Asthma - Acute Paediatric - 2

Important: Accurate assessment of severity is crucial for appropriate management - ask for help if you are unsure   

 Patterns of asthma

It is important to understand the patterns of asthma in children - infrequent episodic, frequent episodic, and persistent.

The pattern of asthma determines the need for preventive therapy.    

 Infrequent episodic
- 70-75% paediatric asthma is this sort
- lasts 1-2 days up to a fortnight
- oftent triggered by RTI or allergen
- episodes 6-8 weeks apart
- do not require preventer, only management of individual episode. 
 Frequent episodic
- interval between episodes shorter
- some symptoms within interval period eg exercise induced wheeze
- may require preventer (especially in Winter)
- approximately 20% of paediatric asthma is this sort.    

- acute episodes AND sypmtoms on most days
- often have sleep disturbances, morning chest tightness, exercise intolerance and spontaneous wheeze
- 5-10% asthma is persistant asthma.    

What happens during an asthma attack?

Play this video.


The following chart, provided by the National Asthma Council, provides a classification guide for diagnosising paediatric astham.  

asthma asses

 Source : Asthma Management Handbook, 2006, National Asthma Council, Australia    

(Download Asthma Management Handbook here)

A note about pulsus paradoxus

Pulsus paradoxus is often cited as a measure of acute asthma. This is true, but its continued inclusion in guidelines is a reflection of the distance of the writers from acute medicine.

Children, with their high respiratory rate make this even more difficult to assess quantitatively.

Pulsus paradoxus is difficult to measure, has poor inter-observer variability in the acute clinical setting. Pulse oximetry as a qualitative screening measure is promising, although has not been validated in an emergency population.

If a child is sick enough to have a pulsus paradoxus measured, you should probably be spending your time doing something useful.   

Link High inter-observer variation in the clinical assessment of pulsus paradoxus: Chest 2000 Aug;118(2):348-52

Link Pulsus paradoxus - lab study of oxygen saturation assessment: Acad Emerg Med 1995 Oct;2(10):894-900

Link ICU study of diagnosis of pulsus paradoxus in children: Intensive Care Med 1998 Mar;24(3):242-6