Critical IllnessDIRECTNCT06053216
Indirect Calorimetry Guided Energy Provision in Critically Ill Patients With Obesity
A study testing Indirect calorimetry in people with Critical Illness and Obesity, run by Australian and New Zealand Intensive Care Research Centre at 5 sites in 2 countries.
Trial summary
The DIRECT trial is a prospective, multi-centre, two arm parallel feasibility pilot randomised controlled trial. The primary aim is to determine the feasibility of using repeat indirect calorimetry measurements to direct energy delivery in critically ill patients with obesity. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Critical Illness, Obesity
- What is being tested?
- Indirect calorimetry
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 5 sitesin 2 countries
- Study dates
- 16 Oct 2023to 1 Feb 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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
Who may be able to join
- Adult (≥ 18 years) patients
- Body mass index ≥30 kg/m2
- Between day 3 and 6 of index ICU admission
- Receiving invasive mechanical ventilation
- Receiving enteral or parenteral nutrition
Who cannot join
- Receiving extracorporeal membrane oxygenation support
- Major burns (≥20% total body surface area)
- Unable to perform indirect calorimetry within 24 hours of randomisation
- Known pregnancy
- Death is imminent
- Treating clinician believes the study is not in the best interest of the patient
Trial locations and contacts
5 sites in 2 countries.
5 sites in 2 countries
Australia4 sites
Ballarat Base Hospital, Grampians Health
Ballarat Central, Victoria, 3550
Blacktown Hospital
Blacktown, New South Wales, 2148
Royal Prince Alfred Hospital
Camperdown, New South Wales, 2050
The Alfred Hospital
Melbourne, Victoria, 3004
New Zealand1 site
Department of Critical Care Medicine, Auckland City Hospital
Auckland, 1023
About this study
Official title: GuiDIng Energy Provision Using indiREct CalorimeTry: a Pilot Feasibility Randomised Controlled Trial in Critically Ill Adults With Obesity
The DIRECT trial is a prospective, multi-centre, two arm parallel feasibility pilot randomised controlled trial. The primary aim is to determine the feasibility of using repeat indirect calorimetry measurements to direct energy delivery in critically ill patients with obesity.
The trial will recruit 60 mechanically ventilated patients from 4-6 ICUs in Australia and New Zealand.
Read the detailed description
Indirect calorimetry is the current reference standard for measuring energy expenditure during critical illness, allowing for personalisation of energy delivery. Use of indirect calorimetry may be important in mitigating under- and overfeeding and associated adverse outcomes. This may be particularly important in patients with obesity, where energy expenditure is difficult to estimate, and limited data is available on the optimal nutritional management of this subgroup.
Although access to indirect calorimetry is gradually improving, it remains an underutilised tool and skills required to complete and interpret measurements are limited which may hinder use and integration into practice. There is a resulting knowledge gap on the impact of indirect calorimetry on outcomes in comparison to standard care predictive equations.
A definitive and pragmatic trial is needed to assess the impact of guiding energy delivery with indirect calorimetry on patient outcomes. Importantly, confirming the feasibility of using indirect calorimetry to guide energy delivery is needed to define optimal measurement protocols prior to completion of a larger trial.
The primary aim of the DIRECT trial is to determine the feasibility of using repeat indirect calorimetry measurements to direct energy delivery in critically ill patients with obesity. The secondary aim is to inform a larger trial by collecting process, nutrition, functional, clinical and safety outcomes.
The investigators will consider the main trial feasible to conduct if 2 of the following 3 feasibility criteria are achieved: (a) recruitment rate is ≥ 1 patient per calendar month; (b) between group separation of ≥20% in energy adequacy during ICU admission is achieved in relation to measured energy expenditure and; (c) the number of indirect calorimetry measurements completed/planned ≥60% during ICU admission.
- Conditions
- Critical Illness, Obesity
- Being tested
- Indirect calorimetry, Indirect calorimetry (Standard care nutrition arm)
- Keywords
- Critical care nutrition, Indirect calorimetry
- Medical subject headings
- Critical Illness, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Indirect calorimetryOther
Weekly indirect calorimetry measurements using the Q-NRG+ device will be used to guide energy delivery up to day 28 of hospital admission.
