Intrathecal Midazolam, Fentanyl and Nalbuphine as Adjuvants to Bupivacaine in Spinal Anesthesia for Cesarean Section
Condition: Pain, Acute
MeSH terms: Acute Pain
Study type: Interventional

Summary: 
      The main limitations of spinal anesthesia are its short duration of action and do not provide
      prolonged postoperative analgesia when it is performed only with local anesthetics. Adding
      adjuvants drugs to intrathecal local anesthetics improves quality and duration of spinal
      blockade, and prolongs postoperative analgesia. It is also possible to reduce dose of local
      anesthetics, as well as total amount of systemic postoperative analgesics.
    

Detailed description: 
      Several spinal adjuvants have been used to improve spinal anesthesia quality and to prolong
      postsurgical analgesia; Intrathecal opioids are the most commonly utilized. Intrathecal
      opioids cause analgesia by binding to opioid receptors in the dorsal horn of the spinal cord.
      They prolong the duration of analgesia and allow early ambulation of patients.

      Fentanyl, a short-acting lipophilic opioid, is known to augment the quality of subarachnoid
      block in many studies. However, worrisome adverse effects such as pruritus, urinary
      retention, post-operative vomiting, and respiratory depression limit the use of opioids.

      Nalbuphine is a synthetic opioid with mixed agonist antagonist effect. It binds to both mu-
      and kappa receptors; binding of nalbuphine to mu receptors competitively displaces other
      mu-agonists from these receptors without any agonist activity, therefore decreasing the side
      effects on mu agonist (nausea, vomiting, respiratory depression, urinary retention, pruritis,
      and prolonged sedation). While when binding to kappa receptors, nalbuphine has agonist effect
      (analgesic effect) through the kappa receptors distributed in the brain and spinal cord.
      There have been no documented studies of nalbuphine neurotoxicity.

      Midazolam is a short acting benzodiazepine with anxiolytic, sedative, anticonvulsant and
      muscle relaxant effects, influencing GABA receptor and influence on neurons by entering
      chloride into them. It is water soluble in its acid formulation but is highly lipid soluble
      in vivo. It has been reported to have a spinally mediated anti-nociceptive effect. Previous
      studies have shown that intrathecal administration of midazolam added to bupivacaine improves
      the duration and quality of spinal anesthesia.

      This study is carried out to evaluate and compare the effects of intrathecal midazolam (2
      mg), fentanyl (25 micrograms) and nalbuphine (800 micrograms) as additives to intrathecal
      hyperbaric bupivacaine (0.5 %) with regards to: onset and duration of sensory block, onset
      and duration of motor block, duration of effective analgesia postoperative, side effects
      associated with the drug.
    

Intervention name(s): Bupivacaine; Fentanyl; Nalbuphine; Midazolam
Intervention type(s): Drug; Drug; Drug; Drug
Intervention description(s): patients will be put in the sitting position and lean forward. After sterilization, Dural puncture will be performed at L4-L5 interspace or L3-L4 with a 25 gauge Quincke spinal needle.
patients will receive the local anesthetic dose of 0.5% heavy bupivacaine (12.5 mg) and 0.5 ml of sterile water will be added.; patients will be put in the sitting position and lean forward. After sterilization, Dural puncture will be performed at L4-L5 interspace or L3-L4 with a 25 gauge Quincke spinal needle.
patients will receive the local anesthetic dose of 0.5% heavy bupivacaine (12.5 mg) and 0.5 ml of fentanyl (25µg) will be added.; patients will be put in the sitting position and lean forward. After sterilization, Dural puncture will be performed at L4-L5 interspace or L3-L4 with a 25 gauge Quincke spinal needle.
patients will receive the local anesthetic dose of 0.5% heavy bupivacaine (12.5 mg) and 0.8 mg nalbuphine hydrochloride in 0.5 ml sterile water will be added.; patients will be put in the sitting position and lean forward. After sterilization, Dural puncture will be performed at L4-L5 interspace or L3-L4 with a 25 gauge Quincke spinal needle.
patients will receive the local anesthetic dose of 0.5% heavy bupivacaine (12.5 mg) and 0.4 ml of midazolam (2mg) + 0.1 ml of sterile water will be added.
Intervention MeSH terms: Midazolam; Fentanyl; Nalbuphine; Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment