asra guidelines.pptx

Asra guidelines

1. ASRA / ESRA GUIDELINES for Regional Anaesthesia: AN UPDATE DR AMRITA RATH DR APOORVA AGARWAL

2. Introduction Regional Anaesthesia is practiced more and more because of better outcome and patient satisfaction. Anticoagulants, antiplatelets & thrombolytic medications are used more and more.

3. What is the problem Incidence of spinal hematoma was 1: 1.5 lakh with epidural and 1:2.2 lakh with spinal. Incidence of hematoma is higher in patients on anticoagulants. 1: 1 lakh for spinal and 33:1 lakh for epidural. Focus should not only be on prevention of hematoma formation but also on early detection and treatment.

4. Thromboprophylaxis: when needed

5. Risk factors for hematoma formation

6. 1 ASRA Consensus 1998 2003 2010 2018 2022- ESRA recommendations

7. Recommendations are often pharmacologically based. Recommended time intervals between discontinuation of the drug during therapeutic anticoagulation and subsequent neuraxial blocks are 5 half lives and is dependent on renal function. This allows for resolution of 97% of the anticoagulant effect. 1 st – 50% 2 nd - 75% (+25%) 3 rd - 87.5% (+12.5%) 4 th - 93.75% (+6.25%) 5 th - 96.875% (+3.125%) With lower levels of anticoagulation associated with prophylactic doses, only 2 half life interval is sufficient.

8. Proposed that subsequent dosing of antithrombotic therapy based on 8 hrs minus the time it takes for the anticoagulation to reach peak effect. Given the 4 hour time to peak effect with LMWH, the time to subsequent dosing following catheter manipulation would be 8hrs minus 4 hrs, i.e: 4 hrs.

9. Level of Evidence A – RCT and meta analysis B- Observational studies C- Case reports and Expert opinion Grade of Recommendation 1(I) – General aggrement on efficacy 2(II)- Conflicting evidence or opinion on the usefulness 3(III)- Procedure may not be useful We recommend- Grades 1A, 1B & 1C We suggest- Grades 2A, 2B & 2C

10. Mechanism of plug formation

11. Antiplatelets

12. Anticoagulants

13. ANTICOAGULANT DRUGS ORAL DIRECT THROMBIN INHIBITOR - DABIGATRON ORAL Xa INHIBITORS - APIXABAN - RIVAROXABAN - EDOXABAN WARFARIN PARENTERAL DIRECT THROMBIN INHIBITORS - DESIRUDIN - BIVALIRUDIN - ARGATROBAN INDIRECT THROMBIN INHIBITORS - UNFRACTIONATED HEPARIN ( UFH ) - LOW MOLECULAR WEIGHT HEPARIN ( LMWH ) - FONDAPARINUX

14. Anticoagulants Heparin Binds to AT III – inactivates Thrombin (factor IIa), factor Xa & factor IXa. IV- for vascular & cardiac surgeries SC- Prophylaxis against VTE Monitoring – aPTT ACT(when higher doses are used) Anti Factor Xa levels Reversal – Protamine (1 mg neutralizes 100 U of heparin) Some patients may develop HIT.

15. MEDICATION PRIOR TO CATHETER PLACEMENT ( MINIMUM TIME BETWEEN LAST DOSE OF ANTICOAGULATION AND INITIAL CATHETER PLACEMENT ) AFTER CATHETER REMOVAL ( WHEN TO START ANTICOAGULATION THERAPY ONCE THE CATHETER IS REMOVED ) ADDITIONAL INFORMATION ( IF ANY ) 1) UNFRACTIONATED HEPARIN I/V OR S/C UFH FOR >4 DAYS HAVE A PLATELET COUNT ASSESSED PRIOR TO NEURAXIAL BLOCK OR CATHETER REMOVAL(Gr 1C) (No change) 2) I/V HEPARIN DISCONTINUE HEPARIN 4-6 HOURS & VERIFY NORMAL COAGULATION STATUS PRIOR TO NEURAXIAL BLOCKADE(Gr 1A) DELAY HEPARIN ADMINISTRATION FOR 1 HOUR AFTER NEEDLE PLACEMENT (Gr 1A) (No change) REMOVE INDWELLING NEURAXIAL CATHETERS 4-6 HOURS AFTER THE LAST HEPARIN DOSE (ASSESS PATIENT’S COAGULATION STATUS), REHEPARINIZE 1 HOUR AFTER CATHETER REMOVAL (Gr 1A) (No change) MONITOR POSTOP FOR MOTOR BLOCKADE & MINIMAL CONC. OF LA FOR EARLY DETECTION OF SPINAL HEMATOMA (Gr 1A (No change)

16. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 3) S/C HEPARIN (i) PROPHYLACTIC LOW DOSE- 5000 U BD OR TDS NEURAXIAL BLOCK TO OCCUR 4-6 HOURS AFTER HEPARIN ADMINISTRATION OR COAGULATION STATUS BE ASSESSED (Gr 2C) (No change) CATHETER REMOVAL OCCUR 4-6 HOURS AFTER HEPARIN ADMINISTRATION. SUBSEQUENT HEPARIN ADMINISTRATION MAY OCCUR 1 HOUR AFTER CATHETER REMOVAL (Gr 2C) (No change) If bloody tap has occurred it should be communicated to the surgeon. No data suggests the mandatory cancellation of the surgical case. (ii) PROPHYLACTIC HIGH DOSE- 7500 -10000 U BD OR daily dose < 20000 U NEURAXIAL BLOCK TO OCCUR 12 HOURS AFTER S/C HEPARIN ADMINISTRATION & ASSESS COAGULATION STATUS (Gr 2C) (New recommendation) (iii) THERAPEUTIC DOSE- > 10000 U BD OR daily dose >20000 U NEURAXIAL BLOCK TO OCCUR 24 HOURS AFTER S/C HEPARIN ADMINISTRATION & ASSESS COAGULATION STATUS (Gr 2C) (New recommendation)

17. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 4) LOW MOLECULAR WEIGHT HEPARIN (LMWH) prolonged T1/2 Not Reversible with protamine Asses- Anti –factor Xa Elimination T1/2- 3-6 hrs PROPHYLACTIC LMWH (for DVT prevention) enoxaparin 30 mg BD or 40 mg /day NEEDLE PLACEMENT SHOULD OCCUR ATLEAST 12 HOURS AFTER PROPHYLACTIC LMWH DOSE (Gr 1C) (No change) INDWELLING CATHETERS SHOULD BE REMOVED PRIOR TO INITIATION OF LMWH THROMBOPROPHYLAXIS. ADMINISTRATION OF LMWH SHOULD BE DELAYED FOR 4 HOURS AFTER CATHETER REMOVAL (Gr 1C) (8hrs – the time for peak effect) (New recommendation) PATIENT’S RECEIVING LMWH FOR >4 DAYS HAVE A PLATELET COUNT ASSESSED PRIOR TO NEURAXIAL BLOCK OR CATHETER REMOVAL[HIT ](Gr 1A) (No change) (ii) THERAPEUTIC LMWH (T/t of Ac. VTE or ACS) Enoxa 1mg/kg BD or 1.5 mg /kg/ day, dalteparin 120u/kg BD or 200u/kg/day Anti factor Xa – 0.5 -1 u/ml DELAY ATLEAST 24 HOURS PRIOR TO NEEDLE/CATHETER PLACEMENT (Gr 1C) (No change) CATHETERS TO BE REMOVED 4 HOURS PRIOR TO THE FIRST POSTOPERATIVE DOSE & ATLEAST AFTER 24 HOURS OF CATHETER PLACEMENT (WHICH EVER IS GREATER) (Gr 1C) (No change) Concomitant medications affecting hemostasis is not advised along with LMWH (Gr 1A) (No change) Blood during catheter placement- delay LMWH for 24hrs Postop (Gr 2C) (No change)

18. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 5) ANTI FACTOR Xa AGENTS FONDAPARINUX Irreversible antithrombotic Peak effect- 3 hrs Half life 17- 21 hrs Single needle pass, atraumatic needle placement and avoidance of neuraxial catheter (No change) NEURAXIAL CATHETERS ARE TO BE REMOVED 6 HOURS PRIOR TO THE FIRST POSTOPERATIVE DOSE (Gr 2C) (No change)

19. Warfarin (VKA) MOA- Interfering with Synthesis of Vit K dependent factors II, VII, IX & X Onset- 8-12 hrs, peak - 36-72 hrs Monitored by PT/ INR. Reversal Elevated INR without bleeding- PO Vit K Elevated INR with bleeding – IV Vit K Life threatening bleeding- 4 factor PCC > 3 factor PCC > FFP

20. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 6) WARFARIN ANTICOAGULATION MUST BE STOPPED 5 DAYS PRIOR TO THE PROCEDURE & INR TO BE NORMALIZED PRIOR TO INITIATION OF NEURAXIAL BLOCK (Gr 1B) (No change) Concurrent use of medications is not advised(Gr 1B) (No change) INR should be monitiored daily in pts receiving low dose warfarin during epidural analgesia (Gr 2C) (No change) For patients who are high risk of Thromboembolism- bridging therapy with LMWH can be started. THROMBOPROPHYLAXIS WITH WARFARIN IS INITIATED & CATHETERS ARE TO BE REMOVED WHEN THE INR <1.5 Removal of catheter within 12-24 hrs carries lesser risk than at 48 hrs after warfarin is initiated. (New recommendation) IF INR >1.5 BUT <3 THE INCREASE IN RISK WITH PROGRESSIVE INR PROLONGATION REMAINS UNKNOWN, CATHETERS MAY BE MAINTAINED WITH CAUTION (Gr 2C) (New recommendation) IF INR >3 WARFARIN DOSE SHOULD BE HELD OR DOSE IS REDUCED IN PATIENTS WITH INDWELLING CATHETERS (Gr 1A). (No change) Neurological assessment be continued for 24hrs (Gr 2C). (No change)

21. Direct Oral Anti Factor (DOAC’S) Xa Agents Safer, rapid onset, short half life, devoid of the need for monitoring Uses- prevention & T/t of VTE & PE, Prevention of stroke in NVAF. Rivaroxaban Oral Bioavailability- 80-100%, protein binding 90% 1/3 rd eliminated by kidneys, 2/3 rd metabolized by liver. Monitored by Anti factor Xa Assay. Andexanet is antidote for Rivaroxaban

22. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 7) NEWER ORAL ANTICOAGULATION AGENTS RIVAROXABAN Half life – 9 Hrs and 13 rs in elderly with altered renal function. DISCONTINUE 72 HOURS PRIOR TO NEURAXIAL BLOCK CONSIDER ANTI FACTOR Xa ACTIVITY LEVEL IF LESS THAN 72 HRS (Gr 2C). (New recommendation) NEURAXIAL CATHETERS ARE TO BE REMOVED 6 HOURS PRIOR TO THE FIRST POSTOPERATIVE DOSE (Gr 2C). (New recommendation) UNANTICIPATED ADMINISTRATION WITH INDWELLING CATHETER, RIVAROXABAN DOSING BE HELD FOR 22-26 HOURS BEFORE OR AN ANTI Xa ASSAY CALIBRATED TO RIVAROXABAN BE ASSESSED BEFORE THE CATHETER IS REMOVED (Gr 2C). (New recommendation)

23. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION (ii) APIXABAN Oral Bioavailability- 50-85%, protein binding 87% Kidney clearence- 27% Terminal half life 10-15 hrs DISCONTINUE 72 HOURS PRIOR TO NEURAXIAL BLOCK, CONSIDER ANTI FACTOR Xa ACTIVITY LEVEL IF LESS THAN 72 HRS (Gr 2C). (New recommendation) NEURAXIAL CATHETERS ARE TO BE REMOVED 6 HOURS PRIOR TO THE FIRST POSTOPERATIVE DOSE (Gr 2C). (New recommendation) UNANTICIPATED ADMINISTRATION WITH INDWELLING CATHETER, APIXABAN DOSING BE HELD FOR 26-30 HOURS BEFORE OR AN ANTI Xa ASSAY CALIBRATED TO APIXABAN BE ASSESSED BEFORE THE CATHETER IS REMOVED (Gr 2C). (New recommendation) (iii) EDOXABAN Oral Bioavailability- 62%, protein binding 55% Kidney clearence- 50% Terminal half life 10-14 hrs Highest Kidney clearence amongst all Factor Xa Inhibitors DISCONTINUE 72 HOURS PRIOR TO NEURAXIAL BLOCK, CONSIDER ANTI FACTOR Xa ACTIVITY LEVEL IF LESS THAN 72 HRS (Gr 2C). (New recommendation) NEURAXIAL CATHETERS ARE TO BE REMOVED 6 HOURS PRIOR TO THE FIRST POSTOPERATIVE DOSE (Gr 2C). (New recommendation) UNANTICIPATED ADMINISTRATION WITH INDWELLING CATHETER, EDOXABAN DOSING BE HELD FOR 20-28 HOURS BEFORE OR AN ANTI Xa ASSAY CALIBRATED TO EDOXABAN BE ASSESSED BEFORE THE CATHETER IS REMOVED (Gr 2C). (New recommendation)

24. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION (iv) BETRIXABAN Oral Bioavailability- 34%, protein binding 60% Kidney clearence- 5-10% Terminal half life 37 hrs Least kidney dependent factor Xa inhibitor. DISCONTINUED MINIMUM OF 3 DAYS PRIOR TO NEURAXIAL BLOCK, , CONSIDER ANTI FACTOR Xa ACTIVITY LEVEL IF LESS THAN 72 HRS (Gr 2C). (New recommendation) NEURAXIAL CATHETERS ARE TO BE REMOVED 5 HOURS PRIOR TO THE NEXT DOSE (Gr 2C). (New recommendation) NEURAXIAL BLOCKS ARE CONTRAINDICATED IN PATIENT’S WITH CrCl <30 mL/Min. WITH UNANTICIPATED ADMINISTRATION WITH INDWELLING CATHETER, BETRIXABAN DOSING BE HELD FOR 72 HOURS BEFORE THE CATHETER IS REMOVED (Gr 2C). (New recommendation) 8) PARENTAL THROMBIN INHIBITORS DESIRUDIN BIVALIRUDIN ARGATROBAN Indicated for T/t & prevention of thrombosis in HIT. NEURAXIAL BLOCKS ARE TO BE AVOIDED IN PATIENTS RECEIVING PARENTERAL THROMBIN INHIBITORS (Gr 2C). (No change)

25. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 9) ORAL THROMBIN INHIBITORS DABIGATRAN 80% eliminated by kidneys Dilute TT is used for monitoring Idarucizumab(MAB)- reverses dabigatran DISCONTINUED 120 HOURS IN PATIENT’S WITH CrCl OF 30-49mL/min (Gr 2C) DISCONTINUED 96 HOURS IN PATIENT’S WITH CrCl OF 50-79mL/min (Gr 2C). DISCONTINUED 72 HOURS IN PATIENT’S WITH CrCl OF 80mL/min (Gr 2C). (New recommendation) CATHETERS TO BE REMOVED 6 HOURS PRIOR TO THE FIRST POSTOPERATIVE DOSE (Gr 2C). (New recommendation) NEURAXIAL BLOCKS ARE CONTRAINDICATED IN PATIENT’S WITH CrCl <30 mL/Min (Gr 2C). WITH UNANTICIPATED ADMINISTRATION WITH INDWELLING CATHETER, DABIGATRAN DOSING BE HELD FOR 34-36 HOURS BEFORE THE CATHETER IS REMOVED (Gr 2C). (New recommendation)

