Clinical Features and Outcomes of Severe Acute Respiratory Syndrome and Predictive Factors for Acute Respiratory Distress Syndrome

BACKGROUND: Severe acute respiratory syndrome (SARS) is an emerging infectious disease, and indeed, the SARS epidemic in Taiwan from March to July 2003 had a great impact. This study depicts the clinical characteristics and short-term outcomes of patients with SARS treated at Taipei Veterans General Hospital; potential predictive factors for acute respiratory distress syndrome (ARDS) are also analyzed. METHODS: This study retrospectively analyzed data for 67 SARS patients, who were grouped according to whether or not ARDS developed during the clinical course of SARS. RESULTS: There were 32 males (mean age, 50.3 years; range, 20–75 years) and 35 females (mean age, 51.1 years; range, 23–86 years). Twenty-five patients (37.3%) were health care workers. At admission, 50 patients (74.6%) had abnormal chest radiographs, and all patients developed pulmonary infiltrates during the following week. During hospitalization, lymphopenia was found in 57 patients (85.1%); and elevated levels of lactate dehydrogenase (LDH; n = 55; 83.3%), C-reactive protein (n = 55; 83.3%), aminotransferases (n = 44; 65.7%), and creatine kinase (n = 14; 20.9%) were also noted. ARDS developed in 33 patients (49.3%), who were generally older than the patients in whom ARDS did not develop, male, non-health care workers, and who generally had dyspnea at the time of diagnosis, and a history of diabetes mellitus, hypertension or cerebrovascular accident. Patients with, versus those without, ARDS also tended to present with more severe lymphopenia and leukocytosis, and with higher levels of LDH and aspartate aminotransferase. The overall mortality rate was 31.3% (21/67), whereas the rate for patients who developed ARDS was 63.6% (21/33). Multivariate analyses showed that age greater than 65 years (odds ratio, OR, 10.6; 95% confidence interval, CI, 2.1–54.1), pre-existing diabetes mellitus (OR, 13.7; 95% CI, 1.3–146.9), and elevated levels of LDH (OR, 8.4; 95% CI, 1.9–36.9) at admission, were independent predictors of ARDS. CONCLUSION: The clinical manifestations of SARS showed high variability, and were related to the underlying health status of individual patients. Importantly, the development of ARDS was associated with significant mortality, despite aggressive therapy.