Internal Medicine

0521779407-B02 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:52

Bronchiolitis 255

➣BOOP: bilateral ground glass densities in 81%; also miliary nod-

ules and symmetric lower lobe interstitial infiltrates

➣Respiratory bronchiolitis: diffuse interstitial infiltrates or reticu-

lonodular opacities

➣Panbronchiolitis: diffuse small centrilobular nodular opacities

and hyperinflation

■PFTs

➣ABG often normal; hypoxemia and hypercapnia late

➣Because total cross-sectional area of bronchioles large and

changes in bronchiolar caliber contribute little to airway resis-

tance (silent zone of lung), PFTs may be normal until late

➣Bronchiolitis obliterans: progressive obstruction, often with

reduced diffusing capacity

➣BOOP: restrictive pattern, with reduced diffusing capacity in 72%

➣Respiratory bronchiolitis: restrictive pattern, with reduced dif-

fusing capacity

➣Panbronchiolitis: progressive obstruction or restriction, with

reduced diffusing capacity

■Lung Biopsy

➣Often required for specific diagnosis, esp to distinguish BOOP

from ILD

➣Consider in any patient with progressive disease

differential diagnosis

■Asthma: reversible airflow obstruction

■Bronchiolitis: clinical history most helpful

■Bronchiolitis obliterans

■BOOP: usually requires lung biopsy for diagnosis; steroid responsive,

important to confirm diagnosis

■Respiratory bronchiolitis: HRCT (diffuse or patchy ground glass

opacities or fine nodules) useful to distinguish from ILD (periph-

eral reticulation, honeycombing)

■Panbronchiolitis: characteristic HRCT: diffuse small centrilobular

nodular opacities and hyperinflation

■Interstitial lung diseases

■Pneumonia

management

What to Do First

■Symptomatic treatment (oxygen, cough suppressants, hydration for

acute bronchiolitis)