Preemptive Oral Gabapentin and Pregabilin for Post- Operative Pain Management after Surgery under Spinal Subarachnoid Block

Background: Pregabalin has been used and found effective in preventing neuropathic component of acute nociceptive pain during and after surgery. We conducted a study to compare the effect of oral gabapentin and pregabalin on different block characteristics. Methods: A total of 90 ASA grade I and II patients posted for elective surgeries were randomized into 3 groups (groups A, B and C 30 patients each). One hour before entering into the operation theatre the blinded drug selected for the study was given with a sip of water. Group A – received identical placebo capsule, Group B-received 600 mg of gabapentin capsule and Group Creceived 150 mg of pregabalin capsule. Spinal anaesthesia was performed at the L3-L4 interspace. 3.5 ml of 0.5% bupivacaine heavy injected over 30 sec through a 25 G spinal needle. VAS score at first rescue analgesia, mean time of onset of analgesia, level of sensory block at 5 min and 10 min interval, onset of motor block, total duration of analgesia and total requirement of rescue analgesia were observed. Hemodynamics parameters and side effects were recorded in all patients. Results: A significantly longer mean duration of effective analgesia in group C was observed compared with other groups (p<0.001). The mean duration of effective analgesia in group C was 535.16 ± 32.86 min versus 151.83 ±16. 21 minutes in group A and 302.00 ± 24.26 minutes in group B. The mean numbers of doses of rescue analgesia in the first 24 hours in group A, B and C were 4.7 ± 0.65, 4.1 ± 0.66 and 3.9 ± 0.614 respectively. (P value <0.001). Conclusion: We conclude that pre-emptive use of gabapentin 600mg and pregabalin 150 mg orally significantly reduces the postoperative rescue analgesic requirement and increases the duration of postoperative analgesia in patients undergoing elective surgeries under spinal anaesthesia.