Asthma In Children Flashcards
Asthma triggers in younger children
- Respiratory syncytial virus (RSV)
- Rhinovirus
- Parainfluenza virus infection
Asthma triggers in older children
- Pneumonia
- Exercise (Playing)
- Emotions
- Inhaled irritants
- Cold, dry air
Symptoms
- Chest tightness
- Cough
- Wheezing
- Dyspnea/SOB
Signs of asthma
1 Tachycardia
- Tachypnea
- Wheezing
- Cynosis
- Expiratory phase is prolonged
- Use of accessory muscles, nasal flaring, inability to speak and pursed lips.
- Diminished breath sounds
- Hyper resonant lung fields.
Risk factors
- Family Hx
- Allergies
- Viral respiratory infections
- Obesity
- Exposure to exhaust fumes or other types of pollution
Diagnosis
- Clinical, through thorough Hx and physical examination.
NB. Spirometry and lung function tests are difficult to perform in young children.°If a child has more than one of the ff symp: Wheezing, cough, dyspnea, chest tightness, 1. Particularly if these are frequent, or recurrent, or worse in the early morning or worse at night. 2. If they occur in response to, or worse after exercise, or other triggers.
Diagnosis with thorough Hx and exam
A child can be classified as:
- High probability-dx of asthma is likely
2. Low probability-dx other than asthma is likely
3. Intermediate probability- dx uncertain
DDx
- COPD
- Foreign body in the trachea or bronchus
- Bronchiolitis
- Pneumonia
Pathophysiology of Asthma
genetic factors or genetic predisposition
- Bronchial inflammation
- Bronchial hyperreactivity + trigger factors
- Oedema Bronchoconstriction ⬆ Mucus production.
- Airway narrowing
- symptoms: Cough, wheeze, breathlessness, chest tightness
The pattern of Asthma should be assessed by asking:
- How frequent are the symptoms?
- How much school has been missed due to symptoms?
- Are sport and general activities affected by asthma?
- how often is sleep disturbed by asthma?
- How severe are the interval symptoms between exacerbations?
Diagnostic investigations
1Skin prick test (common allergens)
2. Peak expiratory flow rate (PEFR) : increased variability <92%
The danger signs in acute, severe asthma that need referral:
- Restlessness
- Disturbance in the level of consciousness
- PEFR <60% of predicted value
- Decreased oxygen saturation <85%
- Rising PaCO2
- Silent chest on auscultation
- Palpable pulses paradoxus
- Chest pain (air leaks)
Classify Mild Asthma
- Oxygen sat: >95%
- PEFR: 70-90%
- Arterial PaCO2: <35mmHg
- Pulsus paradoxus: <10mmHg
- Wheezing: Expiratory
- RR: <40
- Additional signs: nil
- Management: B2 agonist MDI 2 puffs, repeat as needed up to 10 puffs. In children <5years use a spacer +/- Mask. Consider Prednisone 1-2mg/kg PO
Classify Moderate Asthma
- Oxygen sat: 92-95%
- PEFR: 50-70%
- Arterial PaCO2: <40mmHg (5.3kPa
- Pulsus paradoxus: 10-20mmHg may be palpable
- Wheezing: Expiratory and inspiratory
- RR: >40
- Additional signs: Speaks normally, Difficulty feeding, chest indrawing
- Management:
° Oxygen 100% via face mask 4-6L OR 1-2L via nasal cannula.
+
°Short acting B2 agonist e.g. Salbutamol,inhalation using MDI (4-6 puffs) up to 10 puffs repeated every 20-30mins OR Nebulise.
+/- iprattopium bromide inhalation. Prednisone 2mg/kg oral
General measures
- Admit child to high care if available
- Monitor:
Heart rate
Blood pressure
Respiratory rate
Acid-base status
PEFR
Pulse oximetry
Blood gases - Ensure adequate hydration: Normal maintenance volume of oral fluids, to avoid overhydration
- If unable to drink give 0.45% sodium chloride OR 5% Dextrose, IV. Avoid overhydrating children with severe asthma, because they become dehydrated because of poor intake or vomiting. Do not exceed children recommended max Dosage i.e 5mL/kg/24 hours.
