Hypotension (MeSH: D007022)CARFLOWNCT07847203
Carotid Artery Blood Flow, Blood Pressure, and Cardiac Output During Anesthesia in Children Aged 0-5 Years
An observational study of Hypotension (MeSH: D007022), run by Karolinska Institutet.
Trial summary
Blood pressure is routinely monitored during anesthesia in children, but blood pressure alone may not accurately reflect blood flow to vital organs. This is particularly important in infants and young children, in whom normal cardiovascular values vary with age. Read more about this study
- Who is it for?
- Ages 0 to 5 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypotension (MeSH: D007022)
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 1 Oct 2026to 31 Dec 2029
- 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 0 to 5 years
- All sexes
- Healthy volunteers accepted
- Child
Study population: The study population will be recruited from children undergoing elective surgical procedures requiring general anesthesia at the Pediatric Operating Department, Karolinska University Hospital, Solna, Sweden. Participants will be identified among patients scheduled for routine clinical care at the study site.
Who may be able to join
- Age 0-5 years
- Scheduled for elective surgery under general anesthesia at the Pediatric Operating Department, Karolinska University Hospital
- Written informed consent provided by a parent or legal guardian
Who cannot join
- Emergency surgery
- American Society of Anesthesiologists (ASA) physical status ≥3
- Significant comorbidity
- Expected complicated anesthesia or surgical procedure
- Parent or legal guardian does not provide informed consent
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
Jacob Karlsson, Associate Professor contact
About this study
Official title: Carotid Artery Blood Flow in Young Children Aged 0-5 Years in Relation to Blood Pressure and Cardiac Output During Anesthesia and Surgery
Blood pressure is routinely monitored during anesthesia in children, but blood pressure alone may not accurately reflect blood flow to vital organs. This is particularly important in infants and young children, in whom normal cardiovascular values vary with age.
The CARFLOW study is a prospective observational study of 100 children aged 0-5 years undergoing anesthesia and surgery. The purpose is to investigate how blood flow in the common carotid artery, measured non-invasively using Doppler ultrasound, relates to blood pressure and cardiac output during anesthesia.
Read more
Carotid artery blood flow will be measured before and during anesthesia and compared with blood pressure recorded as part of routine monitoring. In children who are intubated, cardiac output will also be measured non-invasively using a capnodynamic method.
The main questions are whether changes in blood pressure are associated with changes in carotid artery blood flow, how carotid artery blood flow relates to cardiac output, and whether reference values for carotid artery blood flow during anesthesia can be established for young children.
All clinical decisions and treatment will follow routine clinical practice. Measurements performed as part of the study will not be used to guide treatment.
Read the detailed description
Blood pressure is routinely used as a surrogate for cardiovascular status during pediatric anesthesia. However, arterial blood pressure represents only one component of the circulation and may not directly reflect cardiac output or blood flow to individual organs. This is particularly relevant in infants and young children, in whom cardiovascular physiology and normal blood pressure values change substantially with age.
Blood flow in the common carotid artery can be assessed non-invasively using Doppler ultrasound. Because the carotid arteries contribute substantially to cerebral blood supply, measurement of carotid artery blood flow may provide additional information about changes in organ-directed blood flow during anesthesia. The CARFLOW study will investigate the relationship between Doppler ultrasound-derived common carotid artery blood flow, arterial blood pressure, and cardiac output in young children undergoing anesthesia and surgery.
Common carotid artery blood flow will be assessed using Doppler ultrasound, with the ultrasound probe positioned over the right common carotid artery just above the clavicle. Measurements will be obtained before induction of anesthesia, after induction and securing of the airway, and repeatedly during anesthesia. Additional measurements will be performed when blood pressure decreases below a predefined threshold and following clinically indicated treatment intended to increase blood pressure. Blood pressure monitoring and all decisions regarding treatment will remain part of routine clinical care.
In children managed with tracheal intubation, cardiac output will also be assessed using a non-invasive capnodynamic method based on controlled variations in carbon dioxide elimination during mechanical ventilation. This will allow simultaneous assessment of carotid artery blood flow, blood pressure, and cardiac output.
The study is intended to characterize how carotid artery blood flow varies during anesthesia in young children and how these changes relate to changes in blood pressure and cardiac output. The collected measurements will also provide data for describing carotid artery blood flow across the studied age range and may contribute to the development of reference values for carotid artery blood flow during pediatric anesthesia.
No treatment decisions will be based on the study-specific carotid blood flow or capnodynamic measurements. Anesthesia, hemodynamic management, and treatment of low blood pressure will be determined by the responsible clinical team according to routine clinical practice.
