Role of Preoperative Pregabalin in Reducing Inhalational Anaesthetic Requirements in Abdominal Hysterectomy: Randomized Controlled Trial

Abstract

Background: preoperative oral pregabalin controls postoperative pain & decreases anesthetic requirements in total intravenous anaesthesia . In this study, we hypothesized that preoperative pregabalin reduces inhaled isoflurane requirements. Methods: Study was conducted in a university hospital, included 50 women (18-60 yrs.), ASA I or II, admitted to undergo elective abdominal hysterectomy under general anaesthesia. Time of study: June to September 2017. Exclusion criteria were allergy or hypersensitivity to pregabalin; patients on calcium channel blockers, antiepileptic drugs, antidepression drugs, any analgesics or sedatives, or oral hypoglycemic agents; and patients with severe cardiovascular, renal, hepatic or neurological dysfunction. Interventions: giving either oral pregabalin 150 mg or placebo to patients of both groups. Primary outcome measures: inhaled isoflurane requirements to maintain haemodynamics ± 20% of baseline& bispectral index (BIS) of 40 - 60, measured using MAQUET Flow-I anaesthetic machine. Secondary outcomes : attenuation of pressor response to intubation, postoperative pain, first time for rescue analgesia, total anaglesics and adverse effects. Results: Isoflurane consumption was significantly less in pregabalin group (7.80 ± 1.27ml h -1) versus (12.27 ± 2.49 ml h-1) in control group, (P= 0.00). Better haemodynamic stability was in pregabalin group after intubation. 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. All patients in control group received pethidine intramuscular. More patients in pregabalin group suffered dizziness. Conclusion: preoperative pregabalin 150 mg ,1 h before total abdominal hysterectomy has an inhaled anaesthetic-sparing effect, maintain haemodynamics and optimizes postoperative analgesia. Keywords: Gabapentinoids, Pregabalin; Inhalation Anaesthetics, Isoflurane; Monitoring, Bispectral Index; Surgery, Abdominal Hysterectomy Objectives: We aimed to investigate the effectiveness and safety of preoperative oral pregabalin 150 mg in women undergoing elective total abdominal hysterectomy under general anaesthesia. Design: A prospective, randomized, double-blind, controlled study. Trial Registry Number: ClinicalTrials.gov: NCT 03302208