How Does Gabapentin Affects Post-operative Tonsillectomy Pain?
Condition: Post-operative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional
Phase: Phase 3

Summary: 
      Gabapentin is a medicine that has been used in adults (but not yet in children) to treat pain
      after surgery. In children it has been used for many years to treat other conditions and has
      been shown to be very safe.

      Removal of tonsils is a common operation with each child experiencing a similar pattern of
      pain; this makes it good for looking at the effect of pain relieving medicines. In our study
      each child will get the same operation and medicines, as they would have normally. Before the
      operation and in a random way, half will get gabapentin and half will get the same syrup but
      with no gabapentin. Afterwards we will record how much pain the children have and how much of
      our standard medicine is needed to make them comfortable. We expect both of these results to
      be lower in the half who received gabapentin. We will also record the amount and type of
      unwanted effects, both from the gabapentin and from any other pain relief medicines.
    

Detailed description: 
      Tonsillectomy is one of the most commonly performed children's surgeries and produces a
      consistent pattern and intensity of pain in the recovery period. These qualities make this
      surgery ideal for the investigation of pain relieving medications. Adequate analgesia for
      tonsillectomy in the perioperative period presents a challenge to the anesthetist because
      opiates, which provide the most effective analgesia, are associated with a high incidence of
      nausea and vomiting, respiratory depression, and sedation. These effects make recovery from
      tonsillectomy particularly hazardous in children with Obstructive Sleep Apnea Syndrome (OSAS)
      (the primary indication for tonsillectomy or adenotonsillectomy) thus alternatives to opiates
      have been sought. Gabapentin is a drug with an extensive safety record in the treatment of
      children's seizures, and chronic pain syndromes. Recently studies have demonstrated new modes
      of action for this medication, both directly on pain and in increasing the efficacy of
      conventional opiate (morphine) pain relieving medications. As such it may have role in the
      relief of acute pain. We hypothesize that given preoperatively as a single dose; gabapentin
      will reduce postoperative pain and opiate requirement in children undergoing tonsillectomy.
      Randomization will follow a computer generated random pattern with 14 patients in each group
      (placebo or gabapentin). Pain and sedation will be recorded as will the incidence of
      vomiting, dizziness and pruritis. Pain will be assessed using the Coloured Analogue Scale and
      sedation with the University of Michigan Sedation Scale. The time to first oral intake of
      fluids will also be recorded. All recordings will be made at 5-minute intervals from time of
      extubation (time = 0) and will be made by an independent blinded recovery nurse. Subjects
      will stay in the PACU for a minimum of one hour from time zero, and will only be discharged
      to the Surgical Daycare Unit at a point after this when two successive pain measurements
      demonstrate a score of 3 or less. In the Surgical Daycare Unit pain assessment will continue
      at intervals of 30 minutes to a total time of 4 hours from time zero and will be recorded by
      a member of the research team blinded to nature of premedication. A telephone interview will
      be scheduled with the subject's parents at 24 hours from time zero.
    

Intervention name(s): Gabapentin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): One dose of oral premedication of Gabapentin 10 mg kg-1 given at least 30 but not more than 90 minutes before surgery. Max dose is 600mg.; Placebo
Intervention MeSH terms: Gabapentin
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Gabapentin; tonsillectomy; post-operative pain; morphine requirements; randomized double blind; adenotonsillectomy