Compliance with Platelet Count Monitoring Recommendations and Management of Possible Heparin-Induced Thrombocytopenia in Hospitalized Patients Receiving Low-Molecular-Weight Heparin

Background: Summaries of product characteristics (SPCs) and clinical guideline recommendations are available for monitoring the platelet count for heparin-induced thrombocytopenia (HIT) in patients receiving low-molecular-weight heparin (LMWH). Testing for the presence of heparin-platelet factor 4 antibodies (HPF4-Ab) and starting alternative anticoagulation is recommended when HIT is suspected. Objective: To investigate the frequency of compliance with recommendations for platelet count monitoring and management of possible HIT in hospitalized patients receiving prophylaxis and treatment dosing of LMWH for at least 5 consecutive days. Methods: A retrospective cohort study within the Utrecht Patient Oriented Database (UPOD) was conducted. For all inpatients, all episodes of exposure to dalteparin or nadroparin for at least 5 consecutive days in 2004–2005 were selected. In 4 different nonexclusive groups of patients (all pts. receiving dalteparin, all pts. receiving nadroparin, surgical pts. with a prophylactic dose of either dalteparin or nadroparin, and pts. exposed to unfractionated heparin [UFH] within 100 days before receiving either dalteparin or nadroparin), compliance with recommendations for platelet count monitoring from SPCs and a clinical guideline was studied. The frequency of compliance with these recommendations was determined. In addition, it was determined whether patient and treatment characteristics were associated with regular platelet count monitoring. Finally, the frequency of testing for HPF4-Ab and the initiation of danaparoid treatment in patients with a drop of at least 50% in platelet count were investigated. Results: A total of 6804 patients, with 7770 episodes of LMWH treatment, were included in the analysis. The frequency of compliance with platelet count monitoring recommendations was 26.3% for all patients receiving dalteparin, 35.6% for all patients receiving nadroparin, 23.0% for surgical patients receiving prophylactic dosing of either dalteparin or nadroparin, and 41.5% for patients exposed to UFH within 100 days before the start of either dalteparin or nadroparin treatment. Regular platelet count monitoring was strongly positively associated with medical patients (relative risk [RR] 2.33), surgical patients (RR 2.03), critically ill patients (RR 2.60), and those with recent exposure to UFH (RR 2.19). The frequency of testing for HPF4-Ab was 5.4% and the initiation of alternative anticoagulation with danaparoid in patients with a 50% drop in platelet count was 0%. Conclusions: The results suggest that compliance with recommendations for platelet count monitoring and management of possible HIT is low at our institution. Policies and tools to improve compliance with recommended laboratory monitoring should be developed to secure the safe use of LMWH and other medications.

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Adherence to Guidelines for Monitoring for Heparin-Induced Thrombocytopenia in Patients Treated with Low Molecular Weight Heparin

Blood ◽

10.1182/blood.v112.11.1282.1282 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1282-1282

Author(s):

Maarten ten Berg ◽

Patricia Van den Bemt ◽

Albert huisman ◽

Fred Schobben ◽

Toine Egberts ◽

...

Keyword(s):

Molecular Weight ◽

Platelet Count ◽

Clinical Guidelines ◽

Low Molecular Weight Heparin ◽

Low Molecular Weight ◽

Platelet Factor ◽

Heparin Induced Thrombocytopenia ◽

Alternative Anticoagulation ◽

Life Threatening ◽

Platelet Count Monitoring

Abstract Laboratory monitoring for early detection of adverse drug reactions is recommended for many drugs. For patients treated with low molecular weight heparin (LMWH), the Summary of Product Characteristics (SPC) and clinical guidelines recommend to monitor the platelet count for heparin-induced thrombocytopenia (HIT), a potentially life-threatening adverse event, characterised by a typical drop in platelet count. When the platelet count drops without obvious explanation in these patients, testing for heparin-platelet factor 4 antibodies (HPF4-Ab) and initiating alternative anticoagulation are advised. In the current study adherence to recommended platelet count monitoring in clinical patients without thrombocytopenia-associated diseases treated with LMWH for at least five days at our institution, and adherence to recommended testing for HPF4-Ab and initiation of alternative anticoagulation in patients with potential HIT (defined as a drop of at least 50% in platelet count between days 5 and 14 following the start of LMWH treatment, or stopdate, whichever occurred first, compared to the highest platelet count within days 1–4) were investigated. Data from the Utrecht Patient Oriented Database (UPOD) were used for this retrospective cohort study. Inpatients exposed to the LMWHs dalteparin or nadroparin for at least five days during the period 2004–2005 were included. Patients with thrombocytopenia-related diseases were excluded. Firstly, adherence to recommended platelet count monitoring, based on recommendations from SPCs and clinical guidelines, was investigated. Secondly, the association between patient- and treatment characteristics and obtaining at least 2 platelets counts during treatment was investigated. Thirdly, adherence to recommended testing for HPF4-Ab and initiating treatment with danaparoid was investigated in patients with potential HIT. 6,804 patients with 7,770 episodes of LMWH treatment of at least five days were included. Adherence to the recommendations for platelet count monitoring from the SPC of nadroparin and dalteparin was 36.5% and 26.3% respectively. Adherence to the different platelet count monitoring recommendations from the 2002 clinical guideline on HIT was 23.0% and 41.5%. Obtaining at least 2 platelet counts during treatment was found to be strongly associated with ICU admission, previous UFH exposure, and a treatment duration of at least 10 days. There were 98 patients with potential HIT. Adherence to testing for HPF4-Ab in patients with potential HIT was 6.1%. Adherence to starting alternative anticoagulation in patients with potential HIT treatment was 0%. The results of this study suggest that adherence to recommendations for monitoring for HIT with LMWH is low at our institution. The results of this study justify to say that there is a need to think of appropriate actions for improving the awareness of HIT as an adverse reaction to LMWH, and to secure the safe use of LMWH.

