Influence Of Low Dose Intrathecal Naloxone On Bupivacaine - Fentanyl Spinal Anaesthesia For Lower Limb Orthopedic Surgery In Elderly Patients
Condition: Anesthesia, Spinal; Elderly
Study type: Interventional

Summary: 
      Fentanyl is a safer alternative than morphine in the management of postoperative pain in
      elderly. However, pruritus, nausea and vomiting are unwanted side effects of intrathecal
      fentanyl administration, that can decrease patient satisfaction with anaesthesia, delay post
      anaesthesia care unit ( PACU ) discharge, and increase costs.

      The incidence of pruritus with neuraxial fentanyl is high. The incidence of pruritus in
      non-obstetric surgery patients after intrathecal fentanyl ranges from 53% to 79%.

      Naloxone hydrochloride is a pure opioid competitive antagonist. Small doses of naloxone may
      reduce Fentanyl-associated adverse effects, such as pruritus, nausea and vomiting without
      affecting analgesia.
    

Detailed description: 
      The aim of this study is to evaluate the effect of adding low dose intathecal naloxone to
      bupivacaine - fentanyl spinal anesthesia in elderly patients scheduled for unilateral lower
      limb orthopedic surgeries on opioid induced side effects namely pruritus, postoperative
      analgesia and the incidence of postoperative cognitive dysfunction (POCD) in elderly.

      A four category verbal rating scale VRS-4 ( 0 to 3 scale ) will be used for assessment of
      intrathecal fentanyl induced side effects including pruritus, nausea, vomiting and shivering.

      Mini Mental State Examination ( MMSE ) test will be applied to all patients pre- and post-
      operative to assess the incidence and the degree of POCD.

      An 11 points Verbal Numerical Rating Scale VNRS for pain assessment will be also applied to
      all patients postoperatively to assess the effect on postoperative analgesia.

        -  Cannulation: Peripheral cannulae ( size 20 gauge or 18 gauge ) will be inserted to all
           patients . Ringer's acetate warmed up to 37°C will be infused slowly at rate of 7ml/kg,
           30 min before induction of spinal anaesthesia. A single intravenous ( I.V. ) dose of
           prophylactic antibiotic after a negative sensitivity test will be given to all patients
           15-30 min. before operation.

        -  Induction: Patient will receive spinal anaesthesia with 12.5 mg hyperbaric Bupivacaine
           0.5% ( 2.5 mL ) plus 25 µg Fentanyl ( 0.5 mL ) and 20 µg Naloxone ( prepared in 0.5 mL
           normal saline ) added in the same syringe in a total volume of 3.5 mL..

        -  Spinal anaesthesia will be conducted while the patients are in the sitting position and
           under complete aseptic conditions; a lumber puncture at L3-4 or L4-5 interspaces will be
           performed with a 25- gauge Quincke spinal needle after infiltrating the skin with 2 ml
           of lidocaine 2%. After a successful dural puncture and ensuring free flow of
           cerebrospinal fluid, injectates will be injected slowly over 20 seconds without
           barbotage or aspiration according to group of the patient. Immediately, patients will be
           turned into the supine position. Oxygen 2-3 L/min will be applied to all patients via
           nasal prongs.

      Evolution and regression of sensory and motor block will be evaluated. Sensation will be
      assessed by pinprick in the mid-clavicular line as follows; Grade 0: Sharp pain felt, Grade
      I: Analgesia, dull sensation felt, Grade II: Anesthesia, no sensation felt. Motor blockade
      will be assessed according to Modified Bromage Scale.

      Hemodynamics ( mean arterial blood pressure MAP, heart rate HR and oxygen saturation SpO2 )
      will be also recorded at predetermined accurate times.
    

Intervention name(s): Bupivacaine-fentanyl
Intervention type(s): Drug
Intervention description(s): Bupivacaine-Fentanyl (BF) group (46 patients): will receive spinal anaesthesia with 12.5 mg hyperbaric Bupivacaine 0.5% (2.5 mL) plus 25 µg Fentanyl (0.5 mL) and (0.5 mL) normal saline added in the same syringe in a total volume of 3.5 mL.
Bupivacaine-Fentanyl-Naloxone (BFN) group (46 patients): will receive spinal anaesthesia with 12.5 mg hyperbaric Bupivacaine 0.5% (2.5 mL) plus 25 µg Fentanyl (0.5 mL) and 20 µg Naloxone (prepared in 0.5 mL normal saline) added in the same syringe in a total volume of 3.5 mL.
Other intervention name(s): Naloxone hydrochloride
Intervention MeSH terms: Fentanyl; Bupivacaine; Naloxone
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Prevention
Keywords: spinal anesthesia; elderly; naloxone; pruritus; post operative cognitive dysfunction