Patterns of diffuse parenchymal lung disease manifestations in collagen vascular disease and in relation to DLCO

Sangamithra, G (2009) Patterns of diffuse parenchymal lung disease manifestations in collagen vascular disease and in relation to DLCO. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION : Diffuse parenchymal lung diseases (DPLD) are a diverse group of pulmonary disorders that are classified together because of similar clinical, roentgenographic, physiologic, or pathologic manifestations1. They are also referred to as interstitial lung diseases (ILD).DPLD alter mechanical and gas exchange properties of the lungs. In general, the hall marks of DPLD are restrictive changes in pulmonary physiology i.e decreased total lung capacity, reduced residual volume, diminished static compliance and reduced vital capacity often with an increased FEV1/FVC ratio and a reduced diffusing capacity with carbon monoxide. Hence pulmonary function testing (PFT) aids in the evaluation and management of patients with DPLD by provide an estimate of histologic severity, baseline estimation of prognosis and be used to monitor disease progression or response to therapy. The forced vital capacity and diffusion capacity are the most valuable serial measurements for diagnosing DPLD. The collagen vascular diseases are a heterogeneous group of immunologically mediated inflammatory diseases. It is not surprising that, by virtue of their abundant connective tissue and blood supply, the lungs are frequently involved in these disorders. Consequently, collagen vascular diseases affect all areas of the lung (i.e. airways, alveoli, vascular system, and pleura), and do so in various degrees and combinations2. Diffuse parenchymal lung diseases in CVD patients are characterised by deteriorating parenchymal fibrosis and gas exchange. It remains innocuous in the early stage, as most of the rheumatic patients have restricted mobility manifesting with subtle or nil pulmonary symptoms. Hence, the respiratory physician should be prudent in diagnosing the cases as early as possible. Because the pulmonary specialist often involved in care of these patients, a comprehensive understanding of collagen vascular disease and usual course of Diffuse parenchymal lung diseases are important. AIM OF THE STUDY : To evaluate the Diffusing capacity for carbon monoxide among patients with Diffuse parenchymal lung disease in proven Rheumatologic illness showing various pattern of abnormalities in the High Resolution Computerised Tomography and correlate the same with spirometry. DESIGN OF THE STUDY : Prospective study. Approval from Medical Ethical Committee has been obtained. MATERIALS AND METHODS This prospective study was organized in the Institute of Thoracic medicine and department of Thoracic medicine, Government General Hospital in association with department of Rheumatology, Government General Hospital. Subjects were recruited from the Pulmonary and Rheumatology outpatient clinic of our hospital. This study was approved by the ethical committee of this institution. The design of the work is a prospective study. The study extended from the period of January 2008 to November 2008 and it was performed at the Institute of Thoracic medicine with the same population referred from the department of Rheumatology, Government General Hospital, Chennai. INCLUSION CRITERIA : 1. Clinically and radiologically confirmed cases of DPLD. 2. Age > 12 years. 3. Sex- Both genders. 4. Patients who are able to perform spirometry and diffusion capacity with a breath holding period of at least 10 seconds. 5. Serologically positive collagen vascular disease patients. EXCLUSION CRITERIA : 1. Patient associated with history suggestive of Infection, Allergy and immunosuppression. 2. Patient associated with any other respiratory disease, cardiovascular disease, and malignancy. 3 Smokers are virtually eliminated from the study as a confounding factor (For example respiratory bronchiolitis of smoking can be falsely attributed to collagen vascular disease). 4. DPLD due to other causes or of unknown aetiology. 5. Breath-holding time <9 or >11 seconds, or with an inspiratory capacity less than 85% of the largest previously measured vital capacity. RESULTS : In our study 55 patients were screened for Diffuse Parenchymal Lung Diseases with collagen vascular diseases. Out of which 36 patients were taken up for the study after satisfying eligible criteria. All were nonsmokers. Remaining patients were excluded from the study group based on exclusion criteria. CONCLUSION : Altered DLCO may be the first and only abnormality found in early stage of Diffuse parenchymal lung diseases. The earlier discussed studies show the correlation between individual collagen vascular disease and pulmonary function testing. But this study focuses on evaluation of Diffusing capacity for carbon monoxide among patients with Diffuse parenchymal lung diseases in all classified Collagen vascular diseases showing various HRCT pattern abnormalities and correlate the same with spirometry. Among the various combinations of HRCT patterns in Collagen vascular diseases presence of Honeycombing is associated with significant severe reduction in DLCO and DLCOHb with varying grades of severity in Forced vital capacity.When individual HRCT patterns analysed Honey combing and Traction bronchiectasis patterns have significant severe reduction in DLCO and DLCOHb with varying grades of spirometry severity . When DLCO and DLCOHb are within normal limits the reduction in Forced vital capacity has to be correlated with age factor. In summary DLCO and DLCOHb are in significant association with spirometry. The percent predicted DLCO and DLCOHb best reflect the extent of Honeycombing which is considered as fibrotic index in Diffuse parenchymal lung diseases with Collagen vascular diseases, and therefore should be measured in routine evaluations. So we conclude DLCO and DLCOHb in collagen vascular disease will be of use in initial evaluation of severity of collagen vascular disease as well as to assess the response to treatment in these disorders.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Patterns ; diffuse parenchymal lung disease manifestations ; collagen vascular disease ; DLCO.
Subjects: MEDICAL > Tuberculosis and Respiratory Medicine
Depositing User: Subramani R
Date Deposited: 28 Feb 2018 16:37
Last Modified: 28 Feb 2018 16:37

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