Asthma- avoiding common pitfalls

Asthma is quite an interesting condition to treat acutely, not only because it is gratifying when patients get better rapidly (which most of them do) but also because they are a group that can deteriorate quickly and hide their signs of deterioration well given their young age and relative health.

Given the nature of the disease it is not uncommon for patients to feel much better after being treated down in ED, then get worse again on the ward, perhaps as the frequency of their B agonist therapy is reduced. It is therefore imperative to avoid the common pitfalls when called to see these patients on the ward. The information below is directed at adult patients, but a lot of it will also apply to paediatrics too.

Asthmatics can die quickly

asthma phenotypes
Credit: Reference (1)

If you look at near fatal asthma cases two distinct phenotypes emerge as seen in the table above- the group that worsens over several days and whose pathology involves mainly mucus plugging, and the group who mainly develops bronchoconstriction with very rapid deterioration but faster responses to therapy. The latter are more commonly known as brittle asthmatics.

It is this group that are particularly relevant to ward calls as respiratory failure can develop in as little as 2 hours, and death is often sudden and unexpected (1). Such patients often show marked diurnal variation in peak flow, especially a large dip in the early morning, even when their previous peak flow was normal (1). Looking back at a patient’s previous discharge summaries and clinic letters should help you identify who might fit into the “sudden onset” phenotype.

In hospital death is not related to admission findings but is related to the phenotypes above

Continue reading