Background: 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.
Methods: 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.
Results: 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.
Conclusions: Preoperative pregabalin 150 mg, 1 h before total abdominal hysterectomy has an inhaled anesthetic-sparing effect, maintain hemodynamics and optimizes postoperative analgesia.