PP336 - METABOLIC TRANSITION FROM EARLY ICU PHASE TO POST ICU RECOVERY: CHANGES IN RESPIRATORY QUOTIENT ASSESSED BY INDIRECT CALORIMETRY
PP336
METABOLIC TRANSITION FROM EARLY ICU PHASE TO POST ICU RECOVERY: CHANGES IN RESPIRATORY QUOTIENT ASSESSED BY INDIRECT CALORIMETRY
G. B. Yacoub1, D. O. Toledo1,*, F. A. Ribeiro1, J. R. Moraes1, J. M. S. Junior1,2
1Clinical Nutrion, Einstein Israeli Hospital, 2University of São Paulo, São Paulo, Brazil
Rationale: Metabolic alterations during critical illness are dynamic and may persist beyond ICU discharge. The transition from acute critical illness to recovery phase remains poorly characterized, particularly regarding substrate utilization. This study aimed to evaluate changes in respiratory quotient, RQ, and metabolic parameters from early ICU phase to post ICU recovery using indirect calorimetry.
Methods: This observational study included adult critically ill patients who underwent two indirect calorimetry measurements: one during early ICU stay and another after ICU discharge, in the ward. Oxygen consumption, VO2, carbon dioxide production, VCO2, and measured energy expenditure were recorded. RQ was recalculated as VCO2 divided by VO2 to ensure physiological accuracy. Paired comparisons were performed using Wilcoxon signed rank test or paired t test, as appropriate.
Results: A total of 74 patients with paired calorimetry data were analyzed. Median RQ increased from 0.91 in the ICU phase to 1.00 in the post ICU phase, with a median delta of +0.08. This change was statistically significant, p = 0.022. VCO2 increased significantly between measurements, p = 0.021, while VO2 showed distributional changes without consistent mean increase, p = 0.024. Measured energy expenditure remained stable between phases, p = 0.270. These findings indicate a shift in metabolic substrate utilization during the transition from critical illness to recovery.
Conclusion: Respiratory quotient increases from early ICU phase to post ICU recovery, suggesting a metabolic transition characterized by changes in substrate utilization. These findings highlight the dynamic nature of metabolism beyond ICU discharge and reinforce the importance of reassessing nutritional strategies during recovery.
Disclosure of Interest: None declared