Effectiveness of Preemptive Oral Gabapentin 600 mg on Morphine Requirement After Non Obstetric Lower Abdominal Surgery

Seventy-two subjects were given informed consent before enrolling the study and randomized into two groups; gabapentin and placebo. Two hours before the incision, patients were given preemptive analgesia, either gabapentin or placebo. Non-invasive blood pressure monitor, electrocardiogram (ECG), and pulse oxymetry were set on the subjects in the operating room. General anesthesia induction was done by fentanyl 2 mcg/kg and propofol 2 mg/kg. Endotracheal tube (ETT) intubation was facilitated with atracurium 0.5 mg/kg as muscle relaxant. Maintenance was done by sevoflurane, oxygen, and compressed air. After surgery, patients were extubated until fully conscious. Patients will be transported to recovery room postoperatively. Besides paracetamol as the postoperative analgesia, we also attached patient controlled analgesia (PCA) system to patients' intravenous line using continuous ambulatory delivery device (CADD) contained morphine 1 mg/ml with settings 1 mg per requirement, interval limit within 5 minutes, maximum dose 6 mg/hour intravenously. Cumulative morphine requirement, mean visual analogue scale, and time interval after surgery to the first administration of morphine will be assessed in this study.