The nurse knows that an advantage of intraspinal analgesia is the:

Question

a. smaller doses of epidural than intrathecal medication.
b. lack of significant patient complications.
c. systemic distribution of morphine faster than fentanyl.
d. ability to achieve appropriate analgesia with smaller dosages.

Answer 1

D
Because opioids are delivered close to their site of action, the central nervous system (CNS), they have greater bioavailability and thus require much smaller doses to achieve adequate pain relief. Epidural and intrathecal doses are not equivalent. Intrathecal doses are much smaller than epidural doses. As an example, the epidural dose of morphine is 10 to 20 times greater than that required for an intrathecal dose. The catheter poses a threat to patient safety because of its anatomical location, its potential for migration through the dura, and its proximity to spinal nerves and vessels. Migration of an epidural catheter into the subarachnoid space can produce medication levels too high for intrathecal use. Fentanyl and sufentanil are hydrolipid, which causes them to have a quicker onset and a shorter duration of action (2 hours). Morphine and hydromorphone are hydrophilic, resulting in a longer onset and a longer duration of action (up to 24 hours with a single bolus dose).