Role of preoperative pregabalin in reducing inhalational anesthetic requirements in abdominal hysterectomy: randomized controlled trial.

Abstract

Preoperative oral pregabalin controls postoperative pain and decreases anesthetic requirements in total intravenous anesthesia. In this study, we hypothesized that preoperative pregabalin reduces inhaled isoflurane requirements. We investigated the effectiveness of preoperative oral pregabalin 150 mg in women undergoing elective open total abdominal hysterectomy under general anesthesia. A prospective, randomized, double-blind, controlled study was conducted in a university hospital. The study included 50 women (18-60 yrs.), ASA I or II, admitted for abdominal hysterectomy under general anesthesia. Exclusion criteria were allergy to pregabalin; calcium channel blockers, antiepileptic drugs, antidepressant drugs, any analgesics, sedatives, or oral hypoglycemic agents. Patients were randomized into two groups; Pregabalin group received oral pregabalin 150 mg and placebo group. Main outcome measures was inhaled isoflurane requirements to maintain hemodynamics ±20% of baseline and bispectral index of 40 - 60, measured using MAQUET Flow-I anesthetic machine. Secondary outcomes were attenuation of pressor response to intubation, postoperative pain, and first time for rescue analgesia, total analgesics and adverse effects. Isoflurane consumption was significantly less in pregabalin group (7.80±1.27 mL h -1) versus (12.27±2.49 mL h-1) in the control group, (P=0.00). Better hemodynamic stability was in pregabalin group. First postoperative hour: the mean VAS Score was significantly higher in control group (7.10±1.20) compared to pregabalin group (4.50±1.70), P<0.001. More dizziness was in pregabalin group. Preoperative pregabalin 150 mg, 1 h before total abdominal hysterectomy has an inhaled anesthetic-sparing effect, maintain hemodynamics and optimizes postoperative analgesia.