Predictive value of resting energy expenditure and oxygen consumption of breathing for ventilator weaning in surgical intensive care patients in Viet Nam: a cross-sectional study

BACKGROUND: Patients being weaned from mechanical ventilation are evaluated using portable metabolic carts to measure oxygen consumption (V̇O2) and carbon dioxide production (V̇CO2) to determine resting energy expenditure (REE) and oxygen cost of breathing (OCOB). The purpose of this study was to investigate the cutoff threshold and the predictive values of OCOB and REE variation in such patients at a surgical critical care unit. METHODS: A cross-sectional study was conducted from March 2023 to February 2024. A total of 58 patients who were at least 18 years old and receiving orotracheal ventilation for more than 48 hours met the criteria for weaning. The relationship among OCOB, variation in resting energy expenditure (ΔREE) index, and weaning results was examined. Calculations were performed to determine the receiver operating characteristic (ROC) curve, area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values (PPV and NPV). RESULTS: The overall weaning success rate was 72.4% (42/58). Compared to the failure group, the successful weaning group had significantly lower median values of ∆REE and OCOB (6.3% and 6.93% vs. 15.64% and 16.21%, P=0.002, respectively). According to ROC analysis, weaning success was predicted when ∆REE ≤8.28% (AUC, 0.768) or OCOB ≤9.1% (AUC, 0.762). CONCLUSIONS: Both OCOB and ∆REE can be used to predict a successful outcome of ventilator weaning, with a criterion of OCOB ≤9.1% or ∆REE ≤8.28% in surgical critical care patients.