12. Anticoagulants and neuraxial blockade Flashcards
What is the incidence of spinal haematoma in neuraxial blockade?
one in 117,000 for all CNBs NAP 3
There is also no current laboratory model. The actual incidence of neurological
dysfunction resulting from haemorrhagic complications associated with
central neuraxial block is unknown.
What are recommendations for neuraxial blockade in the presence of anticoagulation based on?
They are based on case reports, clinical series, pharmacology, haematology,
and risk factors for surgical bleeding.
All the above factors are taken into consideration by recognised experts in
the field of neuraxial anaesthesia and anticoagulation
How do you decide whether or not to perform a neuraxial block in a
patient taking anticoagulants?
The decision to perform a neuraxial block and the timing of catheter removal
in a patient receiving anti-thrombotic therapy should be made on an
individual basis, weighing up the small, though definite risk of spinal
haematoma with the benefits of regional analgesia for a specific patient.
Indwelling catheters should not be sited or removed in the presence of
therapeutic anticoagulation, as this appears to significantly increase the risk of
spinal haematoma
Identification of risk factors and establishment of guidelines will not
completely eliminate the complication of spinal haematoma.
Post-operative monitoring and a robust Pain Service are essential to allow
early evaluation of neurological dysfunction and prompt intervention
What are ticlopidine and clopidogrel?
Ticlopidine and clopidogrel are thienopyridine derivatives that inhibit
adenosine diphosphate-induced platelet aggregation.
They also interfere with platelet fibrinogen binding and platelet–platelet interactions.
These drugs are used in the prevention of cerebrovascular and cardiac thromboembolic events
How long prior to the insertion of an epidural should these drugs
be stopped?
Based on labelling and surgical reviews, the suggested time interval between
discontinuation of
thienopyridine therapy and
neuraxial blockade is
14 days for ticlopidine
7 days for clopidogrel.
Would you perform an epidural on a patient who is taking platelet GPIIb/IIIa inhibitors?
No.
Platelet GP IIb/IIIa inhibitors exert a profound effect on platelet aggregation.
They interfere with platelet–fibrinogen binding and platelet–Von Willebrand factor binding.
Their use is primarily in acute coronary syndromes.
Following administration,
the time to normal platelet aggregation is 24–48 hours for abciximab
4–8 hours for eptifibatide and tirofiban.
Neuraxial techniques should be avoided until platelet function has recovered.
GP IIb/IIIa antagonists are contraindicated within 4 weeks of surgery.
Should one be administered in the post-operative period
(following a neuraxial technique),
the patient should be carefully monitored neurologically.
Would you perform an epidural on a patient taking long term NSAIDs?
Yes. NSAIDs appear to represent no added significant risk
for the development of spinal haematoma in patients having epidural or spinal analgesia.
The use of NSAIDs alone does not create a level of risk that
will interfere with the performance of neuraxial blocks.
What if your patient were taking ginseng or garlic?
Garlic has been shown in vivo to inhibit platelet aggregation with one of its
constituents, ajoene, found to potentiate the effect of other platelet
inhibitors. Ginseng and ginsenosides have been found to prolong APTT and
thrombin time in rats and demonstrate in vitro inhibition of platelet
aggregation. There does, however, not seem to be specific concerns as to the
timing of neuraxial block in relationship to the dosing of herbal therapy,
post-operative monitoring or the timing of neuraxial catheter removal with
regards to present data.
How would your anaesthetic technique be influenced if the patient had been treated with a hirudin derivative?
Recombinant hirudin derivatives, including desirudin, lepirudin and bivalirudin
inhibit both free and clot-bound thrombin.
These drugs are used for the treatment and prevention of thrombosis in patients with heparin-induced
thrombocytopaenia Argatroban, an L-arginine derivative, has a similar
mechanism of action.
Although there are no case reports of spinal haematoma
related to neuraxial anaesthesia among patients who have received a
thrombin inhibitor, spontaneous intracranial bleeding has been reported.
Due to the lack of information available, no statement regarding risk assessment
and patient management can be made.
How would your anaesthetic technique be influenced if the patient was prescribed Fondaparinux
Fondaparinux produces its anti-thrombotic effect through factor Xa
inhibition and has a single daily dosing schedule due to a half-life of 21 hours.
The actual risk of spinal haematoma with fondaparinux is unknown.
Consensus statements are based on the sustained and irreversible
Only where: single-needle pass, atraumatic needle placement, avoidance of indwelling neuraxial catheters
Prophylactic dose: 36–42 h (consider anti-Xa levels)
Treatment dose: avoid (consider anti-Xa levels)
