Adult ICU PatientsMetaChronicNCT07268274
Metabolic Trajectories and Protein Intake in Long-Stay Ventilated Intensive Care Unit (ICU) Patients
An observational study of Adult ICU Patients, run by Universidade do Algarve at 1 site in Portugal.
Trial summary
Survival of critically ill patients has improved, resulting in a growing population of chronically critically ill (CCI) individuals with prolonged organ dysfunction, mechanical ventilation, and high morbidity. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Adult ICU Patients
- How many people
- 100 participants
- Where
- 1 sitePortugal
- Study dates
- 15 Mar 2024to 31 Dec 2025
- How long will I take part?
- 90 Days
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The study will include adult critically ill patients admitted to intensive care who meet the eligibility criteria described.
Who may be able to join
- Adult critically ill patients admitted to Intensive Care Unit > 7 days
- Invasive mechanical ventilation (IMV) > 48 hours
Who cannot join
- Active oncological disease
- Neuromuscular diseases
- Confirmed or predicted Glasgow Coma Score < 10 at 14 days in Intensive Care Unit
- Pregnant women
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Metabolism and the Impact of Protein Intake in Chronic Critically Ill Adult Patients: Protocol for a Unicentric Prospective Cohort Study (MetaChronic Study)
Survival of critically ill patients has improved, resulting in a growing population of chronically critically ill (CCI) individuals with prolonged organ dysfunction, mechanical ventilation, and high morbidity. While nutritional guidelines during the acute phase are well established, evidence on protein intake in CCI patients is limited. Inflammation may influence metabolic responses and clinical outcomes, highlighting the need for prospective studies.
The MetaChronic Study is a single-center, prospective cohort designed to describe metabolic trajectories and evaluate the effect of protein intake on outcomes in critically ill adults. Resting energy expenditure will be measured by serial indirect calorimetry, protein and caloric intake will be recorded weekly, and inflammation will be assessed using C-reactive protein (CRP) and procalcitonin. Secondary objectives include subgroup analyses, assessment of protein delivery routes, and exploration of interactions between protein intake, caloric intake, and inflammation.
Read the detailed description
This single-center, longitudinal observational study enrolls critically ill adults who require invasive mechanical ventilation (IMV) for at least 48 hours and remain in the Intensive Care Unit (ICU) for more than 7 days. Participants are followed in-hospital for up to 42 days after ICU admission, unless discharged, deceased, or unable to continue accurate nutritional monitoring due to transition to oral feeding for nutritional purposes. The final assessment occurs on Day 90 after onset of critical illness, when functional status is evaluated using the Portuguese validated version of the EuroQol 5-Dimension Questionnaire (EQ-5D), administered either by telephone or in person depending on patient location.
Baseline characterization includes:
- Demographic information (age, sex)
- Pre-ICU hospitalization days
- Nutritional risk assessed with the modified Nutrition Risk in the Critically Ill (NUTRIC) score (without interleukin-6)
- Category of critical illness (septic with/without abdominal surgery, trauma with/without head injury, neurocritical, and other categories)
- Severity upon ICU admission measured by the Simplified Acute Physiology Score II (SAPS II)
Metabolic assessment is performed using serial indirect calorimetry beginning on Day 7 of ICU stay and repeated one to three times per week up to Day 42 or until hospital discharge. Feasibility requires absence of air leaks in the respiratory system. For patients on invasive mechanical ventilation (IMV), measurements follow device requirements (fraction of inspired oxygen < 70% and positive end-expiratory pressure < 12 cmH₂O); for spontaneous ventilation, measurements are obtained in canopy mode at FiO₂ 21%. Weekly metabolic values are calculated as the average of available measurements.
Protein intake is recorded according to routine clinical practice and quantified weekly after Day 7, expressed in grams (g) per kilogram of adjusted body weight per day (g/kg/day). Protein delivered as amino acids is converted to grams of protein using a standard factor (100 g hydrolyzed protein = 83 g amino acids). Total caloric intake is also quantified weekly, including enteral and parenteral nutrition as well as non-nutritional caloric sources such as glucose-containing solutions and propofol.
Inflammatory status is assessed weekly using C-reactive protein (CRP) and procalcitonin measurements.
