Comparison between oral gabapentin and oral clonidine premedication for post operative pain relief in patient undergoing lower abdomen surgery under spinal anaesthesia A randomized controlled trial

Methodology

A pre-anesthetic checkup was conducted one day prior to surgery Detailed history and presenting complaints were noted followed by general and systemic examinations Routine laboratory investigations were performed All patients were instructed to remain nil per oral for solids for six hours prior to surgery Informed written consent was obtained after explaining the procedure During the preoperative visit and again in the preparation room the Visual Analog Scale VAS and Ramsay Sedation Score RSS were explained to all patients

In the preparation room standard monitors including electrocardiogram ECG non-invasive blood pressure NIBP and pulse oximetry were connected Baseline parameters such as heart rate HR systolic and diastolic blood pressure and peripheral oxygen saturation SpO2 were recorded An intravenous IV line was secured using an 18-gauge cannula

A total of 82 patients were randomized into two groups n 41 each using a computer-generated randomization table wwwrandomizationcom

Group C Clonidine group received tablet clonidine 100 µg orally 1 hour before administration of spinal anesthesia with sips of water Group G Gabapentin group received tablet gabapentin 600 mg orally 1 hour before administration of spinal anesthesia with sips of water

Both the investigator and the patient were blinded to the group allocation The premedication was administered by nursing staff

In the operating room baseline vitals were again recorded Co-loading was done with Ringers lactate solution at 10 mlkg prior to spinal anesthesia Under aseptic precautions a lumbar puncture was performed at the L3-L4 interspace using a 26-gauge Quincke spinal needle via a midline approach in either the right or left lateral decubitus position Skin infiltration was done using 2 percent lignocaine A subarachnoid block was achieved using 3 ml of 05 percent hyperbaric bupivacaine

Immediately after drug administration the spinal needle was withdrawn and the patient was placed in the supine position The onset of sensory block up to the T10 dermatome was assessed bilaterally using loss of pinprick sensation with a short hypodermic needle The onset of motor block was defined when the Modified Bromage Score reached 3

Maintenance fluids were administered using Ringers lactate at 6 mlkgh Post-spinal anesthesia vital signs were recorded at 2 5 15 30 minutes and then at 1-hour intervals until the end of surgery Hypotension if encountered was managed with IV injection of mephentermine 6 mg

After surgery patients were shifted to the Post-Anesthesia Care Unit PACU where hemodynamic monitoring was continued

Assessment Parameters****Efficacy Parameters

• Duration of Sensory Block Time from onset of sensory block to return of tactile sensation at L5 dermatome great toe
• Duration of Motor Block Time from onset of motor block to the ability to lift both lower limbs
• Duration of Analgesia Time from onset of sensory block to the administration of the first rescue analgesic

Pain was assessed using VAS at 2 4 6 8 12 and 24 hours postoperatively If VAS was greater than 3 injection diclofenac 1 mgkg IM was administered as rescue analgesia The time of first rescue analgesic dose was recorded by the attending nurse

Sedation was evaluated using the Ramsay Sedation Score RSS at 2 4 6 8 12 and 24 hours postoperatively

Safety ParametersSide effects including dizziness bradycardia hypotension sedation drowsiness nausea and vomiting were monitored and treated as necessary These were assessed and scored by a blinded investigator