Cardiogenic Shock
Cardiogenic Shock¶
1. Persistent hypotension
- (SBP <90 mmHg or MAP below baseline)
2. Cardiac Index <1.8 L/min/m^2 w/o support
- (<2.2 L/min/m^2 with support)
3. Adequate or elevated filling pressure
- (LVEDP >18 mmHg, RVEDP >10 mmHg)
Etiology¶
- Ischemic
- Acute MI most commonly
- Valve related
- Acute Aortic or Mitral Regurgitation
- Rate Related
- Cardiomyopathy
- Toxicologic
Calculating CO, CI, and CPO¶
- CO (Cardiac Output), L/min = VO2 / [(SaO2 - SvO2) x Hb x 13.4]
- Where VO2 = 125 mL O2/min x BSA
- BSA = [(Height, cm x Weight, kg)/ 3,600]½
- In elderly patients (age ≥70 years), use 110 mL O2 x BSA for VO2
- CI (Cardiac Index), L/min/m2 = CO/BSA
- SV (Stroke Volume), mL/beat = CO/HR
- Normal Values
- CO = 4.0-8.0 L/min
- CI = 2.5-4.0 L/min/m2
- SV = 60-100 mL/beat
- MAP ≥60 mmHg
- Note: SaO2 should be acquired by arterial blood gas measurement. SvO2 should be acquired by mixed venous gas from a pulmonary artery catheter. Formula assumes decimal values, not percentages
- CPO (Cardiac Power), W = (CO x MAP) / 451
- CPO < 0.6 watts is indicative of hemodynamic compromise and is associated with increased risk of mortality
- Cardiac power is the strongest hemodynamic correlate of mortality in cardiogenic shock: a report from the SHOCK trial registry
- Improved Prognostic Performance of Cardiac Power Output With Right Atrial Pressure: A Subanalysis of the ESCAPE Trial
- CPO Calculator
- CPO < 0.6 watts is indicative of hemodynamic compromise and is associated with increased risk of mortality
Management¶
- Management of Cardiogenic Shock
- Contemporary Management
- Figure out etiology
- Valve related
- Ischemic
- Rate Related
- Cardiomyopathy
- Toxicologic
- Inotropic Therapy
- Milrinone = Dobutamine
- Use in hypotension, endo-organ hypoperfusion, shock
- Generally, presents with hypoperfusion (reduced urine output)
- If due to contractile failure
- Dobutamine + Norepinephrine to get MAP ≥65 w/ Mechanical circulatory support
- Intra-aortic Balloon Counter Pulsation
- Dobutamine + Norepinephrine to get MAP ≥65 w/ Mechanical circulatory support
- Short-term intravenous milrinone for acute exacerbation of chronic heart failure: a randomized controlled trial
- Pressors if needed for MAP > 65
- IV Vasopressor (norepinephrine)
- Levophed > Dopamine
- Useful in Pulmonary congestion for rapid dyspnea relief if preserved Blood pressure
- Epinephrine is good too but more arrhythmogenic
- Mechanical Cardiac Support (MCS)
- Shock Centers
Further Reading¶
- Manual of Cardiovascular Medicine by Brian P. Griffin MD is high yield and covers just about every topic you may encounter in the CICU. This manual is particularly useful for first-year fellows
- Managing Patients with Short-Term MCS
- Great EMCrit article
- Journal Feed