Cardiogenic shock

Definition

Shock due to the heart not pumping properly

Epidemiology

Pathophysiology

Something stops your heart pumping; this is bad. Here's a list of somethings:

• MI
• Arrhythmias
• PE
• Tension pneumothorax
• Cardiac tamponade
• Myocarditis/myocardial depression (usually due to drugs, hypoxia, acidsosis, sepsis)
• Endocarditis
• Aortic dissection

Clinical Features

Depends on the cause.

Investigations

• ECG
• U+E
• FBC
• ABG
• CXR
• Echo
• Chest CT if necessary (suspected aortic dissection or PE)

Keep your eye on central venous pressure, BP, ABG, ECG.

Management

• ABC
• Give high-flow 100% O₂
• Diamorphine 2.5-5mg for pain/anxiety
• Correct arrhythmias, electrolyte abnormalities and acid-base disturbance

Generally, by this point they'll have all sorts of clever stuff like a central line in. This allows you to measure stuff and it you can measure Pulmonary Capillary Wedge Pressure (PCWP). (They ram a pressure-measuring device as far into the lung as possible. It's wedge shaped. It gets stuck. You measure the pressure.) If PCWP <15mmHg

• Give plasma expander (typically colloid) 100ml/15min iv. Aim for PCWP 15-20mmHg.

If PCWP >15mmHg

• Dobutamine (inotropic support) 2.5-10 micrograms/kg/min. Aim systolic BP >80mmHg.

If both these fail, consider:

• Dopamine 2.5microgrames/kg/min via central line
• Intra-aortic balloon pump

Treat the cause when you can.