Role of Pulmonary Function Tests in the Assessment of Lung Impairment in Patients with Diffuse Parenchymal Lung Diseases: Association with Clinicoradiological-Histopathological Profile OC06-OC11
Dr. Ajai Kumar Tentu,
Medical Division, Department of Pulmonary Medicine, Military Hospital, Namkum, Ranchi-834010, Jharkhand, India.
Introduction: Diffuse Parenchymal Lung Disease (DPLD) is known to be a common sequela of various lung insults. DPLD is diagnosed by various modalities such as clinical, radiological, lung function and histopathological techniques. There is a limited understanding on the potential clinical application of the non-invasive lung function tests in the evaluation of DPLD.
Aim: To study the role of Pulmonary Function Tests (PFTs) in the assessment of lung impairment in DPLD patients and its association with clinicoradiological and histopathological profiles.
Materials and Methods: A prospective observational study was conducted with 50 DPLD patients who were selected as per the study criteria over a period of 30 months at our tertiary care respiratory centre. Clinicoradiological evaluation and PFTs were carried out for all of the patients. Histopathological examination was done for patients with inconclusive diagnosis. Lung impairment was assessed and its association with clinicoradiologic and histopathologic profile was analysed.
Results: Of the 50 selected patients, diagnosis of a specific subset of DPLD was possible in 33 through the clinicoradiological findings while in 17 through histopathological findings. Overall, idiopathic interstitial pneumonia was found to be common in 31 (62%) followed by sarcoidosis in 14 (28%). Patients showed restrictive and mixed spirometry pattern in 35 (70%), decreased lung volumes in 30 (60%) and some form of diffusion impairment in 42 (84%) while 17 (34%) patients had showed reduced 6-minute walk distance (6MWD). Significant association was noted between: (i) severe diffusion impairment and crackles (p=0.011); (ii) severe diffusion impairment and honeycombing pattern (p<0.001); (iii) decreased lung volumes and crackles (p=0.0009); and (iv) reduced 6MWD and honeycombing pattern (p<0.001).
Conclusion: This study confirms the role of the PFTs in the comprehensive assessment of lung impairment in DPLD patients.