Routine clotting studies - a bloody waste of resources?

1. Routine clotting studies -a bloody waste of resources? Joanne Bratchell Lead Nurse Pre-operative Assessment St George’s Hospital, Tooting Antonia Field-Smith Specialist Registrar in Haematology

2. Defensive?

3. Persuasion?

4. The problem with clotting screens • Do not predict bleeding risk in most patients • Do not accurately reflect in vivo haemostatic response • Designed to detect factor deficiencies in patients with high pre-test probability of bleeding • Low sensitivity and specificity

5. The clotting cascade

6. Shortened clotting times slow or difficult venepuncture incorrect volume of blood in tube inadequate mixing usually not clinically significant ?increased thrombotic risk Prolonged clotting times flawed collection or prolonged storage anticoagulants heparin contamination coagulation factor deficiency inherited acquired lupus anticoagulant factor inhibitor Causes of abnormal clotting screens

7. Background • Lack of clear NICE guidelines meant clotting screens routinely ordered pre-operatively in our Trust • All evidence available concludes that routine testing in apparently healthy or asymptomatic individuals is unlikely to lead to little if any benefit (Munro et al 1997, ASA 2002, NICE 2003, British Committee Standards in Haematology 2008 )

8. Aims and Objectives • To determine whether preoperative clotting screens were requested in adherence with Trust guidelines • To determine whether abnormal clotting results affect the clinical management or surgical outcome of elective surgical patients

9. Methodology • Data collected over 2 week period • Included all elective surgery patients over 18 years of age from 4 care groups attending pre-op clinic • Staff asked to record whether clotting screen requested and why indicated

10. Results • 120/181 (66.2%) patients had clotting screens requested • Only 16 (13.3%) studies requested in line with guidelines • 78 (65%) ordered routinely • 23/120 (19%) prolonged abnormal clotting screens

11. Abnormal results

12. Outcome • No change to clinical management in patients with abnormal clotting results • Only 5 out of 14 patients with unexplained prolonged clotting times had repeat testing • Perioperative bleeding in 5 patients with prolonged clotting screens • All major orthopaedic cases – likely surgical bleeding

13. The best way forward?

14. Bleeding history

15. Revised guidelines

16. Recommendations for practice • Stop ordering routine clotting studies! • If positive bleeding history, refer to haematology • All abnormal results should be repeated • Refer to haematologist if result remains abnormal • Stop ordering clotting test for warfarin pts at pre-op visit

17. Financial implications • Clotting studies at St George’s cost £3.51 a time representing £ thousands per year • In average year, approx £10,500 on pre-op clotting tests • Potential saving of £9000 by adhering to guidelines

18. Conclusion • Routine clotting studies have no value in the management of elective surgery patients • Limited value to patients and significant cost implications to the Trust • Clotting studies should only be ordered when indicated by medical history or local guidelines

19. Thank you • Any questions?