COMPARISON OF BUPIVACAINE AND LIDOCAINE BUPIVACAINE FOR LOCAL-ANESTHESIA DIGITAL NERVE BLOCK

Study objective: We compared the efficacy, degree of discomfort, and t ime elapsed before anesthesia of digital block with a combination of 1 % lidocaine/.25% bupivacaine and with .25% bupivacaine alone. Methods: We carried out a randomized, double-blinded, prospective study in whi ch subjects served as their own controls. The study group comprised 19 normal adult volunteer medical students and members of the community who volunteered to participate in a study evaluating ''the use of comm only used local anesthetics by physicians.'' Two digital blocks were p erformed on each subject: one with a lidocaine/bupivacaine combination and one with bupivacaine alone. Two subjects did not complete the stu dy; therefore 34 blocks were performed. Both the physicians and subjec ts were blinded to the anesthetic used for each block. Patients immedi ately rated the pain associated with each technique on a standard visu al analog scale. Time elapsed before onset of anesthesia to pinprick w as assessed and recorded after each block in 1-minute increments. We a ssessed efficacy on the basis of anesthesia to pinprick. Results: Mean visual analog scale pain scores were not different between the two ty pes of blocks: 3 cm for lidocaine/bupivacaine and for bupivacaine alon e (P=.76, Student t test; P=.44, Wilcoxon signed-rank test). Time elap sed before anesthesia to pinprick was not significantly different betw een the groups: mean, 5.0 minutes for lidocaine/bupivacaine and 5.35 m inutes for bupivacaine alone (P=.75, Wilcoxon signed- rank test). Conc lusion: Bupivacaine .25% digital block induces anesthesia in the same period of time and with equivalent pain of injection as a 1:1 lidocain e 1%/bupivacaine .25% combination. It is not necessary to use lidocain e/bupivacaine in an attempt to achieve faster onset of local anesthesi a.