Suma K. V1 , K. Udaya Bhaskar2
BACKGROUND: Bupivacaine is the most commonly used drug for spinal anesthesia. Ropivacaine is a relatively new enantomerically pure isomer of bupivacaine with a low pKa and low lipid solubility as well as less cardiotoxicity with a possibility of shorter duration of sensory as well as motor block compared to bupivacaine. The shorter duration of block could be helpful in early ambulation and early discharge particularly in day care settings. AIMS AND OBJECTIVES: The aim of the study were to evaluate the onset and duration of sensory and motor block, the maximum height of sensory block as well as the degree of motor block and haemodynamic stability of ropivacaine in comparision with bupivacaine. METHODS AND MATERIALS: Eighty ASA I or II patients undergoing lower abdominal and lower limb surgeries were randomly divided into two groups, Group R(n=40) revceived 3ml (15mg)of isobaric ropivacaine intrathecally and Group B(n=40) received isobaric bupivacaine 3ml(15mg) intrathecally. The onset and duration of sensory and motor block, height of sensory block and degree of motor block and haemodynamic stability were noted. RESULTS: Onset of sensory block and motor block were similar in both the groups. Onset time of sensory block in group R was 7.49±3.o5min and in group B was 6.75±2.01min (p value 0.2). Onset of motor block in group R was 2.23±1.63min and in group B was 2.27±1.34 min(pvalue0.16). The highest level of sensory block (T4) obtained in group R was n=3(7.5%), and in group B n=8(20%) (p<0.01) The duration of sensory block in group R was 181.93±46.87min and in group B was 247±51.77min (pvalue<0.001). The duration of motor block in group R was 158.49±42.7min and in group B was 222±48.53min (p<0.001). The degree of motor block was complete in both groups. There was no significant difference in haemodynamic stability between the groups. CONCLUSION: Intrathecal isobaric ropivacaine 15mg is similar to isobaric bupivacaine 15mg with respect to onset of sensory and motor block as well as degree of motor block. However a shorter duration of both sensory and motor block was seen in ropivacaine group compared to bupivacaine group.
