Page 242 Acute Pain Management

are 4 to 8 hours for eptifibatide and tirofiban, 24 to 48 hours for abciximab, 7 days for
clopidogrel and 14 days for ticlopidine.
Unfractionated SC heparin — thromboprophylaxis with SC heparin given twice‐daily is not
a contraindication to neuraxial blockade. To identify heparin‐induced thrombocytopenia,
a platelet count should be done prior to removal of an epidural catheter in patients who have
had more than 4 days of heparin therapy. Epidural catheters should be removed a minimum
of 6 hours after the last heparin dose and not less than 2 hours before the next dose.
Safety in patients receiving total daily doses of greater than 10 000 units, or if doses are given
more often than twice a day, has not yet been established.
Unfractionated IV heparin — intraoperative anticoagulation with IV heparin should start no
sooner that 1 hour after placement of the epidural or spinal needle. Epidural catheters should
be removed 2–4 hours after the last heparin dose. A bloody tap may increase the risk, but
there are insufficient data to support cancellation of a case. Careful patient monitoring should
be continued postoperatively.
Low molecular weight heparin — Epidural catheter placement should occur at least
10–12 hours after standard prophylactic once‐daily LMWH doses. The first postoperative
dose of LMWH dose should be given 6 to 8 hours after surgery and subsequent doses every
24 hours after that. The epidural catheter should be removed at least 10–12 hours after the
last dose of LMWH and the next dose should not be given until at least 2 hours after removal.
Concurrent administration of other drugs that may affect haemostasis (eg antiplatlet drugs)
should be avoided.
Epidural catheters should be removed at least 2 hours before twice‐daily LMWH dose
regimens are started.
Oral anticoagulants (warfarin) — Established warfarin therapy should be discontinued at least
4 to 5 days prior to neuraxial blockade and the INR normalised. Preoperative initiation of
CHAPTER 7 warfarin therapy requires an INR check prior to neuraxial blockade if a single dose of warfarin
5 mg was given more than 24 hours preoperatively or a second dose was given. INR should
also be checked prior to removal of indwelling epidural catheters if warfarin was administered
more than 36 hours preoperatively. An INR < 1.5 is a value estimated to be a safe level for
removal, while an INR > 3 requires withholding or reducing warfarin therapy before the
catheter is removed.
Fibrinolysis and thrombolysis — Patients receiving fibrinolytic or thrombolytic drugs should
not undergo neuraxial blockade except in exceptional circumstances; no data are available
on a safe time interval after use of such drugs. No definite recommendations are given for
the removal of neuraxial catheters after initiation of such therapy, although determination
of fibrinogen level might be a useful guide in such situations.
Herbal therapy — Although garlic, ginkgo and ginseng have effects on haemostasis, there are
currently no specific concerns about their use with neuraxial blockade.
New anticoagulants — The situation with regard to the newer anticoagulants remains unclear.
Recommendations are to avoid neuraxial techniques with thrombin inhibitors present and to
use extreme caution in association with fondaparinux, avoiding indwelling catheters.
Recommendations for newer anticoagulants and antiplatelet drugs are also discussed in other
reviews (Vitin et al, 2008; Rosencher et al, 2007; Kopp & Horlocker, 2008).

194 Acute Pain Management: Scientific Evidence