Severe acute respiratory syndrome: correlation between clinical outcome and radiologic features

To evaluate whether there is a correlation between the clinical outcomes and radiologic features of severe acute respiratory syndrome (SARS).

The clinical, laboratory, and radiologic features of 138 patients with SARS were analyzed. Three radiologists in consensus retrospectively assessed the frontal chest radiographs obtained at presentation and during treatment (n = 2045) for the distribution (each lung was divided into upper, middle, and lower zones) and extent of lung parenchymal abnormality. Clinical end points included intensive care unit (ICU) admission and death.

Thirty-six (26.1%) patients required ICU care, and eight (5.8%) died. The patients who required ICU care and/or died had more extensive consolidation on chest radiographs obtained initially (median percentage of consolidation, 3.30%, with interquartile range [IR] of 1.70%-8.78% vs 1.70% [IR, 0%-3.30%]; P < .001) and on day 7 after fever onset (median percentage of consolidation, 15.00% [IR, 6.48%-28.73%] vs 5.00% [IR, 2.50%-7.50%]; P < .001) than did surviving patients who did not require ICU care. Patients with involvement of more than one lung zone on initial and day 7 chest radiographs were more likely to require ICU care and/or die than were those with involvement of one or fewer zones (P < .001). Patients with bilateral pneumonic changes at presentation were more likely to have an adverse outcome than were those with unilateral pneumonia (P < .001). Involvement of more than one lung zone at baseline chest radiography was an independent predictor of ICU admission and/or death (odds ratio, 3.16; 95% confidence interval: 1.07, 9.32; P = .037) after adjustments for other significant factors (ie, patient age, and baseline neutrophil count and lactate dehydrogenase level).

More extensive airspace disease at presentation is an independent predictor of adverse outcome in patients with SARS.