Understanding Anesthesiology - The Global Regional Anesthesia ...

at the extremes of age as well as in very ill or debilitated
patients.
PCA would be appropriately used for patients recovering
from breast reconstruction or lumbar spine decompression
and fusion. Typically, the PCA modality is
used for 24-72 hours. The patient must be capable of
oral (fluid) intake prior to converting from PCA to oral
analgesics, a factor which is most relevant for those recovering
from bowel surgery.
Central Neuraxial Analgesia
Central neuraxial analgesia involves the delivery of local
anesthetics and/or opioids to either the intrathecal
(spinal) space or the epidural space.
Because intraspinal catheters are rarely used, intrathecal
analgesia is usually an extension of a “one-shot” spinal
anesthetic used intra-operatively. Opioids added to
the (spinal) local anesthetic solution provide longlasting
analgesia after a single injection, lasting well
into the post-operative period. The duration of effect is
directly proportional to the water-solubility of the compound,
with hydrophilic compounds such as morphine
providing the longest relief.
Epidural catheters are safe and easy to insert. Contraindications
can be reviewed in Table 11. Epidural analgesia
can be used to provide pain relief for days through
the infusion of a solution containing local anesthetic,
opioid or both. The infusion is usually delivered continuously.
Intermittent or “bolus” doses lack titratability
and are associated with a higher incidence of side
effects such as respiratory depression. Continuous
epidural infusions provide a steady level of analgesia
while reducing the side-effects associated with bolus
administration.
Overall, epidural analgesia can provide highly effective
management of post-operative pain. It is believed to
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