Pulmonary function in cured pulmonary tuberculosis cases

In clinical practice it has been observed that several patients of cured pulmonary tuberculosis (PTB) suffer with lung dysfunction and these problems are less documented routinely. Prevalence of these abnormalities remains unknown. Aim of this study is to estimate the lung function abnormality and exercise capacity including diffusion capacity of lung for carbon monoxide (DLCO) in cured PTB cases.

A hospital based observational descriptive study was carried out among 100 patients with PTB, who had been declared cured. These patients were evaluated by spirometry and DLCO to assess their lung function and were classified as normal or abnormal. Modified medical research council (mMRC) dyspnea scale for symptom assessment and 6-minute walk test (6MWT) to determine the exercise capacity was also done. Borg's scale was used for dyspnea assessment in 6MWT.

83 (83%) patients having abnormal spirometry, 17 (17%) had obstructive pattern, 32 (32%) had restrictive pattern and 34 (34%) had mixed pattern. 22 (22%) patients had mild decrease in DLCO, 43 (43%) patients had moderate decrease in DLCO, while only 4 (4%) had severe decrease in DLCO. More than half of the patients having normal spirometry had reduced in DLCO.

The prevalence of abnormal lung functions is high even after complete anti-tubercular treatment. DLCO could be a better tool for evaluation of lung function in these patients. There is need to strengthen the National Programme to detect and treat TB patient earlier, also there is need to formulate guidelines for pulmonary rehabilitation of cured PTB patient.