26. Antiplatelets COX inhibitors ADP/P2Y12R INHIBITORS GLYCOPROTEIN IIB/IIIA INHIBITORS PDE-3 Inhibitors

27. MOST COMMONLY USED ANTIAGGREGANTS 1) ASPIRIN:- MECHANISM OF ACTION : BLOCKS CYCLOOXYGENASE -1(COX-1) IRREVERSIBLY & DECREASES THROMBOXANE A2 (TxA2) DOSE FOR ANTIAGGREGANT ACTION : 50-325 MG OD USES : SECONDARY PROPHYLAXIS OF ACUTE CORONARY SYNDROME SECONDARY PROPHYLAXIS OF ISCHAEMIC STROKE TREATMENT OF ACUTE CORONARY SYNDROME ESSENTIAL THROMBOCYTHEMIA KAWASAKI DISEASE SIDE EFFECT : BLEEDING

28. MEDICATION PRIOR TO CATHETER PLACEMENT ADDITIONAL INFORMATION 10) Aspirin (ASA) Irreversibly inhibits platelets NSAIDS Reversibly inhibits platelets Low dose aspirin (<200 mg) is not a contraindication for neuraxial procedure, if careful risk benefit analysis is undertaken. (ESRA 2022 - 1C) Single puncture spinal anaesthesia is preferable to epidural anaesthesia. (ESRA 2022 - 1C) Increased risk with concurrent use of other medications. With high doses of aspirin (>200 mg), the last dose should be minimum of 3 days, assuming normal platelet counts, up to 7 days before neuraxial procedures. (ESRA 2022 - 1C) The next high dose of aspirin may be administered a minimum of 6 hrs after neuraxial procedure. (ESRA 2022 - 2C)

29. 2) ADP/P2Y12R INHIBITORS :- ADP/P2Y12R INHIBITORS REVERSIBLE COMPETITIVE 1) CANGRELOR NON-COMPETITIVE 1) TICAGRELOR IRREVERSIBLE 1) CLOPIDOGREL 2) TICLOPIDINE 3) PRASUGREL

30. CLOPIDOGREL :- IT’S A PRODRUG, GETS ACTIVATED BY CYP2C19 IN CASE OF CYP2C19 GENE POLYMORPHISM, THE ACTIVATION OF CLOPIDOGREL IS BLUNTED AND HENCE IT’S EFFECT DECREASES. OMEPRAZOLE IS METABOLIZED BY CYP2C19, HENCE IT INHIBITS THE ACTIVATION OF CLOPIDOGREL, THEREBY DECREASES IT’S EFFECTS. ( OMEPRAZOLE IS CONTRAINDICATED WITH CLOPIDOGREL ) USES : SECONDARY PROPHYLAXIS OF MI & UNSTABLE ANGINA TREATMENT OF ACUTE CORONARY SYNDROME

31. TICLOPIDINE :- BEING THE MOST TOXIC DRUG, TICLOPIDINE IS NOT PREFERRED CURRENTLY. SIDE EFFECTS : NAUSEA,VOMITING & DIARRHOEA AGRANULOCYTOSIS THROMBOTIC THROMBOCYTOPENIC PURPURA USES : ONLY IN RESISTANT CASES (i) SECONDARY PROPHYLAXIS OF THROMBOEMBOLIC STROKE

32. PRASUGREL :- MOST POTENT & FASTEST ACTING DRUG USES : (i) PERCUTANEOUS INTERVENTIONS IN MI SIDE EFFECTS : INCREASES THE RISK OF INTRACRANIAL BLEED. CONTRAINDICATONS : PATIENTS WITH HISTORY OF CEREBROVASCULAR DISEASES LIKE STROKE & TIA

33. CANGRELOR :- IT IS AN ADENOSINE ANALOGUE. ROUTE OF ADMINISTRATION IS INTRAVENOUS. HALF LIFE IS 3-6 MIN, HENCE IT IS A SHORT ACTING DRUG. USES : (i) PERCUTANEOUS INTERVENTIONS IN MI.

