INTERSTITIAL INTERSTITIAL LUNG DISEASESLUNG DISEASES

Dr.QURA_TUL_AIN

CONTENTS

DEFINITION

CLASSIFICATIN

SYMPTOMS & SIGNS

COMPLICATIONS

INVESTIGATIONS

MANAGEMENT

DEFINITIONThe term interstitial lung disease (ILD) refers to

a broad category of lung diseases rather than a specific disease entity.1,2 It includes a variety of illnesses with diverse causes, treatments, and prognoses. These disorders are grouped together because of similarities in their clinical presentations, plain chest radiographic appearance, and physiologic features.

CLASSIFICATION

SYMPTOMS

Breathlessness (most common): Initially, dyspnea on exertion→ later at rest Nonproductive cough Fatigue Pleuritic chest pain Hemoptysis-- infrequent A family history of ILDs should be sought.

SIGNS

PULMONARY SIGNS

With advanced disease, patients may have

tachypnea and tachycardia, even at rest.

Bilateral, basilar, Velcro-like rales

Signs of pulmonary hypertension

EXTRAPULMONARY SIGNS

Clubbing (e.g. IPF) Skin abnormalities, peripheral lymphadenopathy, hepatosplenomegaly (SARCOIDOSIS) Subcutaneous nodules (RHEUMATOID

ARTHRITIS) Muscle tenderness and proximal weakness

(POLYMYOSITIS)

D/D BASED ON ONSET:

ACUTE ONSET: DAYS TO WEEKS Acute interstitial pneumonia Acute pneumonitis from collagen vascular

disease(especially SLE) Diffuse alveolar hemorrhage Hypersensitivity pneumonitis

CHRONIC: MONTHS TO YEARS Idiopathic pulmonary fibrosis Chronic hypersensitivity pneumonitis Collagen vascular disease–associated ILD

INVESTIGATIONSCHEST RADIOGRAPHY Nodules, linear (reticular) infiltrates, or a

combination of the two (reticulonodular infiltrates)

Diffuse ground glass pattern– EARLY Cystic areas (honeycomb pattern)-Late

HIGH-RESOLUTION CT SCAN

INVESYIGATIONSPULMONARY FUNCTION TESTS

ARTERIAL BLOOD GAS ANALYSIS BRONCHOSCOPIC STUDIES

LUNG BIOPSY

MANEGEMENT

PRINCIPAL AIMS:

(1) to remove exposure to injurious agents,

(2) to suppress inflammation to prevent further

destruction of the pulmonary parenchyma

(3) to palliate the manifestations of these diseases.

MANEGEMENT

General– Oxygen therapy

•For patients with documentedhypoxia

– SpO2< 89%– PaO2< 55 mmHg

•Improves exercise tolerance

CORTICOSTERIODS

Prednisone, 1 mg/kg for 1 month, followed by 40 mg/day given for 2 months

Gradually tapered (5 mg/week) over several months to a maintenance dose of 15 to 20 mg/day

Corticosteroids are continued until pulmonary function is stable for 1 year

Immunizations (pneumococcal, influenza) Pulmonary Rehabitation Treatment of PHT

IMMUNO SUPRISSIVE AGENTS

Cytotoxic agents (Cyclophosphamide)or immunosuppressive agents (Azathioprine) may be used in patients who do not improve on steroid therapy or who cannot tolerate corticosteroids

Pirfenidone (antifibrotic)–Reduces acute exacerbations and reduction in FVC

N-acetyl cystein (antioxydant)N Engl J Med 2005;353:2229-42–NAC 600 mg PO tid added to prednisone and azathioprine, preserves vital capacity and FVC and DLCO