By the end of this session you will be able to:
demonstrate an understanding of the pathophysiology relevant to asthma
describe how this applies to paramedic practice and the assessment of a patient
explain how to manage patients with asthma in the pre-hospital setting
explain the management of cardiac arrest patients with asthma in the pre-hospital setting
Asthma is a respiratory disease characterised by significant variations in airflow resistance over short periods of time. Wheezing, breathlessness and a reduction in airflow occur due to episodes of reversible bronchospasm, increased mucous secretion and mucosal oedema
Background
In the UK, 8 million people have been diagnosed with asthma. That is more than 12% of the population.
It does not mean there are 8 million people living with the condition, as many children diagnosed with asthma grow out of it. Research also suggests asthma may be considerably over diagnosed (British Lung Foundation).
Select the photos for some statistics about asthma.
In the UK, around 5.4 million people are currently receiving treatment for asthma. That's 1 in every 12 adults and one in every 11 children
In the UK, around 5.4 million people are currently receiving treatment for asthma. That's 1 in every 12 adults and one in every 11 children
Asthma affects more boys than girls.
In the UK, around 5.4 million people are currently receiving treatment for asthma. That's 1 in every 12 adults and one in every 11 children
Asthma affects more boys than girls
In adults, it is more common in women than men.
In the UK, around 5.4 million people are currently receiving treatment for asthma. That's 1 in every 12 adults and one in every 11 children
Asthma affects more boys than girls
In adults, it is more common in women than men
Asthma can sometimes be defined as a type, such as "occupational"
In the UK, around 5.4 million people are currently receiving treatment for asthma. That's 1 in every 12 adults and one in every 11 children
Asthma affects more boys than girls
In adults, it is more common in women than men
Asthma can sometimes be defined as a type, such as "occupational"
Approximately 5% of people with asthma have severe asthma
Tragically, 3 people die every day because of asthma attacks and research shows that two-thirds of asthma deaths are preventable.
The reassuring fact is that most people with asthma who get the right treatment, and take it correctly, can manage their symptoms and get on with what they want to do in life (BTS 2016)
Pathophysiology of asthma
The asthmatic response can be divided into an early phase, which begins up to an hour after exposure to a trigger antigen, and a late phase, which occurs approximately 4 to 8 hours later.
Normal Airway
In the early phase, an antigen to which the bronchial mucosa have previously been sensitised contacts the mucosal surface, mast cells release antibody mediators which open mucosal intercellular junctions, allowing further penetration of the antigen. The parasympathetic nervous system is also involved in bronchoconstriction. Branches of the vagus nerve terminate in the bronchial walls, and release acetylcholine, causing smooth muscle contraction and mucosal hyper-secretion.
Airway during asthma symptoms
An array of other mediators are also released, causing the late inflammation phase. Leukotrienes promote prolonged bronchoconstriction and increase mucosal secretion. Prostaglandin causes bronchoconstriction and histamine is released.
Audible wheeze, classically expiratory.
Short of breath (SOB) or difficulty in breathing (DIB).
Inability to speak full sentences. This can be subjective, though one way of potentially getting consistency is to ask the patient to count in one breath and see how far they get.
Increased respiratory rate (RR), consider the effect of anxiety surrounding assessment of SOB or DIB.
Heart rate (HR), remember to consider effects of medications such as salbutamol.
Patient position, classically described as "tripod" where the patient is attempting to maximise intrathoracic volume allowing exchange of as much gas as possible.
Use of accessory muscles, look for recession:
intercostal
sub-costal
sub-sternal
Evidence of medication, (for example inhalers, breathing spacers).
