Indirect Calorimetry

Published on 22/03/2015 by admin

Filed under Critical Care Medicine

Last modified 22/04/2025

Print this page

rate 1 star rate 2 star rate 3 star rate 4 star rate 5 star
Your rating: none, Average: 0 (0 votes)

This article have been viewed 1797 times

W21 Indirect Calorimetry

Pierre Singer, Jonathan Cohen

image Before Procedure

Indications

• A need for estimating energy expenditure (EE) in critically ill patients in whom the EE is highly variable and difficult to predict by simple equations, such as:

• Patients with liver disease
• Obese patients

Contraindications

• Absolute contraindications:

• Situations preventing complete collection of expired gases
• Leaks of gas from the ventilator circuit
• Leaks around endotracheal tubes
• Leaks through chest tubes
• Instability of delivered oxygen concentration
• Oxygen concentration above 65

• Relative contraindications:

• Ongoing hemodialysis
• Hemodynamically unstable patient:

• Large bias flow
• Extreme circuit flow rates

Equipment

• Indirect Calorimeter

image Procedure

• Select the patient.
• Connect the inspiratory sampling line tube to the water trap container.
• Switch on the monitor.
• Warm up for 30 minutes.
• Choose the correct respiratory mode.
• Perform gas calibration.
• Insert patient data.
• Connect the mixing chamber inlet to the expiratory outlet of the respirator.
• Place the inspiratory sampling line in the inspiratory tube of the respirator.
• Press start.
• Measure for at least 30 minutes.
• Get a report.

image After Procedure

• Adjust metabolic care according to metabolic measurements.

Complications

• Common:

• Inaccurate measurements due to equipment malfunction and methodological problems

• Infrequent:

• Infections cross over

Suggested Reading

Lev S, Cohen J, Singer P. Calorimetric measurements in the ICU. Facts and controversies. The heat is on. Crit Care Clin. 2010;26:1e-9e.

A comprehensive review on calorimetric measurements in critically ill patients.

Loh NHW, Griffiths RD. The curse of overfeeding and the blight of underfeeding. In: Vincent JL, editor. Yearbook of intensive care and emergency medicine. Berlin: Springer-Verlag; 2009:675-683.

This paper summarizes the various deleterious effects of overfeeding.

MacDonald A, Hildebrandt L. Comparison of formulaic equations to determine energy expenditure in the critically ill patient. Nutrition. 2003;19:233-239.

This paper summarizes the various equations available for predicting REE in critically ill patients and shows their limitations.

Related posts:

Toxic Inhalants Basic Ethical Principles in Critical Care Central Nervous System Infections Fluids and Electrolytes in Children Teaching Critical Care Pathophysiology and Classification of Shock States