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Calcimator

Cardiac Output (Fick) Calculator

Calculate cardiac output using the Fick principle from oxygen consumption and arteriovenous oxygen difference.

Inputs

mL/min
g/dL
%
%
mmHg
mmHg
sq ft

Results

Cardiac Output

5.56 L/min

Cardiac Index

2.93 L/min/m²

Arterial O2 Content (CaO2)18.68 mL/dL
Venous O2 Content (CvO2)14.19 mL/dL
A-V O2 Difference4.49 mL/dL
O2 Delivery (DO2)1,039 mL/min
O2 Extraction Ratio24.1%
How to Use This Calculator
  1. Enter oxygen consumption (VO₂ in mL/min), hemoglobin (g/dL), and arterial O₂ saturation (SaO₂ %).
  2. Set mixed venous O₂ saturation (SvO₂ %), arterial PaO₂, mixed venous PvO₂, and body surface area (m²).
  3. Review Cardiac Output (L/min), Cardiac Index (L/min/m²), CaO₂, CvO₂, and A-V O₂ Difference.
  4. Normal resting CO is 4–8 L/min; CI < 2.2 L/min/m² suggests cardiogenic shock.

How the result changes with Arterial O2 saturation (SaO2)

Arterial O2 saturation (SaO2)Cardiac OutputCardiac Index
550 L/min0 L/min/m²
680 L/min0 L/min/m²
8314.87 L/min7.83 L/min/m²
956.36 L/min3.35 L/min/m²

What each input means

VO2 (O2 consumption)
Oxygen consumption, typically 200-300 mL/min at rest.
Hemoglobin
Blood hemoglobin concentration.
Arterial O2 saturation (SaO2)
Arterial oxygen saturation from ABG or pulse oximetry.
Mixed venous O2 saturation (SvO2)
Mixed venous saturation from PA catheter. Normal 60-80%.
Arterial PaO2
Partial pressure of oxygen in arterial blood.
Mixed venous PvO2
Partial pressure of oxygen in mixed venous blood.
Body surface area
Body surface area for cardiac index calculation.

What each result means

Cardiac Output
CO by Fick principle. Normal 4-8 L/min.
Cardiac Index
CO normalized to BSA. Normal 2.5-4.0 L/min/m².
Arterial O2 Content (CaO2)
Oxygen content of arterial blood. Normal 16-22 mL/dL.
Venous O2 Content (CvO2)
Oxygen content of mixed venous blood. Normal 12-17 mL/dL.
A-V O2 Difference
Arteriovenous oxygen difference. Normal 3.5-5.5 mL/dL.
O2 Delivery (DO2)
Systemic oxygen delivery. Normal 800-1200 mL/min.
O2 Extraction Ratio
Fraction of delivered O2 consumed. Normal 22-32%.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    VO2 (O2 consumption) = 250, Hemoglobin = 14, Arterial O2 saturation (SaO2) = 98, Mixed venous O2 saturation (SvO2) = 75 = 7 input(s) provided
  2. Calculate Cardiac Output
    5.56 = 5.56
  3. Calculate Cardiac Index
    2.93 = 2.93
  4. Calculate Arterial O2 Content
    Arterial O2 Content = hemoglobin * 1.34 * (saO2 / 100) + 0.003 * paO2
    18.68 = 18.68
  5. Calculate Venous O2 Content
    Venous O2 Content = hemoglobin * 1.34 * (svO2 / 100) + 0.003 * pvO2
    14.19 = 14.19

Engine last updated .

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