Protein Dosing Strategies in Critically Ill Patients: Comparing Actual Body Weight and Fat-Free Mass Approaches in an Observational Cohort Study

Official title

LEan Body Mass Development in CriTically Ill Patients, Obtained by bioelectRical impEdance Analysis: a Combined Retrospective and Prospective Observational Cohort Study

Overview

This study investigates how different methods of calculating protein intake affect recovery and muscle preservation in critically ill patients in the Intensive Care Unit (ICU). Protein is essential for maintaining muscle strength, supporting healing, and improving recovery during critical illness. At Hospital Gelderse Vallei, patients admitted to the ICU received protein based on actual body weight until 2023; more recently, protein prescriptions have been based on fat-free mass. Bioelectrical impedance analysis (BIA) has been part of standard clinical practice in the ICU since April 2020, meaning that all patients admitted since then have been screened for inclusion in the study. This design allows for comparison between two groups: one group receiving protein based on actual body weight according to current clinical guidelines (1.5 g/kg body weight), and another group whose protein intake is calculated based on lean body mass (LBM) measured by BIA. BIA measurements are repeated during the ICU stay to monitor changes in body composition. A total of 310 patients admitted to the ICU between the start of BIA implementation in April 2020 and the transition to fat-free mass-based dosing in 2023 were identified. To allow for balanced comparison, an equal number of 310 patients from the subsequent period, in which protein dosing was based on fat-free mass, were included in the study. The study compares these two groups to determine whether calculating protein requirements based on lean body mass leads to better clinical outcomes-such as improved recovery (lower mortality and shorter hospital stay), preservation of muscle mass, and lower UCR-than the traditional method based on actual body weight. The data analysis plan was established prior to completion of patient inclusion and database lock.

Detailed description

Patients were enrolled through an opt-out procedure using an information leaflet included in the admission folder. The acquisition of informed consent from patients admitted between April 2020 and July 2023 was deemed neither necessary nor feasible, as the study relies on an anonymized database and no additional measurements are performed. Therefore, the internal committee for research evaluation approved the waiver of informed consent for these patients.

Primary outcome measures

• Mortality [Time frame: Mortality, defined as death from any cause, from ICU admission until 90 days post-admission]

Secondary outcome measures (6)

• ICU and hospital length of stay [Time frame: From ICU admission until the date of ICU discharge or the documented date of death from any cause, whichever comes first, assessed up to 52 weeks after ICU admission]
• Duration of invasive mechanical ventilation (IMV) [Time frame: Number of days on invasive mechanical ventilation (IMV), defined as the total number of days with IMV from initiation until ICU discharge, assessed up to 52 weeks after ICU admission]
• Urea-creatinine ratio during ICU stay [Time frame: All UCR measurements taken during the ICU stay, from ICU admission to ICU discharge, with each measurement recorded daily and specified by the day relative to ICU admission, up to a maximum of 52 weeks]
• Changes in BIA parameters over time (in kg) [Time frame: All BIA measurements during the ICU stay, including dry fat-free mass, skeletal muscle mass and fat mass, recorded daily from ICU admission to ICU discharge, up to 52 weeks.]
• Changes in BIA water parameters over time (in L) [Time frame: All BIA measurements during the ICU stay, such as intracellular water, extracellular water, and total body water, recorded daily from ICU admission to ICU discharge, up to 52 weeks]
• Changes in BIA phase angle [Time frame: All BIA measurements during the ICU stay, such as phase angle, recorded daily from ICU admission to ICU discharge, up to 52 weeks]

Eligibility criteria

Inclusion criteria

• ≥18 years old
• a BIA measurement available within 48 hours after ICU admission
• at least one follow-up BIA measurement during ICU stay.

Exclusion criteria

• transfer from another ICU resulting in the first BIA measurement >48 hours after admission to GVH
• a previous ICU admission within 2 weeks before the current admission.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Netherlands · 1 center

• Gelderse Vallei Hospital — Ede

Publications

• Paulus MC, Hajeer F, van Zanten ARH. Body composition-guided protein dosing in critically ill patients: a before-and-after study (PROGRESS-ICU). Crit Care. 2026 Jun 22. doi: 10.1186/s13054-026-06107-5. Online ahead of print. PMID 42332775

Identifiers

NCT: NCT07312708 · 2403-017

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