Clinical validation of the Deltatrac monitoring system in mechanically ventilated patients.

OBJECTIVE

To evaluate a monitor of pulmonary gas exchange (Deltatrac, Datex) in a clinical setting.

DESIGN

After in vitro evaluation, comparison over 2 min between VO2 and VCO2 values measured by the Deltatrac and the Douglas bag technique. Comparisons were also achieved over 8 h periods between the Deltatrac and a system using a mass-spectrometer.

SETTING

Polyvalent intensive care unit (ICU 15 beds) in a 1200 bed general hospital.

PATIENTS

Comparison with the Douglas bag technique in 10 patients undergoing controlled ventilation. Comparison with the mass-spectrometer system in 25 other patients undergoing controlled or pressure support ventilation.

MEASUREMENTS AND RESULTS

Compared to the results obtained by the Douglas bag technique, the bias (+/- 2 SD) for VO2 and VCO2 was -3.5 +/- 26.6 and 6.1 +/- 12.7 ml.min-1, respectively. By comparison with the mass-spectrometer system, the bias for VO2 and RQ was -5.8 +/- 16.0 ml.min-1 and 0.018 +/- 0.048, respectively. No drift between the two systems was observed over time.

CONCLUSIONS

The Deltatrac appears suitable for VO2 and VCO2 measurements in ventilated patients and equivalent to a mass-spectrometer system for long term measurements.