Midazolam, Propofol and Dexmedatomedine In Sedation For Patients Undergoing Vitreoretinal Surgeries Under Local Anesthesia

Abstract

For many ophthalmic surgeons, local anesthesia has become the preferred option over general anesthesia because of the quicker rehabilitation and the avoidance of possible complications of general anesthesia. Vitreoretinal surgery is commonly done under peribulbar anesthesia supplemented with intravenous sedation. Sedation is regarded as an important adjunct to ophthalmic anesthesia. Pharmacological sedation results in depression of the level of consciousness that is sufficient to achieve anxiolysis, amnesia and somnolence without loss of verbal communication. The clinical practice of sedation during ophthalmic local anesthesia varies among procedures and clinicians and is not without complications. The ideal sedative for ophthalmic procedures performed under local anesthesia should have a rapid onset but a short duration of action to ensure rapid awakening and early return-to-home readiness, especially in the setting of day surgery. The agent should be non-toxic, non-accumulating and have predictable activity with minimal side effects. In a cost-conscious environment, cost-effectiveness is another important attribute. The available drugs are benzodiazepines, intravenous anesthetic induction agents (e.g. propofol), opiates and α2 agonists such as dexmedetomidine or clonidine. Common adverse effects of midazolam include prolonged recovery after long term or high dose use, hypoxemia, hypotension and respiratory depression when paired with an opioid. The adverse respiratory profile, unpredictable attenuation of stress response to surgery (tachycardia and hypertension) and associated post-operative nausea and vomiting of benzodiazepines and opioids create the need for a sedative drug that can be used safely during monitored anesthesia care.