Levobupivacaine vs. racemic bupivacaine in peribulbar anaesthesia: a randomized double blind study in ophthalmic surgery

Aims: The Authors examine the employement of a new anaesthetic agent, levobupivacaine 0.50% (S enantiomer of racemic mixture of bupivacaine), for peribulbar anaesthesia in a randomized double blind study vs.racemic bupivacaine 0.50% alone or in association with hyaluronidase 10 IU.ml(-1). Materials and Methods: 120 patients were divided into four groups of 30 each: group L (levobupivacaine 0.50%), group B (racemic bupivacaine 0.50%), group LH (levobupivacaine hyaluronidase 10 IU.ml(-1)), group BH (racemic bupivacaine hyaluronidase10 IU.ml(-1)). Results: The onset-time (14 +/- 3.2 min vs. 13 +/- 4.8 min) and the duration of anaesthesia (195 +/- 34.2 vs. 204 +/- 37.6) were similar. The ocular akinesia was evaluated with an 8 point system: it was considered sufficient for surgery with values of less than 5 points. The association with hyaluronidase increased the spread of local anaesthetics (76.6% of group LH, 73.3% of group BH) with local anaesthetics alone (60% of group L, 56.6% of group B). Moderate hypotension (<30% baseline) was reported in 3 patients (10%) of group L, 2 (6.6%) of group B, 1 (3.3%) of group LH and 2 (6.6%) of group BH. Statistical analysis (Student-Newman-Keuls test) was significant between group L vs. BH, B vs. BH and LH vs. BH as regards onset-time of anaesthesia; between group B vs. LH, B vs. BH and L vs. LH for the duration of anaesthesia. Chi square test for the general akinesia score showed significant results in group L vs. LH (p=0.043) and B vs. LH 8P =0.018); as regards the score 0, test reported significant values between groups B vs. LH (p=0.004) and B vs. BH (p=0.017). Conclusions: In conclusion levobupivacaine, a longlasting local anaesthetic with limited cardio and neurotoxicity, might be useful for vitreo-retinal surgery in elderly patients, compared with general anaesthesia.