Follow-up of surviving acute respiratory distress syndrome patients using quantitative computed tomography

The accumulation of exudates in the air spaces characterizes acute respiratory distress syndrome (ARDS) and accounts for its dramatic clinicoradiographic presentation. Lung aeration assessed by quantitative computed tomography-based (qCT) can help to assess and monitor ARDS survivors. We aimed to evaluate qCT on follow-up of patients with ARDS and the relationship with concomitant pulmonary function test. METODS: Patients with moderate and severe ARDS were followed-up and evaluated one and two months after ARDS diagnoses with pulmonary function tests (lung volume assessed by body plethysmography) and high-resolution computed tomography (HRCT). RESULTS: A total of 22 patients with ARDS survived after 2 months. Global lung density one month after ARDS was 280.2 mg/cm3 and decrease to 174.7 mg/cm3 two months after ARDS (p < 0.01). Total lung mass has not changed (p = 0.13). One month after ARDS the lung density adjusted for the volume was significantly correlated with forced vital capacity (FVC) (r = -0.68, p < 0,01), carbon monoxide diffusion capacity (DLCO) (r = -0.54, p = 0.02), and total lung capacity (TLC) (r = -0.76, p < 0.01). After two months of ARDS, the lung density adjusted for the volume was significantly correlated with FVC (r = -0.87, p < 0,01), DLCO (r = -0.84, p < 0.01), and TLC (r = -0.83, p < 0.01). The total lung mass was only correlated with TLC one month of ARDS. CONCLUSION: The lung density decreased and is correlated with pulmonary function test results two months after ARDS. In surviving ARDS patients, qCT may be used to evaluate pulmonary dysfunction particularly early in the monitoring when some patients may not be able to perform pulmonary lung tests.