Critically Ill PatientsBICAR-CCNCT07782658
Bicarbonate Variation Monitoring With Indirect Calorimetry
An observational study of Critically Ill Patients and Acid-Base Disturbance, run by Hospices Civils de Lyon at 1 site in France.
Trial summary
Patients admitted to the intensive care unit frequently exhibit abnormal blood bicarbonate levels. These abnormalities are associated with patient outcomes and often prompt clinicians to modify management, either diagnostically or therapeutically (e.g., initiation or adjustment of mechanical ventilation, initiation or… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Critically Ill Patients, Acid-Base Disturbance, Indirect Calorimetry
- What is being tested?
- Indirect calorimetry measurement
- Type of treatment
- Medical device
- How many people
- 91 participants
- Where
- 1 siteFrance
- Study dates
- 1 Nov 2026to 1 Nov 2027
- 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: Patients admitted to the ICU
Who may be able to join
- Adult patient admitted to the ICU within the past 72 hours
- Receiving invasive mechanical ventilation
- For whom the treating clinician plans to perform at least two blood bicarbonate measurements within the next 6 hours
- No objection from the participant or their next of kin
Who cannot join
- Planned weaning from invasive mechanical ventilation or ventilator change before the second bicarbonate measurement
- Conditions interfering with the interpretation of indirect calorimetry data:
- Inspiratory oxygen fraction > 60%
- Administration of inhaled medications, including nitric oxide
- Positive end-expiratory pressure (PEEP) > 15 cmH₂O
- Excessive leaks in the ventilator circuit, defined as expired volume < 95% of inspired volume
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- Patient on mechanical circulatory support with a gas exchanger, or planned initiation before the second blood gas analysis
- Patient on extracorporeal renal replacement therapy, or planned initiation before the second bicarbonate measurement
- Patient who received sodium bicarbonate within 2 hours prior to inclusion, or planned administration before the second bicarbonate measurement
- Frequent disconnections of the ventilator circuit, or planned bronchoscopy before the second bicarbonate measurement
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Service d'Anesthésie-Réanimation, Hôpital Louis Pradel, Hospices Civils de Lyon
Bron, Rhone, 69500
Rémi SCHWEIZER, Dr, 0033472357093, remi.schweizer@chu-lyon.fr
Rémi SCHWEIZER, Dr
About this study
Official title: BICARbonate and Indirect Calorimetry Correlation in Critical Care
Patients admitted to the intensive care unit frequently exhibit abnormal blood bicarbonate levels. These abnormalities are associated with patient outcomes and often prompt clinicians to modify management, either diagnostically or therapeutically (e.g., initiation or adjustment of mechanical ventilation, initiation or modification of extracorporeal renal replacement therapy, administration of specific diuretics, or sodium bicarbonate infusion).
Currently, the only way to determine blood bicarbonate concentration is through repeated blood sampling for laboratory analysis. However, this method is both discontinuous and invasive.
Read more
We have generated an in silico hypothesis suggesting that the mismatch between cellular CO₂ production/elimination and pulmonary CO₂ elimination reflects changes in blood bicarbonate levels. We propose to test this hypothesis in a cohort of intensive care unit patients.
If confirmed, indirect calorimetry could be positioned as a continuous, non-invasive monitoring tool for blood bicarbonate.
- Being tested
- Indirect calorimetry measurement
- Keywords
- Bicarbonate, Acid-Base disturbance, Indirect calorimetry
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Indirect calorimetry measurementDevice
Setup of an indirect calorimetry monitor
| Study group | Role | What they receive |
|---|---|---|
| Study group | Ventilated patient admitted to intensive care unit Receives: Device: Indirect calorimetry measurement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation coefficient between the CO₂ production/elimination mismatch assessed by indirect calorimetry and the change in blood bicarbonate over the study period.
CO₂ production/elimination mismatch is estimated using the indirect calorimetry, assuming that the respiratory quotient remains constant throughout the study.
Change in blood bicarbonate is obtained using two consecutive arterial blood samples.
