This document discusses guidelines for managing patients on anticoagulant therapy who require surgery. It is important to balance the risk of thromboembolic events from stopping anticoagulants against the risk of bleeding from continued anticoagulation. Factors like the urgency and type of surgery, the indication for anticoagulation and the patient's risk profile are considered. Bridging with low molecular weight heparin may be used when anticoagulants need to be stopped temporarily to reduce thromboembolic risk. Regional anesthesia can be used cautiously in anticoagulated patients when benefits outweigh bleeding risks.

1. PERIOPERATIVE MANAGEMENT FOR PATIENT WITH ANTICOAGULANT THERAPY MODERATOR: DR AISAI ABD RAHMAN PRESENTER : NOR FADHILAH SHAFIII

2. Management of pt on anticoagulant for surgery presently is very crucial It is involving the decision to continue/ discontinue of the anticoagulant h/ever this decision must be weigh the effect of stopping the medication

3. Risk of thromboembolism vs bleeding intraop Major bleeding event can be fatal but pt who bleeds can be resuscitated Recurrent thromboembolism is fatal,if not causes permanent disability

4. Case…. A 58-year-old Indian lady, a known case of rheumatic heart disease since the age of 16 had undergone a successful mitral and aortic valve replacement surgery 11 years previously, sustained a fall and fractured the neck of right femur. She was scheduled for hemireplacement arthroplasty

5. She was a known diabetic on insulin therapy. Her past history revealed that prior to the valve replacement, she used to get breathless even while doing routine daily activities. Presently, she could climb two flights of stairs without any syncope, palpitations, fatigue, chest pain or breathlessness prior to the trauma. She was receiving oral warfarin 2 mg once daily.

6. Physical examination revealed her to be afebrile, with an irregularly irregular pulse-104 beats per minute, respiratory rate 18 breaths per minute blood pressure 160/86 mmHg. Her systemic examination unremarkable Ecg: atrial fibrillation with a heart rate of 110 per minute.

7. ECHO showed 54% ejection fraction, normally functioning valves, no paravalvular leak and confirmed absence of vegetations and clots. CXR revealed ball in cage mitral valve prosthesis, an aortic prosthesis, sternotomy sutures and cardiomegaly How to manage this pt???????

8. OUTLINE introduction Indication for anticoagulant & thromboembolic risk Management for patient on anticoagulant Special anaesthetic condition : Regional anaesthesia for pt on anticoagulant Mx of Obstetric group on anticoagulant Anticaogulated pt going for emergency surgery Summary

9. Introduction…. Perioperative mx of pt’s on anticoagulant and antiplatelet therapy going for surgery is a common and challenging clinical problem Because the risk of a thromboembolic event during interruption of these drugs needs to be balanced against the risk for bleeding This balancing of risk is guided by the pt’s individual risk

10. Two principal issue should be addressed: Is interruption of antithrombotic therapy needed perioperatively?? If antithrombotic therapy is interrupted, is bridging anticoagulant needed?? (bridging anticoagulation: administration of a short acting anticoagulant, eg: LMWH/UFH during interuption of anticoagulant therapy)

11. Important factor to consider are : Anticoagulation: indication for anticoagulant therapy, nature of anticoagulant drug, degree of anticoagulant required Surgery risk factor: urgency, nature and site of surgery Patient risk factor

12. Pt risk factors Surgical risk factor 1)Type of surgery or procedure 2) Risk of bleeding/difficulty 3) Risk of thromboembolism 4) Time off anticoagulant Weigh consequences of thromboembolism and bleeding Consider pt and provider preference 1)Identify the indication for anticoagulant -mechanical heart valve -valve type -valve location -atrial fibrillation -Hx of thromboembolism 2) Assess patient’s risk for thromboembolism Determine the need for bridge therapy

13. ACCP’S SUGGESTED RISK STRATIFICATION FOR PERIOPERATIVE THROMBOEMBOLISM RISK CATEGORY MECHANICAL HEART VALVE ATRIAL FIBRILLATION VENOUS THROMBOEMBOLISM HIGH (> 10%/yr risk of ATE or >10%/mo risk of VTE) Any mechanical MV Older aortic valve Recent stroke/TIA( < 6/12) CHADS score of 5 or 6 Recent stroke/TIA (<3mo) Rheumatic valvular heart dis Recent VTE(<3mo) Severe thrombophilia Moderate (4%-10%/yr risk of ATE Or 4-10%/mo risk of VTE) Bileaflet aortic valve and 1 of the following : AF, prior stroke/TIA,HPT,DM,heart failure ,age >75yr CHADS score of 3-4 VTE within 3-12mo Recurrent VTE Active cancer Nonsevere thrombophilia Low (< 4%/yr risk of ATE or < 2%/mo risk of VTE) Bileaflet aortic valve without AF and no other risk factor for stroke CHADS score of 0-2 and no prior stroke /TIA Single VTE within past 12mo and no other risk factor

