Clinical Comparison of Three Methods to Determine Resting Energy Expenditure

Abstract

An accurate and reliable method of determining resting energy expenditure in the critical care setting is crucial because inadequate caloric intake and excessive caloric intake are both associated with a number of complications. Energy requirements were determined by three different methods in a group of 25 post-cardiac surgery patients in the intensive care unit. Patients were intubated and had a thermodilution pulmonary artery catheter in place. The first method measured resting energy expenditure by indirect calorimetry. For the second method, the results of blood gases drawn at the same time that indirect calorimetry was measured were used in the Fick equation. In the third method, a registered dietitian assessed each patient by using the Harris-Benedict equation with stress factor modification. Indirect calorimetry was considered the standard with which the other two methods were compared. The results showed that, compared with calorimetry, both the Fick equation and the Harris-Benedict equation underestimated resting energy needs. Statistically, only the difference between the Fick equation method and indirect calorimetry was significant. Clinically, however, both methods seem to have applicability.

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References

Elwyn DH Nutritional requirements of adult surgical patients. Crit Care Med 1980;8:9-20.

Weissman C. , Kemper M. , Askanazi J. , et al. Resting metabolic rate of the critically ill patient: measured vs. predicted. Anesthesiology 1986;64:673-9.

Mann S. , Westenskow DR , Houtchens BA Measured and predicted caloric expenditure in the acutely ill. Crit Care Med 1985;13:173-7.

A.S.P.E.N. Board of Directors. Guidelines for parenteral and enteral nutrition support in pediatric and adult patients. JPEN 1993;17:5SA-26SA.

Walsh BJ , Morley TF Comparison of three methods of determining oxygen consumption and resting energy expenditure. J Am Osteopath Assoc 1989 ;89:43-6.

Damask MC , Askanazi J. , Weissman C. , et al. Artifacts in measurement of resting energy expenditure. Crit Care Med 1983;11:750-2.

Weissman C. , Kemper M. , Elwyn DH , et al. The energy expenditure of the mechanically ventilated critically ill patient : an analysis. Chest 1986;89:254-9.

Lynch J. , Kaemmerer H. Comparison of a modified Fick method with thermodilution for determining cardiac output in critically ill patients on mechanical ventilation. Int Care Med 1990;16:248-51.

Mahutte CK , Jaffe MB , Sassoon CS , et al. Cardiac output from carbon dioxide production and arterial and venous oximetry. Crit Care Med 1991;19:1270-7.

10.

McClave SA , Snider HL , Greene L. , et al. Effective utilization of indirect calorimetry during critical care. Int Care World 1992;9:194-200.

11.

Damask MC , Shawarz Y. , Weissman C. Energy measurements and requirements of critically ill patients. Crit Care Clin 1987;3:71-96.