Wed3November0844PM 20

A 65-year-old man is admitted to the intensive care unit following an inferior myocardial infarction. A pulmonary artery floatation catheter is inserted and the following values obtained:

Right atrial pressure 16 mmHg (1-5 mmHg)

Pulmonary artery pressure 25/0 mmHg (25/9 mmHg)

Pulmonary artery occlusion pressure 3 mmHg (8-12 mmHg)

Mixed venous oxygen saturation 65% (65-70%)

Cardiac index 2.3 L/min/m2 (2.6-4.2 L/min/m2)

With which diagnosis are these findings consistent?

(Please select 1 option)

Mitral regurgitation

Cardiogenic shock Incorrect answer selected

Cardiac tamponade

Hypovolaemia This is the correct answer

Ventricular septal defect

Explanation

Even though the right atrial pressure is high the pulmonary artery occlusion pressure is low with a relatively low cardiac index, suggesting the patient is hypovolaemic. A fluid challenge should be performed and values re-measured to assess response.

In a fluid replete patient the occlusion pressure would be higher (usually >13 mmHg), therefore if the occlusion pressure if high and cardiac index low (i.e. <2.5 L/min/m2) this would be more suggestive of cardiogenic shock.

In a VSD, left to right shunting causes an increase in the SvO2.

Answer Statistics

1

11%

2

35%

3

24%

4

15%

5

18%

Times answered: 275