Techniques, Materials, and Devices I n Vitro Evaluation of a Compact Metabolic Measurement Instrument

ABSTRACT. The ability of the Datex Deltatrac (Sensor-Medics, Anaheim, CA) to accurately measure oxygen consump-tion (V0,v) and carbon dioxide production (VCO,) was exam-ined in vitro using the carbon dioxide addition and nitrogen dilution methods. The accuracy of respiratory quotient (RQ = VCO,/VO,) measurements was assessed using methanol com-bustion (RQ = 0.67). Both in the canopy (blow-by) and respi-rator (FiO,: 0.21-0.6, PEEP: 0-12 cm HzO) modes the Delta-trac’s measurements of VO, and VCO, were within +7 % of values predicted from CO, and N2 simulations. Similar results were obtained with methanol combustion. In vitro testing re-vealed that the Deltatrac accurately measures VO, and VCO, under a variety of simulated clinical conditions. ( Journa l of Parenteral and Enteral Nu t r i t i on 14:216-221, 1990) There has been increasing interest among intensiv