34. TICAGRELOR :- LONG ACTING DRUG. ROUTE OF ADMINISTRATION IS ORAL. USES : ACUTE CORONARY SYNDROME SECONDARY PROPHYLAXIS OF MI OR STROKE.

35. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 11) Thienopyridines Ticlopidine Prasugrel clopidogrel Ticargrelor Cangrelor Stop ticlopidine 10 days prior, prasugrel 7-10 days prior & clopidogrel 5 to 7 days prior to neuraxial block (Gr 1C) (New Time Interval) Stop Ticargrelor 5 -7 days prior to neuraxial block (Gr 1C) (New recommendation) Stop Cangrelor 3Hrs prior to neuraxial block (Gr 1C) (New recommendation) Reinsituted 24hrs postoperatively (Gr 1A). (New recommendation) 6 hrs time gap between catheter removal and drug administration (Gr 2C). (New recommendation) Neuraxial catheters be removed prior to reinstitution of cangrelor therapy postop (Gr 2C). (New recommendation) Neuraxial catheters should not be maintained with prasugrel & Ticargrelor becoz of rapid onset, while it can be maintained with clopidogrel and ticlopidine (Gr 2C). (New recommendation) 1 st postop dose of Cangrelor be administered 8 hrs after catheter removal (Gr 2C). (New recommendation)

36. 3) OTHERS:- OTHER ANTIAGGREGANTS PROTEASE ACTIVATED RECEPTOR (PAR) INHIBITOR VORAPAXAR GLYCOPROTEIN IIB/IIIA INHIBITORS 1) ABCIXIMAB 2) VITRONECTIN 3) TIROFIBAN 4) EPTIFIBATIDE

37. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 12) GP IIb/IIIa inhibitors Abxicimab Tirofiban Eptifibatide Profound effect on platelet aggregation via interference with PLT- FIB and PLT- VWF binding. Reversible Effect Time to normal platelet aggregation is 24-48hrs for abxicimab and 4-8 hrs for eptifibatide & tirofiban. Preop- Neuraxial technique shoud be avoided until platelet function has recovered. (No change) Postop- Gp IIb/IIIa are contraindicated within 4 weeks of SX. In case of emergency, infusions should be limited to drugs minimizing sensory and motor block to facilitate neurological monitoring (Gr 1C). (New recommendation)

38. MEDICATION PRIOR TO CATHETER PLACEMENT AFTER CATHETER REMOVAL ADDITIONAL INFORMATION 13) PDE-3 Inhibitors Dipyridamole Cilastazol Stop Dipyridamole 24 hrs & Cilastozol 48 hrs prior to neuraxial block (Gr 2C). (New recommendation) Postop Neuraxial catheters be removed prior to reinstitution of dipyridamole & Cilastazol therapy (Gr 2C). (New recommendation) 1 st postop dose of dipyridamole & Cilastazol be administered 6hrs after catheter removal (Gr 2C). (New recommendation)

39. Epidural Hematoma- diagnosis and treatment Symptoms/signs Low back pain (sharp and radiating) Sensory and motor loss (numbness and tingling/motor weakness long after block should have abated). Bowel and/or dladder dysfunction. Paraplegia Diagnostic tests MRI (preferred) CT scan (may miss small hematoma) Myelogram

40. Treatment and outcome Must be treated within 8 – 12 hrs of symptom onset. Emergency decompressive laminectomy with hematoma evacuation Outcome is generally poor if treated late. Factors affecting recovery: Size and location of hematoma Speed of hematoma development Severity and nature of pre-existing neurological problems

41. Take home message Concurrent use of coagulation altering medications may increase risk of bleeding without altering coagulation studies. When providing postoperative analgesia with an epidural, use opioids or dilute local anaesthetics to allow for neurological evaluation. Remove catheters at the nadir of anticoagulant activity and do not give additional anticoagulants immediately after removal. Frequent evaluation of neurological status of the patient should be pursued for early detection of epidural hematoma. In high risk cases continue monitoring neurological status for 24 hrs post catheter removal.

