Asthma

Question 1

What is the mechanism of action of aminophylline?

Answer 1

Aminophylline is a short acting theophylline.

binds to adenosine receptors and blocks adenosine-mediated bronchoconstriction

Question 2

What can be triggered following respiratory compromise-mediated hypercapnia?

Answer 2

cerebral vasodilation

may increase ICP (esp. in trauma)

Question 3

What are the main features of a severe asthma attack?

Answer 3

SpO2 < 92%

PEF 33-50% best or predicted

too breathless to talk or feed

HR > 125

Resp rate > 30

use of accessory muscles (neck: SCM and scalene0

Question 4

What are the main features of a life threatening asthma attack?

Answer 4

SpO2 < 92%

PEF < 33% best or predicted

silent chest

poor respiratory effort

agitation, altered consciousness, cyanosis

Question 5

What are the main features of a moderate asthma attack?

Answer 5

PEFR 50-75% best or predicted
Speech normal
RR < 25 / min
Pulse < 110 bpm

Question 6

What are the main features of a near-fatal asthma attack?

Answer 6

same as life-threatening
switch from Type to Type 2 respiratory failure
hypercapnia