Airway Resistance Calculator

Calculates inspiratory airway resistance from PIP, Pplat, and inspiratory flow.

Inputs

The equation uses L/s, so flow is divided by 60.
Color mode links each input to the matching equation term and solving arithmetic.

Equation and Work

Equation:
Solving steps:
PIP − Pplat
—
cmH₂O
Flow
—
L/s
Raw
—
cmH₂O/L/s
Normal/reference: Raw <3 cmH₂O/L/s; ventilated patient reference range 5–10 cmH₂O/L/s.

Clinical Significance

Airway resistance is estimated from the pressure difference between peak and plateau pressure divided by inspiratory flow.

Raw helps identify a resistive load, such as bronchospasm, secretions, tube obstruction, or high flow effects.

The estimate works best with passive breathing, constant inspiratory flow, and a reliable plateau pressure.

References (APA 7th Edition)

  1. Attached equations reference supplied by the user for calculator equation confirmation.