Tag: Metabolic measurement

According to the European Society for Clinical Nutrition and Metabolism (ESPEN), predictive equations for determining energy expenditure are notoriously inaccurate in critically ill patients, sometimes over- or underestimating needs by 500-1000 kcal/day. This highlights why indirect calorimetry (IC) is the gold standard method used to measure the resting energy expenditure on a mechanically ventilated patient, providing crucial data for personalized nutritional support.

The terms respiratory quotient (RQ) and respiratory exchange ratio (RER) are often mistakenly used interchangeably in exercise physiology and metabolic studies. While both involve the ratio of carbon dioxide produced to oxygen consumed, their core difference lies in where the measurement is taken—RQ is at the cellular level, while RER is at the mouth through expired air. This distinction is crucial for accurate interpretation of metabolic processes, especially during high-intensity exercise when they can differ significantly.