The Effect of Gabapentin on Spinal Anesthesia Duration

The Effect of Preoperative Gabapentin on the Duration of Spinal Anesthesia in Patients Undergoing Lower Limb Surgery: A Double-blind, Randomized Clinical Study

This prospective parallel group double blinded randomized study will be conducted over 60 adult participants between 20 and 60 years ASA (American Association of Anesthesiologists) I and II. The participants will be randomly allocated in 2 groups. Group A will receive 900 mg of gabapentin before surgery in 2 divided doses; 300 mg 10 hours prior to surgery and 600 mg 2 hours before surgery, while group B will receive 2 placebo tablets at the same time. The participants will receive spinal anesthesia in the form of 3ml of hyperbaric bupivacaine 0.5%. Hemodynamics will be recorded every 15 minutes till the end of surgery. Sensory, and motor block progression, and regression will be recorded also.

Study Overview

• Status: Completed
• Conditions: Prolongation of Spinal Anesthesia
• Intervention / Treatment: Drug: Gabapentin 300mg

Detailed Description

A prospective double blinded randomized trial to study the effect of gabapentin on the duration of spinal anesthesia. The participants will be divided into 2 groups. Group A will receive 900 mg of gabapentin before surgery in 2 divided doses; 300 mg 10 hours prior to surgery and 600 mg 2 hours before surgery, while group B will receive 2 placebo tablets at the same time.

The patient will be seated and after sterilization of his back with povidone iodine, a midline intrathecal injection of the 3ml of hyperbaric bupivacaine 0.5% at L 3/4 - L4/5 will be done via a 25G needle. Neural block will be assessed by using pin prick test, motor block will be assessed by using the modified Bromage scale, results will be recorded every 3 min until the level is stable for 3 consecutive tests.

After successful intrathecal injection, the patient will be monitored continuously for block progression and complications. The patient's blood pressure will be taken every 3 minutes initially, more frequently if needed. The patient will be monitored for the following:

Ensure that the block is adequate for the surgical procedure and it does not progress too high (motor block will be assessed by modified Bromage score and the sensory level by pin prick test up to T7-T10 level)

Sensory block will be assessed by pin prick test (Hollman test) using a 3-point scale; (0) = Normal sensation, (1) = Loss of sensation of pin prick (analgesia), and (2) = Loss of sensation of touch (anesthesia).

Onset time for sensory block will be defined as the time interval between the end of local anesthetic administration and complete sensory block (score 2 for all nerves). Duration of sensory block will be defined as the time interval between the complete sensory block and complete resolution of anesthesia (score 0 for all nerves).

Motor block is determined by using the modified Bromage scale (Bromage 0, the patient is able to move the hip, knee and ankle; Bromage 1 when the patient is unable to move the hip but is able to move the knee and ankle, Bromage 2 when the patient is unable to move the hip and knee but able to move the ankle, Bromage 3 when the patient is unable to move the hip, knee and ankle). The interval between the injection and block completion was considered as the onset of motor block. Duration of motor block will be defined as the time interval between the complete motor block and complete resolution of anesthesia. Failed block will be considered if the sensory block and motor block were not achieved after 20 min.

- Pain assessment: Patients will be followed every 2 hours postoperatively till 12 hours for analgesic requirements. Postoperative pain will be assessed via the Visual analogue scale (VAS), and when the VAS is more than 4 the patient will receive 0.25mg/kg nalbuphine.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt, 11566
    • Ain Shams University Hospitals

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 58 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• American Society of Anesthesiologists class I, and II
• Age 20 - 60 years
• Weight between 60 and 80 kilograms
• Height between 160 and 180 centimetres

Exclusion Criteria:

• Participants with contraindications to spinal anesthesia.
• Participant refusal
• Extreme short or tall statures
• Body mass index above 40

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Preoperative oral gabapentin before spinal anesthesia; The participants will receive 900 mg of gabapentin before surgery in 2 divided doses; 300 mg 10 hours prior to surgery and 600 mg 2 hours before surgery.	Drug: Gabapentin 300mg; Preoperative gabapentin before spinal anesthesia; Other Names: placebo tablet
Placebo Comparator: Preoperative oral placebo before spinal anesthesia; The participants will receive 1 tablet 10 hours prior to surgery, and then 2 tablets 2 hours prior to surgery	Drug: Gabapentin 300mg; Preoperative gabapentin before spinal anesthesia; Other Names: placebo tablet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of the time of regression of sensory block	Measurement of the time of regression of sensory block by using pin prick test	4 hours
Measurement of time of regression of motor block	Measurement of time of regression of motor block by using Bromage scale from 0-4	4 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of time to onset of sensory block	Measurement of time to onset of sensory block by using pin prick test	15 minutes
Measurement of duration of postoperative analgesia	Measurement of the duration of postoperative analgesia using the visual analogue scale from 0-10	12 hours

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Amount of postoperative analgesics required	Measurement of the number of doses needed of postoperative analgesics	24 hours

Collaborators and Investigators

• Sponsor: Ain Shams University
• Investigators: Principal Investigator: Ain Shams, University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 26, 2022
• Primary Completion (Actual): March 28, 2023
• Study Completion (Actual): April 10, 2023

Study Registration Dates

• First Submitted: November 23, 2022
• First Submitted That Met QC Criteria: December 12, 2022
• First Posted (Actual): December 21, 2022

Study Record Updates

• Last Update Posted (Actual): April 28, 2023
• Last Update Submitted That Met QC Criteria: April 27, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Keywords: Gabapentin, Spinal, Anesthesia, Visual analogue scale
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Excitatory Amino Acid Antagonists; Excitatory Amino Acid Agents; Tranquilizing Agents; Psychotropic Drugs; Anti-Anxiety Agents; Anticonvulsants; Antimanic Agents; Gabapentin
• Other Study ID Numbers: R 177/2022

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No