Anticoagulants and Bleeding DisordersCASSANDRANCT07183605
Comparison of Heparin Anti-Xa Activity From Central Venous Catheter Samples Using a 5 mL Syringe Flush or a Vacuum Tube Flush Versus Peripheral Vein Samples in ICU Patients
A study testing catheter flushing techniques in people with Anticoagulants and Bleeding Disorders, run by Centre Hospitalier Régional d'Orléans at 1 site in France.
Trial summary
The goal is to investigate whether blood samples drawn from a central venous catheter can provide reliable measurements of unfractionated heparin (UFH) anti-Xa activity, compared to the standard method of peripheral vein puncture, in intensive care unit (ICU) patients receiving continuous intravenous UFH. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anticoagulants and Bleeding Disorders
- What is being tested?
- catheter flushing techniques
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteFrance
- Study dates
- 22 Sep 2025to Oct 2026
- Phase
- Interventional
- 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
Who may be able to join
- Person (or support person/relative if unable to do so) who has agreed to participate in the study
- 18 years of age or older
- Hospitalized in intensive care medicine
- Having a central venous catheter with at least three lumens (internal jugular, subclavian or femoral) already in place
- Receiving continuous intravenous unfractionned heparin, with target Anti-Xa activity between 0.3 and 0.7 IU/ml.
Who cannot join
- Protected person (under guardianship or curatorship)
- Person under court protection
- Person deprived of liberty
- Person not affiliated to the French social security
- Pregnant or breast-feeding woman
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, 1 recruiting
- Recruiting
Chu Orleans
Orléans, 45067
Gregoire MULLER, PH, +33238229534, gregoire.muller@chu-orleans.fr
Gregoire MULLER, PH
About this study
Official title: Central Catheter Anti-Xa Sampling Study for Accurate aNalysis and Reliable Dosage Assessment
The goal is to investigate whether blood samples drawn from a central venous catheter can provide reliable measurements of unfractionated heparin (UFH) anti-Xa activity, compared to the standard method of peripheral vein puncture, in intensive care unit (ICU) patients receiving continuous intravenous UFH.
To evaluate the reliability of central venous blood sampling, the study will compare anti-Xa activity levels obtained simultaneously from two different types of blood draws: one from a peripheral vein (reference method), and the other from the central line using one of two flushing techniques.
Read more
The two central flushing techniques being studied are:
- A 5 mL syringe flush performed over 5 seconds, followed by blood collection.
- A vacuum tube flush that draws and discards 5 mL of blood, followed by blood collection.
Each patient will undergo four pairs of simultaneous blood draws, using both central techniques in a randomized sequence. The main objective is to assess whether the anti-Xa levels from central samples are equivalent to those from peripheral vein puncture, with a predefined margin of equivalence of ±0.05 IU/mL.
Findings from this study may support the use of central venous catheters for routine anti-Xa monitoring in ICU patients, potentially avoiding painful or technically difficult peripheral vein punctures.
Read the detailed description
Unfractionated heparin (UFH) is widely used in intensive care units (ICUs) and requires close monitoring, most commonly through the measurement of anti-Xa activity.
The reference method for anti-Xa monitoring involves blood sampling by peripheral vascular puncture. However, in ICU patients, peripheral access may be challenging or painful, and central venous catheters are often available and already used for UFH infusion. Sampling from these central lines could be a convenient alternative, but residual heparin in the catheter may contaminate the sample, leading to falsely elevated anti-Xa results.
The CASSANDRA study (Central catheter Anti-Xa Sampling Study for Accurate aNalysis and Reliable Dosage Assessment) is a prospective, monocentric, comparative study designed to assess whether anti-Xa activity levels obtained from central venous catheter samples are equivalent to those from peripheral vein samples.
To be eligible for inclusion, patients must already have a central venous catheter in place and require continuous intravenous unfractionated heparin administration through the distal lumen of the central venous catheter.
