Podcast # 350: Pressors and Ischemia

Author: Nick Hatch, MD.

Educational Pearls:

  • A common concern using vasopressors is the risk of digital and mesenteric ischemia.
  • The absolute risk of digital ischemia and/or mesenteric ischemia is pretty low. Norepinephrine at its highest doses carries a 5% digital ischemia rate and a 2% mesenteric ischemia rate.
  • The studies demonstrating this complication were predominately patients with pre-existing liver disease.
  • Providers commonly mistake purpura fulminans, a common complication of sepsis, for digital ischemia.

 

References

Brown, SM. et al.  Survival After Shock Requiring High-Dose Vasopressor Therapy. Chest. 2013. 143(3), 664?671. http://doi.org/10.1378/chest.12-1106.

Malay MB et al. Heterogeneity of the vasoconstrictor effect of vasopressin in septic shock. Critical Care Medicine. 2004. 32(6), 1327-31.

Podcast # 340: Drowning

Author: Chris Holmes, MD

Educational Pearls:

  • Epidemiology: 80% male, ages 1-4 at greatest risk, African-American > Caucasian.
  • Freshwater and ocean water may have more bacteria than pool water.
  • Salt water is hyperosmolar, which theoretically increases risk of pulmonary edema.
  • Greatest physiologic insult is from hypoxia secondary to fluid aspiration or laryngeal spasm. Patient survival is related to presentation on arrival.
  • Workup includes CXR and ABG; consider C-spine immobilization/imaging when cervical injury is strongly suspected (i.e. diving injury).
  • Treatment consists of supplemental oxygen therapy. Consider CPAP or intubation.

References

Szpilman D, Bierens JJ, Handley AJ, Orlowski JP. Drowning. N Engl J Med. 2012. 366(22):2102-10. doi: 10.1056/NEJMra1013317.

Schmidt A, Sempsrott J. Drowning In The Adult Population: Emergency Department Resuscitation And Treatment. Emerg Med Pract. 2015. 17(5):1-18.

Podcast #334: Resuscitative Thoracotomy

Author: Dylan Luyten, MD

Educational Pearls:

  • Resuscitative thoracotomies are most commonly used for treatment of cardiac tamponade and to selectively perfuse the brain and heart in setting of hemorrhage control.
  • Resuscitative thoracotomies are indicated in patients with penetrating injuries who lose vitals in the ED or those who had vitals within the last 10 minutes.
  • Do not perform resuscitative thoracotomies on patients who have no signs of life on scene, asystole as their presenting rhythm, or no vitals  > 10 minutes.
  • Resuscitative thoracotomies are not indicated in patients with blunt trauma  unless vitals are present in ED.
  • Do not perform CPR on trauma patients.

References:

Karmy-Jones R, Namias N, Coimbra R, et al. (2014).Western Trauma Association critical decisions in trauma: penetrating chest trauma. Journal of Trauma Acute Care Surgery. 77:994.

Seamon MJ, Shiroff AM, Franco M, et al. (2009) Emergency department thoracotomy for penetrating injuries of the heart and great vessels: an appraisal of 283 consecutive cases from two urban trauma centers. Journal of Trauma. 67:1250.

Podcast #332: Door To Furosemide Time

Author: Nick Hatch, MD

Educational Pearls:

  • Recent study argues that CHF patients receiving furosemide within 60 minutes of arrival had a lower in-hospital mortality than those receiving it after (2.3% vs. 6.0%, p=0.002).
  • A flaw in the study is that there were significant baseline differences between groups.

References:

Matsue Y et al. Time-to-Furosemide Treatment and Mortality in Patients Hospitalized With Acute Heart Failure. JACC 2017. PMID: 28641794

Podcast #320: PE in Pregnancy

Author: Don Stader, M.D.

Educational Pearls:

  • Pulmonary embolism is one of the leading causes of maternal mortality.
  • There is disagreement among different medical societies about the value of D-dimer as a screening modality. If you use it, consider the rational D-dimer approach whereby you add 250 to your cut-off for every trimester.
  • A useful screening modality is an ultrasound of bilateral lower extremities looking for DVT.
  • Keep in mind, both a V/Q scan and CT scan have a significant amount of radiation. CTA is probably the right diagnostic test (less radiation than CT w&w/o).
  • Always use the shared decision-making model and clinical acumen to choose your tests.

References:

Leung AN, et. al. (2011). An official American Thoracic Society/Society of Thoracic Radiology clinical practice guideline: evaluation of suspected pulmonary embolism in pregnancy. American Journal of Respiratory and Critical Care Medicine. 184(10):1200-8

 

Polak JF, Wilkinson DL. (1991). Ultrasonographic diagnosis of symptomatic deep venous thrombosis in pregnancy. American Journal of Obstetrics and Gynecology. 165(3):625-9.

Sachs BP, et. al. (1987). Maternal mortality in Massachusetts. Trends and prevention. New England Journal of Medicine. 316(11):667-72.

Check out this episode!

Podcast #319: Cardiac Arrest Survival Factors

Author: Aaron Lessen, MD

Educational Pearls:

  • Shockable rhythms like V-fib or V-tach have a better prognosis than patients with PEA or asystole.
  • Recent study has shown an initial electrical frequency in PEA between 10-24/min had worse outcomes than PEA with initial rhythm over 60/min.
  • Patients with an initial electrical frequency in PEA over 60/min did just as well as patients with shockable rhythms. Of them, there was a 22% survival rate with 15% having a good neurologic outcome.

References:

Weiser, C., et al. (2018). Initial electrical frequency predicts survival and neurological outcome in out of hospital cardiac arrest patients with pulseless electrical activity. Resuscitation. 125:34-38

Podcast #316: Abnormalities in Alcohol Intoxication

Author: Michael Hunt, M.D.

Educational Pearls:

  • 1% of patients presenting to ED with alcohol intoxication end up going to the ICU.
  • Most common critical illnesses were acute hypoxic respiratory failure, sepsis, and intracranial hemorrhage.
  • Predictive markers: Vital abnormalities (hypoxia, tachycardic, tachypneic, hypothermic, hyperthermia, hypoglycemia) and patients receiving parenteral sedatives had higher incidence of ICU admission.

References:

Klein, LR; et al. (2018). Unsuspected Critical Illness Among Emergency Department Patients Presenting for Acute Alcohol Intoxication. Annals of Emergency Medicine. 71(3):279-288

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 #308: Ultrasound in Cardiac Arrest

Author: Aaron Lessen, M.D.

Educational Pearls:

  • There is currently debate within the medical community about what constitutes cardiac activity on ultrasound in the setting of cardiac arrest. A recent study has shown there providers looking at the same clips from an echo will disagree about what constitutes cardiac activity.
  • Some of the confusion stems from movement that is not cardiac in etiology. For example, some alvular movement can be due to IV fluids and some cardiac motion can be due to the patient being bagged.
  • Cardiac activity is defined as “Any intrinsic motion of the myocardium.” However, even if this is present, it is important to ask if it clinically significant cardiac activity.
  • Despite disagreement, ultrasound can be useful for clinical decision making.

References:

Gaspari R et al. (2016) Emergency Department Point-Of-Care Ultrasound in Out-Of-Hospital  and in-ED Cardiac Arrest. Resuscitation; 109: 33 ? 39.

Hu K et al. (2017) Variability in Interpretation of Cardiac Standstill Among Physician Sonographers. Ann Emerg Med.

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