Body composition-guided protein dosing in critically ill patients: a before-and-after study (PROGRESS-ICU)

Area of Science:

• Critical Care Medicine
• Nutritional Support
• Clinical Nutrition

Background:

• Critically ill patients in the intensive care unit (ICU) require precise nutritional support.
• Protein dosing strategies, based on total body weight (TBW) or fat-free mass (FFM), are debated for their clinical impact.
• Optimizing protein delivery is crucial for patient recovery and metabolic balance.

Purpose of the Study:

• To compare clinical and metabolic outcomes between FFM-adjusted and TBW-based protein dosing in ICU patients.
• To evaluate the association of different protein dosing strategies with mortality, length of stay, and metabolic markers.
• To investigate the efficacy of FFM-based protein dosing in improving patient outcomes.

Main Methods:

• An observational cohort study (PROGRESS-ICU) included adult ICU patients from April 2020 to October 2025.
• Patients received either TBW-based (1.5 g/kg/day) or FFM-based (1.85 g/kg/day dry FFM) protein dosing.
• Outcomes assessed included 90-day mortality, ICU/hospital length of stay, mechanical ventilation duration, and changes in FFM and urea-to-creatinine ratio (UCR).

Main Results:

• No significant difference in 90-day all-cause mortality was observed between FFM-based and TBW-based protein dosing groups (aHR 0.78).
• FFM-based dosing was associated with a shorter ICU length of stay (HR 0.79) and fewer days on invasive mechanical ventilation (IMV) (HR 0.79).
• TBW-based dosing was linked to higher UCR trajectories and greater FFM loss, though findings require cautious interpretation due to observational design.

Conclusions:

• FFM-based protein dosing did not show a significant difference in mortality compared to TBW-based dosing in this observational study.
• Observed associations with reduced ICU stay and IMV duration for FFM-based dosing may be influenced by residual confounding and temporal changes.
• The study was underpowered for mortality differences; findings are exploratory and necessitate confirmation via adequately powered randomized controlled trials.