What volume of 0.5% salbutamol solution should be mixed with normal saline to achieve a 2.5mg dose in a 3ml solution?

Salbutamol Nebulization Dosing

For a 2.5mg dose of salbutamol using 0.5% solution (5mg/mL), you need 0.5mL of salbutamol solution mixed with 2.5mL of normal saline to achieve a total volume of 3mL.

Calculation Breakdown

• The 0.5% salbutamol nebulizer solution contains 5mg/mL 1
• To deliver 2.5mg, you need: 2.5mg ÷ 5mg/mL = 0.5mL of salbutamol solution 1
• Add 2.5mL of normal saline to reach the minimum 2-3mL total volume required for adequate nebulization 1
• Final mixture: 0.5mL salbutamol + 2.5mL saline = 3mL total volume 1

Standard Pediatric Dosing Protocol

• Minimum dose: 2.5mg (0.5mL of 0.5% solution) every 20 minutes for 3 doses, then 0.15-0.30mg/kg up to 10mg every 1-4 hours as needed 1
• Always dilute in a minimum of 2-3mL of saline solution for adequate nebulization 1
• Oxygen is the preferred gas source for nebulization 1

Alternative Dosing Considerations

• For continuous/prolonged nebulization: 0.5mg/kg per hour up to 10-15mg/hour diluted in 25-30mL of saline for 1 hour of nebulization 1
• Levalbuterol (R-salbutamol) may be used at half the racemic albuterol dose, as it contains only the therapeutically active R-enantiomer 1, 2

Important Clinical Notes

• The 2.5mg starting dose represents the minimum effective dose and can be repeated and adjusted until desired clinical effect is achieved, unless symptomatic tachycardia develops 1
• Research suggests 3mg may be an optimal dose for bronchodilation with fewer systemic side effects compared to higher doses 3
• Supplemental oxygen may be needed when compressed air-driven nebulizers are used or when oxygen flow rate is inadequate to maintain oxygen saturation 1