Effect of FiO in the measurement of VO and VCO using the E-COXV metabolic monitor.

Objective: We evaluated the effect of changes in FiO on the bias and accuracy of the determination of oxygen consumption (V˙O) and carbon dioxide production (V˙CO) using the E-COVX monitor in patients with mechanical ventilation.

Design: Descriptive of concordance.

Setting: Intensive Care Unit.

Patients Or Participants: Patients with mechanical ventilation.

Interventions: We measured V˙O and V˙CO using the E-COVX monitor. Values recorded were the average in 5min. Two groups of 30 patients. We analyzed: 1) the reproducibility in the measurement of V˙O and V˙CO at FiO 0.4, and 2) the effect of the changes in FiO on the measurement of V˙O and V˙CO. Statistical analysis was performed using Bland and Altman test.

Variables Of Main Interest: Bias and accuracy.

Results: 1) FiO 0.4 reproducibility: The bias in the measurement of V˙O and V˙CO was 1.6 and 2.1mL/min, respectively, and accuracy was 9.7 to -8.3% and 7.2 to -5.2%, respectively, and 2) effect of FiO on V˙O: The bias of V˙O measured at FiO 0.4 and 0.6 was -4.0mL/min and FiO 0.4 and 0.8 was 5.2mL/min. Accuracy between FiO 0.4 and 0.6 was 11.9 to -14.1%, and between FiO 0.4 and 0.8 was 43.9 to -39.7%.

Conclusions: The E-COVX monitor evaluates V˙O and V˙CO in critical patients with mechanical ventilation with a clinically acceptable accuracy until FiO 0.6.