Patient-Important Outcomes of Cardiac and Non-Cardiac Surgery: Describing the Landscape and Exploring Etiologies and Interventions

Abstract

The patient-important outcomes of cardiac and non-cardiac surgery are well-recognized but poorly understood. The causes of major morbidity and mortality in patients undergoing non-cardiac are not known. This is not the case in cardiac surgery, which is provided to a homogenous patient population that has been well-described through clinical registries. Recent improvements to the care of cardiac surgical patients have led to dramatic decreases in major morbidity and mortality. However, neurocognitive and functional impairments after cardiac surgery remain the most feared by patients and least understood by clinicians. This thesis comprises 6 chapters that inform these knowledge gaps and establish the basis upon which future research will be based. Chapter 1 is an introduction providing the rationale for conducting each of the included studies. Chapter 2 reports the VISION Mortality study, which explores the relationship between major complications and death within 30-days of undergoing inpatient, noncardiac surgery. Chapter 3 reports a study validating the use of the Standardized Assessment of Global activities in the Elderly (SAGE) scale in patients undergoing cardiac surgery. Chapter 4 presents a pilot observational study that establishes the feasibility of conducting a large, prospective cohort study to determine the relationship between decreases in cerebral saturation during cardiac surgery and postoperative functional decline. Chapter 5 presents a pilot study conducted to inform the feasibility of a large, randomized cluster crossover trial examining whether an institutional policy of restricted benzodiazepine administration during cardiac surgery (compared to liberal administration) would reduce delirium after cardiac surgery. Chapter 6 discusses the conclusions, limitations, and implications of the research presented in this PhD thesis.