Perioperative myocardial ischemia in cataract surgery patients: General versus local anesthesia

Patients having cataract surgery are usually elderly and have risk factors for ischemic heart disease. We sought to determine the incidence of perioperative myocardial ischemia in patients having cataract surgery and compare the influence of local anesthesia (LA) and general anesthesia (GA). Eighty-one patients undergoing cataract surgery with at least two risk factors for ischemic heart disease were monitored continuously for 24 h by using electrocardiogram leads II and V5 and a Holter recorder (Medilog 4500, Oxford Ltd, UK). Patients were randomly allocated to two groups, either LA (n = 39) or GA (n = 42). Tn the LA group, a peribulbar block was performed, whereas a similar block was performed in the GA group after tracheal intubation. The study demonstrated that cataract patients suffered from a frequent incidence of perioperative myocardial ischemia (31%). There was no difference in the incidence rate between the groups: 12 of 39 in the LA group and 13 of 42 in the GA group (P = NS). However, the number of ischemic episodes was significantly increased in the GA group (18 vs 13 in the LA group) (P < 0.05), and there were significantly more intraoperatively in the GA group (8 vs 1) (P < 0.01). All intraoperative ischemic events were associated with tachycardia (greater than or equal to 20% of baseline), whereas postoperative ischemic changes were mostly independent of heart rate. Only one of the ischemic patients tin the GA group) was admitted as a result of intractable chest pain. There were significantly less intraoperative episodes in the LA group, suggesting that LA may be safer than GA in patients during this type of surgery.