Asthma in outpatients

We had a clerk teaching session on asthma, and I thought I would share some points with everyone:

Diagnosis

Relative increase in FEV1 of 12% post-bronchodil AND over 200cc change. More sensitive test is methylcholine challenge

Steps for therapy: With each, patient education, environmental control

1) SABA prn
2) low dose ICS
3) (low dose ICS + LABA) or medium dose ICS
4) medium dose ICS + LABA
5) high dose ICS + LABA and consider omalizumab for allergic asthma (eosinophilia or symptoms)
6) high dose ICS + LABA + oral steroid and consider omalizumab

Before stepping up treatment, check puffer technique, adherence, environmental control, comorbidity.

Note that LABAs are never used without inhaled steroids; LABA alone increased mortality in trials

Do not step down unless asthma is well controlled for 3 months.

Parameters of control
daytime sx less than 4x/wk night sx less than 1x/wk normal physical activity mild, infrequent exac, no absenteeism B2 agonist use less than 4x/wk peak flow or FEV1 over 90% of best

Some general differences between asthma and COPD

1) reversible vs fixed obstruction
2) steroid responsiveness higher in asthma than COPD
3) small role for anticholinergics in asthma
4) very rarely use abx for exacerbations in asthma
5) dyspnea, tightness, wheeze in asthma vs dyspnea, cough, sputum in copd
6) early vs. late onset

In the non-responding asthmatic, think about:
1) poor compliance
2) poor inhaler technique
3) environment
4) drugs- B-bl, ASA
5) comorbitites- GERD, sinusitis, allergies, CHF
6) complications- ABPA, churg-strauss, chronic eosinophilic pneumonia
7) psychosocial
8) wrong diagnosis- consider vocal cord dysfcn, airway obstruction, CF (adult)

Links:

Click here for the 2007 NIH asthma guidelines

Acknowledgement:

Some of the above is taken from the University of Toronto Department of Respirology resident handbook