Assessment of Accuracy of the Vacu-Med 17053 Calibrator for Ventilation,Oxygen Uptake (V̇ O 2 ),and Carbon Dioxide Production (V̇ 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 (V̇_O2 ) 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, V̇_O2 , and carbon dioxide production (V̇_CO2 ).

RESULTS:

The Vacu-Med 17053 calibrator overestimated V̇_O2 by a mean 28.6 mL/min (1.3% error), underestimated V̇_CO2 by 6.9 mL/min (−1.7% error), and underestimated pulmonary ventilation by 0.98 L/min (−1.4% error). The V̇_O2 and V̇_CO2 differences between the calibrator and the Douglas bag were larger at higher V̇_O2 levels.

CONCLUSIONS:

The V̇_O2 and V̇_CO2 differences might be attributable to fluctuations of the calibrator settings. The Vacu-Med 17053 calibrator was accurate with the application of a mathematical correction.