Intrathecal Nalbuphine is a Comparable Safer Alternative to Fentanyl for Intraoperative Pain Management During Uterine Exteriorization
Condition: Pain, Acute
MeSH terms: Acute Pain
Study type: Interventional

Summary: 
      In case of cesarean section (CS) delivery, spinal anesthesia is the best anesthetic choice.
      It is simple to perform with rapid onset of anesthesia and lower incidence of failed block.
      Spinal anesthesia avoids the risk of aspiration, the neonatal depressant effect that may
      occur with general anesthesia (GA), and provides postoperative analgesia, however, spinal
      anesthesia has a lesser control on the level of blockade, may give insufficient visceral pain
      block and may be associated with nausea and vomiting especially during peritoneal traction,
      closure and uterine manipulation, exteriorization and rotation. A previous study reported
      nausea and vomiting in up to 70.5% patients in the spinal group while the incidence of
      moderate to severe pain was more frequent in exteriorized uterus patients.

      Increasing the dosage of intrathecal local anesthetic may contribute to a decrease in the
      occurrence of intraoperative visceral pain, but at the cost of the risk and adverse effects
      of greater blockade.A variety of adjuvants have been used to prevent these disadvantages. The
      commonly used adjuvants include opioids; α2 stimulants such as clonidine and dexmedetomidine;
      NMDA receptor antagonist such as ketamine; GABA receptor agonists such as midazolam.

      The added intrathecal opioids as fentanyl and nalbuphine to local anesthetics give a
      sufficient intraoperative visceral analgesia when they were used in C.S., with less
      sympathetic block and hemodynamic effect, and reduces the need for intraoperative analgesics
      with prolongation of postoperative analgesia.

      Nalbuphine, a mixed agonist-antagonist opioid, has a potential to attenuate the mu-opioid
      effects and to enhance the kappa-opioid effects. It was synthesized attempting to produce
      analgesia without the undesirable side effects of mu agonist. Also, its combination with mu
      agonist opioids was tried by many researchers to decrease the incidence and severity of the
      common mu agonist side effects (respiratory depression, undesirable sedation, pruritus,
      bradycardia, nausea, vomiting and urinary retention), plus it can antagonize spinal induced
      shivering. Meanwhile, the benefits of both kappa and mu analgesia can be obtained.

      Few studies compared the effects of intrathecal nalbuphine (opioid agonist-antagonist) and
      fentanyl (opioid agonist) as adjuvants to bupivacaine in spinal blocked for CS with variable
      results. However, they didn't compare their ability to control the visceral pain aggravated
      by uterine exteriorization in cesarean section under spinal anesthesia. This study will try
      to answer the question is nalbuphine effective enough in such scenario to be used routinely
      as a safer alternative to fentanyl, which is the opioid in common practice added to
      bupivacaine?

      Aim of the study:

      To compare the ability of the used doses in the study of intrathecal nalbuphine and
      intrathecal fentanyl to control the visceral pain aggravated by uterine exteriorization in
      cesarean section under spinal anesthesia

      Objectives:

        -  To evaluate the visual analog scale (VAS) for visceral abdominal and shoulder pain every
           5 minutes and the maximum score will be recorded for 30 minutes from the time of baby
           delivery.

        -  To calculate the total fentanyl used for VAS ⩾ 4
    


Intervention name(s): intrathecal drug injection
Intervention type(s): Drug
Intervention description(s): All 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.
The patients will be divided equally into 3 groups according to the additive (fentanyl, nalbuphine or placebo), and all patients will receive the local anesthetic dose of 0.5% heavy bupivacaine according to weight and height
Other intervention name(s): spinal opioid injection
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: intrathecal nalbuphine; intrathecal fentanyl; exteriorization of the uterus; cesarean section