General measures
- Admit child to high care if available
- Monitor:
Heart rate
Blood pressure
Respiratory rate
Acid-base status
PEFR
Pulse oximetry
Blood gases - Ensure adequate hydration: Normal maintenance volume of oral fluids, to avoid overhydration
- If unable to drink give 0.45% sodium chloride OR 5% Dextrose, IV. Avoid overhydrating children with severe asthma, because they become dehydrated because of poor intake or vomiting. Do not exceed children recommended max Dosage i.e 5mL/kg/24 hours.
MEDICINE TREATMENT
Mild And Moderate Asthma
Bronchodilator, i.e. short-acting ß₂ agonist.
Salbutamol, inhalation, using a metered-dose inhaler with a spacer device.
200–400 mcg (2–4 puffs) repeated every 20–30 minutes depending on clinical response.
OR
Salbutamol, solution, 0.15–0.3 mg/kg/dose nebulise at 20 minute intervals for 3 doses.
Maximum dose: 5 mg/dose.
5 mg salbutamol in 4 mL sodium chloride 0.9% delivered at a flow of 5 L/minute with oxygen.
PLUS
Prednisone, oral, 1–2 mg /kg, daily immediately up to a maximum of:
20 mg: Children < 2 years for 5 days.
30 mg: Children 2–5 years for 5 days.
40 mg: Children 6–12 years for 5 days.
Definition
It is an Episodic and reversible airway narrowing in response to certain stimuli
Characterized by presence of at least one of:
- Wheeze
- SOB
- Chest tightness
- Non-productive cough
These symptoms may be chronic, or present acutely with worsening symptoms known as an exacerbation (or ‘attack’) of asthma.
A 12 year old boy with a 1 year history of wheeze, dry cough which is worse at night is brought to the GP. After taking a full history you learn that the boy suffers from eczema, as do his mother and sister. His father also suffers from Asthma and hay fever. The only positive finding on examination is a widespread wheeze heard throughout the chest.
Which of the following immunoglobulin is most likely to be raised on investigation of this patient?
A. Ig A B. Ig D C. Ig E D. Ig G E. Ig M
C. Ig E
Pathophysiology.
Asthma is caused by a combination of:
- Inflammation of the bronchial mucosa with increased mucous production
Inflammation of the mucosa is mediated by T-helper cell activation and the production of the cytokines which such as leukotrines, prostaglandin D2 and histamine.
- Hyper-reactive airways (leading to bronchoconstriction and therefore reversible airway narrowing)
Bronchoconstriction is mediated by the release of acetylcholine onto muscarinic M3 receptors via the parasympathetic nervous system. This also increases mucous secretion.
Bronchodilation is mediated by the release of adrenaline onto beta2-adrenoreceptors via the sympathetic nervous system, which also decreases mucous secretion.
Types of childhood asthma?
- Transient early wheezes: These children commonly develop a wheeze associated with a viral upper respiratory tract infection, but is commonly out of by roughly 3 years of age (especially if there is no family/person of atopy).
- Non-atopic wheezes: These children develop a wheeze, not associated with a viral illness or a history of atopy. Again, this is often grown out of by 3-4 years of age.
- Atopic wheezers:
AKA allergic asthma. These children have a family or personal history of atopy and develop a more persistent, atopic asthma.
A 15 year old boy presents to OPD with a 4 month history of coughing which is waking him up, as well as a wheeze. After taking a full history examination you suspect asthma and decide to perform an investigation to confirm your diagnosis.
Which of the following would you choose as your first line investigation?
A) FeNO (Fractional exhaled nitric oxide)
B) Trial salbutamol and return of review in 2 weeks.
c) Keep a peak flow diary over the next 2 weeks and return for review.
D) Direct bronchial challenge test with histamine or methacholine.
E) Spirometry and BDR (Bronchodilator reversibility)
E) Spirometry and BDR (Bronchodilator reversibility).
