Comparison of the Effects of SIMV-PC and SIMV-VC Ventilation Modes on Resting Energy Expenditure

The primary objective of this prospective observational study is to compare the effects of synchronized intermittent mandatory ventilation in pressure-controlled mode (SIMV-PC) and volume-controlled mode (SIMV-VC) on resting energy expenditure (REE) measured by indirect calorimetry in adult intensive care unit (ICU) patients receiving invasive mechanical ventilation. The primary metabolic parameters to be evaluated are oxygen consumption (VO₂), carbon dioxide production (VCO₂), resting energy expenditure (REE), and respiratory quotient (RQ). Secondary objectives include comparison of respiratory rate, tidal volume, minute ventilation,arterial blood gas parameters, mechanical power, ventilator mechanics, hemodynamic variables, sedation level, and patient-ventilator synchrony between the two ventilation modes. The results of this study may contribute to identifying ventilation strategies associated with lower energy expenditure while maintaining adequate ventilatory support in critically ill patients and may help optimize individualized ventilator management and nutritional therapy.