Ild Assessment

Diagnosis: The clinical assessment of a patient with ILD requires a combination of history and physical examination, laboratory investigation, lung function testing, chest imaging, bronchoalveolar lavage, and histologic examination. Symptoms and Signs: Progressive dyspnea, cough and fatigue may be the prominent complaints. Dyspnea occurs initially with exercise and then at rest,and is by far the most common complaint. About 10% of patients with ILD may have symptoms, with a normal chest radiograph. Alternately, patients with ILD may be asymptomatic and have an abnormal chest radiograph. Substernal or pleuritic chest pain is also reported by some patients.

Physical examination may give evidence for systemic sclerosis. Laboratory Investigation

Laboratory evaluation can help to suggest the possibility of a diagnosis in the ILDs.

Physiologic Testing Ventilatory function and gas exchange assessment is essential in the evaluation of patients with ILD. The “classic” physiologic response in patients with ILD is a restrictive pattern and/or impaired gas exchange.Initially, an anatomic barrier to oxygen caused by a thickened alveolar interstitium (“alveolar–capillary block”) was suspected.(37) Later, ventilation–perfusion mismatching was found to be the major factor (38) and that a diffusion barrier to oxygen was only important during exercise(39). These physiologic measurements aid not only in diagnosis, and to assess disease severity, but also to evaluate the response to therapy, and to follow the course of the

Failure of DLCO to increase normally during exercise in ILD may be due to inadequate recruitment of pulmonary capillaries and relatively reduced capillary blood volume,(43) Several studies have demonstrated superiority of exercise testing over resting pulmonary function tests in determining the nature and extent of physiologic derangements in ILD.(44),(45) . Arterial hypoxia which was corrected on breathing 100 per cent oxygen at rest, but if the correction was not carried during performance of the exercise indicates that the hypoxia is partly due to perfusion of hypoventilated alveoli acting as a physiologic veno-arterial shunt.(46) 6-minute walk test (6MWT) is a practical and simple alternative to CPET to determine exercise capacity. The 6MWT is a simple, safe, noninvasive, reproducible test of exercise capacity(47)(48) which reflects a submaximal level of exertion that is more consistent with daily physical activities. 6MWT does not provide information on the physiologic mechanism of exercise limitation(48). Parameters that should be recorded include the