42. Recommendations Irrespective of target INR, neuraxial procedures should be performed when VKA has been withheld and the INR has returned to normal range. 1C An INR of ˂ 1.5 may be acceptable in individual pts, if GA is to be avoided & neuraxial technique should be used. 2C Last VKA intake of 5 days before the procedure is proposed. 2C Following neuraxial procedures, the next dose of VKA should be administered acc to guidelines on postoperative VTE prophylaxis or therapeutic anticoagulation. 1C In the presence of indwelling neuraxial catheter the next dose of VKA should be administered only after its withdrawal. 1C In the interim, a low dose of LMWH may be used while a neuraxial catheter is in place. 2C

43. Recommendations 7. In obstetric patients treated with VKA and needing a neuraxial block for surgery, the same recommendations as used for nonpregnant population should be applied. 1C 8. Superficial nerve procedures may be performed in the presence of VKA, irrespective of target INR. 1C 9. Following Sup. N Blocks, the next dose may be administered at routinely prescribed next time point. 2C 10. Deep N Blocks shld be performed acc to reccomendations for neuraxial procedures. 1C 11. If the INR is not below the minimum recommended level, regional anaesthetic management should depend on the compressibility of the puncture site, the vicinity of large blood vessel and/or neuraxial structures. 2C

44. PHYSIOLOGY OF BLOOD AGGREGATION BLOOD VESSEL INJURY RELEASE OF COLLAGEN & VWF ACTIVATES PLATELETS

45. PLATELETS FURTHER ACTIVATES., GLYCOPROTEIN IIB/IIIA ( Gp IIbIIIA ) CYCLO OXYGENASE – 1 ( COX-1 ) & PRODUCES THROMBOXANE A2 (TXA2 ) ADENOSINE DI PHOSPHATE ( ADP ) & STIMULATES P2Y12 RECEPTOR (P2Y12R) INCREASE PRODUCTION OF PHOSPHOLIPIDS ALL THESE ARE RESPONSIBLE FOR PLATELET AGGREGATION

46. PHOSPHOLIPIDS VIA COAGULATION SYSTEM HELPS IN THE PRODUCTION OF THROMBIN. FIBRINOGEN THROMBIN FIBRIN PLATELET AGGREGATION ALONG WITH FIBRIN BANDS HELPS IN THE FORMATION OF PERMANENT CLOT .

47. ANTICOAGULANT EFFECTS VIA ., ORAL Xa INHIBITORS DIRECT THROMBIN INHIBITORS (DTI) (ABOVE TWO INHIBITS COAGULATION) INDIRECT THROMBIN INHIBITORS ( CAUSES ANTICOAGULATION ) BY STIMULATING ANTITHROMBIN III.

48. EVOLVING STANDARDS FOR THE PREVENTION OF PERI-OPERATIVE VENOUS THROMBOEMBOLISM (VTM) & THE INTRODUCTION OF INCREASINGLY POTENT ANTITHROMBOTIC MEDICATIONS HAVE RESULTED IN CONCERNS REGARDING THE HEIGHTENED RISK OF NEURAXIAL BLEEDING.

49. IN RESPONSE TO THESE PATIENT SAFETY ISSUES & NEED FOR A MORE INTERNATIONAL APPROACH TO MANAGEMENT, THE AMERICAN SOCIETY OF REGIONAL ANAESTHESIA (ASRA), IN CONJUNCTION WITH THE EUROPEAN SOCIETY OF ANAESTHESIOLOGY (ESA), CONVENED ITS 4 TH CONSENSUS CONFERENCE ON REGIONAL ANAESTHESIA & ANTICOAGULATION.

50. COAGULATION V/S ANTICOAGULATON COAGULATION CASCADE :- X Xa PROTHROMBIN THROMBIN FIBRINOGEN FIBRIN - DIRECT THROMBIN INHIBITORS ORAL Xa INHIBITORS ANTICOAGULATION :- PROTEIN C & PROTEIN S ANTITHROMBIN III (PROTEASE) BREAKS DOWN IIa (THROMBIN), Xa, XIa, XIIa.