Comparison of the Best Method for Measuring Anti-Xa Activity in Children Receiving Unfractionated Heparin in Cardiac Intensive Care (COMPAXE-HNF)

N/ANot Yet RecruitingNCT07365670

Centre Hospitalier Universitaire de la Réunion22 enrolled

Overview

This study aims to compare the accuracy of two different blood sampling methods from a central venous catheter (CVC) for measuring anti-Xa activity in children receiving unfractionated heparin (UFH) from this CVC. The results will be compared to a "gold standard" sample taken from an arterial catheter (KTA) whithout UFH. The objective is to identify a more reliable method for monitoring UFH, thereby reducing the risk of bleeding or thrombosis in these patients.

* Scientific Justification: UFH is widely used in pediatric cardiac intensive care for its short half-life and availability of an antidote. However, monitoring its effect via anti-Xa activity is challenging. The standard method of sampling from a CVC is known to be prone to heparin contamination, leading to inaccurate results (over- or under-anticoagulation). This lack of precision can lead to dangerous complications like major bleeding or thrombotic events. As studies by Palermo et al. (1980) and Bauman et al. (2012) have shown, the unreliability of CVC samples justifies the search for a safer alternative. The arterial catheter (KTA) provides a contamination-free "gold standard," making it the ideal comparison for evaluating the more reliable sampling method. * Procedure: The study will compare two CVC sampling methods (a standard flush protocol and a new experimental method) against the gold standard (KTA sampling without UFH) * Follow-up: The study will be conducted over three consecutive days. Each day, three sets of blood samples will be collected every 6 hours per patient (KTA, standard CVC, and experimental CVC).

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Interventions

blood sampling for measuring anti-Xa activityPROCEDURE

Each patient included in the study will have a series of three samples taken every 4 hours for 3 days: * Sample taken from a non-heparinized arterial catheter (Gold Standard), performed as part of routine care: Method ① * Sample taken from a central venous catheter without stopping the HNF: Method ② * Sampling from a central venous catheter with an HNF pause: Method ③ At each anti-Xa activity check in the included patients, the nurse will take the 3 blood samples. The order in which samples ② and ③ are taken will be determined by randomization.

measurement of anti-XA activityPROCEDURE

Each patient will have, each time that anti-Xa activity needs to be measured, three successive samples taken: * Sample taken from a non-heparinized arterial catheter (gold standard), performed as part of routine care: Method ① * Sample taken from a central venous catheter without stopping the HNF: Method ② * Sample from central venous catheter with HNF pause: Method ③

Eligibility

Sex: ALLMin age: 1 DayMax age: 17 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Minors aged 0 to 17 inclusive * Weight greater than or equal to 3.5 kg * Admitted to resuscitation or congenital cardiac intensive care * Requiring treatment with unfractionated heparin at curative doses administered via central venous access * Equipped with a central arterial and venous catheter * Affiliated with or beneficiary of a social security scheme * Free, informed, and written consent signed by one of the two representatives of parental authority and the investigator (no later than the day of inclusion and before any examination required by the research). Exclusion Criteria: * Newborns \< 37 weeks gestation * Patients treated by a humanitarian organization

Outcomes

Primary Outcomes

Measurement of anti-Xa activity (in IU/mL) from two samples (with and without HNF pause) taken from the central venous line where HNF is administered, compared to a sample taken from a non-heparinized arterial catheter (i.e., gold standard).

Anti-Xa activity and APTT measurements will be performed at the university hospital's central laboratory, which guarantees the consistency of the reagents, automated systems, and techniques used. The recommended therapeutic target is between 0.3 and 0.6 IU/mL.

Time frame: "From enrollment to the end of study at 72hours"

Secondary Outcomes

Measurement of APTT from two samples (with and without HNF pause) taken from the central venous line where HNF is administered, compared to a sample taken from a non-heparinized arterial catheter (i.e., gold standard).

Activated partial thromboplastin time (APTT): Mainly used in the United States and in some French intensive care units, the APTT provides an overall assessment of the activity of several coagulation factors: factor I (or fibrinogen), factor II (or prothrombin), factor V, factor VIII, factor IX, factor X, factor XI, and factor XII. (Figure 1) The APTT is a measure of blood clotting time. It is expressed as a ratio between the patient's APTT and a "control" APTT, which is that of the laboratory. It is expressed in seconds. Normal values for the patient APTT/control APTT ratio are between 0.80 s and 1.20 s. * Above this range: the risk of bleeding increases. * Below this range: treatment is ineffective, with a risk of clot formation.

Time frame: "From enrollment to the end of study at 72 hours"

Measurement of APTT and anti-Xa activity (in IU/mL) from a sample taken from a non-heparinized arterial catheter (i.e., gold standard)

The TCA measurement is performed in the same way.

Time frame: From enrollment to the end of study at 72 hours