Page 1259 - TNFlipTest

Toronto Notes 2019 Interstitial Lung Disease
Investigations
• Genetictesting
■ autosomal recessive- more than 2100 mutations in CFTR described, not all disease causing (https://
www.cftr2.org/) • Sweatchloridetest
■ increasedconcentrationsofNaClandK+([Cl–]>60mmol/Lontwooccasionssupportsthediagnosis)
■ carriers have normal sweat tests (and no symptoms) • PFTs
■ early: airflow limitation in small airways
■ late: severe airflow obstruction, hyperinflation, gas trapping, decreased DLCO (very late) • ABGs
■ hypoxemia, hypercapnia later in disease with eventual respiratory failure and cor pulmonale • CXR
■ hyperinflation, increased pulmonary markings (especially upper lobes)
Treatment
• chestphysiotherapyandposturaldrainage
• pancreaticenzymereplacements,highfat,highcaloriediet
• bronchodilators(salbutamol±ipratropiumbromide)
• inhaledmucolytic(reducesmucusviscosity),hypertonicsalineDNase • inhaledantibiotics(tobramycin,colistin,aztreonam)
• anti-inflammatorymedications(e.g.azithromycin,ICSinsome)
• antibiotics oral and IV (e.g. ciprofloxacin)
• CFTRpotentiatorsandmodulators(e.g.Ivacaftor,Orkambi)
• lungtransplant
Prognosis
• dependson:infections(B.cepaciacolonization),FEV1,acutepulmonaryexacerbations,lungtransplant vs. non-lung transplant
• femalegenderandlowsocioeconomicclasshavegreaterriskofearlydeath
Interstitial Lung Disease
Definition
• agroupofdisorderswhichcauseprogressivescarringoflungtissueandimpairlungfunctionandgas exchange
Pathophysiology
• inflammatoryand/orfibrosingprocessinthealveolarwalls→distortionanddestructionofnormal alveoli and microvasculature
• typicallyassociatedwith:
■ lung restriction (decrease in TLC and VC)
■ decreased lung compliance (increased or normal FEV1/FVC)
■ impaired diffusion (decreased DLCO)
■ hypoxemia due to V/Q mismatch (usually without hypercapnia until end stage)
■ pulmonary HTN and cor pulmonale occur with advanced disease secondary to hypoxemia and
Respirology R13
blood vessel destruction
Etiology
• >100knowndisorderscancauseILD
• majorityduetounknownagentsorcause
In ILD think
FASSTEN and BAD RASH
Upper Lung Disease (FASSTEN)
Farmer’s lung (hypersensitivity pneumonitis) Ankylosing spondylitis
Sarcoidosis
Silicosis
TB
Eosinophilic granuloma (Langerhans-cell histiocytosis)
Neurofibromatosis
Lower Lung Disease (BADRASH) Bronchiolitis obliterans with organizing pneumonia (BOOP)
Asbestosis
Drugs (nitrofurantoin, hydralazine, INH, amiodarone, many chemo drugs) Rheumatologic disease
Aspiration
Scleroderma
Hamman Rich (acute interstitial pneumonia) and IPF
Table 17. Interstitial Lung Diseases
UNKNOWN ETIOLOGY
Idiopathic interstitial pneumonias
UIP (usual interstitial pneumonia e.g. IPF)
NSIP (non-specific interstitial pneumonia)
LIP (lymphocytic interstitial pneumonia)
COP (cryptogenic organizing pneumonia e.g. BOOP) DIP (desquamative interstitial pneumonia)
IPPFE (idiopathic pleuroparenchymal fibroelastosis) AFOP (acute fibrinous and organizing pneumonia)
Sarcoidosis
Langerhans-cell histiocytosis (eosinophilic granuloma) Lymphangioleiomyomatosis
ILD Associated with Systemic Rheumatic Disorders
Scleroderma
Rheumatoid arthritis
SLE
Polymyositis/dermatomyositis
Anti-synthetase syndromes
Mixed connective tissue disease Environment/Occupation Associated ILD Hypersensitivity pneumonitis (usually organic antigen)
Farmer’s lung
Air conditioner/humidifier lung Bird breeder’s lung
Pneumoconioses (inorganic dust) Silicosis
Asbestosis
Coal worker’s pneumoconiosis Chronic beryllium disease
Pneumonitis from gases/fumes/vapour
KNOWN ETIOLOGY
ILD Associated with Drugs or Treatments
Antibiotics (nitrofurantoin)
Anti-inflammatory agents (methotrexate) Cardiovascular drugs (amiodarone) Antineoplastic agents (chemotherapy agents) Illicit drugs (e.g. crack lung, talc granulomatosis) Radiation
ILD Associated with Pulmonary Vasculitis Granulomatosis with Polyangiitis (GPA) Goodpasture’s syndrome
Idiopathic pulmonary hemosiderosis
Inherited Disorders
Familial IPF Telomerase mutations
Neurofibromatosis Tuberous sclerosis Gaucher’s disease
Alveolar Filling Disorders
Chronic eosinophilic pneumonia Pulmonary alveolar proteinosis