Sun10October1036AM 10

A 24-year-old asthmatic patient presents to the emergency department (ED) complaining of increased shortness of breath, wheeze and a productive cough for several days.

On examination he has a respiratory rate of 40 breaths per minute, oxygen saturations (SpO2) of 88% on high flow oxygen. His blood pressure is 160/70mmHg and pulse rate 100 beats per minute. This patient's peak expiratory flow rate is 35% of predicted and is unable to complete sentences. His PaCO2 is within the normal range.

Which of the following is a feature of acute life threatening asthma in this patient?

(Please select 1 option)

Inability to complete sentences

Respiratory rate of 40 breaths per minute

A pulse rate of 100 beats per minute

Oxygen saturations of 88% on high flow oxygen Correct

Peak expiratory flow rate of 35% of predicted

Explanation

The British Thoracic Society (BTS) defines exacerbation of adult asthma into moderate, acute severe or life-threatening.

Moderate symptoms include

Increasing symptoms

Peak expiratory flow (PEF) 50-75% of predicted or best

and no other features.

Features of acute severe asthma include:

PEF 33-50% of predicted or best

Respiratory rate of more than 25 breaths per minute

Heart rate greater than 110 beats per minute or

An inability to complete sentences.

The features of life-threatening asthma include:

A PEF less than 33% of predicted

Oxygen saturations less than 92%

Arterial blood gas demonstrating a PaO2 less than 8 kPa or a PaCO2 in the normal range (4.6-6 kPa)

Silent chest

Cyanosis

Poor respiratory effort

Arrhythmias

Exhaustion or

Altered mental state.

Reference:

British Thoracic Society. Asthma Guideline.

Answer Statistics

1

19%

2

7%

3

3%

4

58%

5

15%

Times answered: 286