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A Benchmark for Platelet Count Monitoring with Low-Molecular-Weight Heparin: Expanding Implementation of National Patient Safety Goals

Annals of Pharmacotherapy ◽

10.1345/aph.1m356 ◽

2009 ◽

Vol 43 (9) ◽

pp. 1519-1521

Author(s):

Sarah A Spinler

Keyword(s):

Molecular Weight ◽

Patient Safety ◽

Platelet Count ◽

Low Molecular Weight Heparin ◽

Thrombin Inhibitor ◽

Low Molecular Weight ◽

Initial Management ◽

National Patient ◽

Monitoring Protocols ◽

Platelet Count Monitoring

Practitioners in US hospitals are implementing anticoagulation dosing and monitoring protocols to improve the safety of anticoagulation, consistent with National Patient Safety Goal 03.05.01. An audit of the Utrecht Patient Oriented Database of patients treated with low-molecular-weight heparin (LMWH) at the University Medical Center Utrecht revealed low compliance with platelet count monitoring as well as initial management of suspected heparin-induced thrombocytopenia (HIT). Limitations to this work included the inability to exclude other drug-induced causes of thrombocytopenia and their definition of the frequency of platelet count monitoring for compliance in patients given venous thromboembolism prophylaxis. Despite these limitations, the authors’ work represents the first published report on extending the quality of heparin anticoagulation management to platelet count monitoring and evaluation for HIT in a large patient population. Clinicians should include evaluations of compliance with platelet count monitoring with unfractionated heparin and LMWH, as well as appropriateness of the initial management strategies for HIT, and direct thrombin inhibitor protocols in their patient safety practice assessments.

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Severe Autoimmune LMWH-Induced Thrombocytopenia Presenting with Aortic Thromboses, Adrenal Hemorrhage and Pulmonary Embolism: Response to High-Dose Intravenous Immunoglobulin

Canadian Journal of General Internal Medicine ◽

10.22374/cjgim.v13i3.254 ◽

2018 ◽

Vol 13 (3) ◽

pp. 29-34

Author(s):

Joshua Nero ◽

Patricia Araneta ◽

Theodore E Warkentin ◽

Otto Moodley

Keyword(s):

Emergency Department ◽

Molecular Weight ◽

Pulmonary Embolism ◽

Platelet Count ◽

Low Molecular Weight Heparin ◽

Adrenal Hemorrhage ◽

Low Molecular Weight ◽

High Dose ◽

Heparin Induced Thrombocytopenia ◽

Delayed Onset

The occurrence of heparin-induced thrombocytopenia (HIT) in the setting of low-molecular-weight heparin (LMWH) exposure is uncommon, with incidence reported at around 0.2%. Delayed-onset (autoimmune) HIT in the setting of LMWH use is rarer, with only two other case reports in the literature. An 83-year old man was admitted to hospital for an acute exacerbation of chronic obstructive pulmonary disease, receiving low-molecular-weight heparin (LMWH, tinzaparin) while in hospital for prophylaxis against deep venous thrombosis (DVT). One day after discharge, he presented to the emergency department with acute chest pain and dyspnea. Computed tomography revealed bilateral pulmonary embolism, multiple abdominal aortic thromboses, and unilateral adrenal hemorrhage, and he was given a bolus of intravenous unfractionated heparin (UFH) in the emergency department. His platelet count (prior to UFH bolus) was found to be markedly reduced (39 × 109/L) from normal values two days prior. We suspected heparin-induced thrombocytopenia (HIT) to have caused the thrombocytopenia and thromboses (arterial and venous), and thus anticoagulation therapy was changed from heparin to argatroban. His HIT assay was strongly positive, including features of autoimmune reactivity (serum-induced platelet activation in the absence of heparin). HIT developing after exposure to tinzaparin is relatively rare, and use of a scoring system helped to facilitate an early diagnosis. Additionally, this case demonstrates heparin-independent platelet activation, a marker for autoimmune HIT (aHIT). The patient's serum tested strongly positive for IgG-specific anti-PF4/heparin EIA and serotonin release assay. The presence of these antibodies would also explain the further decline in his platelet count to 10 x 109/L after he received a bolus dose of heparin at the beginning of his second hospitalization. This case highlights the third reported case of delayed-onset HIT in the setting of LMWH, and the rapid response to high-dose intravenous immunoglobulin.

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