Agents for sedation in ophthalmic surgery: A review of the pharmacodynamics and clinical applications

Summary Sedation is often required to improve patient comfort during the placement of local blocks in eye surgery. The ideal sedative should have a rapid onset of action and be able to ensure immobility while allowing for patients to respond to verbal commands. Furthermore, ideal sedatives should provide amnesia, have a sufficiently short duration of action to facilitate patient cooperation during surgery, have minimal side effects and allow for a rapid return to home-readiness. Combined analgesic and sedative regimes are widely used in tandem with local/regional blocks; however, potential problems with sedative/narcotic agents are considerable. These complications include ventilatory depression and loss of airway control with hypoxia and hypercapnia, and may cause the patient to become confused intra-operatively. The role of sedation in a wide variety of ophthalmic procedures as well as the variation in sedative agents used with regards to dosage regimes and drug combinations as applied in clinical practice can only be illustrated by referring to the published data. As a result, the goal of this paper is to examine the spectrum of sedative drugs that have been used in the process of eye surgery as published in the literature since 1990 with special attention being given to the pharmacodynamics and clinical applications of relevant drugs in current use. In conclusion there does not seem to be one drug or one regimen indicative of standardization of sedation practice in eye surgery. It rather seems as if there could be a competition between drugs and regimens for the position of the best and most favourable place in the armamentarium of sedationists and anaesthesiologists. There could be strong indications from the literature that drugs like midazolam, propofol,and remifentanil are the favourites for sedation in eye surgery. It might be necessary to take another look at the group of alpha-2 adrenergic agonists and also perhaps at low-dose ketamine.