Patients are monitored according to routine clinical practice, and comparative analyses will evaluate outcomes according to protein intake achieved during the second week of ICU stay (>1.3 vs. ≤1.3 g/kg/day). Outcomes include:
- Duration of invasive mechanical ventilation (days)
- Days alive and out of the ICU to Day 90 (days)
- Days alive and out of the hospital to Day 90 (days)
- Need for tracheostomy (Yes/No); if yes, possibility of decannulation (Yes/No)
- Duration of tracheostomy (days)
- Mortality at 28 days, in ICU, in-hospital, and at 90 days
- Number of infections to Day 30 (defined as the number of infectious agents, not deemed colonization, in biological samples obtained per local standard practice)
- Discharge destination (institution/home)
- Functional outcome at Day 90 assessed using the EuroQol 5-Dimension Questionnaire (EQ-5D)
- Conditions
- Adult ICU Patients
- Keywords
- Metabolism, Chronic critically ill adult patients, Nutrition, inflammation
- Medical subject headings
- Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Long-Stay critically ill patients | This cohort includes critically ill adults who remain in the Intensive Care Unit (ICU) for more than 7 days and receive invasive mechanical ventilation for at least 48 hours. Patients are monitored according to routine clinical practice. Resting energy expenditure is assessed by serial indirect calorimetry, and inflammatory status is evaluated weekly using C-reactive protein (CRP) and procalcitonin. Daily protein intake is recorded and expressed in grams per kilogram of body weight per day. Comparative analyses will evaluate outcomes according to protein intake achieved during the second week of ICU stay (>1.3 vs. ≤1.3 g/kg/day). |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resting Energy Expenditure (REE)
Resting energy expenditure will be measured by indirect calorimetry using a calorimeter, which calculates energy expenditure in kilocalories (Kcal) per day from oxygen consumption and carbon dioxide production. Serial measurements will characterize metabolic trajectories during prolonged critical illness.
Measured: From Day 7 of Intensive Care Unit stay through Day 42 or until Intensive Care Unit, whichever occurs first.
Secondary outcomes (9)
Mortality
Mortality at multiple time points. Values: Alive/Dead.
Measured: At Intensive Care Unit (ICU) discharge; at Day 28 after ICU admission; at hospital discharge; at Day 90 after ICU admission.
Duration of Invasive Mechanical Ventilation
Number of days the patient requires invasive mechanical ventilation, from the time of endotracheal intubation until extubation or transition to intermittent ventilation via tracheostomy.
Measured: From endotracheal intubation to extubation or transition to intermittent ventilation via tracheostomy, up to Day 42 of ICU stay.
Protein Intake
Daily protein intake will be recorded based on routine clinical practice. Values will be reported in grams per kilogram of body weight per day (g/kg/day). Weekly averages will be calculated to characterize protein provision during prolonged critical illness.
Measured: From Day 7 of Intensive Care Unit stay through Day 42 or until Intensive Care Unit discharge, whichever occurs first
Tracheostomy Duration
Number of days from tracheostomy insertion to decannulation, if performed.
Measured: From tracheostomy insertion through decannulation, up to 90 days.
Number of Infections
Number of infections diagnosed within 30 days of Intensive Care Unit admission. Defined as the number of infectious agentes, not deemed to be colonization, in biological samples performed in accordance with local standard practice
Measured: From Intensive Care Unit admission through Day 30
Days Alive and Out of the Intensive Care Unit
Number of days the patient is alive and not in the Intensive Care Unit, calculated from Intensive Care Unit admission through Day 90.
Measured: From Intensive Care Unit admission through Day 90.
Days Alive and Out of the Hospital
Number of days the patient is alive and not in the hospital, calculated from hospital admission through Day 90.
Measured: From hospital admission through Day 90.
Discharge Destination
Discharge destination among survivors. Values: Home/Institution (for example, rehabilitation facility).
Measured: At Day 42 after Intensive Care Unit admission
Functional Status at 90 Days
Patient functional status measured using the EQ-5D scale among survivors at Day 90.
Measured: At Day 90 after Intensive Care Unit admission
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Dec 2025
- Study start15 Mar 2024
- Primary completion15 Jun 2024
- Study completion31 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Adult ICU PatientsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 100 participants (actual)
- Target duration
- 90 Days
Sponsor and investigators
- Lead sponsor
- Universidade do Algarve
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sílvia Margarida Correia de Castro, Universidade do Algarve
- Investigators
- Alexandra Binnie, Study chair, Universidade do Algarve
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07268274
- Sponsor's protocol ID
- UAlg_a81228_SCastro
- Acronym
- MetaChronic
- Status last verified
- Dec 2025
- First submitted
- 15 Nov 2025
- Last updated
- 5 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data (IPD) to be shared include: de-identified demographic and clinical variables (age, sex, diagnosis, severity scores), nutritional data (caloric and protein intake, feeding route), indirect calorimetry results, inflammatory markers (C-reactive protein, procalcitonin), and outcome variables (ICU/hospital length of stay, mortality).
