Regional anesthesia on anticoagulants Dr S. Parthasarathy MD DA DNB PhD FICA , Dip software based statistics

Tank of the 1990s When I read MD – it is an useless topic Then a few people had drugs ( antiplatelets- aspirin) Clopidogrel ticlopidine tirofiban were not invented

Why should we know ?? The risk of spinal hematoma Means both intrathecal and epidural The incidence cited in the literature is estimated to be ,1 in 150000 epidurals and ,1 in 220000 spinal anaesthetic

Thrombo embolic episodes Epidural in childbirth - less Old age - more Hip surgery - more Where is the source ? Venous or arterial – the delay in symptoms – points to a venous source

What is the treatment of refractory PDPH ?? Epidural blood patch

We did not bother Usually the bleeds are less than the volume of an epidural blood patch !! The amount does not matter The ongoing coagulopathy ??

Now I see !! almost one in ten of my obstetric cases are receiving heparin ACL test = start heparin !!

DVT prophylaxis awareness Why more bother ??- DVT prophylaxis awareness

Drugs Antiplatelets NSAIDs aspirin Clopidogrel Ticlopidine Not used for thrombo prophylaxis – but patients on such drugs

NSAIDs – ibuprufen, diclofenac, ketoroloc COX 2 inhibitors Aspirin – irreversible inhibition of platelets Cox 1 is more than cox 2 :: 7 days to resume activity – stoppage – 15 % increase in vascular events No major problem for neuraxial anesthesia but surgeons especially dental ?? Cervical and thoracic epidural - better stop aspirin No problem

Dipyridamole Dipyridamole is a pyrimidopyrimidine derivative that has both antiplatelet and vasodilating actions. It is usually used in combination with aspirin in the management of cerebrovascular disease. Phosphodiesterase inhibition Not used nowadays

Clopidogrel The thienopyridines include ticlopidine and clopidogrel. Both act to reduce platelet aggregation by the selective, irreversible inhibition of the P2Y12 ADP receptor on the platelet surface (one of three ADP receptors).

Clopidogrel Similar to aspirin, platelet inhibition can be overcome only by platelet transfusion (in the absence of active drug) or by the generation of new platelets Stop before seven days of neuraxial blocks epidural catheters be removed to be performed 5 days, and not 7 days, after clopidogrel is discontinued

If a neuraxial injection is to be performed in a patient on clopidogrel before 7 days of discontinuation, a P2Y12 assay, a new assay of residual antiplatelet activity, can be performed; Stop   ticlopidine for 10 to 14 days before a neuraxial injection.

prasugrel quicker onset, 60 mg A 7-10 day interval is recommended before a neuraxial injection

IIb/IIIa receptor antagonists- ACS abciximab eptifibatide, and tirofiban inhibit platelet aggregation by interfering with platelet–fibrinogen binding and subsequent platelet– platelet interactions. Discontinuation from 8 h (eptifibatide, tirofiban) 48 h (abciximab).

Neuraxial block and antiplatelets NSAIDs – no problem Aspirin – OK ?? !! Clopidogrel – 7 days otherwise assay P2Y12 Ticlopidine – 10-14 days Tirofiban - 8 hours Abciximab – 48 hours

There is no wholly accepted test, including the bleeding time, to guide antiplatelet therapy. Careful preoperative assessment of the patient is important in identifying conditions that might lead to increased risk of bleeding.

Oral anticoagulants Warfarin exerts its anticoagulant effect by interfering with the synthesis of the vitamin K-dependent clotting factors (VII, IX, X, and thrombin) Start action after 5 days Stop for five days before block But we can restart on the day of surgery Can we remove catheter on day 2 = ok ? !

The current ASRA guidelines recommends an INR value of ≤1 The current ASRA guidelines recommends an INR value of ≤1.4 as acceptable for the performance of neuraxial blocks. The value was based on studies that showed excellent perioperative hemostasis when the INR value was ≤1.5. The concurrent use of other medications, such as aspirin, NSAIDs, and heparins increases the risk of bleeding complications without affecting the INR.

Heparin Heparin is a complex polysaccharide that exerts its anti- coagulant effect by binding to antithrombin III. The conformational change in antithrombin accelerates its ability to inactivate thrombin, factor Xa, and factor IXa. Subcutaneous heparin – 1-2 hours but IV is faster Half life is 1 – 1.5 hours

Intravenous heparin therapeutic anticoagulation is achieved with a prolongation of the aPTT to >1.5 times the baseline value. See aPTT here but in warfarin it is INR and PT 1 hour stoppage for IV dose for blocks 2 – 3 hours later remove catheter

Subcutaneous heparin In patients who are on LMWH, needle/catheter placement should be performed at least 12  hours after the last prophylactic dose of enoxaparin or 24 hours after higher doses of enoxaparin (1 mg/kg every 12 hours), and 24 hours after dalteparin (120 U/kg every 12 hours or 200 U/kg every 12 hours) or tinzaparin (175 U/kg     daily). 5. The LMWH can be administered 2 hours after the epidural catheter is removed. monitoring of anti-Xa level is not recommended

On bypass !! Neuraxial procedures should be avoided in patients with known coagulopathy. Surgery should be delayed 24 h in the patient with a traumatic tap. The time from the neuraxial procedure to the systemic heparinization should exceed 1 h. Heparinization and reversal should be monitored and controlled tightly. The epidural catheter should be removed when normal coagulation is restored, and the patient should be monitored closely for signs of spinal hematoma

LMWH The administration of other anticoagulant medications with LMWHs may increase the risk of spinal hematoma. The presence of blood during needle placement and catheter placement does not necessitate postponement of    surgery. However, the initiation of LMWH therapy should be delayed for 24 hours postoperatively. Can we monitor ??

Heart attack – cellulitis - spinal ?? Plasminogen activators, such as streptokinase and urokinase, dissolve thrombus and affect circulating plasminogen leading to decreased levels of both plasminogen and fibrin. No clear cut guidelines But ten days later . Measurement of fibrinogen levels may be helpful in guiding a decision about removal of the catheter.

Fondaparinux Fondaparinux produces its antithrombotic effect through factor Xa inhibition. The plasma half-life of fondaparinux is 21 h, allowing for single daily dosing, with the first dose administered 6 h after operation 36 hours and 12 hours ?? But go for other drugs for DVT

Recombinant hirudin derivatives, such as desirudin (Revasc), lepirudin (Refludan), and bivalirudin (Angiomax), inhibit both free and clot-bound thrombin. Argatroban The most recent ASRA guidelines recommend against the performance of neuraxial techniques in patients who received thrombin inhibitors.

Herbal Therapy garlic inhibits platelet aggregation and its effect on hemostasis appears to last 7 days. Ginkgo biloba inhibits platelet-activating factor and its effect lasts 36 hours. Is there a risk ? Do we need to discontinue ?? Presently NO

Peripheral nerve blocks Spontaneous hematomas have been reported in patients who took anticoagulants. Abdominal wall hematomas, intracranial hemorrhage, psoas hematoma, and intrahepatic hemorrhage have occurred after LMWH

For patients undergoing deep plexus or deep peripheral block, recommendations regarding neuraxial techniques should be similarly applied Superficial blocks USG – no vessels- risk Vs benefit – OK

Mixture ?? Aspirin + heparin Clopidogrel + aspirin Clopidogrel aspirin + LMWH No clear cut recommendations – play safe

Another mixture Play safe Thank you