PB1104 - Evaluation of abnormal routine coagulation results (PT and APTT) for specialist review in a tertiary teaching hospital

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

LM

Laura JB Mawer, BA MBBS BChir MRCP PGCert MedEd

Haematology Doctor (Registrar)
Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust. London, United Kingdom
London, England, United Kingdom

Co-Author(s)

DC

Dhanwanth Chigurupati

Clinical Fellow
Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London, UK
London, England, United Kingdom
DC

Derek Chan

Haematology Registrar
University College London Hospital, London, UK.
London, England, United Kingdom
NC

Nick Chadwick

Database Administrator
Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London, UK
London, England, United Kingdom
AR

Anne Riddell

Laboratory Head of Department (Special Coagulation, Haemophilia) and HSL Scientific Lead Coagulation
Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free Hospital, London, UK
London, England, United Kingdom
Paul Batty, MBBS, PhD (he/him/his)

Associate Professor
University College London
London, United Kingdom
PC

Pratima Chowdary, MD

Consultant Haematologist
Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London, United Kingdom
London, England, United Kingdom

Background: There is a paucity of national and international guidance on the evaluation and investigation of abnormal routine coagulation results. This is concerning as there is potential for results suggestive of an undiagnosed bleeding disorder to be missed.

Aims: Evaluate the cause, severity, and prevalence of abnormal coagulation results in our hospital. Develop pathways for evaluation based on information easily available to laboratory staff.

Methods: Retrospective review of all coagulation results over one week in March 2022 at Royal Free Hospital (RFH) was undertaken to assess for cause and severity of coagulopathy (abnormal PT ± APTT). The cause of coagulopathy was ascertained from the medical notes. Core information accessible on the lab information systems (LIMS) was identified for abnormal coagulopathy evaluation algorithms. The algorithms were tested on a second set of results (three days in November 2022).

Results: In the March 2022 dataset 2580 routine coagulation results were reviewed, with 67.6% of results being normal, 19.7% borderline or mild coagulopathy, 9.3% moderate or severe and 1% very severe. Table 1 gives the categorisation of severity of coagulopathy and table 2 provides the causes of coagulopathy. The most common causes were critical illness, warfarin, and liver disease. The coagulopathy in the second dataset was reviewed for presumed cause using the core information of location, consultant, Hb, Platelet, WCC, AST, ALP, and CRP available on LIMS. The definitive cause was available through review of medical notes. The core information correctly identified 68% of causes of coagulopathy, increasing to 80% with knowledge of anticoagulant use. Preliminary algorithms have been developed, which appear to correctly escalate 97% of abnormal results for clinician or haematology review including a case of lupus anticoagulant.

Conclusion(s): Escalation pathways for abnormal coagulation results address an unmet laboratory need. Our preliminary algorithms show promise at identifying abnormal routine coagulation results for investigation of factor deficiency.