Cardiac Surgery Requiring Cardiopulmonary BypassVO2-EPOCNCT06930443
Oxygen Consumption, Hypoperfusion and Organ Injury After Cardio-pulmonary Bypass
An observational study of Cardiac Surgery Requiring Cardiopulmonary Bypass, run by Uppsala University Hospital at 1 site in Sweden.
Trial summary
The goal of this observational study is to understand how oxygen consumption after heart surgery relates to blood flow problems and organ injury. The study focuses on patients over 18 years old who are having planned heart surgery with a heart-lung machine (cardiopulmonary bypass). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Surgery Requiring Cardiopulmonary Bypass
- What is being tested?
- Oxygen consumption measurement
- Type of treatment
- Injection or infusion
- How many people
- 65 participants
- Where
- 1 siteSweden
- Study dates
- 5 May 2025to Feb 2026
- 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: Adult patients undergoing elective cardiac surgery at a university hospital
Who may be able to join
- Elective cardiac surgery requiring cardiopulmonary bypass
Who cannot join
- Combined, redo or annuloplasty procedures
- Surgical procedures involving other vascular cannulation than standard direct, such as bicaval or femoral cannulation
- Preoperative hyperlactatemia (>2mmol/L) or anaemia (Hb <90 g/dL)
- Preoperative need for supplementary oxygen or ICU care
- Consent not obtainable.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Sweden1 site, 1 recruiting
- Recruiting
Uppsala University Hospital
Uppsala, Sweden
Julia Jakobsson, MD PhD, +46186100000, julia.o.jakobsson@akademiska.se
About this study
Official title: Oxygen Consumption, Early Postoperative Hypoperfusion and Organ Injury After Cardio-pulmonary Bypass: a Prospective Observational Study
The goal of this observational study is to understand how oxygen consumption after heart surgery relates to blood flow problems and organ injury. The study focuses on patients over 18 years old who are having planned heart surgery with a heart-lung machine (cardiopulmonary bypass).
The main questions the study aims to answer are:
Read more
- How does oxygen consumption in the early hours after surgery relate to lactate levels (a sign of low oxygen supply to the tissues)?
- How is oxygen consumption linked to signs of poor blood flow and organ injury (such as heart, kidney, liver, brain, and gut damage)?
Researchers will measure oxygen consumption after surgery using a technique called indirect calorimetry. They will also track blood flow and oxygen use during surgery and check for signs of organ injury the day after the procedure. The study will include 65 participants. People with certain health conditions, like severe anemia, high lactate levels before surgery, or needing intensive care or extra oxygen supply before surgery, will not be included. By understanding how oxygen consumption relates to blood flow and organ injury, this research may help to better manage patients after heart surgery and reduce complications.
- Being tested
- Oxygen consumption measurement
- Keywords
- cardiac surgery, cardiopulmonary bypass, postoperative care
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oxygen consumption measurementOther
After arrival to the ICU, prior to cessation of iv anaesthetics and extubation, indirect calorimetry will be performed by connecting a metabolic monitor to the ventilator during a minimum of 20 minutes.
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in oxygen consumption in early postoperative hypoperfusion
Difference in oxygen consumption (VO2I via indirect calorimetry) in ml min-1 m-2 between patients with and without early hyperlactatemia (>2mmol/L)
Measured: 0-4 hours after surgery
Secondary outcomes (3)
Evaluation of hypoperfusion parameters as predictors of postoperative oxygen consumption
Hypoperfusion parameters will be evaluated as a predictors of postoperative oxygen consumption (VO2I, ml min-1 m-2 via indirect calorimetry).
Blood gas parameters taken preoperatively and at spaced time-points up to 24 hrs after start of surgery:
- Central venous oxygen saturation (ScvO2, %, central venous blood gas), 2) Arterial lactate (mmol/L, arterial blood gas), 3) Base excess (BE, mmol/L, arterial blood gas), 4) Venous-to-arterial CO2 difference (ΔPCO2, mmHg, arterial and central venous blood gas) and its ratio with arterial -central venous oxygen content.
Clinical variables measured hourly or otherwise specified:
- Heart rate (beats/min), 6) Mean arterial pressure (MAP, mmHg), 7) Central venous pressure (CVP, mmHg), 8) Vasopressor or inotrope requirement (Y/N, low-intermediate-high), 9) Urine output (mL/24 hours), and 10) net fluid balance (mL/24 hours).
Additional explorative data analyses for hypothesis generating purposes can be performed.
Measured: 0-24 hours after surgery
Evaluation of oxygen delivery and consumption during cardiopulmonary bypass as predictors of postoperative oxygen consumption
Oxygen delivery (DO2I, ml min-1 m-2) and oxygen consumption (VO2I ml min-1 m-2) will be measured during cardiopulmonary bypass by continuous blood parameter monitoring or calculated by blood oxygen content and pump flow. Both mean levels and repeated measures will be analysed as predictors for postoperative oxygen consumption. Additional explorative data analyses for hypothesis generating purposes can be performed.
Measured: 0-4 hours during and after surgery
Evaluation of organ injury biomarkers as predictors of postoperative oxygen consumption
Organ injury markers will be evaluated as predictors for postoperative oxygen consumption. Absolute levels, changes from preoperative values, and above normal predicted value (yes/no) will be used in the analysis.
Blood sampling preoperatively and the day after surgery.