Indirect calorimetry (Standard care nutrition arm)Other
Weekly indirect calorimetry measurements using the Q-NRG+ device will be conducted up to day 28 of hospital admission. In the standard care nutrition arm, clinicians will be blinded to indirect calorimetry measurements.
| Study group | Role | What they receive |
|---|---|---|
| Individualised energy delivery | Experimental | Energy delivery will be guided by indirect calorimetry, with the aim to meet 80-100% of the most recent energy expenditure measurement from day 4 to 28 of hospital admission. Receives: Other: Indirect calorimetry |
| Standard care nutrition | Active comparator | Energy delivery will be according to predictive equation estimates and usual site practice from day 4 to 28 of hospital admission. Receives: Other: Indirect calorimetry (Standard care nutrition arm) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Feasibility: Recruitment rate
Patients per site, per month
Measured: During ICU admission (up to day 28)
Feasibility: Treatment separation in energy adequacy
Energy adequacy % will be calculated as daily energy delivery (kcal)/ measured energy expenditure (kcal) and expressed as a percentage.
Measured: During ICU admission (up to day 28)
Feasibility: Protocol adherence
Number of indirect calorimetry measurements completed/planned.
Measured: During ICU admission (up to day 28)
Secondary outcomes (15)
Treatment separation in energy adequacy
Energy adequacy % will be calculated as energy delivery (kcal)/ measured energy expenditure (kcal) and expressed as a percentage
Measured: Post-ICU period (up to day 28)
Protocol adherence
Number of indirect calorimetry measurements completed/ planned
Measured: Post-ICU period (up to day 28)
Reasons for indirect calorimetry measurement non-completion
Reported overall and separately for ventilated and canopy measurements
Measured: Up to day 28
Clinician acceptability relating to use of indirect calorimetry in routine clinical care (questionnaire)
Reported separately for ventilated and canopy measurements. A combination of yes/no, multiple-choice and Likert scale (1 (minimum) - 5 (maximum)) questions are included.
Measured: Up to day 28
Patient acceptability relating to use of indirect calorimetry in routine clinical care (questionnaire)
Reported for canopy measurements only. A combination of yes/no, multiple-choice and Likert scale (1 (minimum) - 5 (maximum)) questions are included.
Measured: Up to day 28
Cumulative difference in energy delivery compared to measured energy expenditure
kcal; reported overall and separately for ventilated and canopy measurements
Measured: Day 28
Cumulative difference in energy delivery compared to prescribed energy expenditure
kcal; reported overall and separately for ventilated and canopy measurements
Measured: Day 28
Nutritional status
Assessed using the Global Leadership Initiative on Malnutrition (GLIM) criteria where malnutrition diagnosis is based on meeting predefined phenotypic and etiologic criteria (PMID: 30181091). Severity of malnutrition (moderate or severe) is determined based on the phenotypic criterion related to severity of unintentional weight loss.