14. CHADS2 score is used for identifying Annual stroke risk in patients with atrial fibrillation CHADS2 score :congestive heart failure/hypertension/age>75/diabetes( 1 each point) /stroke or TIA( 2 point)

15. ANNUAL STROKE RISK 0 1 2 3 4 5 6 1.2-3% 2.0-3.8% 3.1-5.1% 4.6-7.3% 6.3-11.1% 8.2-17.5% 10.5-27.4% CHADS2 SCORE STROKE RATE

16. Discontinuing anticoagulant is usually necessay for major surgery but increase risk of thrombotic events. Bridge therapy, the temporary periop substitution of LMWH/UFH in place of warfarin is an effective means of reducing risk of thromboembolism but may increase risk of bleeding the timing of warfarin withdrawal and starting bridge therapy are critical to balance these risk

17. General management of patient on anticoagulant Warfarin LMWH/UFH Antiplatelet

18. GENERAL ANAESTHESIA : Is not a contraindicated for pt w anticoagulant Precaution should be consider : Avoid IM/Subcutaneous drug administration Premed should be oral or IV If IM administration is necessary, the arm should be used ( since local haemorrhage is easier to detect & treat) All venopuncture /arterial puncture should be carried out meticulously

19. Cont … CVL by subclavian/int jugular route is contraindicated If CVL is necessary, used antecubital fossa External jugular can be used as haematoma formation can be treat w external pressure Atraumatic laryngoscopy and tracheal intubation Avoid nasal intubation/NG tube No precaution are necessary for pt receiving prophylactic low dose heparin

20. stopping warfarin before operation Check INR INR 2-3: discont warfarin 5 days before op INR 3-4.5: discont 6 days before op Target preop INR < 1.2 Elderly asso w slower rate of decrease in INR If INR >1.5 (1-2 days before surg), to give 1-2mg oral vitamin K Warfarin need not be stopped for all procedures

21. Procedure that can be perform without discontinuing warfarin Opthalmic surg: Cataract surg Trabeculectomy Dental surg : Extraction Endodontic Prosthetics Dental hygiene Dermatologic Simple excision GIT: OGDS Colonoscopy without biopsy ERCP Biliary stent without sphincterotomy

22. Starting heparin before the operation Assessment of the pt which require bridging therapy based on individual risk factors recommandation for periop bridge therapy : High risk gr : bridging anticoagulant w therapeutic dose of s/c LMWH/iv UFH Moderate risk gr: therapeutic dose of LMWH/UFH or low dose s/c LMWH Low risk : low dose s/c LMWH or no bridging

23. Therapeutic dose of UFH Commonly used prevly but declined in recent years It’s a dose adjusted IV infusion administered to achieve a target APTT of 1.5-2 times the control Infusion stopped 4hrs before surgery Resume back during initial 24hrs after surgery Alternative to IV UFH is S/C UFH ( no need APTT monitoring)

24. Therapeutic dose LMWH Preferable recently No need laboratory monitoring Start LMWH ( enoxaparin 1mg/kg or deltaparin 100IU/kg subcutaneously every 12hrs) 36hrs after last dose of warfarin Give last dose of LMWH 12hrs prior to surgery (preferable 24hrs)

25. Low dose LMWH Eg: s/c heparin 5000IU bd/enoxaparin 30mg bd Typically used for DVT prevention Used in lower risk pt for thromboembolism

26. After surgery…. Minor surgery ( high risk group): reinitiate LMWH at full dose 24hrs after surg Major surgery / high risk of bleeding : Use prophylactic dose on the first 2 post op day then full dose of LMWH or Delay the initiation of therapeutic dose for 48-72hrs post op Discuss w surgeon regarding reinitiation of anticoagulant

27. Restarting warfarin after the operation Restart warfarin as prev dose 1 day post op(12-24hrs post op) when haemostasis are adequate Daily PT/INR till discharge and periodically after discharge till INR reach therapeutic range Discontinue LMWH when INR is between 2-3 for 2 consecutive day

28. Pt on antiplatelet.. Pt on aspirin or clopidogrel need to discont tx for 7-10days prior to op Resuming back antiplatelet after 24hrs If pt are at high risk for cardiac event Cont the aspirin up to and beyond the surgery If pt on clopidogrel, stopped at least 5days prior to surgery (preferably 10days)

29. REGIONAL ANAESTHESIA The choice of regional anesthesia may offer considerable advantages over general anesthesia for various surgical procedures or for certain patients . h/ever the benifit of of RA outweigh the risk of altered haemostasis. Such as in patients with compromised cardio respiratory function.

