Validation of the Sensormedics (S2900Z) metabolic cart for pediatric exercise testing

The accuracy of many microprocessor controlled exercise testing systems has not been established, particularly for testing children. A metabolic cart (Sensormedics S2900Z) was validated against a reference system (Douglas bag) in children. The systems were tested using 10 active, healthy children (age 11.6 ± 2.3 yrs) during physiological steady state at two exercise intensities, submaximal walking and running. Eight children performed a high ventilatory flow (HVF) protocol, running for 11 min. All 10 performed a low ventilatory flow (LVF) protocol, walking for 11 min. In both, gas samples were measured after 6 to 7 and 10 to 11 min into the Douglas bag, and after 8 to 9 min by the test system. There was minimal evidence of bias for at either ventilation rate. Greater variability was noted for FeCO2 and . In conclusion, the Sensormedics S2900Z appears to be adequate for testing children.