Sun31October0735PM 20

A 58-year-old man is admitted to the coronary care unit (CCU) post anterior myocardial infarction.

On examination you are concerned about him. He is breathless and clinically appears to be in pulmonary oedema. There is also evidence of a new pansystolic murmur.

The central venous pressure is approximately 20 cmH2O, blood pressure 80/50 mmHg. He is currently being treated with boluses of intravenous furosemide. The patient has central access and an arterial line. A cardiac output monitor reveals low cardiac output, low cardiac index and a high systemic vascular resistance.

He is presently on adrenaline and dobutamine infusions, but is still not passing good volumes of urine.

Which of the following interventions would be most appropriate?

(Please select 1 option)

Intravenous furosemide infusion

Intra-aortic balloon pump (IABP) This is the correct answer

Left ventricular assist device (LVAD)

Angiogram +/- Angioplasty

Glyceryl trinitrate (GTN) infusion Incorrect answer selected

Explanation

This patient has ruptured a papillary muscle post myocardial infarction and has proceeded to go into cardiogenic shock. He requires a definitive intervention to assist with the circulatory failure. Intra-aortic balloon pump (IABP) remains the most widely used circulatory assist device in critically ill patients with cardiac disease.

The primary goal of intra-aortic balloon pump (IABP) treatment is to increase myocardial oxygen supply and decrease myocardial oxygen demand. Although percutaneous LVAD provides superior haemodynamic support in patients with cardiogenic shock compared with IABP, the use of these more powerful devices does not improve early survival. Results do not yet support percutaneous LVAD as first choice approach in the mechanical management of cardiogenic shock.

The patient is too unstable to undergo an angiogram at this time and the other options are insufficient to achieve haemodynamic stability. Severe mitral regurgitation secondary to papillary muscle dysfunction or rupture after myocardial infarction can lead to significant haemodynamic instability. This can initially be managed by IABP, pending definitive surgery.

Reference:

Cheng JM, den Uil CA, Hoeks SE, et al. Percutaneous left ventricular assist devices vs. intra-aortic balloon pump counterpulsation for treatment of cardiogenic shock: a meta-analysis of controlled trials. Eur Heart J. 2009;30(17):2102-8.

Krishna M, Zacharowski K. Principles of intra-aortic balloon pump counterpulsation. Contin Educ Anaesth Crit Care Pain. 2009;9(1):24-28.

Answer Statistics

1

3%

2

56%

3

10%

4

25%

5

9%

Times answered: 291