Perioperative Dexmedetomidine for outpatient cataract surgery: a systematic review

BACKGROUND: Cataract surgery is one of the most common procedures performed worldwide in the elderly. Various medications can provide effective anesthesia and analgesia for cataract surgery, but undesirable side effects limit the utility of each medication or combination of medications. Dexmedetomidine may serve as an anesthesia adjunct for outpatient cataract surgery in the elderly. METHODS: Searches were conducted in Cochrane, Embase, and PubMed for randomized clinical trials investigating the use of dexmedetomidine in adult patients undergoing outpatient, or ambulatory, cataract surgery with sedation and topical or peribulbar block. Ninety-nine publications were identified, of which 15 trials satisfied the inclusion criteria. A total of 914 patients were included in this review. The following data were collected: American Society of Anesthesiologists’ (ASA) physical status and age of study patients; method of blinding and randomization; medication doses and routes of administration; and intraoperative levels of sedation. We also recorded statistically significant differences between dexmedetomidine and other study medications or placebo with respect to the following outcomes: hemodynamic and respiratory parameters; pain; sedation; post-operative nausea and vomiting (PONV); discharge from post-anesthesia care unit (PACU) or recovery times; patient satisfaction; surgeon satisfaction; and effects on intraocular pressure (IOP). RESULTS: Hypotension with or without bradycardia was reported following bolus doses of dexmedetomidine ranging from 0.5–1.0 mcg/kg with or without a continuous dexmedetomidine infusion. Delayed PACU discharge times were associated with the use of dexmedetomidine, but no clear association was identified between delayed recovery and higher levels of intraoperative sedation. Better analgesia and higher patient satisfaction were commonly reported with dexmedetomidine as well as reductions in IOP. CONCLUSIONS: Overall, this review demonstrates better analgesia, higher patient satisfaction, and reduced IOP with dexmedetomidine for outpatient cataract surgery when compared to traditional sedatives, hypnotics, and opioids. These benefits of dexmedetomidine, however, must be weighed against relative cardiovascular depression and delayed PACU discharge or recovery times. Therefore, the utility of dexmedetomidine for outpatient cataract surgery should be considered on a patient-by-patient basis.