Cardiogenic shock

Background

  • Leading cause of death in pts w/ MI who reach the hospital alive

Work-Up

  • Labs
    • Troponin
    • Lactate
    • CBC
    • Chem
    • BNP
      • <100 may rule-out cardiogenic shock
  • ECG
  • CXR
  • TTE

Etiology

  • Myocardial infarction
    • Pump failure
    • Mechanical complications
    • Acute MR (papillary muscle rupture)
    • VSD
    • Free-wall rupture
  • RV infarction
  • Decreased forward flow
    • Sepsis
    • Rate-related
      • Bradycardia
      • Tachycardia
    • Myocarditis
    • Myocardial contusion
    • Cardiomyopathy
  • Mechanical obstruction to forward flow
    • AS
    • HOCM
    • Mitral stenosis
    • Pericardial
  • LV regurgitation
    • Chordal rupture
    • Aortic insufficiency

DDX

  • MI
  • PE
  • COPD exacerbation
  • Peri/myocarditis
  • Aortic dissection
  • Pericardial tamponade
  • Acute valvular insufficiency
  • Sepsis
  • Hemorrhage
  • Toxins/drugs of abuse

Treatment

  • General
    • Intubation
      • Decreases O2 demand BUT may worsen preload
  • Coronary perfusion
  1. Small Fluid challenge
  2. Increase inotropy
    1. Titrate to clinical effect
      • Dobutamine or Milrinone:
      1. Use milrinone if pt is on BB
      2. CaCl 1gm
        1. Give if pt is hypocalcemic
  3. Achieve MAP >65

Pressors

Pressor Initial Dose Max Dose Cardiac Effect BP Effect Arrhythmias Special Notes
Dobutamine 2.5mcg/kg/min 10-40 mcg/kg/min mainly inotrope (ß1) alpha effect minimal Some HR(ß1) increase. Also Increase SA and AV node fx Debut Research 1979[1] Isoproterenol has most Β2 vasodilatory and Β1 HR effects
Dopamine 2mcg/kg/min 20-50 mcg/kg/min β1 and NorEpi release α effects if > 20mcg/kg/min Arrhythmogenic from β1 effects More adverse events when used in shock compared to Norepi[2]
Norepinephrine 8-12mcg/min 30 mcg/min β1 direct effect β1 and α1,2 effects Less arrhythmias than Dopamine[2] Increases MAP, coronary perfusion pressure, little β2 effects.
Milrinone 50mcg/kg x 10 min 0.375-75mcg/kg/min Direct influx of Ca2+ channels Smooth muscle vasodilator PDE Inhibitor which increases Ca2+ uptake by sarcolemma. No venodilatory activity
Phenylephrine 100-180mcg/min then 40-60mcg/min 0.4-9 mcg/kg/min Alpha agonist Long half life
Vasopressin Fixed Dose 0.4 U/min unknown increases via ADH peptide should not be titrated due to ischemic effects
  • Transfusion
    • Consider if Hb < 10
  • Specific
    • Mitral Regurg
      • Need to increase forward flow
        • Dobutamine (contractility)
        • Nitroprusside (afterload reduction)
    • MI
      • PCI or thrombolysis
    • Tox
      • Reverse CCB, BB, or dig toxicity

See Also

Source

Tintinalli EMCrit Podcast 10

  1. Edmund H. Sonnenblick, M.D., William H. Frishman, M.D., and Thierry H. LeJemtel, M.D. Dobutamine: A New Synthetic Cardioactive Sympathetic Amine
  2. 2.0 2.1 De Backer Daniel et al. Comparison of Dopamine and Norepinephrine in the Treatment of Shock. NEJM 363(9). 779-789