Time-course changes in energy expenditure in sepsis: a prospective observational study

Area of Science:

• Critical care medicine
• Human physiology
• Nutritional science

Background:

• Sepsis induces significant metabolic changes, affecting how the body uses energy and nutrients.
• Understanding these metabolic shifts is crucial for managing critically ill patients.

Purpose of the Study:

• To track changes in energy metabolism over time in sepsis patients.
• To identify factors predicting resting energy expenditure (REE) and respiratory quotient (RQ).

Main Methods:

• Prospective observational study of 30 ventilated sepsis patients.
• Indirect calorimetry used on days 1, 2, 3, 5, and 7 post-diagnosis.
• Statistical analysis using linear mixed-effects models to find predictors of REE and RQ.

Main Results:

• Resting energy expenditure (REE) increased by Day 5. Respiratory quotient (RQ) also rose, indicating altered substrate utilization.
• Higher temperature, arterial pH, protein-to-calorie ratio, and protein intake correlated with higher REE.
• Higher lactate and continuous renal replacement therapy (CRRT) use correlated with lower REE; RQ linked to energy intake and blood glucose.

Conclusions:

• Energy metabolism in sepsis is dynamic and changes significantly over the course of the illness.
• Temperature, acid-base balance, CRRT, and nutritional intake influence energy expenditure variability.
• Individualized metabolic monitoring and nutrition are essential for sepsis management.