Adverse intraoperative medical events and their association with anesthesia management strategies in cataract surgery

OBJECTIVE: To compare adverse medical events by different anesthesia strategies for cataract surgery. DESIGN: Prospective cohort study. PARTICIPANTS: Patients 50 years of age and older undergoing 19,250 cataract surgeries at nine centers in the United States and Canada between June 1995 and June 1997. INTERVENTION: Local anesthesia applied topically or by injection, with or without oral and intravenous sedatives, opioid analgesia, hypnotics, and diphenhydramine (Benadryl). MAIN OUTCOME MEASURES: Intraoperative and postoperative adverse medical events. RESULTS: Twenty-six percent of surgeries were performed with topical anesthesia and the remainder with injection anesthesia. There was no increase in deaths and hospitalizations associated with any specific anesthesia strategy. No statistically significant difference was observed in the prevalence of intraoperative events between topical and injection anesthesia without intravenous sedatives (0.13% and 0.78%, respectively). The use of intravenous sedatives was associated with a significant increase in adverse events for topical (1.20%) and injection anesthesia (1.18%), relative to topical anesthesia without intravenous sedation. The use of short-acting hypnotic agents with injection anesthesia was also associated with a significant increase in adverse events when used alone (1.40%) or in combination with opiates (1.75%), sedatives (2.65%), and with the combination of opiates and sedatives (4.04%). These differences remained after adjusting for age, gender, duration of surgery, and American Society of Anesthesiologists risk class. CONCLUSIONS: Adjuvant intravenous anesthetic agents used to decrease pain and alleviate anxiety are associated with increases in medical events. However, cataract surgery is a safe procedure with a low absolute risk of medical complications with either topical or injection anesthesia. Clinicians should weigh the risks and benefits of their use for individual patients.