An interventional study of catheter flushing techniques in Anticoagulants and Bleeding Disorders, sponsored by Centre Hospitalier Régional d'Orléans. Recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-11-25.
Sponsored by Centre Hospitalier Régional d'Orléans · Not applicable, Interventional, and Diagnostic
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:
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.
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:
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.
361 studies on the registry are indexed under Hemostatic Disorders; 65 are open to participants now.
This study's planned enrollment of 30 is below the median of 60 across 171 interventional studies indexed under Hemostatic Disorders.
Browse Hemostatic Disorders studies →Centre Hospitalier Régional d'Orléans is the lead sponsor of 132 studies on the registry; 32 are open to participants now.
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Exclusion Criteria:
First and third samples with syringe flush; second and fourth with vacuum tube flush
Procedure: catheter flushing techniques
First and fourth samples with syringe flush; second and third with vacuum tube flush
Procedure: catheter flushing techniques
Second and fourth samples with syringe flush; first and third with vacuum tube flush
Procedure: catheter flushing techniques
Second and third samples with syringe flush; first and fourth with vacuum tube flush
Procedure: catheter flushing techniques
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).
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.
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 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.
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.
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
Time frame: From inclusion to the four pairs of simultaneous blood samples collected assessed up to Day 28
Types and durations of organ support therapies
Organ support requirements, including number of days on mechanical ventilation, renal replacement therapy, or extracorporeal membrane oxygenation (ECMO).
Time frame: From enrollment to Day 28 or discharge (whichever comes first)
Thromboembolic and bleeding complications
Description of thrombotic and bleeding complications during the ICU stay, with bleeding events graded according to ISTH severity criteria.
Time frame: From enrollment to Day 28 or discharge (whichever comes first)
Types of blood products transfused
Type of blood products transfused (red blood cells, frozen plasma, platelets) during the ICU stay will be recorded.
Time frame: From enrollment to Day 28 or discharge (whichever comes first)
Number of blood products transfused
Number of blood products transfused during the ICU stay.
Time frame: Day 28 or discharge (whichever comes first)
Volumes of blood products transfused
Volume of blood products transfused during the ICU stay.
Time frame: Day 28 or discharge (whichever comes first)
Inflammatory status, as reflected by fibrinogen levels.
Fibrinogen level
Time frame: Day 28 or discharge (whichever comes first)
Inflammatory status, as reflected by platelet levels.
Platelets count
Time frame: Day 28 or discharge (whichever comes first)
Total dose of protamine administered during the ICU stay
Time frame: Day 28 or discharge (whichever comes first)
Hemoglobin variations during the ICU stay
Time frame: Day 28 or discharge (whichever comes first)
Number and values of anti-Xa UFH assays performed
Time frame: Day 28 or discharge (whichever comes first)
Vital status at ICU discharge
Vital status (alive or deceased) assessed at the time of intensive care unit (ICU) discharge, based on the final medical record and discharge summary.
Time frame: Up to 6 months
Number of discrepancies between therapeutic actions
Comparison of the number of discrepancies between therapeutic actions (i.e., heparin dose adjustments based on the unit's therapeutic protocol) undertaken in response to anti-Xa results obtained from the reference method (peripheral vein puncture) and those that would have been undertaken if anti-Xa results from central venous catheter samples had been used.
Time frame: From inclusion to Day 28
Reason for ICU admission
Descriptive classification of the primary reason for ICU admission, based on the initial diagnosis recorded in the patient's medical chart at inclusion.
Time frame: From enrollment to Day 28 or discharge (whichever comes first)
Indication for anticoagulation
Descriptive classification of the medical indication for initiating therapeutic anticoagulation with unfractionated heparin (e.g., venous thromboembolism, atrial fibrillation, extracorporeal support, etc.) as recorded at ICU admission.
Time frame: From enrollment to Day 28 or discharge (whichever comes first)
Types and durations of organ support therapies
Number of days each organ support therapy was used during the ICU stay, including mechanical ventilation, renal replacement therapy, vasopressors, or extracorporeal membrane oxygenation (ECMO), as documented in the medical record.
Time frame: From enrollment to Day 28 or discharge (whichever comes first)
Started Sep 2025 (actual). Primary completion is estimated for Sep 2026, 12 months after the start.
Of 31 non-industry interventional studies with no phase under Hemostatic Disorders, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 40. This study's planned 12 months is below that.
Counting every sponsor, half of 33 studies reached it within 22 months; a quarter within 13 and three quarters within 40.
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