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

Podcast #130: DIC

disseminated-intravascular-coagulation-4Run Time: 3 minutes

Author: Susan Brion M.D.

Educational Pearls:

  • Presentation: an elderly known diabetic presents via EMS confused with an elevated blood glucose. Upon arrival the patient is found to be in DKA, with evidence of a hip fracture from a fall yesterday. The patient develops signs of shock with declining BP. INR is 4, but the patient is not on anticoagulants. Platelets are 45, creatinine 2.9, LFTs are all elevated, and hematocrit is 32.
  • This patient is in DIC, disseminated intravascular coagulation, an acute systemic process where the coagulation pathway and fibrinolytic pathway are activated at the same time.
  • May be acute or chronic: Acute DIC has more bleeding, and chronic DIC has more thrombosis.
  • DIC may result in end-organ damage or death, and is worsened by acidosis and hypothermia, the deadly triad in trauma.
  • Heat stroke, crush injuries, amphetamine overdose, aortic aneurysms, and rattlesnake bites can also cause DIC.
  • PCC or other factor replacement is not helpful in treatment because it causes more thrombus formation, “fueling the fire”.

Link to Podcast: http://medicalminute.madewithopinion.com/dic/

References:  https://medlineplus.gov/ency/article/000573.htm

Podcast #110:  Elevated Lactate


lactate-plus-is-a-highly-recommended-analyzer-both-in-a-clinical-and-athletic-setting-1Run Time:
 3 minutes

Author:  Susan Brion M.D.

Educational Pearls:

  • Not all that is elevated lactate is sepsis.
  • Lactate is produced under anaerobic conditions whenever there is any state of hypoperfusion or hypermetabolic state. It is produced by all tissues, most prominently by muscle tissue, and is cleared by the liver.
  • A normal level can be anywhere from 2 to 2.5, and an elevated lactate is generally caused by an increase in production of lactate, decreased clearance of lactate, or both. A decrease in the enzyme cofactors, like thiamine, can also elevate a lactate and is often seen in alcoholics.
  • Etiologies of an elevated lactate include sepsis, septic shock, undifferentiated shock, trauma, seizure, increase in muscle activity, severe asthmatics, regional ischemia, burns, smoke inhalation, DKA, thiamine deficiency, liver dysfunction, malignancy, and a long list of medications including metformin, epinephrine, extended use of propofol, Tylenol overdose, and beta2 agonists.

Link to Podcast: http://medicalminute.madewithopinion.com/elevated-lactate/

References: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3975915/