Respiratory
Minute Ventilation Calculator
Respiratory rate times tidal volume: the air moved per minute, which sets how fast CO2 is cleared.
Formula
(RR * Vt) / 1000
How it is used
- Alveolar ventilation, rate × (Vt − dead space), is what clears CO₂; minute ventilation includes the dead space.
- With CO₂ production and dead space unchanged, PaCO₂ falls in proportion as ventilation rises: new rate = current rate × current PaCO₂ ÷ target PaCO₂.
- After intubation for metabolic acidosis (DKA, salicylates), match the patient’s own minute ventilation, often 15–25 L/min, and recheck a gas within about 30 minutes.
- A rising PaCO₂ on unchanged settings means more CO₂ production (fever, shivering, overfeeding, bicarbonate) or more dead space (PE, low output, auto-PEEP).
Related one-pagers
- Ventilator Modes and SettingsPaCO₂ and pH · Rate or Vt (minute ventilation = RR × Vt)
- ABG Interpretation in 6 StepsMetabolic acidosis · Keep minute ventilation high · Standard settings drop pH fast
- BurnsProgressive tachypnea · >25/min, or minute ventilation >12 L/min
- Aerosol Drugs and HumiditySwitch an HME to a heated humidifier for thick, copious or bloody secretions; exhaled volume under 70% of delivered; temperature under 32 °C; minute ventilation over 10 L/min; low-tidal-volume ventilation; or NIV.
Related calculators
- A-a Gradient
- Alveolar Gas Equation (PAO₂)
- Arterial Oxygen Content (CaO₂)
- Dead Space Fraction (Bohr)
- Driving Pressure
- Dynamic Compliance
- O₂ Extraction Ratio
- Oxygen Consumption (VO₂)
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For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.