Original Research Article DOI: 10.18231/2394-4994.2017.0052 Indian Journal of Clinical Anaesthesia, 2017;4(2): 247-250 247 Comparative evaluation of the clinical efficacy of 0.5% levobupivacaine and 0.5% racemic bupivacaine in epidural anaesthesia for elective varicose vein surgery Senthil Kumar VS 1,* , S. Kannan 2 1 Professor, 2 Associate Professor, Saveetha Medical College Hospital, Thandalam, Chennai *Corresponding Author: Email: dr.vs.md@gmail.com Abstract Background and Aim: Racemic bupivacaine is known to be the most cardio toxic among the amide local anaesthetic. In search of an alternative it was found that the levo enantiomer has a better safety profile. This purpose of this study is to compare the clinical efficacy of 0.5% levobupivacaine with 0.5% racemic bupivacaine in epidural anaesthesia. Materials and Methods: After the institutional ethical committee approval this double blind randomized prospective study was conducted on 50 male patients between January and August 2011. 25 patients were allocated to each group; group L received levobupivacaine and group R received racemic bupivacaine. Onset time, duration of block, level of sensory block and motor block were assessed and compared. Observation and Results: The mean onset time was 7.739±3.3033 and 8.04±3.048 minutes in group L and in group R respectively. Level of sensory block level noted was between T10 to T5, but most patients had the level at T6. The mean duration of residual analgesia was 412.56 ± 39.11 minutes in L group and 409.56 ± 44.46 minutes in R group. The onset time, duration of block, level of sensory block were comparable and were not statistically significant. But the motor block was found to be intense and was statistically significant in the patients in R group (p 0.0498) than in L group. Conclusion: In comparison to racemic bupivacaine, levobupivacaine produces a differential blockade but onset, duration, level of sensory blocks was similar. However racemic bupivacaine produces intense motor blockade when compared with levobupivacaine. Keywords: Chirality, Racemic bupivacaine, Levobupivacaine, Epidural, Bromage scale, Differential block. Date of Acceptance: 6 th December, 2016 Date of Manuscript Receive: 13 th October, 2016 Introduction Chirality is a Greek word which means hand. Stereoisomers are molecules that have identical atomic and chemical properties with different spatial arrangement of their atoms and they cannot be superimposed on one another. A pair of such a stereo isomer is termed as enantiomers and each will rotate the plane polarized light in a magnitude that is equal but in opposite directions. Compound that rotate plane polarized light clockwise is `R’ isomer from Latin Rectus (right) and when a compound moves the plane polarized light anti-clockwise it is called `S’ isomer from Latin Sinister (left). When these isomers are present in equal molar amounts in a compound it is called as a racemic or racemate mixture. Enantiomers have identical physical and chemical properties so they will have similar pKa and lipid solubility. (1,2) Bupivacaine is widely used local anaesthetic and is a mixture of dextro and levo enantiomers and it is also cardiotoxic. (1,2) Toxic effects of bupivacaine were first described by Aberg and colleagues in 1972. (1,2,3,4) It was discovered that the R form of the drug is much more toxic than the S enantiomer. (2,3) Once this was recognized the search to isolate an alternative less toxic long acting anaesthetic was made and developed – Levobupivacaine the S enantiomer. (2,3,4,5) The present study was conducted to compare the onset time, duration of analgesia, sensory and motor block of 0.5% levobupivacaine and 0.5% racemic bupivacaine on randomly allocated 50 male patients. Materials and Methods After the institutional ethical committee approval 50 male patients in the age group of 20 to 50 years who were to undergo elective varicose vein surgery between January and August 2011 were chosen for this double blind randomized prospective study. Patients involved were given a detailed explanation about the study and an explained informed consent was obtained. Anaesthesiologist who allotted the local anaesthetic samples was not involved in this study. Therefore the observer was not aware of the type of local anaesthetic in each presentation. Inclusion Criteria  ASA physical class I or II scheduled for varicose vein surgery  Weight between 45 – 65 Kilograms Exclusion Criteria  ASA physical class III or more  Patient refusal  Patients with coagulation disorders  Patients with systemic illness such as cardiac, respiratory and neurologic disorders etc.  Allergy to local Anaesthetics  Local infection at the site of injection