A three-way stopcock will be placed upstream of the infusion tubing to allow temporary interruption of UFH infusion during sampling.
Two catheter flushing techniques will be compared:
- Method A: A 5 mL flush performed with a syringe over 5 seconds.
- Method B: A 5 mL flush using a vacuum tube (standard discard tube).
For each patient, four pairs of simultaneous blood samples will be collected, according to a randomized sequence alternating between methods A and B. In each pair, one sample will be drawn from the central venous catheter and the other from a fresh peripheral vein puncture (reference). All anti-Xa assays will be performed, but only the results from peripheral vein samples (reference method) will be made available to clinicians. Anti-Xa results from central venous catheter samples will remain blinded to the clinical team to avoid influencing patient management.
The primary outcome is the absolute difference in anti-Xa activity between central venous catheter samples (either method) and peripheral samples. Equivalence is defined as a mean difference not exceeding 0.05 IU/mL. Secondary outcomes include Bland-Altman agreement limits between each central method and the peripheral reference.
Results of this study may support the safe use of central venous sampling for routine anti-Xa monitoring in ICU patients, provided an appropriate flushing method is used.
- Conditions
- Anticoagulants and Bleeding Disorders
- Being tested
- catheter flushing techniques
- Keywords
- Unfractionated Heparin, Anti-Xa Activity, Catheterization, Central Venous, Blood Specimen Collection, Intensive care
- Medical subject headings
- Hemostatic Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
catheter flushing techniquesProcedure or surgery
Two catheter flushing techniques will be compared:
- Method A: A 5 mL flush performed with a syringe over 5 seconds.
- Method B: A 5 mL flush using a vacuum tube (standard discard tube).
| Study group | Role | What they receive |
|---|---|---|
| Sequence A, B, A, B | Experimental | First and third samples with syringe flush; second and fourth with vacuum tube flush Receives: Procedure: catheter flushing techniques |
| Sequence A, B, B, A | Experimental | First and fourth samples with syringe flush; second and third with vacuum tube flush Receives: Procedure: catheter flushing techniques |
| Sequence B, A, B, A | Experimental | Second and fourth samples with syringe flush; first and third with vacuum tube flush Receives: Procedure: catheter flushing techniques |
| Sequence B, A, A, B | Experimental | Second and third samples with syringe flush; first and fourth with vacuum tube flush Receives: Procedure: catheter flushing techniques |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in anti-Xa activity values between the two sampling sites.
Difference in anti-Xa activity values between the two sampling sites: central venous catheter with a 5 mL discard using either a syringe or a vacuum tube, versus peripheral vein puncture, the latter being considered the reference method.
Equivalence is defined a priori as a mean absolute difference not exceeding 0.05 IU/mL of anti-Xa activity.
Measured: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
Secondary outcomes (2)
Equivalence of anti-Xa activity measurements between central venous catheter sampling using flush method A (5 mL syringe discard) and peripheral vein puncture.
Agreement limits of anti-Xa activity measurements between central venous catheter sampling using flush method A and peripheral vein puncture.
Measured: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
Equivalence of anti-Xa activity measurements between central venous catheter sampling using flush method B (5 mL vacuum tube discard) and peripheral vein puncture.
Agreement limits of anti-Xa activity measurements between central venous catheter sampling using flush method B and peripheral vein puncture.
