Estimated vs measured energy expenditure in ventilated surgical‐trauma critically ill patients

Abstract

Background:The American and European guidelines recommend measuring resting energy expenditure (REE) using indirect calorimetry (IC). Predictive equations (PEs) are used to estimate REE, but there is limited evidence for their use in critically ill patients. The aim of this study is to evaluate the degree of agreement and accuracy between IC-measured REE (REE-IC) and 10 different PEs in mechanically ventilated critically ill patients with surgical trauma who met their estimated energy requirement. Methods: REE-IC was retrospectively compared with REE-PE by 10 PEs. The degree of agreement between REE-PE and REE-IC was analyzed by the Bland-Altman test (BAt) and the concordance correlation coefficient (CCC). The accuracy was calculated by the percentage of patients whose REE-PE values differ by up to ±10% in relation to REE-IC.All analyses were stratified by gender and body mass index (BMI; <25 vs ≥25). Results:We analyzed 104 patients and the closest estimate to REE-IC was the modified Harris-Benedict equation (mHB) by the BAt with a mean difference of 49.2 overall (61.6 for males, 28.5 for females, 67.5 for BMI <25, and 42.5 for BMI ≥25). The overall CCC between the REE-IC and mHB was 0.652 (0.560 for males, 0.496 for females, 0.570 for BMI <25, and 0.598 for BMI ≥25). The mHB equation was the most accurate with an overall accuracy of 44.2%. Conclusion:The effectiveness of PEs for estimating the REE of mechanically ventilated surgical-trauma critically ill patients is limited. [Correction added on 17 February 2022, after first online publication: The word "with" was deleted before "is limited" in the preceding sentence.] Nonetheless, of the 10 equations examined, the closest to REE-IC was the mHB equation.

Estimates of resting energy expenditure using predictive equations in adults with severe burns: A systematic review and meta‐analysis

“…19,28 Subsequently, modified HB equations for use in specific populations were developed by multiplying by stress factors, changing the constant values, and so forth. [29][30][31] For adult patients with severe burns, the HB equation is usually multiplied by a stress factor of 1.2 or 1.5. 1,11 Our results showed that a stress factor of 1.2 significantly underestimates the REE of patients with severe burns; a stress factor of 1.5 is more suitable.…”

Measurement and estimation of energy in the critically ill

“…Alternatively, energy needs can be estimated using weight based or predictive equations (PEs), however, they are regression-based with over and underestimation risks rendering them inaccurate [20 ▪▪ ,21,22,23].…”

Indirect calorimetry: should it be part of routine care or only used in specific situations?

“…Over the course of ICU admission, this can result in substantial underfeeding or overfeeding. Data describing the accuracy and/or bias of predictive equations continues to be published in various ICU populations including surgical [ 9 , 10 ], trauma [ 11 , 12 ], medical [ 13 ] and mixed [ 14 , 15 ] critically ill patients, reinforcing the poor predictive value of equations. Unsurprisingly, the last few years have also seen an increase in the number of publications describing mREE in patients with SARS-CoV-2 infection [ 16 ▪ , 17 , 18 ▪ ].…”