Evaluation of three indirect calorimetry devices in mechanically ventilated patients: which device compares best with the Deltatrac II(®)? A prospective observational study.
OBJECTIVE
Indirect calorimetry (IC) is the gold standard to measure energy expenditure (EE) in hospitalized patients. The popular 30 year-old Deltatrac II(®) (Datex) IC is no more commercialized, but other manufacturers have developed new devices. This study aims at comparing for the first time simultaneously, two new IC, the CCM express(®) (Medgraphics) and the Quark RMR(®) (Cosmed) with the Deltatrac II(®) to assess their potential use in intensive care unit (ICU) patients.


METHODS
ICU patients on mechanical ventilation, with positive end-expiratory pressure <9 cm H2O and fraction of inspired oxygen <60%, underwent measurements by the three IC simultaneously connected during 20 min to the ventilator (Evita XL(®), Dräger). Patients' characteristics, VO2 consumption, VCO2 production, respiratory quotient and EE were recorded. Data were presented as mean (SD) and compared by linear regression, repeated measure one-way ANOVA and Bland & Altman diagrams.


RESULTS
Forty patients (23 males, 60(17) yrs, BMI 25.4(7.0) kg/m(2)) were included. For the Deltatrac II(®), VO2 was 227(61) ml/min, VCO2 189(52) ml/min and EE 1562(412) kcal/d. VO2, VCO2, and EE differed significantly between Deltatrac II(®) and CCM express(®) (p < 0.001), but not between Deltatrac II(®) and Quark RMR(®). For EE, diagrams showed a mean difference (2SD) of 25.2(441) kcal between Deltatrac II(®) vs. the Quark RMR(®), and -273 (532) kcal between Deltatrac II(®) vs CCM express(®).


CONCLUSIONS
Quark RMR(®) compares better with Deltatrac II(®) than CCM express(®), but it suffers an EE variance of 441 kcal, which is not acceptable for clinical practice. New indirect IC should be further improved before recommending their clinical use in ICU.
Clinical Nutrition Unit, University Hospital, 1211 Geneva, Switzerland; Intensive Care Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: severine.graf@hcuge.ch.
Séverine
S
Graf
Clinical Nutrition Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: laurie.karsegard@hcuge.ch.
Véronique Laurie
VL
Karsegard
Clinical Nutrition Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: valerie.viatte@hcuge.ch.
Valérie
V
Viatte
Intensive Care Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: claudia-paula.heidegger@hcuge.ch.
Claudia Paula
CP
Heidegger
Intensive Care Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: yvan.fleury@hcuge.ch.
Yvan
Y
Fleury
Clinical Nutrition Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: claude.pichard@hcuge.ch.
Claude
C
Pichard
Clinical Nutrition Unit, University Hospital, 1211 Geneva, Switzerland. Electronic address: laurence.genton@hcuge.ch.
Laurence
L
Genton
D000328:Adult; D000368:Aged; D002153:Calorimetry, Indirect / Q000295:instrumentation*; D003422:Critical Care; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D018529:Nutritional Support / Q000379:methods; D010101:Oxygen Consumption; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial
Energy expenditure; Indirect calorimetry; Intensive care unit; Mechanical ventilation