NICU Calculator

Surfactant Dose Calculator

Calculate estimated neonatal surfactant dose volume by weight for common surfactant products. This tool is for respiratory therapy education and must be checked against the provider order, product insert, and facility policy.

Educational Tool Only

Do not use this calculator as a medication order. Surfactant is a neonatal medication administered intratracheally by trained clinicians. Always verify the ordered product, dose, concentration, route, aliquot method, patient weight, vial size, redosing criteria, and institutional policy before administration.

Calculate Surfactant Dose Volume

Choose the product and enter weight. Preset values use commonly listed mL/kg dosing for selected products.

Dose Volume
mL
Enter weight and product to calculate estimated dose volume.

Surfactant Dose Formula

Dose volume = weight in kg × ordered dose in mL/kg

Example: 1.2 kg infant receiving 2.5 mL/kg
Dose volume = 1.2 × 2.5 = 3.0 mL

Common Product Presets Included

ProductPreset DoseNotes
Curosurf / poractant alfaInitial: 2.5 mL/kg
Repeat: 1.25 mL/kg
Product information describes an initial recommended dose of 2.5 mL/kg birth weight and repeat doses of 1.25 mL/kg.
Survanta / beractant4 mL/kgCommon product dosing is volume-based at 4 mL/kg.
Infasurf / calfactant3 mL/kgProduct information describes a dose of 3 mL/kg birth weight.

Dose Follows the Baby’s Weight

For volume-based surfactant dosing, the weight is the multiplier.

Remember:
If the dose is mL/kg, multiply by kg. A 1 kg infant receives the mL/kg amount. A 2 kg infant receives twice that amount.

Surfactant Can Rapidly Change Lung Mechanics

After surfactant administration, oxygenation and lung compliance may improve quickly. Ventilator pressures, FiO₂, and monitoring may need prompt reassessment according to the care team and facility protocol.

Verify
Product, dose, route, aliquot method, weight, and order.
Monitor
SpO₂, heart rate, tube position, breath sounds, and ventilator pressures.
Watch for events
Desaturation, bradycardia, airway obstruction, reflux into ET tube, or rapid compliance change.
Reassess support
FiO₂ and pressures may need adjustment as lung mechanics improve.

Avoid These Errors

Using grams as kg
1200 g is 1.2 kg, not 1200 kg. The calculator converts grams if selected.
Mixing product doses
Different surfactants have different volume-based dosing.
Ignoring repeat-dose differences
Curosurf initial and repeat doses are different.
Skipping policy verification
Always follow the provider order, product insert, and facility policy.

Connect Surfactant to Oxygenation Severity

Surfactant therapy connects neonatal respiratory distress, oxygenation support, MAP, OI/OSI, and ventilator management.