ORBICULAR MUSCLE AKINESIA IN REGIONAL OPHTHALMIC ANESTHESIA WITH PH-ADJUSTED BUPIVACAINE - EFFECTS OF HYALURONIDASE AND EPINEPHRINE

The success rate and duration of lid akinesia after adding hyaluronida se and/or epinephrine to pH-adjusted bupivacaine was examined in a dou ble-blind fashion in patients undergoing cataract surgery under local anaesthesia. A two-injection-site technique was used For globe akinesi a all patients (n = 120) received an inferolateral intraconal injectio n (3 ml) of pH-adjusted bupivacaine 0.75% and hyaluronidase. Lid akine sia was obtained with a medial extraconal injection (3.5 ml) of alkali nized bupivacaine with or without an adjunct. The patients were random ized to four groups as follows: a medial injection of plain bupivacain e (n = 31), with added hyaluronidase (n = 30), with added epinephrine (n = 29) or with both epinephrine and hyaluronidase (n = 30). The fina l solutions had a pH of 6.7. Lid akinesia was supplemented with perios teal injections if needed. The degree of akinesia from clinical assess ment was graded from 0-2 and also measured with electromyography at te n minute intervals for 30 min after surgery, and three hours after the block. The kast satisfactory result (P < 0.01) and shortest duration of the lid block (P < 0.05) was obtained with plain pH-adjusted bupiva caine. No differences in the success rate or duration of the block amo ng the other groups were seen. The duration of the block was longer in the epinephrine groups than in the two other groups (P < 0.01) and lo nger in the epinephrine and hyaluronidase group than in the group rece iving only hyaluronidase (P < 0.05). We conclude that the best initial results and longest duration of blocks were shown in the groups recei ving epinephrine or epinephrine and hyaluronidase.