[EngO5-6] Comparison of measured energy expenditure using indirect calorimetry versus predictive equations for liver transplant recipients
Background & aims: We compared three commonly used predictive equations with indirect calorimetry for assessing the appropriate energy expenditure requirement of liver transplant (LT) recipients in South Korea.
Methods: 50 mechanically ventilated patients who had received liver transplants and were expected to stay in the ICU more than 2 days were studied. Resting energy expenditure (REE) was measured 48 hours after ICU admission using open-circuit indirect calorimetry. Theoretical REE was estimated using three predictive equations: Harris-Benedict methods, lreton-Jones ventilated, and Penn state 1988. The REEs derived from each predictive equation were compared with the measured REE using an intraclass correlation coefficient (ICC) and a Bland-Altman plot.
Result: Penn-state 1988 equation showed 65.0% agreement (ICC 0.65) with indirect calorimetry measurement, and Harris-Benedict method 56.0%, Ireton-Jones 39.0%, respectively. The mean difference between measured and predicted REE for each method was as follows: Harris-Benedict method, 148.50± 247.67 kcal; Ireton-Jones ventilated, -105.30± 284.72 kcal; and Penn state 1988, -52.49± 249.86 kcal. In the Bland-Altman plot, all three predictive equations seemed to have fixed bias, but the Penn state 1988 method had the least. Harris Benedict method tended to underestimate REE, while Ireton-Jones ventilated and Penn state 1988 tended to overestimate REE.
Conclusion: Although predicted REE calculated using the Penn state 1988 method agreed (ICC 0.650) with the measured REE, all three predictive equations had a fixed bias and appeared to be inaccurate for predicting REE for liver transplantation recipients. Therefore, precise measurements using indirect calorimetry may be helpful when treating critically ill patients to avoid underestimating or overestimating their metabolic needs.
Registered at: www.clinicalTrials.gov (NCT03622268)
Keyword: Indirect calorimetry, Predictive equations, Liver transplant, Energy expenditure assessment, ICU
Methods: 50 mechanically ventilated patients who had received liver transplants and were expected to stay in the ICU more than 2 days were studied. Resting energy expenditure (REE) was measured 48 hours after ICU admission using open-circuit indirect calorimetry. Theoretical REE was estimated using three predictive equations: Harris-Benedict methods, lreton-Jones ventilated, and Penn state 1988. The REEs derived from each predictive equation were compared with the measured REE using an intraclass correlation coefficient (ICC) and a Bland-Altman plot.
Result: Penn-state 1988 equation showed 65.0% agreement (ICC 0.65) with indirect calorimetry measurement, and Harris-Benedict method 56.0%, Ireton-Jones 39.0%, respectively. The mean difference between measured and predicted REE for each method was as follows: Harris-Benedict method, 148.50± 247.67 kcal; Ireton-Jones ventilated, -105.30± 284.72 kcal; and Penn state 1988, -52.49± 249.86 kcal. In the Bland-Altman plot, all three predictive equations seemed to have fixed bias, but the Penn state 1988 method had the least. Harris Benedict method tended to underestimate REE, while Ireton-Jones ventilated and Penn state 1988 tended to overestimate REE.
Conclusion: Although predicted REE calculated using the Penn state 1988 method agreed (ICC 0.650) with the measured REE, all three predictive equations had a fixed bias and appeared to be inaccurate for predicting REE for liver transplantation recipients. Therefore, precise measurements using indirect calorimetry may be helpful when treating critically ill patients to avoid underestimating or overestimating their metabolic needs.
Registered at: www.clinicalTrials.gov (NCT03622268)
Keyword: Indirect calorimetry, Predictive equations, Liver transplant, Energy expenditure assessment, ICU