The clinico-radiological profile of obliterative bronchiolitis in a tertiary care center

Background: Obliterative bronchiolitis (OB) forms a major proportion of chronic airway diseases (CADs). OB is often misdiagnosed and included under the umbrella term 'chronic obstructive pulmonary disease'. We set out to identify the proportion of OB cases among the CADs and study the clinical profile of OB. Materials and Methods: This prospective, observational study noted all patients with Chronic airway obstruction (CAO), of which patients with OB were included and the clinical profile was studied. Data were subjected to statistical analysis. Results: Five hundred patients with CAO were noted in the study period, of which 115 patients were found to be OB amounting to a prevalence of 23%. The mean age of presentation was 51.8 years (standard deviation 12.1) with a male-female ratio of 1:1. The most common etiology for OB was as sequelae to past treated pulmonary tuberculosis (PTB) seen in 82 patients (71%) of cases. Dyspnea in 114 patients (99%) and productive cough in 110 patients (95%) were the predominant symptoms. Postexercise desaturation was seen in all 115 patients (100%). Forty-six patients (43%) presented with either Type 1 or Type 2 respiratory failure. Spirometry showed obstructive pattern in 68 patients (59%) with forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio of <70% and FEV1 <70% postbronchodilator and mixed pattern in 47 patients (41%) with a reduction in both FEV1 and FVC and normal FEV1/FVC ratio. There was the presence of mosaic attenuation on high-resolution computerized tomography (HRCT) of the chest with expiratory scans in all 115 patients (100%). Pulmonary hypertension was documented in 109 patients (95%). Conclusion: OB is one of the major causes of CAO. HRCT of the chest with expiratory scans plays a important role in the diagnosis. Early diagnosis can prevent irrevocable complications.