Measured: Baseline, ICU (up to day 28) and hospital discharge (up to day 28)
Handgrip strength
Measured using a hand dynamometer
Measured: Hospital discharge (up to day 28)
Duration of mechanical ventilation
Duration of mechanical ventilation (days)
Measured: Day 28
ICU length of stay
Duration of ICU stay (days)
Measured: Day 28
Hospital length of stay
Duration of hospital stay (days)
Measured: Day 28
Survival
ICU, in-hospital and 90 day mortality
Measured: ICU discharge (up to day 28), in-hospital (up to day 28) and 90 day
European Quality Of Life 5 Dimensions 5 Level (EQ5D-5L)
Health related quality of life assessment using EQ5D-5L. Each dimension has 5 levels ranging from no problems (1) to extreme problems (5), there is no overall score. It also has a visual analogue scale (VAS) ranging 0-100 with 0 being worst imaginable health state and 100 being best imaginable health state
Measured: Day 90
World Health Organization Disability Assessment Schedule 2.0 (WHODAS)
WHODAS is a 12 point disability assessment with a raw score range of 0-48. 0 is no disability and 48 being full disability
Measured: Day 90
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Sep 2023
- Study start16 Oct 2023
- Primary completion3 Nov 2025
- Study completion1 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Critical IllnessStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A multi-centre, prospective, two arm parallel feasibility pilot randomised controlled trial
- Masking
- None (open label)
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Australian and New Zealand Intensive Care Research Centre
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06053216
- Sponsor's protocol ID
- ANZIC-RC/OT001
- Acronym
- DIRECT
- Status last verified
- May 2026
- First submitted
- 21 Aug 2023
- Last updated
- 22 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data sharing requests will be considered following publication of the primary trial data on an individual basis by the trial management committee (the data custodians). Data sharing will only be considered for investigator-initiated, independent researchers who provide a written data evaluation proposal that is judged to be methodologically sound. A data sharing agreement will be required to detail conditions under which data is shared and used. Resulting publications should appropriately cite and acknowledge the original data custodians. Requests for data sharing are to be made to anzicrc@monash.edu and the corresponding author, Dr Oana Tatucu; oana.tatucu@monash.edu
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- GuiDIng Energy Provision Using indiREct CalorimeTry: a Pilot Feasibility Randomised Controlled Trial in Critically Ill Adults With Obesity
- ClinicalTrials.gov ID
- NCT06053216
- Acronym / sponsor ID
- DIRECT / ANZIC-RC/OT001
- Conditions
- Critical Illness, Obesity
- Keywords
- Critical care nutrition, Indirect calorimetry
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Australian and New Zealand Intensive Care Research CentreUniversity, hospital or other
- Study start
- 16 Oct 2023 (actual)
- Primary completion
- 3 Nov 2025 (actual)
- Study completion
- 1 Feb 2026 (actual)
- First posted
- 25 Sep 2023 (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.
The DIRECT trial is a prospective, multi-centre, two arm parallel feasibility pilot randomised controlled trial. The primary aim is to determine the feasibility of using repeat indirect calorimetry measurements to direct energy delivery in critically ill patients with obesity.
The trial will recruit 60 mechanically ventilated patients from 4-6 ICUs in Australia and New Zealand.
Detailed description
Indirect calorimetry is the current reference standard for measuring energy expenditure during critical illness, allowing for personalisation of energy delivery. Use of indirect calorimetry may be important in mitigating under- and overfeeding and associated adverse outcomes. This may be particularly important in patients with obesity, where energy expenditure is difficult to estimate, and limited data is available on the optimal nutritional management of this subgroup.
Although access to indirect calorimetry is gradually improving, it remains an underutilised tool and skills required to complete and interpret measurements are limited which may hinder use and integration into practice. There is a resulting knowledge gap on the impact of indirect calorimetry on outcomes in comparison to standard care predictive equations.
A definitive and pragmatic trial is needed to assess the impact of guiding energy delivery with indirect calorimetry on patient outcomes. Importantly, confirming the feasibility of using indirect calorimetry to guide energy delivery is needed to define optimal measurement protocols prior to completion of a larger trial.
The primary aim of the DIRECT trial is to determine the feasibility of using repeat indirect calorimetry measurements to direct energy delivery in critically ill patients with obesity. The secondary aim is to inform a larger trial by collecting process, nutrition, functional, clinical and safety outcomes.
