Predicting and preventing postoperative decline in older cardiac surgery patients

Introduction: Delirium, depression, pressure ulcers and infection are frequently occurring postoperative complications in older cardiac surgery patients. Prevention of postoperative complications in cardiac surgery is mainly focused on the period of the hospital admission itself. There is however a window of opportunity for preventive action before the hospital admission, as over 95% of the older cardiac surgery patients is scheduled for elective surgery. Improving patients’ health condition in the preadmission period, aiming at decreasing the risk of postoperative complications, is one of the fundamentals of nursing care. Aim: 1. To identify in the preadmission period older cardiac surgery patients at risk for postoperative delirium, depression, pressure ulcers or infection. 2. To provide nurses with an intervention for preparing these older patients before their hospital admission to prevent postoperative delirium, depression, pressure ulcers or infection. Methods: The first part of the thesis addresses the question how to identify patients at increased risk of the four postoperative complications. The second part of the thesis focuses on development of an intervention program for older patients undergoing cardiac surgery to increase their physical and psychosocial condition before surgery, in order to reduce their risk of postoperative complications Main findings: Among twelve other models, two widely implemented models (Parsonnet, EuroSCORE) are superior in identifying patients with prolonged ICU length of stay in a patient population of all ages. (Chapter 1). However, the Parsonnet and the EuroSCORE models have relatively low discrimination and calibration in older patients. Consequently, both models should be applied with great care in the older cardiac surgery population, (Chapter 2). Patients appear to be predominantly at risk for only one specific postoperative complication. We identified sixteen preadmission patient characteristics with a predictive value for either postoperative delirium or depression or pressure ulcers or infection (Chapter 3). In systematically reviewing the literature we found that in preadmission prevention of postoperative complications, multi-component approaches are most effective in the prevention of postoperative depression and infection. High quality studies are urgently needed to evaluate preadmission preventive strategies to reduce postoperative delirium or pressure ulcers in older elective cardiac surgery patients (Chapter 4). Following the MRC guidelines, we developed the multi component ‘PREDOCS’ programme, which is to be applied two to four weeks before admission to the hospital. In this programme the nurse assesses the risk of postoperative complications in older cardiac surgical patients and provides tailor made interventions (Chapter 5). The PREDOCS programme was tested in clinical practice and appears to be feasible. However, it should be well integrated into the cardiac surgery clinical pathway. Alternatively, one might consider applying the programme in a home care setting (Chapter 6). Discussion: Frailty is related to many common and comorbid health problems and is multifactorial in etiology. Therefore, in research with the aim to develop an effective prediction model for older patients, this multifactorial origin should be properly addressed, preferably by developing specific models for predicting specific adverse outcomes, specifically in the older population.