Understanding Anesthesiology - The Global Regional Anesthesia ...

Regional Anesthesia
Regional anesthesia involves the blockade (with local
anesthetics) of the nerve supply to the surgical site.
This may be achieved by blocking peripheral nerves
(e.g. ankle block) or by blocking the spinal cord and/or
nerve roots (spinal, epidural block). A single nerve
block may be sufficient (e.g. ulnar nerve block for repair
of 5th digit) or a group of nerves may need to be
blocked (e.g. brachial plexus block for forearm fasciotomy).
While regional techniques are perceived to be
“safer” than general anesthesia, they do carry risks of
their own. The most serious “early” complication of a
peripheral nerve block is local anesthetic toxicity. The
most worrisome “late” complication is neuropraxis or
nerve injury. The central neuraxial blocks have many
potential complications, both early and late, which will
be discussed in the next section.
case reports of sudden cardio-respiratory arrest in patients
under central nerve blocks emphasize this point
all too clearly. Principles of pre-operative assessment
and preparation must be applied just as vigilantly to
the patient undergoing regional anesthesia.
There are some patients in whom a regional technique
offers at least short term benefits over general anesthesia.
For example, in those undergoing total hip arthroplasty,
the use of spinal or epidural anesthesia is associated
with less intra-operative blood loss, less postoperative
hypoxemia and a lower risk of post-operative
deep venous thrombosis formation. While it seems intuitive
that physiologic homeostasis is more readily
achieved when regional anesthesia is employed, the anesthesiologist
must always remain vigilant: numerous
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