Effects of local and general anaesthesia on myocardial ischemia and postoperative complications during cataract surgery

Abstract

Aim: The purpose of this study was to interpret the effects of both local and general anaesthesia on the incidence of preoperative and postoperative myocardial ischemia and postoperative complications. Materials and Methods: Fifty-seven patients undergoing cataract surgery (>65 years, ASA I-III) were randomly divided into 2 groups. Thirty of them underwent cataract surgery under general anaesthesia (Group GA), and 27 under local anesthesia (Group LA). All patients were Holter-monitorized during 12 hours preoperatively and 24 hours post-operatively. An episode of ischemia was defined as ST depression more than 1mm or ST elevation more than 2mm, lasting more than 1min. Postoperative complications and onset of the pain and Visual Analogous Scale (VAS) scores at that moment were recorded. Results: The incidence of preoperative ischemia in the GA and LA groups were 42.1% and 57.9%, respectively and the incidences of intra/postoperative ischemia were 57.1% and 42.9%, respectively (p>0.05). The presence of preoperative ischemia increased the likelihood of the intra/postoperative ischemia by 8 fold in the GA group and by 12.5 fold in the LA group (p<0.05). The incidences of nausea, vomiting and throat-ache were 50%, 13.3% and 60%, respectively in the GA group. VAS scores of ocular pain were higher in Group GA than Group LA (p<0.05). More patients in Group GA required postoperative analgesia (p<0.05). Conclusion: The incidence of ischemia in patients older than 65 years old undergoing cataract surgery is 47.3 %. General anesthesia causes an increase in the incidence of nausea, vomiting and analgesic requirement.