Introduction: Cardio-pulmonary exercise test (CPET) systems should estimate accurate gas exchange with variable respiratory rates and tidal volumes in breath-by-breath and mixing chamber mode. The validity of the CPET metabolic cart outcome result depends on ongoing calibration and maintenance of the equipment, including verification with a metabolic simulator (MS). This study was conducted to test the accuracy of gas exchange measured by identical CPET metabolic systems in breath-by-breath and mixing chamber mode by MS. Based on the specified accuracy of devices and the MS, the device-measured values should be within <5% of the MS.

Methods: Five identical CPET systems (Vyntus CPX, Vyaire Medical) were tested by MS (Relitech B.V.): Tidal volume (VT) was set at two and three liters, and respiratory rate ranging from 20 to 80 breaths per minute for each VT. At each set point, from a set of 40 breaths, the last 10 stable consecutive breaths were evaluated. The primary outcome parameters collected were oxygen consumption (V?O2), and carbon dioxide production (V?CO2) at each respiratory rate level.

Results

Conclusion:

All tested devices showed identical breath-by-breath and mixing chamber gas exchange values within the expected range up to high respiratory rates