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The following tick boxes represent conclusions based on clinical experience and expert
opinion.
Clinical experience with morphine, fentanyl and sufentanil has shown no neurotoxicity or
behavioural changes at normal clinical intrathecal doses (U).
The absence of consistent dose‐responsiveness to the efficacy of intrathecal opioids or the
adverse event rate, suggests that the lowest effective dose should be used in all
circumstances (N).
7.4 REGIONAL ANALGESIA AND CONCURRENT
ANTICOAGULANT MEDICATIONS
7.4.1 Neuraxial blockade
The low event rate of epidural haematoma makes RCTs and subsequent evidence‐based
statements impossible. Information comes only from case reports and case series. An
American Society of Regional Anesthesia and Pain Medicine (ASRA&PM) Practice Advisory
publication provides a good overview of and guidance on neurological complications in
regional anaesthesia (Neal et al, 2008 Level IV). The ASRA&PM guidelines on regional
anaesthesia in patients receiving antithrombotic or thrombolytic therapy have also been
updated (Horlocker et al, 2010).
Such information suggests that the incidence is possibly smaller than that of spontaneous
epidural haematoma. Between 1962 and 1992, 326 case reports of spontaneous epidural
haematoma were published (Schmidt & Nolte, 1992), while between 1966 and 1996 only
51 cases of epidural haematoma following epidural anaesthesia or analgesia were reported
(Wulf, 1996).
Anticoagulation (48% of cases) was the most important risk factor for epidural haematoma
following insertion of an epidural needle/catheter, followed by coagulopathy (38% of cases) CHAPTER 7
(Wulf, 1996 Level IV). This was confirmed by the series of epidural haematomas that followed
epidural anaesthesia/analgesia in combination with inappropriate low molecular weight
heparin (LMWH) regimens in the USA, where the incidence was reported to be 1 in 3,000
(Horlocker et al, 2003).
In view of the increased risk of epidural haematoma associated with the concurrent use
of epidural analgesia and anticoagulants, ASRA&PM published updated evidence‐based
guidelines on regional anaesthesia in patients receiving antithrombotic or thrombolytic
therapy (Horlocker et al, 2010). These statements have to be seen as ‘a panel of experts’ best
faith efforts to offer reasonable pathways for patient management’ (Bergqvist et al, 2003) to
provide safe and quality patient care while allowing for clinical differences based on individual
situations. It is recognised that variances from recommendations outlined in the ASRA&APM
guidelines ‘may be acceptable based on the judgement of the responsible anesthesiologist’
(Horlocker et al, 2010). That is, they will not substitute for an individual risk/benefit assessment
of every patient by the individual anaesthetist.
The most relevant statements are summarised as follows (Horlocker et al, 2010):
Antiplatelet medications — NSAIDs alone do not significantly increase the risk of spinal
haematoma, but should be regarded as a risk factor if combined with other classes of
anticoagulants. In such situations COX‐2 inhibitors should be considered. Recommended time
intervals between discontinuation of other antiplatelet medications and neuraxial blockade
Acute pain management: scientific evidence 193
