Salbutamol Dosing for a 3-Month-Old Infant (5.5 kg)
For a 3-month-old infant weighing 5.5 kg with acute bronchospasm, administer 2.5 mg of nebulized salbutamol diluted in 2-3 mL of normal saline via face mask every 20 minutes for up to 3 doses, then continue with 2.5 mg every 1-4 hours as needed based on clinical response. 1, 2
Initial Treatment Protocol
Start with 2.5 mg salbutamol (the minimum effective dose) rather than weight-based dosing (which would calculate to 0.15 mg/kg × 5.5 kg = 0.825 mg), as the fixed 2.5 mg dose is as effective as weight-based dosing in infants and young children with mild to moderate acute asthma 1, 2
Dilute in 2-3 mL of normal saline for adequate nebulization 1
Use a face mask rather than a mouthpiece for delivery, as infants will not tolerate a mouthpiece 2, 3
Administer every 20 minutes for 3 doses in the first hour for acute exacerbations 4, 2
Continue with 2.5 mg every 1-4 hours as needed based on clinical response after the initial 3 doses 1, 2
Critical Administration Details
Use oxygen as the gas source for nebulization when available, with supplemental oxygen administered to maintain oxygen saturation >92% during treatment 1, 2
Monitor continuously: heart rate, respiratory rate, oxygen saturation, and clinical response after each nebulization 1, 3
Watch for side effects: tachycardia, tremors, and hypokalemia from overdosing 2, 3
Important Considerations for Infants
Salbutamol should be restricted to symptomatic infants with obvious bronchospasm and is not recommended for routine use in all infants due to variable response 3
Response is primarily dependent on symptom status and presence of lung function abnormalities in this age group 3
Begin simultaneous treatment with corticosteroids for acute asthma exacerbations (prednisolone 1-2 mg/kg/day, maximum 60 mg/day) 4, 2
Regarding Ipratropium Bromide (PNSS is Normal Saline, Not Ipratropium)
Note: PNSS refers to "physiologic normal saline solution" (0.9% NaCl), which is the diluent for nebulization, NOT ipratropium bromide.
If you are asking about ipratropium bromide dosing:
For infants and children <12 years: 0.25 mg (250 mcg) nebulized every 20 minutes for 3 doses, then as needed 4
Can be mixed with salbutamol in the same nebulizer 4
Should be added to salbutamol therapy for severe exacerbations only, not as first-line therapy 4
The addition of ipratropium has not been shown to provide further benefit once the patient is hospitalized 4
For moderate-to-severe asthma exacerbations, combination therapy may reduce hospital admission risk compared to salbutamol alone 5
Common Pitfalls to Avoid
Do not underdose: Using less than 2.5 mg may result in inadequate bronchodilation and treatment failure 2
Do not use a mouthpiece: Infants require face mask delivery for effective nebulization 2
Do not delay corticosteroids: Begin systemic corticosteroids early in acute exacerbations 2
Do not add ipratropium routinely: Reserve for severe exacerbations only, as it provides no additional benefit in mild-moderate cases or after hospitalization 4