[Spinal anesthesia with isobaric 0.5% bupivacaine for lower limb surgery: effects of different volumes].

Background: The effects of different volumes (2.4, 2.6, 2.8 and 3.0 ml) of isobaric 0.5% bupivacaine used for spinal anesthesia were compared in 206 patients scheduled for lower limb surgery.

Methods: The spinal anesthesia was performed with the patients in the lateral position and the isobaric 0.5% bupivacaine was injected intrathecally at the L3-4 interspace.

Results: The time to maximum cephalad spread of anesthesia (loss of cold sensation) varied between 25 and 40 min. A significant difference was found in cephalad spread between 2.4 ml group and 3.0 ml group (T11 vs T7), and between 2.6 ml group and 3.0 ml group (T11 vs T7). Severe hypotension did not occur during the study.

Conclusions: Spinal anesthesia with 2.8 ml of isobaric 0.5% bupivacaine proved satisfactory for lower limb surgery.