De prevalentie van incorrecte anti-Xa-bloedspiegels bij patiënten met een verminderde nierfunctie die laag-moleculairgewicht-heparines gebruiken

OBJECTIVE: To determine the prevalence of incorrect anti-Xa activity in patients with renal insufficiency after three days of therapeutic use of nadroparin, as advised in the guideline of the Dutch federation of Nephrology. DESIGN: Prospective, observational study. METHODS: The source population consisted of patients aged ≥18 years old with renal insufficiency (eGFR [MDRD] < 60 mL/min/1.73 m²) from the Jeroen Bosch hospital who were treated therapeutically with nadroparin. All patients were followed from the start of nadroparin use (index date) for three days. At day three (t=3) the anti-Xa activity was monitored. Weight, eGFR [MDRD] and nadroparin use during the three days were obtained from the electronic patient file. We also checked if the patients received a dose of nadroparin according to the guideline during the three days of use. RESULTS: In total 15 patients were included. Nadroparin dose was not adjusted according to the guideline in 13 patients. 4 of these patients (31%) still had a correct anti-Xa activity at t=3 and 9 had an incorrect anti-Xa activity. Only 2 patients received a nadroparin dose according to the guideline but had an incorrect anti-Xa activity at t=3. CONCLUSION: The results of this study suggest that therapeutic use of nadroparin with and without dose adjustment often leads to incorrect anti-Xa activity in patients with renal insufficiency. Therefore we advise to individualise nadroparin dose according to the first anti-Xa activity which is measured at day three of nadroparin use. To confirm this conclusion, additional research with more patients is needed.