The investigators will consider the main trial feasible to conduct if 2 of the following 3 feasibility criteria are achieved: (a) recruitment rate is ≥ 1 patient per calendar month; (b) between group separation of ≥20% in energy adequacy during ICU admission is achieved in relation to measured energy expenditure and; (c) the number of indirect calorimetry measurements completed/planned ≥60% during ICU admission.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- A multi-centre, prospective, two arm parallel feasibility pilot randomised controlled trial
| Arm | Type | Receives |
|---|---|---|
| Individualised energy delivery | Experimental | Other: Indirect calorimetryEnergy delivery will be guided by indirect calorimetry, with the aim to meet 80-100% of the most recent energy expenditure measurement from day 4 to 28 of hospital admission. |
| Standard care nutrition | Active comparator | Other: Indirect calorimetry (Standard care nutrition arm)Energy delivery will be according to predictive equation estimates and usual site practice from day 4 to 28 of hospital admission. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Adult (≥ 18 years) patients
- Body mass index ≥30 kg/m2
- Between day 3 and 6 of index ICU admission
- Receiving invasive mechanical ventilation
- Receiving enteral or parenteral nutrition
Key exclusion criteria (6 listed)
- Receiving extracorporeal membrane oxygenation support
- Major burns (≥20% total body surface area)
- Unable to perform indirect calorimetry within 24 hours of randomisation
- Known pregnancy
- Death is imminent
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Indirect calorimetryWeekly indirect calorimetry measurements using the Q-NRG+ device will be used to guide energy delivery up to day 28 of hospital admission. | Other | Individualised energy delivery |
| Indirect calorimetry (Standard care nutrition arm)Weekly indirect calorimetry measurements using the Q-NRG+ device will be conducted up to day 28 of hospital admission. In the standard care nutrition arm, clinicians will be blinded to indirect calorimetry measurements. | Other | Standard care nutrition |
Primary outcome
Feasibility: Recruitment rate
Time frame: During ICU admission (up to day 28)
Patients per site, per month
Feasibility: Treatment separation in energy adequacy
Time frame: During ICU admission (up to day 28)
Energy adequacy % will be calculated as daily energy delivery (kcal)/ measured energy expenditure (kcal) and expressed as a percentage.
Feasibility: Protocol adherence
Time frame: During ICU admission (up to day 28)
Number of indirect calorimetry measurements completed/planned.
15 secondary outcomes
Treatment separation in energy adequacy
Time frame: Post-ICU period (up to day 28)
Protocol adherence
Time frame: Post-ICU period (up to day 28)
Reasons for indirect calorimetry measurement non-completion
Time frame: Up to day 28
Clinician acceptability relating to use of indirect calorimetry in routine clinical care (questionnaire)
Time frame: Up to day 28
Patient acceptability relating to use of indirect calorimetry in routine clinical care (questionnaire)
Time frame: Up to day 28
Cumulative difference in energy delivery compared to measured energy expenditure
Time frame: Day 28
Cumulative difference in energy delivery compared to prescribed energy expenditure
Time frame: Day 28
Nutritional status
Time frame: Baseline, ICU (up to day 28) and hospital discharge (up to day 28)
Handgrip strength
Time frame: Hospital discharge (up to day 28)
Duration of mechanical ventilation
Time frame: Day 28
ICU length of stay
Time frame: Day 28
Hospital length of stay
Time frame: Day 28
Survival
Time frame: ICU discharge (up to day 28), in-hospital (up to day 28) and 90 day
European Quality Of Life 5 Dimensions 5 Level (EQ5D-5L)
Time frame: Day 90
World Health Organization Disability Assessment Schedule 2.0 (WHODAS)
Time frame: Day 90
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2026.
- Individual participant dataSharing planned: Yes. Data sharing requests will be considered following publication of the primary trial data on an individual basis by the trial management committee (the data custodians). Data sharing will only be considered for investigator-initiated, independent researchers who provide a written data evaluation proposal that is judged to be methodologically sound. A data sharing agreement will be required to detail conditions under which data is shared and used. Resulting publications should appropriately cite and acknowledge the original data custodians. Requests for data sharing are to be made to anzicrc@monash.edu and the corresponding author, Dr Oana Tatucu; oana.tatucu@monash.edu
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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.
The record lists no contact. Use the official record to reach the sponsor.
5 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Indirect calorimetry in people with Critical Illness and Obesity, run by Australian and New Zealand Intensive Care Research Centre at 5 sites in 2 countries.
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 5 inclusion and 6 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: finished, as of the sponsor's last update on 22 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in Australia, New Zealand. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Feasibility: Recruitment rate (time frame: During ICU admission (up to day 28)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 22 May 2026.