Publications
Moonen HPFX, Beckers KJH, van Zanten ARH. Energy expenditure and indirect calorimetry in critical illness and convalescence: current evidence and practical considerations. J Intensive Care. 2021 Jan 12;9(1):8. doi: 10.1186/s40560-021-00524-0.
PubMed 33436084
Study at a glance
From the registry record, last updated by the sponsor on 5 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Metabolism and the Impact of Protein Intake in Chronic Critically Ill Adult Patients: Protocol for a Unicentric Prospective Cohort Study (MetaChronic Study)
- ClinicalTrials.gov ID
- NCT07268274
- Acronym / sponsor ID
- MetaChronic / UAlg_a81228_SCastro
- Conditions
- Adult ICU Patients
- Keywords
- Metabolism, Chronic critically ill adult patients, Nutrition, inflammation
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Universidade do AlgarveUniversity, hospital or other
- Study start
- 15 Mar 2024 (actual)
- Primary completion
- 15 Jun 2024 (actual)
- Study completion
- 31 Dec 2025 (estimated)
- First posted
- 5 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Survival of critically ill patients has improved, resulting in a growing population of chronically critically ill (CCI) individuals with prolonged organ dysfunction, mechanical ventilation, and high morbidity. While nutritional guidelines during the acute phase are well established, evidence on protein intake in CCI patients is limited. Inflammation may influence metabolic responses and clinical outcomes, highlighting the need for prospective studies.
The MetaChronic Study is a single-center, prospective cohort designed to describe metabolic trajectories and evaluate the effect of protein intake on outcomes in critically ill adults. Resting energy expenditure will be measured by serial indirect calorimetry, protein and caloric intake will be recorded weekly, and inflammation will be assessed using C-reactive protein (CRP) and procalcitonin. Secondary objectives include subgroup analyses, assessment of protein delivery routes, and exploration of interactions between protein intake, caloric intake, and inflammation.
Detailed description
This single-center, longitudinal observational study enrolls critically ill adults who require invasive mechanical ventilation (IMV) for at least 48 hours and remain in the Intensive Care Unit (ICU) for more than 7 days. Participants are followed in-hospital for up to 42 days after ICU admission, unless discharged, deceased, or unable to continue accurate nutritional monitoring due to transition to oral feeding for nutritional purposes. The final assessment occurs on Day 90 after onset of critical illness, when functional status is evaluated using the Portuguese validated version of the EuroQol 5-Dimension Questionnaire (EQ-5D), administered either by telephone or in person depending on patient location.
Baseline characterization includes:
- Demographic information (age, sex)
- Pre-ICU hospitalization days
- Nutritional risk assessed with the modified Nutrition Risk in the Critically Ill (NUTRIC) score (without interleukin-6)
- Category of critical illness (septic with/without abdominal surgery, trauma with/without head injury, neurocritical, and other categories)
- Severity upon ICU admission measured by the Simplified Acute Physiology Score II (SAPS II)
Metabolic assessment is performed using serial indirect calorimetry beginning on Day 7 of ICU stay and repeated one to three times per week up to Day 42 or until hospital discharge. Feasibility requires absence of air leaks in the respiratory system. For patients on invasive mechanical ventilation (IMV), measurements follow device requirements (fraction of inspired oxygen < 70% and positive end-expiratory pressure < 12 cmH₂O); for spontaneous ventilation, measurements are obtained in canopy mode at FiO₂ 21%. Weekly metabolic values are calculated as the average of available measurements.
Protein intake is recorded according to routine clinical practice and quantified weekly after Day 7, expressed in grams (g) per kilogram of adjusted body weight per day (g/kg/day). Protein delivered as amino acids is converted to grams of protein using a standard factor (100 g hydrolyzed protein = 83 g amino acids). Total caloric intake is also quantified weekly, including enteral and parenteral nutrition as well as non-nutritional caloric sources such as glucose-containing solutions and propofol.
Inflammatory status is assessed weekly using C-reactive protein (CRP) and procalcitonin measurements.
