Question 7.4

Created on Tue, 05/12/2015 - 00:39
Last updated on Tue, 01/19/2016 - 23:16
Pass rate: 66%
Highest mark: 9.5

Other SAQs in this paper

Other SAQs on this topic

The following haemodynamic and metabolic data were obtained from a patient admitted to the ICU with sepsis.

Pulmonary artery catheter data:

  • CI 4.2 L/min/m2
  • DO2 900 ml/min
  • VO2 190 ml/min

Indirect calorimetry data:

  • VO2 220 ml/min
  • VCO2 290 ml/min

a) Why is the VO2 different between the two methods? (Assume no measurement errors.)

b) What changes in patient management will you consider based on the indirect calorimetry data?

[Click here to toggle visibility of the answers]

College Answer

a) Indirect calorimetry also measures lung oxygen consumption.


b) A high RQ suggests excess carbohydrate load. Reduce caloric intake and consider changing to a higher fat intake.

Discussion

This question is identical to Question 25.4 from the second paper of 2010.

Indirect calorimetry and the reverse Fick method are discussed in detail elsewhere.