What are the long-term sequelae of acute respiratory distress syndrome (ARDS)? Have there been any recent advances in improving patient outcomes?
* Recent research has been instrumental to understanding the long-term sequelae of acute lung injury (ALI)/ARDS. The information we present here is based on a recent review of this topic. (1) It is important to note that since patients' baseline status is not usually known, the understanding of long-term outcomes is frequently based on an imperfect comparison with population norms. These norms may not accurately represent the baseline status of patients with ALI, since these patients may be less healthy than the general population.
The major sequelae
The 6 general categories of the common sequelae of ALI are pulmonary, neuromuscular, physical function, neurocognitive, psychiatric, and quality of life (QOL).
* Pulmonary sequelae: Most ALI survivors initially have some impairment in lung function. (1,2) A reduction in carbon monoxide--diffusing capacity is the most common abnormality; it persists for at least 1 to 2 years after the patient is discharged. (1,2) Obstructive and restrictive defects in pulmonary function also are common and are typically mild.
* Neuromuscular sequelae: Neuromuscular weakness and other musculoskeletal problems are important in patients with ALI because they attribute these sequelae to impaired physical function, which is experienced during the first year of recovery. (2) The cause of neuromuscular sequelae is poorly understood, but it is likely multifactorial, with contributions from disuse atrophy, systemic corticosteroid use, and critical illness neuromyopathy. (2-4)
* Physical function: Objective measures of impaired physical function have included patient-reported outcomes, such as delayed return to work and impairment of activities of daily living, and lower-than-predicted performance on the 6-minute walk test. (1,2)
* Neurocognitive sequelae: At hospital discharge, patients with ALI have a variety of neurocognitive impairments, including deficits in attention, short-term memory, and concentration and/or global loss of cognitive function. There is improvement in these deficits at 1 and 2 years' follow-up, but 80% of patients still demonstrate some impairment in at least one measure of cognitive function. (5,6)
* Psychiatric sequelae: Patients with ALI are exposed to significant physical and emotional stress in the ICU. These stressors put them at risk for long-term psychiatric morbidity. Specifically,...