Background: The aim of the study is to describe serious adverse events in patients with renal insufficiency administered low molecular weight heparins (LMWHs).
Methods: Systematic case note review from July 2002 to March 2003, Hope Hospital, Salford, UK, was used.
Results: Ten patients experienced an adverse incident on LMWH therapy. Five patients were on maintenance hemodialysis therapy, and 1 patient was on continuous ambulatory peritoneal dialysis therapy. Three patients had calculated creatinine clearances of 5, 11, and 33 mL/min (0.08, 0.18, and 0.55 mL/s), and 1 patient had an estimated glomerular filtration rate of 12 mL/min. Age range was 45 to 89 years. Indications for anticoagulation were suspected pulmonary embolism (1 patient), acute coronary syndrome (7 patients), severe nephrotic syndrome (1 patient), and postoperative venous thromboembolic prophylaxis (1 patient). Three patients also were administered aspirin; 1 patient, clopidogrel; and 3 patients, aspirin and clopidogrel. LMWHs used were enoxaparin (6 patients), tinzaparin (3 patients), and dalteparin sodium (1 patient). Bleeding sources were retroperitoneal (1 patient), spontaneous soft tissue (3 patients), gastrointestinal (2 patients), dialysis catheter and cannula sites (2 patients), hemorrhagic pericardial effusion (1 patient), and intracranial (1 patient). Activated partial thromboplastin time was prolonged in 7 of 10 patients, with no other identifiable cause found. Three patients died despite aggressive resuscitation, including packed red blood cell infusions and protamine sulfate administration. Eight of the 10 prescriptions for LMWHs were either started or continued within our directorate, giving an approximate incidence of major hemorrhagic events in patients with chronic kidney disease of 7.8%.
Conclusion: LMWHs administered at fixed-weight doses and without monitoring show unpredictable anticoagulant effects in patients with chronic kidney disease stages 4 and 5, leading to serious and even fatal adverse incidents.