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Indirect Calorimetry in Mechanically Ventilated Patients: A Prospective, Randomized, Clinical Validation of 2 Devices Against a Gold Standard
Author(s) -
Allingstrup Matilde Jo,
Kondrup Jens,
Perner Anders,
Christensen Poul Lunau,
Jensen Tom Hartvig,
Henneberg Steen Winther
Publication year - 2017
Publication title -
journal of parenteral and enteral nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.935
H-Index - 98
eISSN - 1941-2444
pISSN - 0148-6071
DOI - 10.1177/0148607116662000
Subject(s) - calorimeter (particle physics) , limits of agreement , spirometer , calorimetry , gold standard (test) , respiratory quotient , critically ill , anesthesia , medicine , nuclear medicine , physics , thermodynamics , airway , exhaled nitric oxide , detector , bronchoconstriction , optics
Background and Aims: The 2 currently available indirect calorimeters, CCM Express Indirect Calorimeter (MedGraphics, St Paul, MN) and Quark RMR ICU Indirect Calorimeter (COSMED, Rome, Italy), have not been validated against a gold standard in mechanically ventilated patients. Our aim was to do so using a gold‐standard, modified Tissot bell‐spirometer method in mechanically ventilated patients who were hemodynamically, respiratory, and metabolically stable. Methods: We studied 30 patients undergoing general anesthesia and major gynecological surgery. We measured oxygen consumption ( V . O 2 ) and resting energy expenditure (REE) in a randomized, sequential, crossover design with double determination of each device. Results: Compared with the modified Tissot bell‐spirometer, the CCM Express Indirect Calorimeter demonstrated a mean Δ‐REE of +361 kcal/d, corresponding to a 31% overestimation of energy requirements. Bland‐Altman analysis for REE showed a mean (SD) bias of 384 (124) with limits of agreement 142–627 kcal/d. QUARK RMR ICU demonstrated a mean Δ‐REE of 81 kcal/d, corresponding to a 7% overestimation of energy requirements. Bland‐Altman plot analysis showed a mean (SD) bias of 77 (167) with limits of agreement −249 to 404 kcal/d. Conclusions: The QUARK RMR ICU Indirect Calorimeter compared better with the gold standard for values of V . O 2 and REE than did the CCM Express Indirect Calorimeter in mechanically ventilated patients who were circulatory and respiratory stable. Both indirect calorimeters had low precision.