Radiological resolution of community-acquired pneumonia in hospitalised patients in North India

Background:Community-acquired pneumonia (CAP) is the most common infectious cause of death, and radiology is a corner stone of its management. No data are available from India regarding the radiological resolution of CAP in the current antibiotic era. We set out to study determine the radiological resolution of CAP. Methods:The study was conducted in a 1250-bedded North Indian hospital. Consecutive consenting adults admitted with CAP over a period of 2 years from July 2019 were enrolled for the study. The patients were subjected to routine investigations and radiological imaging and treated with standard antibiotic/antiviral therapy as per standard protocols and followed daily till clinical resolution and discharge from the hospital. Serial chest radiographs were taken at 2, 4, 8, and 12 weeks after admission, and the follow-up terminated at either complete clinical or radiological resolution. Results:176 patients (age 20 to 90 years, median 60 years; 109 (61.9%) male) participated. Eighty-nine (50.6%) patients were current smokers. Chest radiographs revealed lobar consolidation as the most common finding (n = 97, 55.1%), followed by pulmonary infiltrates (n = 73, 41.5%) and pleural effusion (n = 6, 3.1%); 44 (25%) patients had multi-lobar consolidation The rates of radiological resolution at 2, 4, 8, and 12 weeks follow-up were 30%, 38.5% (cumulative 68.5%), 25.7% (cumulative 94.2%), and 5.9% (cumulative 100%) of patients, respectively. The average time taken for radiological resolution was 31.49 (+/- 20.2) days in 70 cases, where documented. On multi-variate analysis, smoking was an independent factor for delayed radiological resolution (P = 0.007). Conclusion:Radiological resolution of CAP occurs in the majority (68.5%) of the patients at 4 weeks from the time of clinical presentation, with smoking as an independent risk factor for delayed (>4 week) radiological resolution. Clinicians can wait for 4 weeks to document radiological recovery unless clinical features suggest otherwise.