Emergency - Asthma exacerbation

Question 1

You are on duty in ED and a paramedic crew brought in a patient, Mr Benjamin Tanaka. After a SBAR handover, you found out that Mr Tanaka has been brought into the hospital complaining of shortness of breath. He is struggling to speak and can only manage a few words, not sentences. He is a known asthmatic.

You carry out an ABCDE assessment and note the following:

A - Clear
B - RR 30 min-1, PEFR unrecordable, SpO2 86% on 6 litres min-1, oxygen, widespread wheeze on auscultation; nebuliser started
C - P 140 min-1, BP 100/60 mmHg
D - Can only manage a few words and appears tired
E - Pale and clammy

Assess the severity of this asthma exacerbation and describe how you would manage this patient.

Answer 1

Acute severe asthma

call for senior help

follow the ABCDE approach

ensure optimal medical management of asthma: O SHIT ME I

• Oxygen high flow 15L
• Salbutamol nebs
• Hydrocortisone IV / Prednisolone PO
• Ipratropium bromide nebs
• Try more salbutamol nebs (back to back every 20 mins if req) (only use IV salbutamol if nebs cannot be given because bag valve mask ventilation)
• Magnesium sulphate IV 2g over 20min
• Expert help from senior - consider Aminophylline IV loading dose followed by infusion
• ITU/HDU support - intubation + ventilation

Question 2

If a patient with an asthma exacerbation deteriorates, ventilation may be necessary. Why is ventilation with a bag-valve mask difficult in patients with asthma exacerbations?

Answer 2

The patient will be difficult to ventilate because of bronchospasm - there is a high risk of gastric inflation with a bag-mask. Early tracheal intubation is desirable.

Question 3

Name some common triggers of an asthma exacerbation.

Answer 3

• Smoking
• Infection
• Allergens - pollen, dust, mites, pets
• Exercise
• Cold air
• Pollution
• Stress
• Drugs - NSAIDs, beta blockers

Question 4

What are the features of a mild asthma exacerbation?

Answer 4

• PEFR >75%
• No features of severe asthma

Question 5

What are the features of a moderate asthma exacerbation?

Answer 5

• PEFR 50-75%
• No features of severe asthma

Question 6

What are the features of an acute severe asthma exacerbation?

Answer 6

• PEFR 33-50%
• Cannot complete sentences in 1 breath
• Respiratory rate > 25/min
• Heart rate > 110/min

Question 7

What are the features of a life-threatening asthma exacerbation?

Answer 7

• PEFR <33%
• Sats <92% or ABG pO2 < 8kPa
• Cyanosis, poor respiratory effort or fully silent chest
• Exhaustion, confusion, hypotension or arrhythmias
• Normal pCO2

Question 8

What are the features of a near fatal asthma exacerbation?

Answer 8

raised pCO2

Question 9

What are the criteria for safe discharge after an asthma exacerbation?

Answer 9

• PEFR >75%
• Switch regular nebulisers to inhalers for 24 hours prior to discharge
• Inpatient asthma nurse review to reassess inhaler technique and adherence
• Provide PEFR meter and written asthma action plan
• At least 5 days oral prednisolone
• GP follow up within 2 working days
• Respiratory Clinic follow up within 4 weeks
• For severe or worse, consider psychosocial factors

Question 10

Asthma can only be diagnosed at 5 years of age. So how is an acute episode of childhood wheeze/possible asthma managed in children 1-5 years?

Answer 10

• Oxygen
  
  • If SPO2<94%, high flow oxygen via a non-rebreather mask aiming for saturations of 94-98%
• Bronchodilators
  
  • Mild cases
    
    • Can be managed as an outpatient with regular salbutamol inhalers via spacer e.g. 4-6 puffs every 4 hours
  • Moderate to severe cases – stepwise approach working upwards until control achieved (reassess every 30 mins)
    
    • Inhaled salbutamol via a spacer: starting with 5-10 puffs every 30 mins – this is usually very effective
    • Nebulised salbutamol/Ipratropium bromide (monitor serum potassium when on high doses of salbutamol)
    • If still deteriorating, consider a capillary blood gas (do not generally do ABGs in children)
    • IV magnesium sulphate
    • IV salbutamol/IV aminophylline
    • If control still inadequate, consider NIV (CPAP), call an anaesthetist and consider ICU
• Steroid therapy
  
  • Mild cases
    
    • No evidence for any corticosteroids!
  • Moderate to severe cases
    
    • Oral prednisolone e.g. 1mg per kg of body weigh once a day for 3 days
    • IV hydrocortisone if vomiting
  • Antibiotics
    
    • Only if a bacterial cause is suspected e.g. amoxicillin or erythromycin

Question 11

When is discharge considered safe in children with an asthma exacerbation/wheeze episode?

Answer 11

Discharge is considered when the child is on 6 puffs 4 hourly