[The effect of barbotage on the sensory spread in spinal anesthesia using isobaric and hyperbaric 0.5% bupivacaine]

The effect of spinal anesthesia with barbotage versus without barbotage on the spread of analgesia was investigated. For comparison, hyper- and isobaric bupivacaine 0.5% with adrenaline 1:200,000 was used. MATERIAL AND METHODS. Barbotage was accomplished as follows: after lumbar puncture 0.5 ml CSF was aspirated into the local anesthetic solution, followed by reinjection of 1.0 ml of the solution. This process was repeated six times. Sixty patients who were scheduled for urological or lower limb surgery under spinal anesthesia were selected for this study. Patients were each arbitrarily assigned to one of four groups (isobaric and hyperbaric, without and with barbotage). RESULTS. There was no statistically significant difference in the maximum level of sensory analgesia. The mean maximum level of sensory analgesia reached T9 (group 1), T8 (group 2), T9 (group 3) and T8 (group 4). Time to highest dermatome was significantly shorter with barbotage (groups 1-4: 19.0 min, 13.0 min, 18.7 min, 12.3 min). Times for regression of analgesia to T12 (mean maximum duration) were 142 (+/- 54.9) min, 164 (+/- 29.7) min, 130 (+/- 40.4) min and 144 (+/- 36.2) min (groups 1-4). Motor block grade 3 (Bromage) was achieved in significantly shorter times with barbotage than without. The shortest onset time was recorded with isobaric bupivacaine. The onset time of a complete motor block was 12.5 (+/- 5.5) min in group 1, 6.1 (+/- 2.9) min in group 2, 15.8 (+/- 4.7) min in group 3, and 11.7 (+/- 5.1) min in group 4. CONCLUSIONS. The results showed no significant differences between the maximum segmental sensory levels or duration of anesthesia observed with isobaric and with hyperbaric bupivacaine (with and without barbotage). Sufficient analgesia was obtained with barbotage and without barbotage. Uncontrolled cephalad spread of spinal anesthesia was not observed. Barbotage has the advantage of shortening time for spread to highest dermatome and the time to onset of complete motor block.