- Conditions
- Hypotension (MeSH: D007022)
- Keywords
- Carotid artery blood flow, Doppler ultrasound, Blood pressure, Cardiac output, Pediatric anesthesia, Hemodynamics, Intraoperative hypotension, Capnodynamics, Cerebral perfusion, Infants, Young children
- Medical subject headings
- Hypotension
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 |
|---|---|---|
| Children Undergoing General Anesthesia | Children aged 0-5 years undergoing general anesthesia for elective surgery. Common carotid artery blood flow is measured non-invasively using Doppler ultrasound before and during anesthesia. Blood pressure is recorded as part of routine clinical monitoring. In children who are intubated, cardiac output is also assessed non-invasively using a capnodynamic method. Study-specific measurements do not guide clinical treatment. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Common Carotid Artery Blood Flow in Relation to Blood Pressure During Anesthesia
Common carotid artery blood flow will be measured in the right common carotid artery using Doppler ultrasound and analyzed in relation to simultaneously recorded blood pressure. Measurements will include observations before and after induction of anesthesia and repeated paired measurements during anesthesia, including measurements obtained when blood pressure falls below the predefined clinical threshold and after clinically indicated treatment to increase blood pressure.
Measured: During anesthesia, up to 2 hours
Relationship between common carotid artery blood flow and blood pressure during anesthesia.
Common carotid artery blood flow will be measured non-invasively in the common carotid artery using Doppler ultrasound and compared with simultaneously recorded blood pressure. Measurements will be obtained before induction of anesthesia, after induction and securing of the airway, at 15-minute intervals during anesthesia, when blood pressure falls below the predefined clinical threshold, and approximately 3 minutes after clinically indicated treatment to increase blood pressure. The analysis will assess the relationship between carotid artery blood flow and blood pressure and whether low blood pressure is consistently associated with reduced carotid artery blood flow.
Measured: From before induction of anesthesia until the end of anesthesia, up to 2 hours
Secondary outcomes (1)
Common Carotid Artery Blood Flow in Relation to Cardiac Output During Anesthesia
In children who are tracheally intubated, cardiac output will be measured non-invasively using the capnodynamic method. Common carotid artery blood flow measured using Doppler ultrasound will be analyzed in relation to simultaneously measured cardiac output.
Measured: During anesthesia, up to 2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start1 Oct 2026 (estimated)
- Primary completion30 Jun 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hypotension (MeSH: D007022)Studies of the same condition, open and under way.
- More trials run by Karolinska InstitutetThe 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
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Karolinska Institutet
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jacob Karlsson, Karolinska Institutet
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07847203
- Sponsor's protocol ID
- 2025-07408-01
- Other IDs
- 2025
- Acronym
- CARFLOW
- Status last verified
- Sep 2026
- First submitted
- 22 Sep 2026
- Last updated
- 7 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- Individual data sharing
- No: Individual participant data are not planned to be made publicly available due to the pediatric study population and data protection considerations.
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Carotid Artery Blood Flow in Young Children Aged 0-5 Years in Relation to Blood Pressure and Cardiac Output During Anesthesia and Surgery
- ClinicalTrials.gov ID
- NCT07847203
- Acronym / sponsor ID
- CARFLOW / 2025-07408-01
- Conditions
- Hypotension (MeSH: D007022)
- Keywords
- Carotid artery blood flow, Doppler ultrasound, Blood pressure, Cardiac output, Pediatric anesthesia, Hemodynamics, Intraoperative hypotension, Capnodynamics
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Karolinska InstitutetUniversity, hospital or other
- Study start
- 1 Oct 2026 (estimated)
- Primary completion
- 30 Jun 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 29 Sep 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.
Blood pressure is routinely monitored during anesthesia in children, but blood pressure alone may not accurately reflect blood flow to vital organs. This is particularly important in infants and young children, in whom normal cardiovascular values vary with age.
The CARFLOW study is a prospective observational study of 100 children aged 0-5 years undergoing anesthesia and surgery. The purpose is to investigate how blood flow in the common carotid artery, measured non-invasively using Doppler ultrasound, relates to blood pressure and cardiac output during anesthesia.
Carotid artery blood flow will be measured before and during anesthesia and compared with blood pressure recorded as part of routine monitoring. In children who are intubated, cardiac output will also be measured non-invasively using a capnodynamic method.
The main questions are whether changes in blood pressure are associated with changes in carotid artery blood flow, how carotid artery blood flow relates to cardiac output, and whether reference values for carotid artery blood flow during anesthesia can be established for young children.
All clinical decisions and treatment will follow routine clinical practice. Measurements performed as part of the study will not be used to guide treatment.
Detailed description
Blood pressure is routinely used as a surrogate for cardiovascular status during pediatric anesthesia. However, arterial blood pressure represents only one component of the circulation and may not directly reflect cardiac output or blood flow to individual organs. This is particularly relevant in infants and young children, in whom cardiovascular physiology and normal blood pressure values change substantially with age.
