House P H, Hollands R H, Schulzer M
Department of Ophthalmology, University of British Columbia, Vancouver, Canada.
J Cataract Refract Surg. 1991 Jan;17(1):80-3. doi: 10.1016/s0886-3350(13)80989-3.
To determine the effectiveness of various combinations of lidocaine, epinephrine, and hyaluronidase with bupivacaine, a prospective, randomized, masked study on 117 patients having cataract extraction under local anesthesia was undertaken. All patients were given a 9 ml peribulbar block by one surgeon, and a graded assessment of analgesia and akinesia was made in a masked fashion one hour later. A mixture using all these agents gave significantly better results than any of the combinations (P = .001). No single agent was shown to be the major determinant of effectiveness. The result suggests a synergistic effect found only when all the agents are combined.