Novel risk factors for poor outcome in frail cardiac surgery patients

Abstract

Population aging and healthcare innovations have increased the number of elderly patients undergoing cardiac surgery, often resulting in a higher risk of chronic disease, frailty, and polypharmacy. This thesis evaluates novel risk factors for postoperative complications and poor functional outcomes in frail elderly patients using continuous monitoring data and pharmacokinetic models. Chapter 2 identifies polypharmacy as a predictor of postoperative functional decline, showing it improves preoperative risk classification. Chapter 3 reveals that chronic pain is common (35%) and linked to poor mobility, medication use, and preoperative quality of life, emphasizing the importance of frailty assessments for identifying high-risk patients. Chapters 4 and 5 focus on continuous monitoring after ICU discharge, showing that abnormal respiratory rates are associated with clinical deterioration and that opioids and benzodiazepines increase the risk of hypoxemia episodes, highlighting the need for careful monitoring of high-risk medications. Chapter 6 explores morphine pharmacokinetics and analgesic responses, revealing significant variability in pain management effectiveness among frail elderly patients, with oversedation common. This thesis underlines the importance of tailored perioperative care and further research into individualized pain management strategies to improve postoperative outcomes in frail elderly cardiac surgery patients. Recommendations for clinical care and future studies are provided.