Last reviewed: November 2017
Last updated: November  2017

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • hx of recent heparin exposure
  • hx of HIT
  • absence of conditions and medications that cause thrombocytopenia
  • hx of recent surgery or trauma
  • features consistent with recent venous or arterial thromboembolic event (e.g., PE, DVT, stroke, MI)
  • necrosis at heparin injection site(s)

Other diagnostic factors

  • absence of bleeding
  • signs of adrenal haemorrhagic necrosis
  • acute systemic reaction
  • signs of venous limb gangrene

Risk factors

  • recent heparin exposure (within past 100 days)
  • recent orthopaedic or cardiovascular surgery
  • female sex

Diagnostic investigations

Investigations to consider

  • Warkentin (4Ts) Probability Scale
  • HIT antigen assay
  • coagulation studies
  • venous Doppler ultrasound
  • computed tomography pulmonary angiogram (CTPA)
  • ventilation-perfusion scan (V/Q scan)
  • cerebral computed tomography venogram
  • MRI head
Full details

Treatment algorithm

Contributors

Authors VIEW ALL

Associate Professor

Department of Medicine

McMaster University

Thrombosis Consultant

Juravinski Hospital and Cancer Centre

Hamilton

Ontario

Canada

Disclosures

LL is an author of several references cited in this monograph. LL has also been reimbursed for educational lectures for Pfizer Canada (Fragmin; dalteparin) and has received lecture honoraria and research funding from Bayer, Inc (Xarelto; rivaroxaban).

Peer reviewers VIEW ALL

Assistant Clinical Professor of Medicine

Acting Associate Chair of the Division of Hematology and Medical Oncology

University of Connecticut School of Medicine

Farmington

CT

Disclosures

JSW declares that he has no competing interests.

Consultant Haematologist

Aberdeen Royal Infirmary

Foresterhill Health Campus

Aberdeen

UK

Disclosures

HW declares that he has no competing interests.

Clinical Scientist

Royal Brompton Hospital

Honorary Clinical Lecturer

Imperial College London

London

UK

Disclosures

SD is a consultant for Mitsubishi Pharma, the manufacturer of argatroban.

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