Frailty as a novel concept: exploring the impact of acute events and malnutrition on vulnerable critically ill patients

This thesis investigated frailty as a multidimensional clinical syndrome marked by diminished physiological and cognitive reserves, increasing vulnerability to adverse outcomes in critically ill and surgical elderly patients. Frailty, closely linked to aging but also influenced by comorbidities and malnutrition, predisposes patients to complications such as functional decline, prolonged hospitalization, and mortality. The first prospective study assessed the effects of major elective surgery on the functional and cognitive status of patients aged 70 and older. Nearly one-third of patients experienced signifìcant functional decline or death within three months post-surgery, with comorbidities and postoperative complications as key predictors. This suggests a higher risk of developing frailty syndrome, even among previously fit elderly individuals. The second retrospective study showed a significantly higher one-year mortality in older adults treated with noninvasive ventilation (NIV) for hypercapnic respiratory failure. In contrast, in elderly patients undergoing continuous positive airway pressure (CPAP) modality was similar compared to younger patients, supporting the notion that frailty is not an inevitable consequence of aging. In the final retrospective study, an inadequate nutritional intake was documented during NIV, regardless of the feeding route and despite early nutritional support. Higher calorie intake was associated with reduced mortality. This fìnding reinforces the importance of targeted nutritional interventions as part of thè management of criticai patients, particularly since undernutrition exacerbates muscle loss and accelerates functional decline. Overall, the thesis emphasizes the importance of early frailty identifìcation and comprehensive assessment beyond chronological age, as well as integrating screening tools into clinical practice to better predict outcomes and tailor interventions both in elderly surgical and critically ill patients.