Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

OSCE PREP > Asthma Pathophysiology > Flashcards

Asthma Pathophysiology Flashcards

(42 cards)

Start Studying
1
Q

What is asthma?

A

A chronic inflammatory disorder characterised by episodic, reversible bronchospasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does asthma cause?

A

Recurrent attacks of wheezing and breathlessness due to inflammation within the lungs causing the airways to narrow and reduce air flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does asthma predominantly affect?

A

The lower airway, but the upper airway may be affected by excess mucous production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two types of asthma?

A

Atopic and Non-Atopic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many asthmatics have atopic asthma?

A

70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many asthmatics have non-atopic asthma?

A

30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is atopic asthma?

A

It is extrinsic and triggered by an allergen/irritant
Inflammation mediated by systemic IgE production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is non-atopic asthma?

A

It is intrinsic and trigger is unknown as it is not caused by an allergy
Mediated by local IgE production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are children with asthma more susceptible to respiratory failure?

A
  • Increased susceptibility to infection
  • Smaller upper and lower airways are more easily obstructed by mucosal swelling and secretions
  • Increased tendency to airway closure and hypoxia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the presentation of asthma?

A
  • breathlessness
  • accessory muscle use
  • recession
  • tachypnoea
  • wheeze
  • desaturations
  • tachycardia
  • cyanosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some triggers of asthma attacks?

A

Dust, pollen, moulds, pollution, cold/hot weather, exercise, cigarette smoke, infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the three categories of asthma?

A

Moderate
Acute severe
Life threatening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does moderate asthma present?

A

Oxygen saturations above 92%, tachycardia, mild accessory muscle use, can talk in sentences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does acute severe asthma present?

A

Oxygen saturations below 92%, agitated, increased accessory muscle use, tachycardia, can’t complete sentences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does life threatening asthma present?

A

Oxygen saturations below 92%, silent chest, cyanosis, max accessory muscle use, increased tachycardia, drowsy, exhausted, can’t talk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the characteristics of asthma?

A

-Inflammation
-Broncho-constriction
-Bronchospasm
-Mucous production
-Broncho hyper-responsiveness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What can untreated asthma lead to?

Study These Flashcards
A

Airway remodelling

18
Q

What is airway remodelling?

Study These Flashcards
A

Ongoing structural change leading to thickened and narrower airways

19
Q

What may you see in an asthmatic airway at a cellular level?

Study These Flashcards
A
  • Goblet cells produce increased mucous
  • Thickened basement membrane
  • Increase in mast cells that release histamines
  • Cellular infiltration (eosinophils and neutrophils)
  • Smooth muscle hypertrophy
20
Q

What is the cellular response when a pathogen enters an asthmatic airway?

Study These Flashcards
A
  • Allergen/irritant enters the airway
  • B cells act as antigen presenting cells and produce IgE which attach to mast cells causing degranulation
  • Mast cell degranulation release mediators, such as histamine, leukotrienes and prostagladines
  • Mediator effects include increase mucous secretion by goblet cells, bronchiole smooth muscle contraction, vascular permeability and leaking, and eosinophil and neutrophil infiltration
  • Dendritic cells then activate T helper 2 cells to release cytokines, as well as neutrophils also releasing cytokines which amplify inflammatory reactions
  • Cytokines also attract and promote eosinophils which release histamines leading to airway obstruction, air trapping and hypoxaemia and respiratory acidosis
21
Q

What does VQ mean?

Study These Flashcards
A

Measuring whether Ventilation and Perfusion are equal

22
Q

How does VQ and gaseous exchange link?

Study These Flashcards
A

When perfusion and ventilation are similar, gaseous exchange is most efficient
When perfusion and ventilation are unequal, gaseous exchange are less efficient

23
Q

What does a lower VQ ratio imply?

Study These Flashcards
A

Lower VQ ratio impairs gas exchange and causes low partial pressure of oxygen (PaO2) in arteries

24
Q

What is a shunt?

Study These Flashcards
A

perfusion is present but ventilation is absent
(VQ=0)

25
What is deadspace?
ventilation is present and perfusion is absent (VQ=unknown)
26
What are the two types of respiratory failure?
Type 1 = hypoxia - inability to get oxygen into the blood (PaO2 = less than 8kPa) Type 2 = hypercapnia - inability to get carbon dioxide out of the blood (PaCO2 = more than 6kPa)
27
What is the pathophysiology of an asthma attack?
- Allergen triggers IgE mediated response leading to vasodilation and increased capillary permeability leading to mucous production, inflammation and oedema. - This inflammation causes lower airway obstruction causing wheezing due to turbulent air flow. Wheezing causes oscillation of the bronchial wall making the airways hyper-responsiveness and narrow - This causes bronchospasm, broncho-constriction, oedema, airway obstruction, epithelial shedding, increased lung volume, and abnormal gas exchange, leading to atelectasis - Impaired oxygen delivery causes cells to switch from aerobic to anaerobic metabolism which results in lactic acid production at a cellular level - Decreased oxygen intake = hypoxia = cyanosis
28
What does epithelial shedding cause?
Epithelial shedding causes a build up of epithelial cells in the bronchioles leading to airway remodelling as the airway becomes narrower
29
What is the treatment for moderate asthma?
- O2 sats monitoring - High flow O2 - B2 agonists (2-10 puffs via spacer and repeat every 20 minutes) - Ipratropium bromide - Oral steroids
30
What is the treatment for acute severe asthma?
- O2 sats monitoring - High flow O2 - B2 agonists nebulised every 20 minutes - Nebulised ipratropium bromide - Oral/IV steriods - Consider IV magnesium and aminophylline - Arterial Blood Gas - PICU
31
What is the treatment for life threatening asthma?
- O2 sats monitoring - High flow O2 - B2 agonists nebulised every 20 minutes - Nebulised ipratropium bromide - Oral/IV steriods - Consider IV magnesium and aminophylline - Arterial Blood Gas - PICU - Consider single bolus IV salbutamol
32
What is the rationale for the treatments of asthma?
- Oxygen - increases O2 saturations - Steroids - reduce inflammation, swelling and mucous production - Bronchodilators - dilate airways to improve airflow - Ipratropium bromide - control bronchospasm - Aminophylline - broncho-dilation and reduced hypersensitivity IV magnesium - bronchodilator
33
How may an asthmatic patients airway present?
Airway - an inflammatory cellular response causes the hyper-secretion of mucous from the goblet cells so secretions may be seen in the airway
34
What should you do if secretions are seen in the airway?
Suctions the secretions from back of the cheeks using a soft tip catheter with 12-20kPa via wall suction
35
What breathing symptoms would you expect an asthmatic patient to present with?
Due to the inflammatory cellular response, the lower airways narrow and present with oedema, vascular leaking, mucous plugging and broncho-constriction. Therefore a wheeze may be present due to turbulent airflow. Tachypnoea occurs to try and compensate for the hypoxia Increased work of breathing due increased oxygen demand Low oxygen saturations due to hypoxia due to VQ mismatch due decreased ventilation
36
After prolonged asthma symptoms, what may a child present with?
A child may also present with muscle fatigue due to prolonged accessory muscle usage and continuation of tachypnoea results in respiratory failure
37
How does VQ mismatch affect how a child presents?
V-Q mismatch occurs due to increased dead space as the airway is distended due to hyperinflation occurring because of airway obstruction
38
How may an asthma attack affect a child's circulatory assessment?
- Tachycardia may occur as pulmonary vascular resistance increases due to increased lung volume causing right ventricular compromise - Cyanosis due to hypoxia due to decreased levels of oxygenated haemoglobin in the blood - May present with skin pallor due to vasoconstriction - Physiological stress may cause increased heart rate and blood pressure
39
How may an asthma attack affect a child's neurological (disability) assessment?
Reduced cerebral blood flow and oxygenation causes changes to AVPU. If A or V, the patient may be irritable and confused, If at P or U, the patient may not be conscious enough to protect their airway
40
How may an asthma attack affect a child's exposure assessment?
Depending on antigen/allergy reaction a rash may be seen
41
What is a side effect of salbutamol?
Tachycardia
42
What intervention can you apply for tachycardia?
ECG monitoring

OSCE PREP (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions