Management of cardiogenic shock after acute coronary syndromes

Question 1

Definition of cardiogenic shock (Clinical)

Answer 1

Systolic BP <90mmHg with adequate volume and signs of clinical hypoperfusion:
- Cool peripherally
- Oliguria
- Reduced GCS
- Metabolic acidosis
- Raised lactate or Cr

Question 2

Pathophysiology of cardiogenic shock following MI

Answer 2

• coronary artery obstruction leads to myocardial hypoxia ->ischaemia -> infarction
• Myocardial necrosis causes an overall reduced contractility of the left ventricle
• This leads to reduced cardiac output, increased LV filling pressures and increased LVEDP
• Increased LVEDP reduces CPP and worsens myocardial ischaemia
• Carotid baroreceptors stimulate to the reduced CO and activate RAAS and the adrenergic system
• This leads to further vasoconstriction, water retention, acidosis and congestion

Question 3

Management of cardiogenic shock after MI

Answer 3

The only treatment with an effective evidence base is PCI revascularization.

A/B
- Intubation and careful use of PEEP (will reduce LV afterload but can worsen RV pre-load)
- CPAP

C
- Vasopressors and inotropes
- IABP
- VA-ECMO as a bridge to surgery

D
- Adequate sedation to enable optimal ventilation and reduced oxygen consumption
- Care on the harms of oversedation and reduced CO

E/F
- AKI is common, RRT can be useful for treating acidosis and congestion

G
- Liver congestion is common, monitor LFTs
- Glycaemic control and PPI as for ICU

H
- Anaemia can develop may be beneficial to push transfusion target to 90-100 in these patients