In both cases, the anti-Xa activity measured from the peripheral vein is considered the reference
Measured: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2025
- Study start22 Sep 2025
- Primary completionSep 2026 (estimated)
- Study completionOct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Anticoagulants and Bleeding DisordersStudies 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
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Régional d'Orléans
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Gregoire MULLER, Dr, Principal investigator, CHU Orléans
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07183605
- Sponsor's protocol ID
- CHUO-2024-27
- Acronym
- CASSANDRA
- Status last verified
- Nov 2025
- First submitted
- 29 Aug 2025
- Last updated
- 25 Nov 2025
- 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 25 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Central Catheter Anti-Xa Sampling Study for Accurate aNalysis and Reliable Dosage Assessment
- ClinicalTrials.gov ID
- NCT07183605
- Acronym / sponsor ID
- CASSANDRA / CHUO-2024-27
- Conditions
- Anticoagulants and Bleeding Disorders
- Keywords
- Unfractionated Heparin, Anti-Xa Activity, Catheterization, Central Venous, Blood Specimen Collection, Intensive care
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Centre Hospitalier Régional d'OrléansUniversity, hospital or other
- Study start
- 22 Sep 2025 (actual)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Oct 2026 (estimated)
- First posted
- 19 Sep 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 is to investigate whether blood samples drawn from a central venous catheter can provide reliable measurements of unfractionated heparin (UFH) anti-Xa activity, compared to the standard method of peripheral vein puncture, in intensive care unit (ICU) patients receiving continuous intravenous UFH.
To evaluate the reliability of central venous blood sampling, the study will compare anti-Xa activity levels obtained simultaneously from two different types of blood draws: one from a peripheral vein (reference method), and the other from the central line using one of two flushing techniques.
The two central flushing techniques being studied are:
- A 5 mL syringe flush performed over 5 seconds, followed by blood collection.
- A vacuum tube flush that draws and discards 5 mL of blood, followed by blood collection.
Each patient will undergo four pairs of simultaneous blood draws, using both central techniques in a randomized sequence. The main objective is to assess whether the anti-Xa levels from central samples are equivalent to those from peripheral vein puncture, with a predefined margin of equivalence of ±0.05 IU/mL.
Findings from this study may support the use of central venous catheters for routine anti-Xa monitoring in ICU patients, potentially avoiding painful or technically difficult peripheral vein punctures.
Detailed description
Unfractionated heparin (UFH) is widely used in intensive care units (ICUs) and requires close monitoring, most commonly through the measurement of anti-Xa activity.
The reference method for anti-Xa monitoring involves blood sampling by peripheral vascular puncture. However, in ICU patients, peripheral access may be challenging or painful, and central venous catheters are often available and already used for UFH infusion. Sampling from these central lines could be a convenient alternative, but residual heparin in the catheter may contaminate the sample, leading to falsely elevated anti-Xa results.
The CASSANDRA study (Central catheter Anti-Xa Sampling Study for Accurate aNalysis and Reliable Dosage Assessment) is a prospective, monocentric, comparative study designed to assess whether anti-Xa activity levels obtained from central venous catheter samples are equivalent to those from peripheral vein samples.
To be eligible for inclusion, patients must already have a central venous catheter in place and require continuous intravenous unfractionated heparin administration through the distal lumen of the central venous catheter.
A three-way stopcock will be placed upstream of the infusion tubing to allow temporary interruption of UFH infusion during sampling.
Two catheter flushing techniques will be compared:
- Method A: A 5 mL flush performed with a syringe over 5 seconds.
- Method B: A 5 mL flush using a vacuum tube (standard discard tube).
For each patient, four pairs of simultaneous blood samples will be collected, according to a randomized sequence alternating between methods A and B. In each pair, one sample will be drawn from the central venous catheter and the other from a fresh peripheral vein puncture (reference). All anti-Xa assays will be performed, but only the results from peripheral vein samples (reference method) will be made available to clinicians. Anti-Xa results from central venous catheter samples will remain blinded to the clinical team to avoid influencing patient management.
The primary outcome is the absolute difference in anti-Xa activity between central venous catheter samples (either method) and peripheral samples. Equivalence is defined as a mean difference not exceeding 0.05 IU/mL. Secondary outcomes include Bland-Altman agreement limits between each central method and the peripheral reference.
