ٌREGIONAL ANAESTHESIA FOR EYE SURGERY THE PERIBULBAR BOLCK DEVELOPMENT OF A SIMPLE EFFECTIVE TECHNIQE

Abstract

Aiming to develop a simple effective Peri bulbar block technique , one hundred and filly unpremedicated patients undergoing peribulbar block for elcc,tive cataract extraction and intraocular lens implantation shared in our three stages study . In the first stage our results demonstrate the great role of hyaluronidase enzyme in peribulbar block as by its addition to the local ''

anaesthetic mixture in concentration of 15 U I ml it promotes

' diffusion

and

spread the local anaesthetic mixture to the aimed place so it hastens the onset of action and efficiency of the local anaesthetic mixture as regards extraocular muscle movement scores resulting in increase incidence of the initial successful blocks and decrease incidence of supplementary injection and also it helps in solving the minor complications " or prevents its occurrence from the start " which may resulted from the transconjunctival approach of peri bulbar block such as conjunctival edema and the increase in intraocular tension which results from injecting large volume of local 0 anaesthetic mixture . In the second stage , pH adjustment of local anaesthetic mixture to nearly 6.5 resulted in a sign!ficant increase in the efficiency of focal anaesthetic mixture in terms of shortening the onset of action due to increase the incidence of non ionized form entering the nerve sheath as we got an increase in the initial success rate of the block af1er just five minutes. Also this pH reaches the optimal pH for hyaluronidase activity . Another valuable advantage resulted from the pH adjustment is the painless local anaesthetic mixture. This stage demonstrates that the ideal local anaesthetic mixture for

peribulbar block is that used in group IV. 0 In third stage the single infrotemporal or single medial injection

approach are efficient . But it seems that the single medial site injection