Perspectives in Medical Research

Abstract

Introduction: Lignocaine and bupivacaine are the commonly used anesthetic agents for spinal anaesthesia. Ketamine when used intrathecally provides better surgical conditions with cardiovascular stability of short duration.
Materials and Methods : A prospective, randomized, double blinded study was conducted among 80 patients belonging to ASA grade I and II of either sex with age between 16 - 60 years posted for elective surgeries on the lower abdomen or lower extremities admitted in Prathima Institute of Medical Science during December 2012-13. The studied parameters included sensory, motor blockade, cardiovascular stability, side effect and postoperative complications. Statistical analysis was done using chi-square test, unpaired student's t test and paired student's t-test.
Results: A total of 80 patients were divided into two groups (40 each). The group I was given 3.5cc of 0.5% heavy bupivacaine whereas group II was given 2.5cc of 0.5% heavy bupivacaine and 1ml of preservative free ketamine (50mg). Onset of sensory block was quicker (1.95±0.26 min) in group II as compared to group I (2.56±0.55 min) and the difference was statistically significant (p<0.0001). Duration of sensory block (156.62±11.85 min) in group II was observed to be less as compared to group I (184.47±15.01 min) and it was statistically significant (p<0.0001). Mean Onset of motor block in group II (2.56±0.53min) was faster as compared to group I (3.18±0.74min) and was statistically significant (p<0.0001) whereas the mean duration of motor block in group II (181.75±12.17 min) was less as compared to bupivacaine (207.35±20.20 min) alone and this difference was statistically significant (p<0.0001). It was observed that addition of ketamine to bupivacaine showed haemodynamic stability than bupivacaine alone and this finding was found to be statistically significant (p<0.0001). The incidence of postoperative complication in the present study was almost nil except for mild headache in 2 patients (5%) in group I and 1 patient (2.5%) in group II.
Conclusion: The present study recommends the use of preservative free ketamine along with 0.5% bupivacaine intrathecally especially when early onset of block with cardiovascular stability is desirable.