Patients are monitored according to routine clinical practice, and comparative analyses will evaluate outcomes according to protein intake achieved during the second week of ICU stay (>1.3 vs. ≤1.3 g/kg/day). Outcomes include:
- Duration of invasive mechanical ventilation (days)
- Days alive and out of the ICU to Day 90 (days)
- Days alive and out of the hospital to Day 90 (days)
- Need for tracheostomy (Yes/No); if yes, possibility of decannulation (Yes/No)
- Duration of tracheostomy (days)
- Mortality at 28 days, in ICU, in-hospital, and at 90 days
- Number of infections to Day 30 (defined as the number of infectious agents, not deemed colonization, in biological samples obtained per local standard practice)
- Discharge destination (institution/home)
- Functional outcome at Day 90 assessed using the EuroQol 5-Dimension Questionnaire (EQ-5D)
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 90 Days
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Long-Stay critically ill patients | – | –This cohort includes critically ill adults who remain in the Intensive Care Unit (ICU) for more than 7 days and receive invasive mechanical ventilation for at least 48 hours. Patients are monitored according to routine clinical practice. Resting energy expenditure is assessed by serial indirect calorimetry, and inflammatory status is evaluated weekly using C-reactive protein (CRP) and procalcitonin. Daily protein intake is recorded and expressed in grams per kilogram of body weight per day. Comparative analyses will evaluate outcomes according to protein intake achieved during the second week of ICU stay (>1.3 vs. ≤1.3 g/kg/day). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study will include adult critically ill patients admitted to intensive care who meet the eligibility criteria described.
Key inclusion criteria (2 listed)
- Adult critically ill patients admitted to Intensive Care Unit > 7 days
- Invasive mechanical ventilation (IMV) > 48 hours
Key exclusion criteria (4 listed)
- Active oncological disease
- Neuromuscular diseases
- Confirmed or predicted Glasgow Coma Score < 10 at 14 days in Intensive Care Unit
- Pregnant women
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Resting Energy Expenditure (REE)
Time frame: From Day 7 of Intensive Care Unit stay through Day 42 or until Intensive Care Unit, whichever occurs first.
Resting energy expenditure will be measured by indirect calorimetry using a calorimeter, which calculates energy expenditure in kilocalories (Kcal) per day from oxygen consumption and carbon dioxide production. Serial measurements will characterize metabolic trajectories during prolonged critical illness.
9 secondary outcomes
Mortality
Time frame: At Intensive Care Unit (ICU) discharge; at Day 28 after ICU admission; at hospital discharge; at Day 90 after ICU admission.
Duration of Invasive Mechanical Ventilation
Time frame: From endotracheal intubation to extubation or transition to intermittent ventilation via tracheostomy, up to Day 42 of ICU stay.
Protein Intake
Time frame: From Day 7 of Intensive Care Unit stay through Day 42 or until Intensive Care Unit discharge, whichever occurs first
Tracheostomy Duration
Time frame: From tracheostomy insertion through decannulation, up to 90 days.
Number of Infections
Time frame: From Intensive Care Unit admission through Day 30
Days Alive and Out of the Intensive Care Unit
Time frame: From Intensive Care Unit admission through Day 90.
Days Alive and Out of the Hospital
Time frame: From hospital admission through Day 90.
Discharge Destination
Time frame: At Day 42 after Intensive Care Unit admission
Functional Status at 90 Days
Time frame: At Day 90 after Intensive Care Unit admission
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Dec 2025.
- Background: PubMed 33436084Moonen HPFX, Beckers KJH, van Zanten ARH. Energy expenditure and indirect calorimetry in critical illness and convalescence: current evidence and practical considerations. J Intensive Care. 2021 Jan 12;9(1):8. doi: 10.1186/s40560-021-00524-0.
- Individual participant dataSharing planned: Yes. Individual participant data (IPD) to be shared include: de-identified demographic and clinical variables (age, sex, diagnosis, severity scores), nutritional data (caloric and protein intake, feeding route), indirect calorimetry results, inflammatory markers (C-reactive protein, procalcitonin), and outcome variables (ICU/hospital length of stay, mortality).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Alexandra Binnie study chair
Universidade do Algarve
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Adult ICU Patients, run by Universidade do Algarve at 1 site in Portugal.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 5 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Resting Energy Expenditure (REE) (time frame: From Day 7 of Intensive Care Unit stay through Day 42 or until Intensive Care Unit, whichever occurs first.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07268274, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Dec 2025.