Ultra Small Dose of Intrathecal Naloxone to Minimize Morphine Induced Side- Effects in Patients Undergoing Minor Anal Surgery Under Spinal Anesthesia. A Randomized Double Blind Study
Description:
Bupivacaine hydrochloride is a commonly used local anesthetic in spinal anesthesia, however,
the duration of spinal analgesia by bupivacaine is limited to about 75-150 minutes,
therefore, various additives have been used along with bupivacaine for the prolongation of
its effect, to improve the quality of analgesia, and to minimize the requirement for
postoperative analgesics .
Opioids may be added to local anesthetic solutions to enhance surgical anesthesia and provide
postoperative analgesia . This effect is mediated at the dorsal horn of the spinal cord,
where opioids mimic the effect of endogenous enkephalins. The use of intrathecal (IT)
morphine (0.1 to 0.5 mg) can provide effective control of postoperative pain for roughly 24
hours . However, the use of IT morphine may result in serious side effects e.g. pruritus 53%,
nausea and vomiting 43%.urinary retention 43% and delayed respiratory depression . These side
effects may lead to patient discomfort and prolonged hospital stay thus limiting the
usefulness of IT morphine.
Naloxone has an extremely high affinity for μ-opioid receptors in the central nervous system
(CNS). Naloxone is a μ-opioid receptor (MOR) competitive antagonist, and its rapid blockade
of those receptors often produces rapid onset of withdrawal symptoms. Naloxone also has an
antagonist action, though with a lower affinity, at κ- (KOR) and δ-opioid receptors (DOR).
Unlike other opioid receptor antagonists, naloxone is essentially a pure antagonist with no
agonist properties.
I.V naloxone decreases incidence and severity of the common morphine side effects (pruritis,
nausea/emesis, constipation, urinary retention, respiratory depression and undesirable
sedation) The addition of naloxone to morphine decreases the opioid related side effects
without affection of postoperative analgesia. This combination can be used for the treatment
of severe refractory chronic low back pain.
Condition:
Post-Op Complication
Treatment:
Morphine
Start Date:
May 2016
Sponsor:
Assiut University
For More Information:
https://clinicaltrials.gov/show/NCT03230474