Late-stage adult respiratory distress syndrome caused by severe acute respiratory syndrome: abnormal findings at thin-section CT

PURPOSE: To evaluate thin-section computed tomographic (CT) abnormalities in patients in the intensive care unit during the late stage of adult respiratory distress syndrome (ARDS) caused by severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: Eight patients in the late stage of ARDS (ie, more than 2 weeks after onset) were imaged with thin-section CT. Images were evaluated for ground-glass opacification, consolidation, interstitial thickening, evidence of fibrosis, and any other abnormalities. Patient records were reviewed, and relevant respiratory and ventilatory parameters, total steroid dose, and outcome were recorded. RESULTS: All patients received high-dose pulse methylprednisolone (minimum, 2.5 g total), and all patients who received ventilation received low-pressure, low-volume ventilation. Five patients received prolonged mechanical ventilation (for more than 14 days), one received ventilation for 72 hours, and two patients did not receive ventilation. Three patients died, four were discharged from the hospital, and one continued to require ventilation. Ground-glass opacification and interstitial thickening were present at CT in all eight patients. Consolidation was present in six patients. Three patients had evidence of fibrosis. Patients who received long-term ventilation, those who received short-term ventilation, and those who did not receive ventilation had similar pulmonary changes at CT. Pulmonary cysts, most of which were small (<1 cm), were present in five patients. Cysts were present in one patient who received only short-term low-pressure and low-volume ventilation and in one patient who received no mechanical ventilation. CONCLUSION: The CT features of late-stage ARDS caused by SARS are similar to those seen in late-stage ARDS of other causes, with no apparent differences between patients who do and patients who do not receive prolonged mechanical ventilation. The presence of cysts in one patient who received short-term and one patient who received no mechanical ventilation suggests that severe SARS-induced ARDS may independently result in cyst formation.