This relationship will be assessed using Pearson's correlation coefficient if assumptions are met (normality and linearity); otherwise, Spearman's coefficient will be used. The correlation coefficient will be reported with its 95% confidence interval and p-value, and the relationship will be illustrated with a scatter plot and regression line or trend curve.
Measured: At day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Aug 2026
- Study start1 Nov 2026 (estimated)
- Primary completion1 Nov 2027 (estimated)
- Study completion1 Nov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Critically Ill PatientsStudies of the same condition, open and under way.
- More trials run by Hospices Civils de LyonThe sponsor's other registered studies.
- 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
- 91 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospices Civils de Lyon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07782658
- Sponsor's protocol ID
- 69HCL26_0751
- Acronym
- BICAR-CC
- Status last verified
- Aug 2026
- First submitted
- 20 Aug 2026
- Last updated
- 24 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- BICARbonate and Indirect Calorimetry Correlation in Critical Care
- ClinicalTrials.gov ID
- NCT07782658
- Acronym / sponsor ID
- BICAR-CC / 69HCL26_0751
- Keywords
- Bicarbonate, Acid-Base disturbance, Indirect calorimetry
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 91 participants (estimated)
- Lead sponsor
- Hospices Civils de LyonUniversity, hospital or other
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 1 Nov 2027 (estimated)
- Study completion
- 1 Nov 2027 (estimated)
- First posted
- 24 Aug 2026 (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.
Patients admitted to the intensive care unit frequently exhibit abnormal blood bicarbonate levels. These abnormalities are associated with patient outcomes and often prompt clinicians to modify management, either diagnostically or therapeutically (e.g., initiation or adjustment of mechanical ventilation, initiation or modification of extracorporeal renal replacement therapy, administration of specific diuretics, or sodium bicarbonate infusion).
Currently, the only way to determine blood bicarbonate concentration is through repeated blood sampling for laboratory analysis. However, this method is both discontinuous and invasive.
We have generated an in silico hypothesis suggesting that the mismatch between cellular CO₂ production/elimination and pulmonary CO₂ elimination reflects changes in blood bicarbonate levels. We propose to test this hypothesis in a cohort of intensive care unit patients.
If confirmed, indirect calorimetry could be positioned as a continuous, non-invasive monitoring tool for blood bicarbonate.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Study group | – | Device: Indirect calorimetry measurementVentilated patient admitted to intensive care unit |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients admitted to the ICU
Key inclusion criteria (4 listed)
- Adult patient admitted to the ICU within the past 72 hours
- Receiving invasive mechanical ventilation
- For whom the treating clinician plans to perform at least two blood bicarbonate measurements within the next 6 hours
- No objection from the participant or their next of kin
Key exclusion criteria (10 listed)
- Planned weaning from invasive mechanical ventilation or ventilator change before the second bicarbonate measurement
- Conditions interfering with the interpretation of indirect calorimetry data:
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 calorimetry measurementSetup of an indirect calorimetry monitor | Device | Study group |
Primary outcome
Correlation coefficient between the CO₂ production/elimination mismatch assessed by indirect calorimetry and the change in blood bicarbonate over the study period.
Time frame: At day 1
CO₂ production/elimination mismatch is estimated using the indirect calorimetry, assuming that the respiratory quotient remains constant throughout the study. Change in blood bicarbonate is obtained using two consecutive arterial blood samples. This relationship will be assessed using Pearson's correlation coefficient if assumptions are met (normality and linearity); otherwise, Spearman's coefficient will be used. The correlation coefficient will be reported with its 95% confidence interval and p-value, and the relationship will be illustrated with a scatter plot and regression line or trend curve.
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 24 Aug 2026.
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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.
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 Critically Ill Patients and Acid-Base Disturbance, run by Hospices Civils de Lyon at 1 site in France.
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 4 inclusion and 10 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: opening soon, as of the sponsor's last update on 24 Aug 2026. 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 France. 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?
Contact Rémi SCHWEIZER, Dr (0033472357093, Remi.schweizer@chu-lyon.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Correlation coefficient between the CO₂ production/elimination mismatch assessed by indirect calorimetry and the change in blood bicarbonate over the study period. (time frame: At day 1). 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 24 Aug 2026.