Gabapentin as Preanesthetic Medication to Fast Procedures in Pediatric´s Oncology

Children, ranging from 1 to 6 years old, will receive drugs (placebo, gabapentin 15mg/kg or 30mg/kg) 1 to 2 hours before the oncologic procedure (myelogram and/ or puncture lumbar). They will be submitted to the same general anesthesia protocol (sevoflurane 8% plus N2O and oxygen) and postoperative analgesia. All patients will be observed for changes in the Modified Yale Preoperative Anxiety Scale (mYPAS) at baseline (right before drug administration), at 1 hour after group administration, at the separation from parents, and at anesthetic induction time. The mYPAS scale is a compilation of 5 subscales: activity (0 to 4 points), vocalizations (0 to 6 points), emotional expressivity (0 to 4 points), state of apparent arousal (0 to 4 points), and use of parent (0 to 4 points). All scores are summed up, divided by 4, and then multiplied by 100. Total scores above 30 points are interpreted as a patient with anxiety, which would represent a worse outcome.

Patients will be submitted to the same general anesthesia protocol, receiving sevoflurane 8% plus N2O and oxygen prior to the procedure. We will measure the percentage of sevoflurane ended-expired.

After the procedure, all patients will be observed for change in the Paediatric Anaesthesia Emergence Delirium (PAED 0 to 20 points) scale. Score changes will be assessed at baseline (right after the procedure), and at 30 minutes the procedure has finished. Each criterion is assessed through the event frequency, e.g. "eye contact" that "never" occurs corresponds to score 4. The range goes from "never" (4 points) up to "always" (0 points) for positive behavior criteria. Those are "make contact with the caregiver", "actions are purposeful", and "aware of surroundings". Negative behavior criteria range from "never" (0 points) up to "always" (4 points). Those are "restlessness" and "inconsolable". All subscores are summed up into a total score. Total scores above 10 points are interpreted as a patient with emergence delirium, which would indicate a worse outcome.

All patients will be evaluated number of vomits occurrence for 8 hours after procedure.

Patients will be submitted to the same general anesthesia protocol, receiving sevoflurane 8% plus N2O and oxygen prior to the procedure. We will record the time, in seconds, when patients lose their consciousness and corneal reflex.

After the procedure, all patients will be observed for changes in the Children and Infants Postoperative Pain Scale (CHIPPS) scores. Score changes will be assessed at baseline (right after the procedure), and at 30 minutes the procedure has finished. The score ranges from 0 (Behavior not present) to 2 (Intense behavior), to be assessed in each of the following indicators: "crying", "facial expression", "posture of the trunk", "posture of legs", and "motor restlessness". All subscores are summed up into a total score. Total scores above 6 points are interpreted as a patient with severe pain, which would indicate a worse outcome.