Anticoagulation in Chronic Hemodialysis Patients Versus Hemodialyzer Fiber Patency, Bleedings and Quality of Life

Study Overview
=================
Brief Summary
-----------------
Stable chronic hemodialysis patients are included in this observational study. After a midweek dialysis (test moment 1), the hemodialyzer is dried and scanned in a micro Computed Tomography scanner to quantify the number of patent fibers. All dialysis parameters are collected as well as the anticoagulation dose. During the same session, patients are asked about their bleeding and quality of life status. Four (test moment 2) respectively eight weeks later (test moment 3), patients are asked again for their bleeding and quality of life status using validated questionnaires.

Detailed Description
-----------------
All stable chronic hemodialysis (HD) patients having daytime dialysis in the Ghent University Hospital, are included. From the patient's record, data are collected: demographic data (i.e. age, weight, dialysis vintage), blood data related to clotting (i.e. number of platelets, hemoglobin, International Normalized Ratio (INR), C-reactive protein (CRP)). All data is pseudomized. The study has three test moments. During the entire study, patients are dialyzed with their usual dialyzer on their usual dialysis machine and with their usual dialysis settings and anticoagulation dosis. After the first midweek test session (test moment 1), the used hemodialyzer is rinsed with the standard rinsing procedure, dried in blood and dialysate compartment with positive pressure ventilation during 12-24h, eventually stored at 5°C, and finally scanned in a micro-CT scan in order to quantify the number of patent fibers. The dialyzer is vertically mounted on a rotating disc in front of the X-ray bundle. Scans are made every 0.15° with 2401 projections during 500ms each. After image reconstruction, visualisation are obtained from cross-sections of the hemodialyzer. Open fibers are counted with an open source computer program used for biological image analysis. By comparing the number of open fibers with the total number of fibers in an unused hemodialyzer, the percentage of open fibers can be quantified. During the same week of the first test moment, several validated questionnaires will be completed: questionnaires about intention for bleeding (i.e. the International Society of Thrombosis and Haemostasis (ISHT) Bleeding Assessment Tool and the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly (HASBLED) score), and a questionnaire about quality of life (i.e. EuroQoL 5D (EQ5D)). Besides, a visual inspection is performed of the limbs of the patient in order to quantify bruising. By comparing the percentage of open fibers with the administered anticoagulation dosis and the different questionnaires about bleeding, mutual relations can be drawn. In order to check reliability, questionnaires and visual inspection are repeated after 4 weeks and 8 weeks (test moments 2 and 3).

Official Title
-----------------
Mapping of Anticoagulation in Chronic Hemodialysis Patients Versus Hemodialyzer Fiber Patency, Bleedings and Quality of Life

Conditions
-----------------
Blood Coagulation

Intervention / Treatment
-----------------
* Other: Hemodialyzer scanning
* Other: Bleeding Questionnaires
* Other: Quality of life questionnaire
* Other: Visual inspection of the limbs


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: treated with chronic daytime hemodialysis Exclusion Criteria: no active infection at the time of inclusion

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Hemodialyzer scanning|After the hemodialysis session, the used dialyzer is rinsed and dried before scanning in a Micro Computed Tomography scanner. From cross-sectional images, the number of patent fibers is quantified.|
|Other: Bleeding Questionnaires|The ISTH Bleeding Assessment Tool and the HASBLED questionnaires are asked|
|Other: Quality of life questionnaire|The EQ5D questionnaire is asked.|
|Other: Visual inspection of the limbs|Visual inspection is done of the patient's limbs in order to quantify bruising.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relation between anticoagulation dose and number of patent dialyzer fibers | By comparing the anticoagulation dose with the number of patent fibers as measured post dialysis by visualising the dialyzer in a micro computed tomography (CT) machine and by counting the number of open fibers in a cross-section at the dialyzer outlet. | 8 weeks | 
| Relation between anticoagulation dose and bleeding score | Two validated questionnaires about bleeding are used: International Society on Thrombosis and Hemostasis Bleeding Assessment Tool (ISTH BAT) and the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol (HASBLED). ISTH BAT score can be 0-56, with a score >4 (male) and >6 (female) to be considered as abnormal. HASBLED score can be 0-9 with a score >2 to be considered as a patient with high risk of bleeding. Scores are related to the administered anticoagulation dose. | 8 weeks | 
| Relation between bleeding score and quality of life score | Scores of the validated questionnaires about bleeding are related to the EuroQol Five Dimensions questionnaire (EQ5D) about quality of life. Scores per question are 1 to 3. Analysis is done with an online system accounting for patient's age. | 8 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Hemodialyzer, Fibre Clotting, Quality of life, Bleeding, Bruising