Amino acid kinetics in the critically ill

Area of Science:

• Biochemistry
• Critical Care Medicine
• Nutritional Science

Background:

• Stable isotope methods are crucial for studying protein and amino acid kinetics in critically ill patients.
• Recent advancements include novel isotope approaches and tracer insights, offering improved metabolic information and cost-effectiveness.
• The tracer pulse approach presents advantages over traditional primed-continuous infusion methods.

Approach:

• Synthesized current knowledge on amino acid metabolism perturbations in critically ill patients.
• Employed novel methodologies like the pulse tracer approach and computational modeling.
• Evaluated variations in amino acid production, linking them to disease severity (SOFA score) and sex.

Key Points:

• Branched-chain amino acids (BCAAs), glutamine, tau-methylhistidine, and hydroxyproline production were elevated in critical illness.
• Reduced citrulline production suggests impaired gut mucosa function.
• Both sex and disease severity independently influenced amino acid kinetics in intensive care unit (ICU) patients.

Conclusions:

• Novel tracer and computational approaches enable simultaneous measurement of multiple amino acid kinetics in critical illness.
• Findings support the development of targeted, individualized nutritional strategies in ICU settings.
• Considering disease severity and sex is essential for enhancing patient outcomes.