1. Coagulation and anti-coagulants March 2016

2. Normal physiology Patophysiology Diagnostic tests Anticoagulants Anticoagulants and anesthesia

3. Normal physiology 3 steps Vascular spasm Platelet plug Blood coagulation Venous vs arterial thrombus!!!

4. Platelet plug 1. Translocation 2. Adhesion 3. Aggregation 4. Activation 5. Thrombus formation

9. Blood coagulation

10. Arterial thrombi Normally arteries only clot when damaged (trauma) Need endothelial damage and Activated plaque!

12. Patophysiology 1. Disorders of blood vessels 2. Disorders of platelets - numbers ( decreased production/ increased destruction) - function ( drug related/ uremia) 3. Disorders of coagulation proteins - hemophilias - Von Willebrand disease

13. Diagnostic tests 1. Bleeding time platelets fx insensitive 2. APTT Intrinsic pathway 3. PT Extrinsic pathway 4. INR 5. TT 6. Fibrinogen essays 7. D Dimers

14. Anticoagulants

15. Clexane Prophylaxis 40mg/day sc Therapeutic 1mg/kg bd Morbid obesity can increase dose with 30% Renal impairment Cr Cl 30- 60 ml/min 0,8 mgkg bd Urgent reversal with Protamine 1mg:1mg Anti F10 activity will only recover 60% max

16. Anticoagulants and neuroaxial anesthesia Same principles apply plexus blocks Incidence of spinal hematoma 0,1/ 100 000/year Asperin, Nsaids safe Clopidogrel - stop 7 days Warfarin - INR < 1,4 Heparin - > 1 hour before block, remove catheter > 2-4 hours after last dose LMWH- start > 24 hours after catheter placement Next dose > 2 hours after catheter removal

17. Case study 75 yr old male with fracture femur neck. Booked for hemi-arthroplasty. He has significant COPD. Weight 60kg U+E: Na 130 K 3.4 Urea 12 Creatinine 128 Current Px: Diuretic, CaCB, Disprin150mg, Clexane 40mg at 22h00 You also notice Ginseng Biloa and Echinacea herbals between his meds. You decide on a neuroaxial block.

18. Questions: 1. What are your concerns regarding his medication 2. What other factors can influence his Anticoagulants 3. Timing interval between meds and neuroaxial? 4. Can you consider Cyklokapron intra-op to reduce blood loss and risk of spinal hematoma? 5. Postop measures to prevent DVT? 6. Do you still consider a neuroaxial anesthesia?

19. Contra-indications to anti-coagulants Active bleeding Uncontrolled HTS >180/110 Active peptic ulcer Abnormal hemostasis Severe liver disease Severe renal impairment Cr Cl <30ml/min