Chronic ventilator-dependent units

Gracey DR, Viggiano RW, Naessens JM, et aL Outcomes of patients admitted to a chronic ventilator-dependent unit in an acute-care hospital. Mayo Clin Proc 1992 67(2) 131—136. 

Gracey DR, Hardy DC, Koenig GE. The chronic ventilator-dependent unit a lower-cost alternative to intensive care. Mayo Clin Proc 2000 75(5) 445-449. 

Lindsay ME, Bijwadia JS, Schauer WW, et al. Shifting care of chronic ventilator-dependent patients from the intensive care unit to the nursing home. Jt Comm J Qual Saf 2004 30 257-265. 

A three-month prospective cohort study of 26 Italian RICUs reported on 756 patients (14). Of all patients receiving invasive mechanical ventilation, 61% were tracheotomized and therefore considered ventilator dependent. According to the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, the predicted mortality was 22%, while the actual mortality rate was 16%. The results indicate that units with a level of care below ICU can successfiilly manage patients with acute-on-chronic respiratory failure. 

Other challenges may override the medical issues. Financial resources are limited, and in the United States, reimbursement has driven the current care process. These issues will continue to be the major force shaping the nature of care for LTMV patients. The availability of institutions for placement of chronically ventilated patients as well as the infrastructure to manage LTMV patients in the home all depend on funding. Ethical issues also influence the management of chronically ill patients. These issues are considered below. 

The prevalence of PMV depends upon the definition used. Most patients (65-85%) are easily weaned from ventilatory support after less than one week. In a multicenter observational study of >5000 medical and surgical ICU patients, 25% required greater than seven days of MV (23). In the acute physiology and chronic health evaluation III (APACHE III) database of medical and surgical ICUs, one in five patients remained ventilated for at least seven days (24). When the definition of PMV is extended to >21 days, the incidence predictably falls. In a cohort of nearly 600 medical patients admitted to a tertiary care medical intensive care unit, approximately 10% remained invasively ventilated at day 21... 

Each year, over 400,000 patients in the United States receive mechanical ventilation as a result of acute or acute-on-chronic respiratory failure (1,2). About a quarter of acutely ventilated patients repeatedly fail attempts at weaning and may require prolonged mechanical ventilation (PMV) (Fig. 1) (3,4). The proportion of patients experiencing PMV ranges between 0% and 20% (5-13). Out of patients who survive PMV, 9-66% become dependent on long-term mechanical ventilation (LTMV) (4,9,14-21). Two factors account for these wide variations in the outcome. The first factor is differences in patient population. The second one is the nosology of what constitutes PMV and what constitutes LTMV is unsatisfactory. 

Recent advances in intensive care have resulted in an increased salvage of critically ill patients a number of patients have become dependent upon mechanical ventilation as a chronic form of life support (1). The increased use of prolonged mechanical ventilation (PMV) has led to greater intensive care unit (ICU) bed use, resource consumption, and costs (2,3). It is important to characterize such patients to define treatment goals and expectations, to establish ventilatory care units for their specialized care, and to provide prognostic information for overall survival, morbidities, and health-related quality of life. The goals of this chapter are to provide definitions of PMV, to characterize the patient population requiring this modality of treatment, and to briefly describe a multidiscipUnaiy approach to treatment. 

Chronic health care in Europe, like the rest of the developed world, is characterized by an increasingly aging population often with complex medical problems, an increase in societal expectations, and an increase in the dependence on expensive technology. Chronic respiratory failure is no different and is expected to rise in prevalence because of the aging population and possibly because of increased tobacco use. The expansion in Europe (1-3) and the United States (4) over the last three decades in the use of home mechanical ventilation (HMV) mirrors this trend. HMV is used to treat chronic hypercapnic respiratory failure in both adults and children and is usually delivered non-invasively (NIV) with the majority of patients using only nocturnal or nocturnal plus part daytime NIV. NIV has been shown to reduce mortality and morbidity (5,6) and to improve quality of life (7). 

Meanwhile, years of productive research have demonstrated that patients with chronic respiratory insufficiency can also benefit from mechanical ventilation. As the Preface of this volume mentions their survival as well as their health status may be dependent on long-term ventilatory support. The ever increasing incidence and prevalence of chronic respiratory disease suggests that the use of ventilatory support will markedly increase. However, the techniques and strategies to use it, and when and where (non-intensive care unit, or home), are very different from treating the respiratory failure resulting from acute conditions and in patients with structurally near normal lungs. 

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