Internal Medicine

P1: SBT

0521779407-04 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:8

172 Asthma

tests

Laboratory

■Basic blood tests: CBC (eosinophilia common)

Specific Tests

■Pulmonary function:

➣Every patient should have complete PFTs once to confirm diag-

nosis

➣Follow with spirometry and/or peak flow

➣May be normal between attacks

➣Variable airflow obstruction (decreased FEV 1 , FVC, peak flow)

➣Reversible (≥12% and≥200 mL) with inhaled beta-agonist

■IgE elevated in most patients

■Allergy skin tests useful to identify triggers to avoid, or for hyposen-

sitization in severe cases

Other Tests

■Bronchoprovocation (histamine or methacholine):

➣Asthmatics unusually sensitive (PC 20 =8 mg/mL)

➣Useful to confirm diagnosis if PFTs normal

differential diagnosis

■Children: bronchiolitis, cystic fibrosis

■Adults: COPD, vocal cord dysfunction, allergic bronchopulmonary

aspergillosis, Churg-Strauss syndrome, polyarteritis nosodum, car-

diac asthma

management

■See NHLBI National Asthma Education and Prevention Program,

Expert Panel Report 2: Guidelines for the Diagnosis and Man-

agement of Asthma (http://www.nhlbi.nih.gov/guidelines/asthma/

asthgdln.htm)

Chronic Asthma

What to Do First

■Assess severity:

➣Mild intermittent: symptoms≤2 d/wk;≤2 nights/mo;

FEV

1 ≥80%; PEF variability <20%

➣Mild persistent: symptoms >2 d/wk; >2 nights/mo;

FEV 1 ≥80%; PEF variability 20–30%

➣Moderate persistent: symptoms daily; >1 night/wk;

FEV 1 60–80%; PEF variability >30%