Salbutamol Nebulization Dilution Ratios by Age
Salbutamol should be diluted in a minimum of 2-3 mL of normal saline for adequate nebulization across all pediatric and adult age groups, with the dose of salbutamol itself varying by age and severity rather than the dilution ratio. 1
Standard Dilution Protocol
The dilution ratio is not age-dependent—rather, it is standardized across all ages:
- Minimum dilution volume: 2-3 mL of normal saline for all ages 1
- Standard dilution for most protocols: 4 mL of normal saline 2
- The saline serves as a vehicle for adequate nebulization and does not vary by patient age 1, 3
Age-Specific Dosing (Not Dilution Ratios)
What changes with age is the dose of salbutamol, not the dilution ratio:
Infants and Children Under 5 Years
- Dose: 0.15-0.30 mg/kg (minimum 2.5 mg) 1
- Dilution: Mix dose in 2-3 mL normal saline 1
- Frequency: Every 20 minutes for 3 doses, then every 1-4 hours as needed 1
Children 5-11 Years
- Dose: 1.25-5 mg 1
- Dilution: Mix in 3 mL of saline 1
- Frequency: Every 20 minutes for 3 doses, then every 1-4 hours as needed 1
Adults and Children ≥12 Years
- Dose: 2.5-5 mg 1, 4
- Dilution: Mix in 3 mL of saline 1
- Frequency: Every 20 minutes for 3 doses, then every 1-4 hours as needed 4
Critical Clinical Considerations
Continuous Nebulization for Severe Cases
- For refractory severe asthma: 0.5 mg/kg/hour up to 10-15 mg/hour 1, 4
- Requires dilution in larger volume (25-30 mL) for 1 hour of continuous nebulization 1
Combination Therapy
- When adding ipratropium bromide: Use 1.5 mL solution containing 0.25 mg ipratropium + 1.25 mg salbutamol 3
- For severe exacerbations, ipratropium 500 µg can be mixed with salbutamol in the same nebulization 4
Important Safety Points
- Never use water as diluent—it causes bronchoconstriction when nebulized 3
- Oxygen should drive nebulization in acute severe asthma; compressed air for COPD to prevent CO₂ retention 3, 4
- The solution should be iso-osmolar; hypo-osmolar solutions can cause paradoxical bronchoconstriction 5
Common Pitfall to Avoid
The misconception that dilution ratios change with age stems from confusion between dose adjustment (which is age/weight-based) and dilution volume (which remains constant at 2-4 mL normal saline for adequate nebulization across all ages). 1