Long-Term Outcomes After ARDS

Abstract

Early reports of late outcomes among survivors of ARDS indicated that most patients improved dramatically after their intensive care unit stay, and few lived with residua of their once-severe pulmonary injury. Over the last decade, a collection of new studies with improved methodology and novel questions has improved our understanding of life after ARDS. After reviewing these newer investigations in the context of previously published literature, we have drawn several preliminary conclusions: (1) Long-term survival after hospital discharge is unaffected by ARDS, but is strongly affected by ARDS risk factor and comorbidities. (2) Respiratory symptoms after ARDS are more prevalent than previously indicated, but improve over the first 12 months of recovery. (3) Pulmonary function testing reveals marked impairment soon after ARDS. There is improvement over the first 6 months, with lingering mild decreases in lung volume and diffusing capacity in most patients. A small group of patients have severe impairment without improvement. (4) Quality of life, functional independence, and cognitive function are severely affected by ARDS, with dramatic improvement over the first year. Quality of life is lower than in matched critically ill controls. (5) Significant numbers of ARDS survivors suffer from posttraumatic stress syndrome. This is an exciting time for research in long-term outcomes of ARDS, with potential for future studies that validate these single-center hypotheses, explore their ramifications, and investigate the impacts of changing practices in the intensive care unit in the acute phase of ARDS.

1-Year Pulmonary Function and Health Status in Survivors of Severe Acute Respiratory Syndrome

“…In studies among survivors of ARDS, it is known that nearly all of the patients are symptomatic at hospital discharge, but there is significant improvement over the first year after ARDS in most patients. 11 In addition, survivors of ARDS are also much less symptomatic than other patients with chronic lung disease. 11 Nonetheless, the mean activity score of our patients measuring disturbances to their daily physical activity and their mean impacts score covering a wide range of disturbances of psychosocial function remain significantly worse compared with those in healthy subjects.…”

“…Several studies [3][4][5][6][7][8][9] have reported persistent symptoms, as well as radiologic and functional abnormalities during follow-up several weeks or months after hospital discharge, but the prevalence and severity of the longterm sequelae of SARS remain largely unknown. Because lung function is known to improve for up to 1 year after discharge from the hospital in survivors of other causes of acute lung injury, 10,11 it is imperative that long-term studies of SARS survivors be conducted in order to determine the persistence of abnormalities in pulmonary function, and whether these abnormalities contribute to permanent impairment and disability. As the majority of patients with SARS survive the illness 2 and medical personnel, physicians, nurses, and hospital workers are among those commonly infected in most countries, 2 an additional requisite for the identification and quantification of morbidity among survivors may be for the consideration of awarding compensation.…”

Impact of Serum Biomarkers and Clinical Factors on Intensive Care Unit Mortality and 6-Month Outcome in Relatively Healthy Patients with Severe Pneumonia and Acute Respiratory Distress Syndrome

“…In turn, these impairments affect the survivors' overall quality of life (QOL) [8, 9]. Previous studies also suggested that long-term survival is unaffected by ARDS status; however, ARDS severely affects QOL, functional independence, and cognitive function [10–12]. In relatively healthy patients bearing few underlying diseases, severe pneumonia with ARDS status rarely occurs; however, patients that are relatively young and healthy when they develop ARDS may never recover completely and may experience ongoing functional limitations after an episode of critical illness [13].…”

Long-term Outcomes of Mechanical Ventilation

“…In addition to ARDS, studies have demonstrated reductions in health status for patients with other critical illnesses requiring prolonged mechanical ventilation, [23] with permission including sepsis [28], multiple organ dysfunction [29], and general ICU patients [17,30,31]. Although results vary, these studies also suggest decrements in a wide range of the domains of health status.…”

“…These reports are limited to case series and prospective studies of patients recovering from ARDS. A review of 85 cases found that 19% of patients had persistent radiographic abnormalities at 3 or more months after extubation; the most common findings were bibasilar interstitial infiltrates and reticular changes [23]. In Herridge's et al follow-up study of over 100 ARDS survivors, 20% of patients had radiographic abnormalities at 1 year, with findings of linear fibrosis, small bullous cysts, and isolated areas of pleural thickening [19].…”