- Survivors of critical illness experience decreased health-related quality of life due to physical limitations, depression and anxiety, and cognitive impairments.
- There may be irreversible long-term neuromuscular dysfunction (e.g., muscle weakness, critical illness polyneuropathy, and myopathy).
- Other organ dysfunction (e.g., pulmonary) is present following critical illness but does not appear to have the same impact on patients' self-reported quality-of-life outcomes as other morbidities.
- Hypoxia and delirium are risk factors for poor long-term outcome resulting from cognitive impairments.
- Approximately one-third to one-half of survivors of critical illness will develop long-term cognitive impairments.
- Recent reports suggest that exercise capacity and cognitive function plateau at a lower than normal level at 1 year with limited improvement 2 years following ICU discharge.
- Long-term physical and neuropsychological dysfunction may be remediable through the implementation of a multidisciplinary and family-centered rehabilitation program. This is currently being evaluated.
In the United States, 55,000 patients are hospitalized in the ICU on any given day,1 and approximately one-half million Americans undergo protracted (>96 hours) mechanical ventilation in an ICU each year. Historically, outcome studies in adult critically ill patients have focused on mortality. Recently, survival in some of our highest-acuity patients (e.g., acute respiratory distress syndrome, sepsis) has improved significantly2 through novel ventilation strategies,3 early interventions for sepsis,4,5 daily administration of renal replacement therapy,6 tight glycemic control,7 and other emerging therapeutic modalities. These dramatic improvements in ICU survival have reinvigorated interest in understanding the nature, determinants, and modifiers of long-term morbidity in ICU survivors.
Patients who survive critical illness are at risk for permanent physical, functional, emotional, and neurocognitive deficits, of which some or all may contribute to decreased health-related quality of life (HRQL). The reasons for this late morbidity after ICU care are multifactorial and include but are not limited to the following: (1) nature of and treatment for the inciting critical illness; (2) multiple-organ-dysfunction syndrome and hypoxemia; (3) physiologic and emotional stress in the ICU related to the illness itself, sleep fragmentation, psychoactive medications, and impaired drug metabolism owing to simultaneous administration of multiple medications; and (4) prolonged immobility and long ICU stay.
Patients with the acute respiratory distress syndrome (ARDS) represent some of the most complex, highest-acuity, and long-stay ICU patients (see Chap. 38). ARDS affects an estimated 150,000 people per year in the United States and is manifested by acute lung injury and severe hypoxemic respiratory failure.8 ARDS is associated with a variety of insults, including, pneumonia, sepsis, trauma, massive transfusion, and other medical/surgical conditions.9 It is a systemic illness involving inflammatory and coagulopathic disturbances that may induce dysfunction of multiple organ systems, including skeletal muscle and the peripheral and central nervous systems.10,11 Because of the significant potential for morbidity, ARDS patients have been the focus in long-term outcome studies in survivors of critical illness. We are in the early stages of understanding the long-term impact of ARDS on physical, ...