The Comparison of Complications and Mortality after Surgery between General Anesthesia and Regional Anesthesia in the Elderly

Perioperative complications and mortality remains a critical issue of the medical care system, particularly the perioperative health in the elderly. Previous studies have been reported the relationship between type of anesthesia and postoperative complications and mortality. Some studies suggested that patients receiving regional anesthesia had lower complications and mortality compared with those receiving general anesthesia. However, other studies found that there was no significant difference of postoperative complications and mortality between general anesthesia and regional anesthesia. Findings from previous investigations were inconsistent because of several limitations, such as small sample size, lack of adequate comparison group, inappropriate adjustment of confounding factors, focus on single type of surgery, and without comprehensive assessment of postoperative outcomes. Based on the data from the Taiwan National Health insurance Research Database, we will compare the postoperative complications and mortality between the elderly receiving regional anesthesia and general anesthesia in this study. We will use the data from National Health Insurance to establish a surgical cohort underwent general anesthesia and regional anesthesia among the elderly in 2004-2013. In the first year of this study, we will analyze older people aged ≥65 years underwent common surgery which could be conducted both with general anesthesia and general anesthesia. These common surgery (that could be conducted both with general anesthesia and regional anesthesia) included hip fracture repair surgery, appendectomy, knee arthroscopy, total knee replacement, total hip replacement, ureteroscopic lithotripsy, prostatectomy, hernia repair surgery, and surgery for varicose veins. The multivariate logistic regression analysis will be performed to calculate adjusted odds ratios and 95% confidence intervals of postoperative complications (such as postoperative bleeding, stroke, acute myocardial infarction, pulmonary embolism, septicemia, deep wound infection, pneumonia, and acute renal failure) and mortality for the elderly receiving general anesthesia and regional anesthesia. In the second year of this study, we will analyze patients aged ≥65 years receiving all surgeries which conducted with general anesthesia and/or regional anesthesia in 2004-2013. Complications and mortality after surgery with general anesthesia and regional anesthesia will be analyzed for the elderly with preoperative stroke, ischemic heart disease, liver cirrhosis, renal dialysis, and chronic obstructive pulmonary disease compared with surgical patients without preoperative stroke, ischemic heart disease, liver cirrhosis, renal dialysis, and chronic obstructive pulmonary disease, respectively. The multivariate logistic regression analysis will be performed to calculate adjusted odds ratios and 95% confidence intervals of complications and mortality after surgery (separated by general anesthesia and regional anesthesia) associated with the impact of preoperative stroke, ischemic heart disease, liver cirrhosis, renal dialysis, and chronic obstructive pulmonary disease in the elderly. This project will be a large-scale study to investigate the postoperative complication and mortality between surgical patients with general anesthesia and regional anesthesia in the elderly. Findings of this study will provide useful information for medical professional to understand the health and associated factors in the elderly who underwent general anesthesia and regional anesthesia.