Assessment of accuracy of the Vacu-med 17053 calibrator for ventilation, oxygen uptake (V̇ O2), and carbon dioxide production (V̇ CO2)

Abstract

BACKGROUND: Few have examined the accuracy of mechanical calibrators used to calibrate metabolic monitors. OBJECTIVE: To evaluate the Vacu-Med 17053 motorized syringe calibrator for accuracy against the accepted standard method: the Douglas bag. METHODS: We tested oxygen consumption (VO) values of 522-3,210 mL/min. We mixed room air and calibration gases in the pumping syringes of the Vacu-Med 17053 and evacuated those gases into a Douglas bag, measured the Douglas bag volumes and concentrations, and converted to pulmonary ventilation, V̇O, and carbon dioxide production (VCO2). RESULTS: The Vacu-Med 17053 calibrator overestimated VO2 by a mean 28.6 mL/min (1.3% error), underestimated VCO by 6.9 mL/min (-1.7% error), and underestimated pulmonary ventilation by 0.98 L/min (-1.4% error). The VO2 and VCO2 differences between the calibrator and the Douglas bag were larger at higher VO levels. CONCLUSIONS: The VO and VCO2 differences might be attributable to fluctuations of the calibrator settings. The Vacu-Med 17053 calibrator was accurate with the application of a mathematical correction. © 2011 Daedalus Enterprises.