Acute asthma is one of the commonest reasons for presentation to an emergency department and admission to a hospital. Consider acute asthma when a child presents with signs of increased work of breathing, widespread wheezing and shortness of breath. There are other causes to consider such as Mycoplasma pneumonia, aspiration, inhaled foreign body, and cardiac failure. In the setting of a child with a previous history of asthma or when asthma seems the most likely diagnosis, then perform a primary assessment of severity and institute the initial resuscitation and treatment.
Primary assessment and initial resuscitation and management
Table below shows the clinical signs and management of asthma at varying degrees of severity. The arterial oxygen saturation (SaO2) may be reduced in the absence of significant airway obstruction by factors such as atelectasis and mucous plugging of airways. SaO2 is purely a measure of oxygenation, which may be preserved in the presence of deteriorating ventilation (with CO2 retention).
Consider transferring the child to a pediatric intensive care unit if the child:
• is in impending respiratory failure
• requires continuous nebulizers for >1 hour
• requires salbutamol more frequently than every 30 minutes after 2 hours
• is becoming exhausted.
Consider ventilation if:
• PCO2 is >8kPa
• there is persistent hypoxemia with PO2<8kPa in inspired oxygen of 60%
• there is increasing exhaustion despite emergency treatment.
Note that exhaustion, a silent chest, cyanosis, bradycardia and hypotension are preterminal signs.
Tables of Assessment and Management of Asthma in Pediatric
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| Mild Degree |
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| Moderate Degree |
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| Critical Degree |
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| Severe Degree |
If poor response to i.v. salbutamol give aminophylline 10 mg/kgweight i.v. (maximum dose 250 mg) over 60 min.
Following loading dose, give continuous infusion (1–9 years: 1.1 mg/kgweight per hour, 10+ years: 0.7mg/kgweight per hour)
See notes for indications for transfer to PICU
Note: If currently taking oral theophylline, do not give i.v. aminophylline in the Emergency Department—take serum level.
* Salbutamol 6 puffs if <6 years, 12 puffs if >6 years. Note nebulized salbutamol can also be used at a dose of 2.5–5 mg as described above.
** Ipratropium (Atrovent Forte 40 µg per puff) 2 puffs if < 6 years, 4 puffs if >6 years.
History
Inquire specifically about the duration and nature of symptoms, treatments used (relievers, preventers), trigger factors (including upper respiratory tract infection, allergy, passive smoking), pattern and course of previous acute episodes (e.g. admission or ICU admissions), parental understanding of the treatment of acute episodes, and the presence of interval symptoms (see the section on discharge below). Consider other causes of wheeze (e.g. bronchiolitis, mycoplasma, aspiration, foreign body).
Examination
The most important parameters in the assessment of the severity of acute childhood asthma are general appearance and mental state, and work of breathing (accessory muscle use, recession), as indicated in Table 5.1.
Initial SaO2 in air, heart rate and ability to talk are helpful but less reliable additional features. Wheeze intensity, pulsus paradoxus and peak expiratory flow rate are not reliable features. Lung function is hard to measure during an acute attack particularly if the child is tired, is young (<7 years) or if the child has not seen a peak flow meter orspirometer before; focus on the above signs in the assessment.Asymmetry on auscultation is often found due to mucous plugging, but might be due to a foreign body.
Investigation
Chest X-ray is not generally required (discuss with registrar/consultant if you are considering it). Arterial blood gas and spirometry are rarely required in the assessment ofacute asthma in children.
Discharge
Time spent planning a discharge either from the emergency department or the ward willreduce the likelihood of readmission and may also reduce morbidity. When you areorganizing discharge, consider the factors in Box of Discharge pack below.
Review need for preventative treatment
Consider preventative treatment, initially with inhaled steroids, if:
• Wheezing attacks are less than 6 weeks apart
• Attacks are becoming more frequent and severe
• Interval symptoms are increasing
Check inhaler technique
Emergency attendance or admission should provide the patient and family with the opportunity to use a spacer device and MDI. Make sure the child can use the device adequately and the child and family know the importance of using it for all preventative therapy and treatment for significant exacerbations.
Family education
On discharge from the Emergency Department or ward it is important that families understand the immediate management of their child’s asthma and care of spacers etc. It is not appropriate to educate them on all aspects of asthma during an acute episode. This is best reserved for a visit to an outpatient clinic or doctor’s rooms at a time more distant from the acute episode. A reasonable amount of time must be allocated and it is more likely that the information will be understood and retained. Go over the action plan and give the brief parent information handout.
Prescription
A prescription for all medications should be provided at the time of discharge. In mostcases this should include a prescription for a short course of prednisolone for a future attack. The use of this steroid supply should be discussed when the action plan is provided.
Follow up
All patients should have a clear follow up plan. For some it will be appropriate that they visit their general practitioner (GP) for an early review, particularly if their condition deteriorates or fails to improve significantly within 48 hours. At discharge all patients should have an outpatient appointment or appropriate follow up arranged with a pediatrician within 4–6 weeks. This visit will be used for medical review and, most importantly, appropriate education about asthma management.
Written action plan
All patients should have an individual written action plan and the discharging doctor should spend time going over the plan with the family.
Communicate with Medical Doctor
For every emergency attendance or discharge, there should be communication with the patient’s GP (general practitioner) or pediatrician. If possible this should be by fax, telephone or even email. The GP should receive a copy of the action plan.
