Measurement of the international normalized ratio (INR) in hemodialysis patients with heparin-locked central venous catheters: evaluation of a novel blood sampling method
Measurement of the international normalized ratio (INR) in hemodialysis patients with heparin-locked central venous catheters: evaluation of a novel blood sampling method
J Vasc Access 2009; 10(2): 180 - 182
Authors
Jean-Philippe Rioux, Bruno De Bortoli, Serge Quérin, Clément Déziel, Stéphan Troyanov, François Madore
Abstract
Background: Accurate measurement of the international normalized ratio (INR) may be difficult in hemodialysis (HD) patients with heparin-locked central catheters. Blood contamination with locking solutions may interfere with INR measurement when samples are collected directly from the catheter.
Methods: The aim of our study was to evaluate a novel sampling method for the measurement of INR in HD patients with heparin-locked central catheters. This novel method consists of measuring the INR directly from the dialysis circuit (arterial bloodline sample port) after 1 hr of treatment regardless of heparin administration during dialysis. We compared this method to the gold standard (peripheral venipuncture prior to dialysis) using the paired t-test. We included 30 patients (23 with warfarin therapy and 7 without).
Results: INRs obtained using the novel sampling method were only minimally overestimated compared to venipuncture values (mean INR overestimation: 0.2 +/- 0.2). This overestimation was not clinically significant and did not lead to changes in warfarin prescription for any of the patients. Correlation tests confirmed the influence of heparin administration on INR overestimation (R=0.4; p=0.05). This influence was present mostly among patients receiving more than 100 Units/kg of heparin during their treatment.
Conclusion: This novel sampling technique provides a convenient and simple method of monitoring INR among HD patients.
Article History
- • Available online on 6/5/2009
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Authors
- Rioux, Jean-Philippe
[PubMed]
[Google Scholar]
Nephrology Division, Hôpital du Sacré-Coeur de Montréal, Montreal, Québec - Canada
- De Bortoli, Bruno
[PubMed]
[Google Scholar]
Nephrology Division, Hôpital du Sacré-Coeur de Montréal, Montreal, Québec - Canada
- Quérin, Serge
[PubMed]
[Google Scholar]
Nephrology Division, Hôpital du Sacré-Coeur de Montréal, Montreal, Québec - Canada
- Déziel, Clément
[PubMed]
[Google Scholar]
Nephrology Division, Hôpital du Sacré-Coeur de Montréal, Montreal, Québec - Canada
- Troyanov, Stéphan
[PubMed]
[Google Scholar]
Nephrology Division, Hôpital du Sacré-Coeur de Montréal, Montreal, Québec - Canada
- Madore, François
[PubMed]
[Google Scholar]
Nephrology Division, Hôpital du Sacré-Coeur de Montréal, Montreal, Québec - Canada