ABSTRACT 588: APPLICABILITY OF A NEW METABOLIC MONITOR IN CRITICALLY ILL MECHANICALLY VENTILATED CHILDREN

Background and aims: Indirect calorimetry is the golden standard for determining the resting energy expenditure (REE) in critically ill children. Aims: The aim of the study was to compare the applicability of a new device (Quark RMR) with the Deltatrac (which is not manufactured) in mechanically ventilated critically ill children and healthy controls. Methods: 7 mechanically ventilated children, median age 13 yr (6–16) and 4 healthy adult controls on mechanically ventilation, median age 34 yr (27–53), were studied. Both devices were connected to the ventilator and simultaneously minute to minute recordings were stored and a comparison was made for REE, VCO2, VO2, RQ and VE values. Ventilation was done in a support modus (n=9) or a controlled modus (n=2). Results: Overall in 1 child who was ventilated in a control modus and the 4 healthy adults the difference in REE between the 2 devices was within 10%. In the other 6 children with a REE difference >10% respiratory rate was significantly higher. In these children different values were found for VO2 (n=5) and VCO2 (n=4) measurements. Quark RMR presented in two measurements an RQ outside of the physiological range. Conclusions: There is a markedly difference of REE measurements between the Quark and Deltatrac in mechanically ventilated children on a support mode and a high respiratory rate. The difference of measured REE is probably due to large bias flow of the Quark, especially when the ventilator flow-triggered mode is used, because the Quark is unable to separate the inspired and expired gasses related to the bias flow.