Assessment of accuracy of the Vacu-Med 17053 calibrator for ventilation, oxygen uptake (V(O(2))), and carbon dioxide production (V(CO(2))).

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 values (V(O(2))) 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, V(O(2)), and carbon dioxide production (V(CO(2))). RESULTS: The Vacu-Med 17053 calibrator overestimated V(O(2)) by a mean 28.6 mL/min (1.3% error), underestimated V(CO(2)) by 6.9 mL/min (-1.7% error), and underestimated pulmonary ventilation by 0.98 L/min (-1.4% error). The V(O(2)) and V(CO(2)) differences between the calibrator and the Douglas bag were larger at higher V(O(2)) levels. CONCLUSIONS: The V(O(2)) and V(CO(2)) differences might be attributable to fluctuations of the calibrator settings. The Vacu-Med 17053 calibrator was accurate with the application of a mathematical correction.