Results of this study may support the safe use of central venous sampling for routine anti-Xa monitoring in ICU patients, provided an appropriate flushing method is used.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Sequence A, B, A, B | Experimental | Procedure: catheter flushing techniquesFirst and third samples with syringe flush; second and fourth with vacuum tube flush |
| Sequence A, B, B, A | Experimental | Procedure: catheter flushing techniquesFirst and fourth samples with syringe flush; second and third with vacuum tube flush |
| Sequence B, A, B, A | Experimental | Procedure: catheter flushing techniquesSecond and fourth samples with syringe flush; first and third with vacuum tube flush |
| Sequence B, A, A, B | Experimental | Procedure: catheter flushing techniquesSecond and third samples with syringe flush; first and fourth with vacuum tube flush |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Person (or support person/relative if unable to do so) who has agreed to participate in the study
- 18 years of age or older
- Hospitalized in intensive care medicine
- Having a central venous catheter with at least three lumens (internal jugular, subclavian or femoral) already in place
- Receiving continuous intravenous unfractionned heparin, with target Anti-Xa activity between 0.3 and 0.7 IU/ml.
Key exclusion criteria (5 listed)
- Protected person (under guardianship or curatorship)
- Person under court protection
- Person deprived of liberty
- Person not affiliated to the French social security
- Pregnant or breast-feeding woman
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 |
|---|---|---|
| catheter flushing techniquesTwo catheter flushing techniques will be compared: * Method A: A 5 mL flush performed with a syringe over 5 seconds. * Method B: A 5 mL flush using a vacuum tube (standard discard tube). | Procedure or surgery | Sequence A, B, A, B, Sequence A, B, B, A, Sequence B, A, A, B, Sequence B, A, B, A |
Primary outcome
Difference in anti-Xa activity values between the two sampling sites.
Time frame: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
Difference in anti-Xa activity values between the two sampling sites: central venous catheter with a 5 mL discard using either a syringe or a vacuum tube, versus peripheral vein puncture, the latter being considered the reference method. Equivalence is defined a priori as a mean absolute difference not exceeding 0.05 IU/mL of anti-Xa activity.
2 secondary outcomes
Equivalence of anti-Xa activity measurements between central venous catheter sampling using flush method A (5 mL syringe discard) and peripheral vein puncture.
Time frame: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
Equivalence of anti-Xa activity measurements between central venous catheter sampling using flush method B (5 mL vacuum tube discard) and peripheral vein puncture.
Time frame: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
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 25 Nov 2025.
Related trials for Anticoagulants and Bleeding Disorders
RecruitingPhase 3
Thrombolysis in Factor Xa-inhibitors Trial
Stroke, Stroke (in Patients With Atrial Fibrillation)
Not yet recruitingPhase 4
Perioperative Dutasteride for Hemorrhage Control in Bipolar TURP Under Anticoagulation.
Benign Prostatic Hyperplasia, Postoperative Hemorrhage
RecruitingPhase 3
Phase 3 Trial of Reltodecacog Alfa (VMX-C001) vs Usual Pharmacological Care in Patients Taking a FXa Direct Oral Anticoagulant Who Require Urgent Surgery With or Without Heparin.
Blood Loss, Surgical, Coagulation Disorder
Enrolling by invitationPhase 4
LMWH vs Aspirin for VTE Prophylaxis in Orthopaedic Oncology
Sarcoma, Soft Tissue Sarcoma
RecruitingObservational study
Treatment Outcomes of Direct Oral Anticoagulants in Cerebral Venous Thrombosis in Vietnam
Cerebral Venous Thrombosis
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.
Gregoire MULLER, Dr principal investigator
CHU Orléans
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing catheter flushing techniques in people with Anticoagulants and Bleeding Disorders, run by Centre Hospitalier Régional d'Orléans 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 5 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 25 Nov 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 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 Gregoire MULLER, Dr (+33238229534, gregoire.muller@chu-orleans.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in anti-Xa activity values between the two sampling sites. (time frame: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28). 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 25 Nov 2025.