Tools

Respiratory Calculators

Evidence-based formulas used daily in the ICU and ER. Every calculator shows the underlying equation and clinical context.

ABG Analysis

Identify acid-base balance, oxygenation status, and treatment considerations.

ABG · Acid-Base
ABG Interpretation
Complete acid-base analysis with compensation assessment and oxygenation status.
pH · PaCO₂ · HCO₃⁻ · PaO₂ · FiO₂
ABG · Oxygenation
A-a Gradient
Assesses efficiency of gas exchange across the alveolar membrane.
P(A-a)O₂ = PAO₂ − PaO₂

Ventilator Management

Calculations for ventilator settings and lung mechanics.

Ventilator
Tidal Volume
Calculate IBW-based tidal volume for lung-protective ventilation strategies.
VT = 6–8 mL/kg IBW
Ventilator
Desired PaCO₂
Determine the RR, VT, or VE adjustment needed to reach a target PaCO₂.
RR₂ = (RR₁ × PaCO₂₁) / PaCO₂₂
Ventilator
Lung Compliance
Measure static or dynamic compliance to assess ventilator mechanics at the bedside.
C = VT / (Pplat − PEEP)

Labs & Hemodynamics

Supporting calculations for a complete clinical picture.

Labs
Anion Gap
Identify unmeasured anions in metabolic acidosis workup.
AG = Na⁺ − (Cl⁻ + HCO₃⁻)
Hemodynamics
Cardiac Output (Fick)
Estimate cardiac output using oxygen consumption and arteriovenous difference.
CO = VO₂ / (CaO₂ − CvO₂)