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Intraspinal hematoma is a relatively rare condition resulting from a
variety of causes. Its incidence is approximately 0.1 per 100,000 patients
per year.1,2 Traumatic causes include lumbar puncture and
neuraxial anesthesia as well as a complication of spinal surgery. It is more
likely to occur in anticoagulated or thrombocytopenic patients, patients
with neoplastic disease, or in those with liver disease or
alcoholism.3,4 Spontaneous bleeding is rare but may be
seen from a spinal arteriovenous malformation or vertebral hemangioma.
Approximately one quarter to one third of all cases are associated with
anticoagulation therapy.5,6
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Hemorrhage into the spinal canal commonly occurs in the epidural space
because of the presence of a prominent epidural plexus of veins. Puncture of
epidural vessels during placement of epidural catheters occurs in
approximately 3–12% of cases. The incidence of symptomatic epidural
hematoma associated with epidural analgesia is difficult to estimate, but
combined case series of more than 100,000 epidural anesthetics have been
reported without a single epidural hematoma. Spinal hematoma is a rare but
devastating event. The actual incidence of neurologic dysfunction resulting
from hemorrhagic complications associated with neuraxial blockade is
unknown; the incidence cited in the literature is estimated to be 1 in
150,000 epidural and 1 in 220,000 spinal anesthetics. However, the incidence
increased significantly after the introduction of low-molecular-weight
heparin (LMWH), before the Food and Drug Administration issued a warning,
and before the American Society of Regional Anesthesia (ASRA) issued its
initial consensus statement in 1998.7
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The risk of formation of intraspinal hematoma after administration of
neuraxial anesthesia and analgesia is increased in patients who received
anticoagulant therapy or have a coagulation disorder.8 For
that reason neuraxial anesthesia is often contraindicated in the presence of
a coagulopathy. Other risk factors for development of epidural or spinal
hematoma include technical difficulty (multiple attempts) in the performance
of the neuraxial procedures due to anatomic abnormalities of the spine and
multiple or bloody punctures. Intraspinal hematoma is more often associated
with epidural catheter use than with the other neuraxial block techniques.
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ASRA has recommended guidelines for the safer performance of neuraxial
blocks in patients who are on anticoagulants.7,9 These
guidelines were based on extensive review of the literature and of the
pharmacology of the different anticoagulants. Recommendations were made on
the timing of the neuraxial block and removal of the epidural catheter and
the administration of the anticoagulants. In particular, the use of low
concentrations of local anesthetics for epidural infusion (preservation of
motor strength for easier monitoring) and subsequent neurologic monitoring
were recommended by ASRA. The initial consensus guidelines, published in
1998 and updated in 2003,7,9 greatly assisted clinicians
in decision making with regard to the use of neuraxial procedures in the
setting of anticoagulation therapy and possibly decreased the incidence of
epidural and spinal hematoma. In this chapter, we discuss the significance
of ...