The Effect of Gabapentin on Spinal Anesthesia Duration
Condition: Prolongation of Spinal Anesthesia
Study type: Interventional
Phase: Early Phase 1

Summary: 
      This prospective parallel group double blinded randomized study will be conducted over 60
      adult participants between 20 and 60 years ASA (American Association of Anesthesiologists) I
      and II. The participants will be randomly allocated in 2 groups. Group A will receive 900 mg
      of gabapentin before surgery in 2 divided doses; 300 mg 10 hours prior to surgery and 600 mg
      2 hours before surgery, while group B will receive 2 placebo tablets at the same time. The
      participants will receive spinal anesthesia in the form of 3ml of hyperbaric bupivacaine
      0.5%. Hemodynamics will be recorded every 15 minutes till the end of surgery. Sensory, and
      motor block progression, and regression will be recorded also.
    

Detailed description: 
      A prospective double blinded randomized trial to study the effect of gabapentin on the
      duration of spinal anesthesia. The participants will be divided into 2 groups. Group A will
      receive 900 mg of gabapentin before surgery in 2 divided doses; 300 mg 10 hours prior to
      surgery and 600 mg 2 hours before surgery, while group B will receive 2 placebo tablets at
      the same time.

      The patient will be seated and after sterilization of his back with povidone iodine, a
      midline intrathecal injection of the 3ml of hyperbaric bupivacaine 0.5% at L 3/4 - L4/5 will
      be done via a 25G needle. Neural block will be assessed by using pin prick test, motor block
      will be assessed by using the modified Bromage scale, results will be recorded every 3 min
      until the level is stable for 3 consecutive tests.

      After successful intrathecal injection, the patient will be monitored continuously for block
      progression and complications. The patient's blood pressure will be taken every 3 minutes
      initially, more frequently if needed. The patient will be monitored for the following:

      Ensure that the block is adequate for the surgical procedure and it does not progress too
      high (motor block will be assessed by modified Bromage score and the sensory level by pin
      prick test up to T7-T10 level)

      Sensory block will be assessed by pin prick test (Hollman test) using a 3-point scale; (0) =
      Normal sensation, (1) = Loss of sensation of pin prick (analgesia), and (2) = Loss of
      sensation of touch (anesthesia).

      Onset time for sensory block will be defined as the time interval between the end of local
      anesthetic administration and complete sensory block (score 2 for all nerves). Duration of
      sensory block will be defined as the time interval between the complete sensory block and
      complete resolution of anesthesia (score 0 for all nerves).

      Motor block is determined by using the modified Bromage scale (Bromage 0, the patient is able
      to move the hip, knee and ankle; Bromage 1 when the patient is unable to move the hip but is
      able to move the knee and ankle, Bromage 2 when the patient is unable to move the hip and
      knee but able to move the ankle, Bromage 3 when the patient is unable to move the hip, knee
      and ankle). The interval between the injection and block completion was considered as the
      onset of motor block. Duration of motor block will be defined as the time interval between
      the complete motor block and complete resolution of anesthesia. Failed block will be
      considered if the sensory block and motor block were not achieved after 20 min.

      - Pain assessment: Patients will be followed every 2 hours postoperatively till 12 hours for
      analgesic requirements. Postoperative pain will be assessed via the Visual analogue scale
      (VAS), and when the VAS is more than 4 the patient will receive 0.25mg/kg nalbuphine.
    

Intervention name(s): Gabapentin 300mg
Intervention type(s): Drug
Intervention description(s): Preoperative gabapentin before spinal anesthesia
Other intervention name(s): placebo tablet
Intervention MeSH terms: Gabapentin
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomization by concealed envelope method
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Gabapentin, Spinal, Anesthesia, Visual analogue scale