Blood flow in the common carotid artery can be assessed non-invasively using Doppler ultrasound. Because the carotid arteries contribute substantially to cerebral blood supply, measurement of carotid artery blood flow may provide additional information about changes in organ-directed blood flow during anesthesia. The CARFLOW study will investigate the relationship between Doppler ultrasound-derived common carotid artery blood flow, arterial blood pressure, and cardiac output in young children undergoing anesthesia and surgery.
Common carotid artery blood flow will be assessed using Doppler ultrasound, with the ultrasound probe positioned over the right common carotid artery just above the clavicle. Measurements will be obtained before induction of anesthesia, after induction and securing of the airway, and repeatedly during anesthesia. Additional measurements will be performed when blood pressure decreases below a predefined threshold and following clinically indicated treatment intended to increase blood pressure. Blood pressure monitoring and all decisions regarding treatment will remain part of routine clinical care.
In children managed with tracheal intubation, cardiac output will also be assessed using a non-invasive capnodynamic method based on controlled variations in carbon dioxide elimination during mechanical ventilation. This will allow simultaneous assessment of carotid artery blood flow, blood pressure, and cardiac output.
The study is intended to characterize how carotid artery blood flow varies during anesthesia in young children and how these changes relate to changes in blood pressure and cardiac output. The collected measurements will also provide data for describing carotid artery blood flow across the studied age range and may contribute to the development of reference values for carotid artery blood flow during pediatric anesthesia.
No treatment decisions will be based on the study-specific carotid blood flow or capnodynamic measurements. Anesthesia, hemodynamic management, and treatment of low blood pressure will be determined by the responsible clinical team according to routine clinical practice.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Children Undergoing General Anesthesia | – | –Children aged 0-5 years undergoing general anesthesia for elective surgery. Common carotid artery blood flow is measured non-invasively using Doppler ultrasound before and during anesthesia. Blood pressure is recorded as part of routine clinical monitoring. In children who are intubated, cardiac output is also assessed non-invasively using a capnodynamic method. Study-specific measurements do not guide clinical treatment. |
Who may qualify
- Ages
- 0 to 5 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
- Study population
- The study population will be recruited from children undergoing elective surgical procedures requiring general anesthesia at the Pediatric Operating Department, Karolinska University Hospital, Solna, Sweden. Participants will be identified among patients scheduled for routine clinical care at the study site.
Key inclusion criteria (3 listed)
- Age 0-5 years
- Scheduled for elective surgery under general anesthesia at the Pediatric Operating Department, Karolinska University Hospital
- Written informed consent provided by a parent or legal guardian
Key exclusion criteria (5 listed)
- Emergency surgery
- American Society of Anesthesiologists (ASA) physical status ≥3
- Significant comorbidity
- Expected complicated anesthesia or surgical procedure
- Parent or legal guardian does not provide informed consent
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
Common Carotid Artery Blood Flow in Relation to Blood Pressure During Anesthesia
Time frame: During anesthesia, up to 2 hours
Common carotid artery blood flow will be measured in the right common carotid artery using Doppler ultrasound and analyzed in relation to simultaneously recorded blood pressure. Measurements will include observations before and after induction of anesthesia and repeated paired measurements during anesthesia, including measurements obtained when blood pressure falls below the predefined clinical threshold and after clinically indicated treatment to increase blood pressure.
Relationship between common carotid artery blood flow and blood pressure during anesthesia.
Time frame: From before induction of anesthesia until the end of anesthesia, up to 2 hours
Common carotid artery blood flow will be measured non-invasively in the common carotid artery using Doppler ultrasound and compared with simultaneously recorded blood pressure. Measurements will be obtained before induction of anesthesia, after induction and securing of the airway, at 15-minute intervals during anesthesia, when blood pressure falls below the predefined clinical threshold, and approximately 3 minutes after clinically indicated treatment to increase blood pressure. The analysis will assess the relationship between carotid artery blood flow and blood pressure and whether low blood pressure is consistently associated with reduced carotid artery blood flow.
1 secondary outcome
Common Carotid Artery Blood Flow in Relation to Cardiac Output During Anesthesia
Time frame: During anesthesia, up to 2 hours
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 7 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data are not planned to be made publicly available due to the pediatric study population and data protection considerations.
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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.
Jacob Karlsson, Associate Professor contact
Questions about this trial
What is this clinical trial studying?
An observational study of Hypotension (MeSH: D007022), run by Karolinska Institutet.
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 3 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: opening soon, as of the sponsor's last update on 7 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
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 Per-Arne Lönnqvist, Professor MD PhD (+46812377000, per-arne.lonnqvist@ki.se), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Common Carotid Artery Blood Flow in Relation to Blood Pressure During Anesthesia (time frame: During anesthesia, up to 2 hours). The study lists 2 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 7 Oct 2026.