Asthma Flashcards
What is Asthma?
- Asthma is the commonest chronic condition in children
- It is reversible + paroxysmal constriction of the airways
- intermittent obstruction and hyper-reactivity
What is the Pathophysiology of Asthma?
- Type 1 hypersensitivity reaction
- Allergens are presented to these cells by dendritic cells which in these individuals leads to a disproportionate immune response
- The Th2 cells are activated by dendritic cells and cytokines are released causing increased proliferation of mast cells, eosinophils and dendritic cells
- IgE activates Mast cells which release Histamine and Leukotriene C4
What are the Risk Factors for developing Asthma?
- Atopy - Asthma/ Eczema/ Hayfever
- Genetic Factors
- Environmental Factors (low birth weight, prematurity, parental smoking)
- Bronchiolitis in early life
- Diagnosis of atopic dermatitis
What are the Precipitating Factors of Asthma?
- Cold air and exercise: drying of the airways due to cold air and exercise leads to cell shrinkage causing an inflammatory response
- Drugs: NSAIDs + Beta-Blockers
- Exposure to allergens
What are the patterns of wheeze in an asthmatic?
- Infrequent episodic wheezing (discrete episodes last a few days with no interval symptoms)
- Frequent episodic wheezing (occurs more frequent than infrequent)
- Persistent wheezing (wheeze and cough most days and may have disturbed nights
What questions would you want to know from the history of Asthma?
- Age at onset of symptoms
- Frequency of symptoms
- Severity of symptoms (how many school days missed? Can the chid do PE at school? Can they play with their friends without getting symptoms?)
- Previous treatments tried
- Any hospital attendances (A+E or ITU/HDU)
- Prescence of food allergies
- Triggers for symptoms - Exercise, cold air, smoke, allergens, pets
- Disease history - Viral infections, eczema, hayfever
- Family history of Atopy
When would you see Finger Clubbing in children?
- Cystic Fibrosis
- Bronchiectasis
What would you find on examination in a patient with Asthma?
- Chest shape (hyperinflated chest = poorly controlled asthma
- Chest symmetry
- Breath sounds
- Presence of crepitations (not suggestive of asthma)
- Presence of wheeze
- Examination of throat to assess for tonsillar enlargement: infectious cause?
What investigations would you do for Asthma?
- Spirometry (showing an obstructive picture which is reversible after bronchodilators)
- Peak Expiratory Flow Rate (PEFR) measure of respiratory function
- Bronchial Provocation tests (histamine and metacholine) not easy to interpret and require specialist input
- Exercise testing (exercise induced symptoms
- Skin Prick testing (serum specific IgE assay to allergens, limited role in diagnosis or management of asthma)
- Exhaled Nitric Oxide ( NO is produced in bronchial epithelial cells and its production is increased in those with TH2-driven eosinophilic inflammation. Those with Asthma have raised ENO and can be raised in allergic rhinitis
- Chest X-Ray - a good baseline CXR to have
What describes good symptom control in children with Asthma?
full school attendance, no sleep disturbance, <2/week daytime symptoms, no limitation on daily activities, no exacerbations, using salbutamol <2/week, maintaining normal lung function
What is the Maintenance management for people with Asthma?
- 1.SABA (salbutamol)
- Add Inhaled Corticosteroids (Beclomethasone)
-3. Add a LABA (salmeterol/ formeterol)
-4. Increase dose of Inhaled Corticosteroid
-5. No response of LABA stop and add a Leukotriene Receptor antagonist (LTRA)
-6. Persistent poor control = Increase dose of inhaled corticosteroids
-7. Regular oral steroids - referral to respiratory paediatrician
- Add Inhaled Corticosteroids (Beclomethasone)
- Specialist Care: Omalizumab - monoclonal antibody for IgE and reduces the IgE free in the blood, therefore reducing the IgE mediated response
What are Key General Managment Points:
- Aerosol inhaler devices should be used with a spacer device and inhaler technique should be looked at
- Always ask about compliance
- LABA should always be prescribed with an Inhaled Corticosteroid
- Asthma management plan should be in place
- Know Fluticasone is twice as potent as Beclometasone
What describes a mild/ moderate Asthma Exacerbation?
- Sp02 >92%
- RR <30 (over 5’s), RR <40 (under 5’s)
- No Accessory muscle use
- Feeding well/ talking in sentences
- Wheeze (Audible with stethoscope)
What describes a severe Asthma Exacerbation?
- Sp02 <92%
- PEFR 33-50% predicted
- RR >30 (over 5’s), RR >40 (under 5’s)
- Too breathless to feed/ talk
- HR >125 (over 5’s), >140 (under 5’s)
- Use of Accessory Muslces
- Audible Wheeze
What describes a Life-Threatening Asthma Exacerbation?
- Sp02 <92%
- PEFR <33%
- Silent Chest
- Poor respiratory effort
- Altered Consciousness
- Agitation/ Confusion
- Exhaustion
- Cyanosis
What is the Immediate Managment of an Asthma Exacerbation?
- If Sa02 <94% then consider high flow Oxygen
MODERATE: - SABA (salbutamol) nebulised
- Ipratropium Bromide (Anti-Muscarinic) added
- Corticosteroids (5day course of oral prednisolone - if child vomits/ unable to take oral medication IV hydrocortisone should be used
- ABX if suspected bacterial infection
SEVERE:
- IV Aminophylline infusion
- IV SABA
LIFE-THREATENING:
- IV Magnesium Sulphate infusion
- HDU/ICU
- Intubation
What entails the Safe-discharge Criteria?
- Bronchodilators are taken as inhaler device with spacer every 4-hours
- Monitor the serum Potassium when on salbutamol as it causes potassium to be absorbed from the blood into the cells. It also causes a tachycardia
- Sa02 >94% in air
- Inhaler technique assessed
- Asthma management plan written and explained to parents
- GP should review the child 2 days after discharge
What does the ABG show in an intial Asthma Attack?
- It will show Respiratory Alkalosis due to the tachypnoea, causing a drop in the CO2
What does the ABG show in a life-threatening Asthma Attack?
- It will show a Respiratory Acidosis due to the high CO2 this is a very bad sign in asthma
How would you monitor the response to treatment in Asthma?
- Resp Rate
- Resp effort
- Peak flow
- 02 sats
- Chest auscultation
What can the child Present with which suggests a Diagnosis of Asthma?:
- Episodic symptoms with intermittent exacerbations
- Diurnal Variability, typically worse at night and early morning
- Dry cough and wheeze with SOB
- Typical Triggers
- History of Eczema and Hayfever
- Family History
- Bilateral Widespread Polyphonic Wheeze
- Symptoms improve with bronchodilators
What is the Medical Therapy for a Child Under 5 years with Asthma?
- SABA
- Low dose corticosteroid OR LTR Antagonist
- Add the other option from 2
- Refer to a specialist
What is the Medical Therapy for a Child between 5-12 years with Asthma
- SABA
- low dose corticosteroid
- LABA
- Increase corticosteroid to medium dose
- Add Leukotriene Receptor Antagonist OR Oral Theophylline
- Increase the dose of corticosteroid to high dose
- Referral to a specialist.
What is the Medical Therapy for a Child Over 12 years with Asthma?
- SABA
- Low dose corticosteroid
- LABA
- Titrate corticosteroid to a medium dose
- Consider Leukotriene Receptor Antagonist OR Oral Theophylline OR LAMA
- Titrate to a high dose of corticosteroid
- Add oral steroids at the lowest dose possible to achieve good control