30. spinal hematoma is the most significant hemorrhagic complication of regional anesthesia due to the catastrophic nature of bleeding into a fixed and noncompressible space

31. Guidelines for Regional Anesthesia while on Anticoagulation Subcutaneous Heparin Intravenous Heparin Low Molecular Weight Heparin warfarin Antiplatelet Medications

32. Subcutaneous Heparin prophylactic (low dose) sc heparin (5000 u/24h): not a contraindication for regional anesthesia,considering: The coagulation tests are within normal limits (check for Heparin Induced Thrombocytopenia if pt on S/C heparin for more than 4days ), The patient is not receiving other coagulation-altering drugs (e.g. NSAIDs), Puncture or removal of the catheter 2-4 h after the last heparin dose and aPTT normal

33. Intravenous Heparin Should be avoided in patients with concomitant coagulopathies Heparin administration should be delayed for 1 hour after needle placement Indwelling neuraxial catheters should be removed 2-4 hours after the last heparin dose and reevaluation of the patient's coagulation status has occurred.

34. Re-heparinization should occur one hour after catheter removal. For postoperative analgesia use the lowest effective local anesthetic concentration (probably with opioids), to facilitate neurological monitoring.

35. Therapeutic anticoagulation with heparin is a contraindication to regional block accept: intravenous heparin infusion should be discontinued for 4 hours the activated partial thromboplastin time (APTT) should be normal before attempting a block or removing a catheter.

36. Patients receiving LMWH. LMWH have longer half-lives than unfractionated heparin, which allows once daily administration. They have fibrinolytic properties as well as anti-Xa activity There is no LMWH monitoring test for routine Traumatic needle or catheter placement may signify an increased risk of spinal hematoma and initiation of LMWH therapy in this setting should be delayed for 24 hours.

37. Preoperative administration of LMWH: Neuraxial blockade should be performed after 12 h of administration of thromboprophylaxis doses Do not puncture after 2-4 h of LMWH administration, as during this time the anticoagulant effect is at its maximum. If high-dose LMWH is used for therapeutic anticoagulation it takes about 24 hours for coagulation to return to normal. Therefore, an interval of 24 hours should elapse before attempting central neuraxial block or peripheral nerve block.

38. • Postoperative administration of LMWH. Once-daily dose LMWH: - The first dose is administered 6-8 h postoperatively, and the second dose 24 h after the first. - Catheter removal 10-12 h after LMWH administration - at least 2hrs before next LMWH administration.

39. Twice-daily dose LMWH: -The first dose is administered 24 h postoperatively. -Indwelling catheters should be removed prior to initiation of LMWH. - If a continuous technique is selected, the epidural catheter may be left indwelling overnight and removed the following day, with initiation of LMWH occurring at least two hours after catheter removal

40. Fondaparinux this new thromboprophylactic drug is a synthetic pentasaccharide, which has potent anti-Xa activity. It has a longer elimination half-life than LMWH of 17 hours in young patients and 21 hours in healthy elderly patients. It is administered 6 hours after surgery, which makes decisions regarding regional anaesthesia easier. However, its long half-life means that it should be used with caution in patients with neuraxial or peripheral nerve catheters in situ . An interval of at least 24 hours should elapse before removal of neuraxial or peripheral nerve catheters.

41. Post thrombolitic: Absolute contraindication for regional anaesthesia

42. Warfarin for thromboembolic prophylaxis in many cardiovascular conditions. Many older patients presenting for surgery are taking long-term warfarin therapy. For all but the most minor surgical procedures, warfarin should be stopped INR should be <1.4, with no other coagulation defects. this normally takes about 4 days and substitute with LMWH (either prophylaxis or therapeutic dose, depending on thrombosis risk stratification,)

43. Vitamin K and FFP may prove helpful in more urgent cases. If the patient has received only one dose of warfarin preoperatively (to continue with warfarin postoperatively), check INR before puncture and before catheter removal. During continuous epidural analgesia, if the patient receives low doses of warfarin: INR should be kept <1.5. Catheter removal when INR<1.5, neurological monitoring for more than 24 h if INR> 1.5 during catheter removal. Definitely postponed if INR>3.

44. Aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) impair platelet function by irreversibly inhibiting platelet cyclo-oxygenase (COX). Aspirin inhibits COX irreversibly while NSAIDs do so reversibly. Therefore the antiplatelet effect of aspirin persists until a new platelet population is manufactured (at least 7 days), whereas platelet function returns to normal within 3 days after stopping NSAIDs. Despite their widespread use for many years, there have been only five case reports of vertebral canal haematoma in patients receiving aspirin or NSAIDs alone. It is safe to proceed with central neuraxial block in patients taking these drugs, (a view endorsed by the American Society of Regional Anaesthesia. 2 )

45. Clopidogrel or ticlodipine (ADP receptor antagonists). a thienopyridine derivative and is a potent antiplatelet agent. It inhibits ADP-induced platelet aggregation and binding between platelets and fibrinogen. These effects are irreversible and platelet function does not return to normal until at least 7 days after stopping the drug. Neuraxial blockade is contraindicated before 7 days from the discontinuation of clopidogrel and 14 days for ticlodipine.

46. Platelet glycoprotein IIb/IIIa antagonists Eg: abciximab, eptifibatide and tirofiban. A new class of antiplatelet agents for use in patients with acute coronary syndromes. The drugs target the platelet IIb/IIIa receptor complex. The IIb/IIIa complex functions as a receptor for mainly fibrinogen and vitronectin, but also fibronectin and von Willebrand's factor.

47. They have been recommended to prevent coronary ischaemic events in high-risk patients Central neuraxial block should be avoided until platelet aggregation has returned to normal; a minimum of 8 hours after tirofiban and eptifibatide and 24–48 hours after abciximab

48. MANAGEMENT OF MATERNAL WITH ANTICOAGULANT

49. Conditions Warranting Anticoagulation During Pregnancy Mechanical prosthetic valve Inherited deficiency of naturally occuring anticoagulant: Factor V Leiden Protein C deficiency Protein S deficiency Antithrombin III deficiency Prior episode of venous thromboembolism Acute deep venous thrombosis or pulmonary embolism during pregnancy Antiphospholipid antibody syndrome

50. Common risk factors that increase the incidence of thrombosis in pregnant women: pregnancy increasing age prolonged immobilization Obesity Thrombophilia previous thromboembolism cesarean delivery

51. Pregnant women with a prosthetic valve are at high risk for thromboembolic phenomena, valve failure and bacterial endocarditis. All pregnant women with a prosthetic valve require anticoagulation Complications from anticoagulation include fetal teratogenicity, and maternal and fetal hemorrhage

52. Warfarin crosses the placenta and has been associated with fetal malformations and hemorrhage. The teratogenic effects of warfarin are limited to the first trimester. It may be used in the second and third trimester, but must be discontinued prior to delivery.

53. Heparin does not cross the placenta, but can still cause maternal hemorrhage. Low molecular weight heparin has also been used safely in pregnancy as it does not cross the placenta.

54. Management delivery should be scheduled whenever possible oral anticoagulants should be switched to LMWH or UFH at 36 week with similar dosing and monitoring as when used for anticoagulation throughout pregnancy at least 36 hrs before induction of labor or cesarean delivery, LMWH should be discontinued and the patient converted to intravenous or subcutaneous UFH

55. intravenous UFH should be discontinued 4 to 6 hrs before anticipated delivery pregnant patient on LMWH should be advised to withhold her heparin injection if she believes she may be in labor until evaluated by her obstetrician. When possible, an induction or elective cesarean delivery should be scheduled

56. reinitiating anticoagulation postpartum must also be considered when planning the anesthetic management resumption of prophylaxis (eg, 5000 U of UFH every 12 hrs, 40 mg of enoxaparin once daily) should be held until at least 12 hrs after abdominal delivery, or epidural removal (whichever is later ) After cesarean delivery, thromboprophylaxis should be held for at least 24 hrs.

57. Pt on warfarin : INR < 1.4 for needle/catheter insertion and withdrawal Avoid or limit epidural analgesia to <48 hrs. Pt on fundaparinox : Needle placement 36 hrs after last dose. Indwelling epidural catheter not recommended

58. MANAGEMENT FOR PT ON ANTICOAGULANT GOING FOR EMERGENCY SURGERY

59. Perioperative Management of Antithrombotic Therapy Patients Who Require Urgent Surgical or Other Invasive Procedures Pt on warfarin : In the nonbleeding patient who requires rapid (within 12 h) reversal of the anticoagulant effect because of an urgent surgical or other invasive procedure, treatment options with fresh-frozen plasma/prothrombin concentrates/ recombinant factor VIIa

60. If surgery is urgent but can be delayed for 18 to 24 h, the anticoagulant effect of VKAs is likely to be neutralized by IV vitamin K, at a dose of 2.5 to 5.0 mg without the need for blood product

61. Patients Who Are Receiving Antiplatelet Drugs: no pharmacologic agent that can reverse the antithrombotic effect of aspirin, clopidogrel, or ticlopidine Suggest for platelet transfusion Or prohemostatic agents. Eg: aminocaproic acid and tranexamic acid (not much studies to assess the efficacy and safety of this method )

62. Take home message…. Pt on anticoagulant present for surgery bring the risk of morbidity and mortality Proper history and physical examination upon presentation is very important assessment prior to operation

63. Concern about the Risk of bleeding if on anticoagulant and risk of thromboembolic event when interrupt the medication Know when and how to start and stop anticoagulant related to surgery and anaesthesia

64. THANK YOU FOR ATTENTION..