- Renal: Creatinine (mmol L-1), Estimated glomerular filtration rate; eGFR (ml min-1 1.73 m-2):
- Cardiac: Troponin T; TnT, creatinine kinase-MB; CK-MB, probrain natriuretic peptide; Nt-proBNP (ng L-1)
- Hepatic: Aspartate aminotransferase; ASAT, alanine aminotransferase; ALAT(mikrokat L-1)
- Brain: Neurofilament light chain; NFL, Glial fibrillary acidic protein, GFAP (ng L-1)
- Gut: Medium chain fatty acids; MCFA, Short chain fatty acids; SCFA, conjugated and non-conjugated bile acids (ng ml-1) Additional explorative data analyses for hypothesis generating purposes can be performed.
Measured: Preoperative and the day after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Apr 2025
- Study start5 May 2025
- Primary completionDec 2025 (estimated)
- Study completionFeb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cardiac Surgery Requiring Cardiopulmonary BypassStudies 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
- 65 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Uppsala University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Julia Jakobsson, Uppsala University Hospital
- Investigators
- Laila Hellgren Johanssson, MD PhD Associate Professor, Study director, Unit for Cardiothoracic Surgery, Dept. of Surgical Sciences, Uppsala University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06930443
- Sponsor's protocol ID
- FOU2025-00095
- Other IDs
- 284709
- Acronym
- VO2-EPOC
- Status last verified
- May 2025
- First submitted
- 17 Mar 2025
- Last updated
- 11 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Any data will be carefully reviewed to ensure compliance with GDPR and data sharing regulations before being disclosed.
Study at a glance
From the registry record, last updated by the sponsor on 11 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Oxygen Consumption, Early Postoperative Hypoperfusion and Organ Injury After Cardio-pulmonary Bypass: a Prospective Observational Study
- ClinicalTrials.gov ID
- NCT06930443
- Acronym / sponsor ID
- VO2-EPOC / FOU2025-00095
- Keywords
- cardiac surgery, cardiopulmonary bypass, postoperative care
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 65 participants (estimated)
- Lead sponsor
- Uppsala University HospitalUniversity, hospital or other
- Study start
- 5 May 2025 (actual)
- Primary completion
- Dec 2025 (estimated)
- Study completion
- Feb 2026 (estimated)
- First posted
- 16 Apr 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.
The goal of this observational study is to understand how oxygen consumption after heart surgery relates to blood flow problems and organ injury. The study focuses on patients over 18 years old who are having planned heart surgery with a heart-lung machine (cardiopulmonary bypass).
The main questions the study aims to answer are:
- How does oxygen consumption in the early hours after surgery relate to lactate levels (a sign of low oxygen supply to the tissues)?
- How is oxygen consumption linked to signs of poor blood flow and organ injury (such as heart, kidney, liver, brain, and gut damage)?
Researchers will measure oxygen consumption after surgery using a technique called indirect calorimetry. They will also track blood flow and oxygen use during surgery and check for signs of organ injury the day after the procedure. The study will include 65 participants. People with certain health conditions, like severe anemia, high lactate levels before surgery, or needing intensive care or extra oxygen supply before surgery, will not be included. By understanding how oxygen consumption relates to blood flow and organ injury, this research may help to better manage patients after heart surgery and reduce complications.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients undergoing elective cardiac surgery at a university hospital
Key inclusion criteria (1 listed)
- Elective cardiac surgery requiring cardiopulmonary bypass
Key exclusion criteria (5 listed)
- Combined, redo or annuloplasty procedures
- Surgical procedures involving other vascular cannulation than standard direct, such as bicaval or femoral cannulation
- Preoperative hyperlactatemia (>2mmol/L) or anaemia (Hb <90 g/dL)
- Preoperative need for supplementary oxygen or ICU care
- Consent not obtainable.
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 |
|---|---|---|
| Oxygen consumption measurementAfter arrival to the ICU, prior to cessation of iv anaesthetics and extubation, indirect calorimetry will be performed by connecting a metabolic monitor to the ventilator during a minimum of 20 minutes. | Other | – |
Primary outcome
Difference in oxygen consumption in early postoperative hypoperfusion
Time frame: 0-4 hours after surgery
Difference in oxygen consumption (VO2I via indirect calorimetry) in ml min-1 m-2 between patients with and without early hyperlactatemia (>2mmol/L)
3 secondary outcomes
Evaluation of hypoperfusion parameters as predictors of postoperative oxygen consumption
Time frame: 0-24 hours after surgery
Evaluation of oxygen delivery and consumption during cardiopulmonary bypass as predictors of postoperative oxygen consumption
Time frame: 0-4 hours during and after surgery
Evaluation of organ injury biomarkers as predictors of postoperative oxygen consumption
Time frame: Preoperative and the day after surgery
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 11 May 2025.
- Individual participant dataSharing planned: Undecided. Any data will be carefully reviewed to ensure compliance with GDPR and data sharing regulations before being disclosed.
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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.
Laila Hellgren Johanssson, MD PhD Associate Professor study director
Unit for Cardiothoracic Surgery, Dept. of Surgical Sciences, Uppsala University
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 Cardiac Surgery Requiring Cardiopulmonary Bypass, run by Uppsala University Hospital at 1 site in Sweden.
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 1 inclusion and 5 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: looking for participants now, as of the sponsor's last update on 11 May 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 Sweden. 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 Julia Jakobsson MD PhD (+46-18-610 00 00, julia.o.jakobsson@akademiska.se), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in oxygen consumption in early postoperative hypoperfusion (time frame: 0-4 hours after surgery). 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 11 May 2025.