Adults who are relatively young and healthy when they develop acute respiratory distress syndrome may never recover completely, according to a report in the April 7 issue of the New England Journal of Medicine.
In a longitudinal study of 109 survivors of ARDS, patients showed persistent limitations on physical activity, a spectrum of physical and neuropsychological impairments, and reduced quality of life 5 years after discharge from an ICU, even though their pulmonary function had returned to near-normal levels, said Dr. Margaret S. Herridge of Sunnybrook Health Sciences Centre, University of Toronto, and her associates.
To date, the highest-quality prospective studies of long-term outcomes in adult ARDS survivors have been limited to only 2 years of follow-up. Dr. Herridge and her colleagues followed a cohort of 109 patients for 1 year, and 83 of these patients for an additional 4 years, to document longer-term outcomes.
The patients had been treated at four academic medical-surgical ICUs in Toronto in 1998-2001. Their median age was 44 years. More than 80% had been working full time and had zero or only one coexisting condition at the time of hospitalization. Most developed ARDS after contracting pneumonia or sepsis.
None of the study subjects had demonstrable weakness at 5 years, and all attained normal or near-normal results on volumetric and spirometric pulmonary testing. Among the 25 who underwent chest CT imaging at some point during follow-up, the most common finding was minor, nondependent pulmonary fibrotic changes consistent with ventilator-induced lung injury. Only the few patients with bronchiectasis, pulmonary fibrosis, or both on CT examination showed clinically important respiratory symptoms such as cough, sputum production, and exertional dyspnea.
Nevertheless, all the patients said they had residual physical weakness of varying degrees, and all said that their capacity for physical activity was reduced after ARDS. These subjective reports were corroborated by an impaired performance on the 6-minute walk test; the median distance achieved was only 76% of that in an age- and sex-matched control population in the literature.
The mean score on the physical component of the SF-36 also remained approximately one standard deviation below that for an age- and sex-matched control population, indicating increased weakness and reduced ability to engage in physical activity.
The study subjects also had a variety of new or persistent impairments related to physical and neuropsychological disorders with an onset related to the ARDS. These included tracheal stenosis requiring surgical resection and dilation (two patients), disability from heterotopic ossification of the knees and elbows (four patients), frozen shoulder (two patients), vocal cord dysfunction and voice changes (one patient), reactive airway disease (four patients), and dental implants after tooth damage acquired in the ICU (one patient).
One patient was disabled from a bilateral forefoot amputation that was required to treat vasopressor-related necrosis, and two others had sensorineural hearing loss and tinnitus attributed to ototoxic ICU medications.
In addition, 10 patients had cosmesis concerns, which caused social isolation or sexual dysfunction, that were related to medical procedures such as laparotomy; tracheostomy; insertion of chest tubes, central lines, or arterial lines; and burns, striae, and facial scars from prolonged mask ventilation.
More than half of the study subjects reported at least one episode of physician-diagnosed depression, anxiety, or both. One patient had an acute psychotic episode due to ICU-related posttraumatic stress disorder, two had severe agitated depression and agoraphobia, and several had other "substantial" mental health challenges.
Moreover, 27% of the subjects reported new-onset mental health problems such as anxiety, depression, or PTSD in their family members. Job loss, disputes over disability and insurance claims, and social isolation also were commonplace. "Patients often required a gradual transition to work, a modified work schedule, or job retraining," Dr. Herridge and her colleagues wrote (N. Engl. J. Med. 2011;364:1293-304).
Overall, the study results suggest that survivors of ARDS "may have an irreversible decrease in function" and that the process of ICU treatment may entail longer-term outcomes than have been appreciated thus far.
Also, "the finding that relatively young, previously working persons with modest coexisting disorders do not return to baseline levels of health care utilization after an episode of critical illness may have important public health ramifications," they noted.
This study was supported by the Canadian Intensive Care Foundation, the Physician’s Services Incorporated Foundation, and the Ontario Thoracic Society. No conflicts of interest were reported.