TY - JOUR
T1 - Reliability of, and Agreement Between, two Breath-by-Breath Indirect Calorimeters at Varying Levels of Inspiratory Oxygen
AU - Poulsen, Mathias Krogh
AU - Thomsen, Lars Pilegaard
AU - Kjærgaard, Søren
AU - Rees, Stephen Edward
AU - Karbing, Dan Stieper
PY - 2019/10
Y1 - 2019/10
N2 - Background: Indirect calorimetry (IC) is considered the accurate way of measuring energy expenditure (EE). IC devices often apply the Haldane transformation, introducing errors at inspiratory oxygen fraction (FiO
2) >60%. The aim was to assess measurement reliability and agreement between an unevaluated IC (device 2) (Beacon Caresystem, Mermaid Care A/S, Noerresundby, Denmark) not using Haldane transformation and an IC that does (device 1) (Ecovx, GE, Helsinki, Finland) at varying FiO
2. Methods: Twenty healthy male subjects participated, with 16 completing the study (33 ± 9 years, 83.3 ± 16 kg, 1.83 ± 0.08 m). Subjects were mechanically ventilated in pressure support (3cmH
2O; positive end-expiratory pressure: 3cmH
2O) at FiO
2 of 21%, 50%, 85%, and 21% for 15 minutes at each FiO
2. Mean EE, oxygen consumption (VO
2), and CO
2 production (VCO
2) were compared within and between devices across FiO
2 levels. Results: Device 2 showed within-device EE significant differences at 21% vs 50% FiO
2 and device 1 for VCO
2 at 50% vs. 85% FiO
2. For all variables, both devices showed reliable measurements at 21% and 50% FiO
2, but at 85%, FiO
2 bias and limits of agreement increased. Between devices, there were significant differences for EE at both 21% and 85% FiO
2 for VO
2 and for VCO
2 at 85% FiO
2. Conclusion: Both systems measured EE, VO
2, and VCO
2 at 21%–85% FiO
2 reliably but with bias at 85% FiO
2. The devices were in agreement at 21% and 50% FiO
2, but further studies need to confirm accuracy at high FiO
2.
AB - Background: Indirect calorimetry (IC) is considered the accurate way of measuring energy expenditure (EE). IC devices often apply the Haldane transformation, introducing errors at inspiratory oxygen fraction (FiO
2) >60%. The aim was to assess measurement reliability and agreement between an unevaluated IC (device 2) (Beacon Caresystem, Mermaid Care A/S, Noerresundby, Denmark) not using Haldane transformation and an IC that does (device 1) (Ecovx, GE, Helsinki, Finland) at varying FiO
2. Methods: Twenty healthy male subjects participated, with 16 completing the study (33 ± 9 years, 83.3 ± 16 kg, 1.83 ± 0.08 m). Subjects were mechanically ventilated in pressure support (3cmH
2O; positive end-expiratory pressure: 3cmH
2O) at FiO
2 of 21%, 50%, 85%, and 21% for 15 minutes at each FiO
2. Mean EE, oxygen consumption (VO
2), and CO
2 production (VCO
2) were compared within and between devices across FiO
2 levels. Results: Device 2 showed within-device EE significant differences at 21% vs 50% FiO
2 and device 1 for VCO
2 at 50% vs. 85% FiO
2. For all variables, both devices showed reliable measurements at 21% and 50% FiO
2, but at 85%, FiO
2 bias and limits of agreement increased. Between devices, there were significant differences for EE at both 21% and 85% FiO
2 for VO
2 and for VCO
2 at 85% FiO
2. Conclusion: Both systems measured EE, VO
2, and VCO
2 at 21%–85% FiO
2 reliably but with bias at 85% FiO
2. The devices were in agreement at 21% and 50% FiO
2, but further studies need to confirm accuracy at high FiO
2.
KW - bias
KW - indirect calorimetry
KW - mechanical ventilation
KW - reproducibility of results
KW - resting energy expenditure
UR - http://www.scopus.com/inward/record.url?scp=85061031307&partnerID=8YFLogxK
U2 - 10.1002/ncp.10250
DO - 10.1002/ncp.10250
M3 - Journal article
VL - 34
SP - 767
EP - 774
JO - Nutrition in Clinical Practice
JF - Nutrition in Clinical Practice
SN - 0884-5336
IS - 5
ER -