of lupus with previous pulmonary complications and systemic skin changes.
  • Lupus can also cause myocarditis and conduction abnormalities along with the more common skin changes and renal complications.

Link to Podcast: http://medicalminute.madewithopinion.com/lupus-myocarditis/

References: http://rheumatology.oxfordjournals.org/content/45/suppl_4/iv8.full

Podcast #167: Adrenal Glands

6bb5769a-5143-47ec-b641-df1682524916Run Time: 3 minutes

Author: Jared Scott M.D.

Educational Pearls:

  • Adrenal glands sit on top of kidneys, and are approximately the size of a walnut.
  • Each of the different layers of the adrenal glands make hormones and those hormones become more desirable with each layer – salt hormones→ sugar hormones→ sex hormones.
  • Top layer: the zona glomerulosa makes aldosterone, which moderates sodium, potassium, and BP.
  • Zona fasciculata makes cortisol, which helps with sugar and BP management.
  • Zona reticularis makes progesterones, androgens, and estrogen precursors – or the “sex” hormones.
  • Deepest layer: adrenal medulla produces epinephrine and norepinephrine.
  • Critically ill patients without adrenal glands can have major complications and need to have their missing hormones replaced.
  • Adrenal function can also be suppressed from long-term daily steroid use.

Link to Podcast: http://medicalminute.madewithopinion.com/adrenal-glands/ 

References: http://www.hormone.org/diseases-and-conditions/adrenal

Podcast #141: Heat Stroke

836cd891-148b-438a-8707-e60b19737363Run Time: 4 minutes

Author: Nicholas Hatch M.D.

Educational Pearls:

  • It is possible to acclimatize to heat, however it takes approximately 2-3 weeks.
  • Never give tylenol for a heat related illness and heat related hyperthermia, it is not helpful.
  • Heat rash: most common in kids. Lotion should not be used because it blocks the ducts of the skin and can cause irritation and inflammation. The rash, which resembles a sunburn, is the body compensating for the increased heat by vasodilating blood vessels to get blood to the periphery and cool it off.
  • Muscle cramps: Especially in major muscle groups, oral hydration often enough, but the patient will need more than just water. Patients require an electrolyte based solutions like gatorade.
  • Heat syncope: characterized by passing out and returning to a normal level of consciousness and normal temperature. Patients potential can have a temperature up  to 104° Fahrenheit with mild brief altered mental status, but nothing significant.
  • Heat stroke: characterized by major altered mental status, temperature above 104, deceased perspiration, nausea, vomiting, and other end organ dysfunction. This is a life threatening emergency. If a patient says that they have “heat stroke” they probably do not…these people are usually sick as stink.
  • Hydration and rapid cooling are the treatment that should be initiated for heat stroke – undressing the patient and misting with a fan, ice packs applied to the groin and axilla, and chest tube and lavage or bladder irrigation w/ ice cold water are the hallmarks of therapy. .

Link to Podcast: http://medicalminute.madewithopinion.com/heat-stroke/

References: https://medlineplus.gov/ency/article/000056.htm