What is the management for an 18-month-old child with severe asthma exacerbation and severe hypoxemia?

Management of Severe Asthma Exacerbation with Severe Hypoxemia in an 18-Month-Old Child

Immediate treatment should include high-flow oxygen via face mask, nebulized salbutamol (2.5 mg), intravenous hydrocortisone, and nebulized ipratropium bromide, with continuous monitoring of oxygen saturation to maintain SaO2 >92%. 1

Initial Assessment and Recognition

Severe asthma exacerbation in an 18-month-old child may present with:

• Too breathless to talk or feed
• Respiratory rate >50 breaths/min
• Heart rate >140 beats/min
• Agitation or reduced level of consciousness
• Cyanosis
• Silent chest or poor respiratory effort
• Fatigue or exhaustion 2

Assessment may be difficult in very young children, and the presence of any of these features should prompt immediate intervention.

Immediate Treatment Algorithm

1. Oxygen Therapy

   • Administer high-flow oxygen via face mask 2, 1
   • Target oxygen saturation >92% 2
   • Continuous pulse oximetry monitoring 1

2. Bronchodilator Therapy

   • Salbutamol 2.5 mg (half dose for very young children) via oxygen-driven nebulizer 2
   • Can repeat every 20-30 minutes if needed 1
   • Use appropriate spacer device for age 1

3. Anti-inflammatory Treatment

   • Intravenous hydrocortisone immediately 2
   • Follow with oral prednisolone 1-2 mg/kg body weight daily (maximum 40 mg) 2, 3

4. Additional Bronchodilator

   • Add ipratropium bromide 100 μg nebulized 2
   • Repeat every 6 hours until improvement starts 2, 1

5. For Life-Threatening Features

   • Consider intravenous aminophylline 5 mg/kg over 20 minutes followed by maintenance infusion of 1 mg/kg/h 2
   • Omit loading dose if child is already receiving oral theophyllines 2

Subsequent Management

If improving after initial treatment:

• Continue high-flow oxygen
• Prednisolone 1-2 mg/kg daily
• Nebulized salbutamol 4-hourly 2

If not improving after 15-30 minutes:

• Continue oxygen and steroids
• Increase frequency of nebulized salbutamol up to every 30 minutes
• Ensure ipratropium is added to nebulizer and repeated every 6 hours 2, 1

Monitoring and Reassessment

• Reassess respiratory rate, heart rate, and work of breathing regularly 1
• Monitor oxygen saturation continuously 1
• Chart response to treatment 2
• Consider arterial blood gas analysis if severe hypoxemia persists despite treatment 1

Indications for ICU Transfer

Transfer to intensive care unit with a doctor prepared to intubate if:

• Deteriorating clinical status
• Worsening exhaustion
• Feeble respirations
• Persistent hypoxia despite maximal therapy
• Confusion, drowsiness, or coma 2

Discharge Criteria and Follow-up

When discharged, the child should have:

• Been on discharge medication for 24 hours
• Treatment plan including inhaled steroids and bronchodilators
• Written instructions for parents
• GP follow-up within 1 week
• Specialist follow-up within 4 weeks 2, 1

Important Considerations and Pitfalls

• Age-appropriate dosing: Use 2.5 mg salbutamol for children under 2 years 1
• Avoid sedatives: These can worsen respiratory depression 1
• Underestimation of severity: Severe attacks in young children may be difficult to assess; err on the side of more aggressive treatment 2
• Inadequate corticosteroid dosing: Ensure appropriate weight-based dosing of prednisolone (1-2 mg/kg) 3
• Insufficient monitoring: Continuous reassessment is crucial in the first hours of treatment 1
• Early discharge: Ensure adequate stabilization before discharge 1

The British Thoracic Society guidelines emphasize that delays in treatment can be fatal, and each emergency consultation should be regarded as potentially severe until proven otherwise 2. Multiple studies have shown that arterial oxygen saturation is a better predictor than peak expiratory flow rate in evaluating asthma severity in children 4, making pulse oximetry particularly valuable in this age group.