The Effect of Preoperative Gabapentin on the Duration of Spinal Anaesthesia in Patients Undergoing Lower Limb Surgery: A Randomized Controlled Clinical Trial

In the present study, we aim to examine oral gabapentin efficacy as an adjuvant to spinal anesthesia.

This prospective, clinical, randomized trial included subjects between 20 and 60 years undergoing lower limb surgeries categorized into two cohorts. Group (G) received gabapentin (900 mg) in two divided doses prior to spinal anesthesia; (300 mg 10 hrs prior to spinal anesthesia induction as well as 600 mg 2 hrs before spinal anesthesia). In contrast, the control Group (C) received only spinal anesthesia. The onset, as well as the duration of spinal anesthesia, were the primary outcome, while the secondary outcome was the postoperative nalbuphine consumed.

A total of 60 cases were evenly categorized into two cohorts. Both groups demonstrated no differences regarding motor and sensory block onset and duration. The group receiving preoperative gabapentin had a significant decrease in postoperative nalbuphine consumption with a mean of 20.8±9.4 mg compared to the control group, which showed an increased consumption of 28.9±10.4 mg with a p-value of 0.006. Further analysis of the Visual Analog Score (VAS) in both groups revealed that the decrease in total nalbuphine consumption was found at (8 and 10 hrs) postoperatively, with p values of 0.016 and 0009, respectively.

Gabapentin administration (900 mg) within 10 hrs of surgery in two subdivided doses prior to spinal anesthesia had no effect on onset and duration of spinal anesthesia but had a delayed beneficial postoperative analgesic effect.

This trial was registered at ClinicalTrials.gov (NCT05659810, URL: https://clinicaltrials.gov/ct2/show/NCT05659810in 21^st December 2022.