Preoperative Gabapentin for Post-tonsillectomy Pain in Children

The typical post-operative course for children following surgical removal of their tonsils and adenoids can be challenging, especially for pain control. First line medications for pain include intravenous and enteral narcotics, acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) or N-methyl-D-aspartate (NMDA) antagonists but their effects appear to be short-lived. Gabapentin has been shown in adult studies to tone down the body's response to pain and decreases opioid use post-operatively. The purpose of this study is to see if a single preoperative dose will reduce post-operative pain scores and the amount of analgesic used.

This is a randomized, double blind, placebo-controlled trial to study the effect of a preoperative oral dose of gabapentin on postoperative analgesic requirements and subjective pain levels in children undergoing tonsillectomy with adenoidectomy. Investigators will also look for a limited set of genotypic variations to explain any difference between individuals or groups in their response to the medication. Additionally, investigators will document potential adverse effects including excessive sedation, respiratory issues, surgical bleeding and emergence agitation/delirium. Investigators hypothesize that gabapentin will reduce opioid analgesic requirements and pain scores up to 36 hours post adenotonsillectomy without increased adverse effects such as emergence delirium, respiratory complications or bleeding. The clinical effect may depend on the individual's pharmacogenetic profile to look for a specific set of genetic polymorphisms that relate to the metabolism and effect of the study drug, gabapentin, and opioid analgesic pain medications.

pediatric pain, post operative pain, opioids, emergence agitation, preoperative anxiety, pharmacogenomics

subjects randomized to the liquid placebo arm will receive a single dose elixir of 0.4 mL/kg given 60 min prior to surgery

The active comparator, Gabapentin, is a structural analog of g-aminobutyric acid which has anticonvulsant properties. This study is a prospective randomized double-blinded trial examining the effectiveness of a single dose of liquid Gabapentin given 60 minutes prior to surgery for pain management in pediatric tonsillectomy/adenoidectomy pediatric patients.

Subjects randomized to the liquid placebo will receive an identical appearing liquid placebo of 0.4mL/kg.

Total mean oral analgesic requirement (cumulative hydrocodone dose (mg/kg)) at nine time points between 0 and 36 hrs post operatively.

Self-report pain scores at rest, using Bieri Faces Scale-Revised. The Bieri Faces Scale-Revised is a patient-reported measure in which patients indicate their pain level by selecting a face with an expression corresponding to their level of pain. Scores range from 0 to 10, with higher scores indicating worse pain. Pain was assessed at eight time points ranging from 0.5 to 36 hours post op.

Self-report pain scores when swallowing using Bieri Faces Scale-Revised. The Bieri Faces Scale-Revised is a patient-reported measure in which patients indicate their pain level by selecting a face with an expression corresponding to their level of pain. Scores range from 0 to 10, with higher scores indicating worse pain. Pain was assessed at eight time points ranging from 0 to 36 hours post op.

Inclusion Criteria: scheduled for outpatient tonsillectomy and adenoidectomy < 60 Kg, between 5th and 95th percentile for weight ability to self-report pain complete pain diary with assistance from parent or guardian Exclusion Criteria: require pre-anesthesia medication for anxiety require interpreter for verbal or written communication Obstructive sleep apnea significant enough to not qualify for outpatient surgery per surgeon ongoing oxygen dependence, pulmonary hypertension elevated risk of regurgitation history of seizures currently taking psychoactive medications or having a psychiatric condition requiring medications chronic pain disorders requiring medications renal disease developmental or cognitive disabilities history of adverse reactions to components of liquid gabapentin or placebo