ABSTRACT
Background:Dexamethasone appears to be effective in prolonging the duration of analgesia from supraclavicular brachial block using levobupivacaine or Bupivacaine. Long acting local anaesthetic, Bupivacaine is associated with cardiac and central nervous system toxicity which prompted the researchers to develop new local anaesthetic agent with a profile similar to bupivacaine but avoiding the toxic effects. Therefore, the aim of the present study is to test the hypothesis that adding dexamethasone significantly prolongs the duration of analgesia for levobupivacaine and bupivacaine and the magnitude of the effect differs among the two local anaesthetics. Methods: A prospective, randomized study was undertaken at JN Medical College. 120 patients posted for upper limb surgeries under Supraclavicular Brachial Plexus Block were assigned into four groups, each containing 30 patients. Group I received 25 ml Bupivacaine 0.5% and 2ml NS. Group II received 25 ml of Bupivacaine 0.5% and 2ml dexamethasone(8mg) .Group III received 25 ml of Levobupivacaine 0.5% and 2ml NS. Group IV received 25 ml of Levobupivacaine 0.5% and2ml dexamethasone (8mg). Results:Dexamethasone significantly prolonged the duration of analgesia of both levobupivacaine and bupivacaine. Conclusion:Dexamethasone prolongs analgesia in supraclavicular blocks using either levobupivacaine or bupivacaine. Considering the less cardiotoxic profile of levo-bupivacaine it should be preferred over bupivacaine.
ABSTRACT
To assess and evaluate the accuracy of individual types of evoked motor responses [EMRs] for prediction of successful surgical anesthesia following peripheral nerve stimulator [PNS] assisted supraclavicular block. A prospective study was carried out over a period of one and half years from August 2004 to January 2006, at J. N. Medical College, Aligarh Muslim University, Aligarh, India, in 60 patients who underwent various elective operative procedures on the upper limb. Any of the EMR, such as forearm flexion or extension, carpal flexion, or extension, prono-supination, or finger flexion, at a definite current of 0.25 mA for 2 ms was taken as an end point for prediction of successful block, and a local anesthetic solution [0.375% Bupivacaine, 30 ml] was administered at that level. Complete surgical anesthesia was observed in those cases where EMR included: flexion of only second and third fingers [n=15/15] or flexion of all 4 fingers with thumb opposition [n=14/14] or uncommon flexion of all 4 fingers without movement of any other joint of the upper limb [n=2/2], suggesting a sensitivity of 100%. However, thumb opposition to the tip of the flexed little finger revealed a success rate of only 83% [n=5/6], and other EMRs were followed by high rates of inadequate surgical anesthesia or total failure. Specific EMR of flexion of second and third fingers, or all the 4 fingers are reliable predictors of complete surgical anesthesia following PNS assisted single injection supraclavicular nerve block with no incidence of pneumothorax and nerve damage