Energy expenditure in COVID‐19 mechanically ventilated patients: A comparison of three methods of energy estimation

Abstract

Background Indirect calorimetry (IC) is the gold standard for measuring resting energy expenditure. Energy expenditure (EE) estimated by ventilator‐derived carbon dioxide consumption (EEVCO 2 ) has also been proposed. In the absence of IC, predictive weight‐based equations have been recommended to estimate daily energy requirements. This study aims to compare simple predictive weight‐based equations with those estimated by EEVCO 2 and IC in mechanically ventilated patients of COVID‐19. Methods Retrospective study of a cohort of critically ill adult patients with COVID‐19 requiring mechanical ventilation and artificial nutrition to compare energy estimations by three methods through the calculation of bias and precision agreement, reliability, and accuracy rates. Results In 58 mechanically ventilated patients, a total of 117 paired measurements were obtained. The mean estimated energy derived from weight‐based calculations was 2576 ± 469 kcal/24 h, as compared with 1507 ± 499 kcal/24 h when EE was estimated by IC, resulting in a significant bias of 1069 kcal/day (95% CI [−2158 to 18.7 kcal]; P < 0.001). Similarly, estimated mean EEVCO 2 was 1388 ± 467 kcal/24 h when compared with estimation of EE from IC. A significant bias of only 118 kcal/day (95% CI [−187 to 422 kcal]; P < 0.001), compared by the Bland‐Altman plot, was noted. Conclusion The energy estimated with EEVCO 2 correlated better with IC values than energy derived from weight‐based calculations. Our data suggest that the use of simple predictive equations may potentially lead to overfeeding in mechanically ventilated patients with COVID‐19.

Nutrition support for critically ill patients during the COVID-19 pandemic: the Italian SIAARTI survey

“…Recently, an alternative to indirect calorimetry has been described and validated to calculate energy expenditure based on ventilator-derived carbon dioxide production as measured by the built-in capnometer of the mechanical ventilator [ 34 ]. Despite being criticized by some authors [ 35 ], this method was shown to correlate better with indirect calorimetry values than estimates derived from weight-based equations [ 36 ] and has the unique advantage of being easily available at the bedside.…”

Macronutrient and micronutrient requirements and therapeutic effects in critically ill patients with SARS‐CoV‐2: A narrative review

“…15,18 Five studies expressed REE in kilocalories per kilogram of BW for nonobese patients or kilocalories per kilogram of adjusted BW (adj-BW) for patients with obesity. 15,[18][19][20] Figure 1 shows that REE generally increased with time. The weighted mean REE (kilocalories per kilogram of BW) of nonobese patients in week 1, week 2, week 3, and week 4 were approximately 21 (range: 18-25), 26 (range: 23-29), 32 (range: [19][20][21][22][23][24][25][26][27][28][29][30][31], and 29 (range: 19-29), respectively.…”

“…The weighted mean REE (kilocalories per kilogram of BW) of nonobese patients in week 1, week 2, week 3, and week 4 were approximately 21 (range: 18-25), 26 (range: 23-29), 32 (range: [19][20][21][22][23][24][25][26][27][28][29][30][31], and 29 (range: 19-29), respectively. 15,[18][19][20] The weighted mean REE (kilocalories per kilogram of adj-BW) of patients with obesity in week 1, week 2, week 3, and week 4 were approximately 19 (range: 18-20), 27 (range: 26-27), 30 (range: 27-33-25), and 29 kcal/kg, respectively. 15,19 There was no association between the severity of organ failure (measured by the Sequential Organ Failure Assessment score [SOFA]) and inflammatory markers such as C-reactive protein and ferritin.…”

“…Eight studies 9,10,[15][16][17][18][19][20] (n = 4-58) measured the REE of critically ill patients with SARS-CoV-2 (Table 1). Patients' mean age, body mass index (BMI), Acute Physiology and Chronic Health Evaluation (APACHE II), and ICU length of stay (ICU-LOS) ranged from 58 to 66 years, 25.2-31.8 (calculated as weight in kilograms divided by height in meters squared), 18.9-24.0, and 16-29 days, respectively.…”

“…15,19 There was no association between the severity of organ failure (measured by the Sequential Organ Failure Assessment score [SOFA]) and inflammatory markers such as C-reactive protein and ferritin. 10,15,16,20 Several REE predictive equations were compared with the measured REE. Although von Renesse et al 17 showed that Mifflin St. Joer had the highest agreement (defined as 85%-115% of measured REE) and the Penn State with Harris-Benedict had the worst agreement with measured REE, Niederer et al 18 showed opposite findings.…”