Effect of alkalinization and/or hyaluronidase adjuvancy on a local anesthetic mixture for sub-Tenon's ophthalmic block
Authors: Moharib, M. M.1; Mitra, S.2; Rizvi, S. G.3
Source: Acta Anaesthesiologica Scandinavica, Volume 46, Number 5, May 2002 , pp. 599-602(4)
Publisher: Blackwell Publishing
Abstract:
Background and objectives: pH adjustment and/or addition of hyaluronidase to local anesthetic drugs decrease the time to onset and prolong the duration of regional anesthetic techniques for ocular surgery. The objective of this study was to investigate whether these factors are effective also in sub-Tenon's block. Methods: Sixty patients were randomly assigned to four groups in a double blind, prospective fashion, and received 5.125 ml mixtures as follows: 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5% and 0.125 ml isotonic saline (group LB); 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5%, 15 IU hyaluronidase/ml and 0.125 ml isotonic saline (group LBH); 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5% and 0.125 ml sodium bicarbonate 8.4% (group LBpH); and 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5%, 15 IU hyaluronidase/ml and 0.125 ml sodium bicarbonate 8.4% (group LBHpH). This measurement was based on one quadrant sub-Tenon's block. Akinesia was assessed every 30 s. Results: No statistically significant differences were found between the groups regarding mean times to onset and to complete akinesia. Group LBH displayed a significantly lower frequency of patients experiencing pain and a lower need for rescue medication during surgery than the other groups. Conclusion: pH adjustment and/or addition of hyaluronidase to a mixture of lignocaine and bupivacaine did not shorten the time to onset of akinesia following sub-Tenon's technique. However, the addition of hyaluronidase was associated with a lower fraction of patients experiencing pain during surgery.Keywords: regional anesthesia; sub-Tenon's technique; ophtalmic surgery; local anesthetics; lignocaine; bupivacaine; hyaluronidase
Document Type: Research article
DOI: 10.1034/j.1399-6576.2002.460519.x
Affiliations: 1: Anesthesia/ICU, 2: Ophthalmology and 3: Epidemiology and Medical Statistics, Sultan Qaboos University Hospital, Oman

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