fick_cardiac_output: Cardiac Output (Fick's Formula)

In cliot: Clinical Indices and Outcomes Tools

Cardiac Output (Fick's Formula)

Description

Calculates Cardiac Output using the Fick principle, which states that the blood flow through an organ is equal to the uptake or release of a substance by that organ divided by the arteriovenous difference of that substance. In this context, oxygen is the substance used.

Usage

fick_cardiac_output(hemoglobin_g_dl, sa_o2_percent, sv_o2_percent,
                    vo2_ml_min, pa_o2_mmhg = NULL, pv_o2_mmhg = NULL)

Arguments

hemoglobin_g_dl	Numeric. Hemoglobin concentration in g/dL.
sa_o2_percent	Numeric. Arterial Oxygen Saturation percentage (e.g., 98).
sv_o2_percent	Numeric. Mixed Venous Oxygen Saturation percentage (e.g., 75).
vo2_ml_min	Numeric. Oxygen Consumption in mL/min. This can be a measured value or an estimated value (often 125 mL/min/m2 * BSA).
pa_o2_mmhg	Numeric (Optional). Arterial partial pressure of oxygen. Used to calculate dissolved oxygen content.
pv_o2_mmhg	Numeric (Optional). Venous partial pressure of oxygen. Used to calculate dissolved oxygen content.

Value

A list containing:

Cardiac_Output_L_min	The calculated cardiac output in Liters per minute.
Arterial_O2_Content_mL_dL	Calculated arterial oxygen content (CaO2).
Venous_O2_Content_mL_dL	Calculated venous oxygen content (CvO2).
AV_O2_Difference_mL_dL	The arteriovenous oxygen difference.

References

Fick A. Uber die messung des blutquantums in den herzventrikeln. Sitzungsberichte der Physikalisch-Medizinischen Gesellschaft zu Wurzburg. 1870;2:16.

Examples

# Example 1: Standard Values
# Hgb 13 g/dL, SaO2 98%, SvO2 70%, VO2 250 mL/min
fick_cardiac_output(13, 98, 70, 250)

# Example 2: Including Dissolved Oxygen
# Hgb 10 g/dL, SaO2 100%, SvO2 60%, VO2 200 mL/min, PaO2 100, PvO2 35
fick_cardiac_output(10, 100, 60, 200, 100, 35)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.