Preoperative gabapentin augments intraoperative hypotension and reduces postoperative opioid requirements with functional endoscopic sinus surgery

Background
Functional Endoscopic sinus surgery (FESS) is a delicate and time consuming procedure; it is performed routinely under general anesthesia. Hypotensive techniques should be employed for best visualization of operative field. Gabapentin is a structural analog of gamma amino butyric acid. The aim of this study was to determine the analgesic efficacy of gabapentin and its role in deliberate hypotension during and after FESS.
Methods
Eighty patients ASA physical status I–II patients were scheduled to undergo elective FESS under general anesthesia. Patients were randomly assigned to one of two groups using a computer-generated table. Patients in the control group (40 patients) received oral placebo capsules and the study group (40 patients) patients received oral gabapentin (Conventin 400 mg; Evapharma Egypt) 1.2 g 1 h before surgery. Intraoperative, mean arterial blood pressure, infusion rates of the hypotensive agent (sodium nitroprusside) were recorded at 15 min interval. Assessments of pain, opioid usage, and side effects were performed at 1 h interval after arrival in the PACU.
Results
Gabapentin group patients required significantly lower ( value <0.05) infusion rates and total doses of hypotensive agent (sodium nitroprusside) than the placebo group patients at all measured intervals. Postoperative assessment of pain scores revealed that gabapentin group recorded significantly lower mean values of VAS than the control group ( value <0.05).
Conclusion
Oral gabapentin, 1200 mg decreased dose requirements of intraoperative hypotensive agent (sodium nitroprusside) and postoperative morphine. In addition, patients receiving gabapentin had suffered less from opioid side effects (nausea, vomiting and urinary retention) than those receiving placebo.