Use O2 Content Blood when you need to compute arterial oxygen content from hemoglobin, saturation, and PaO2. Enter Hemoglobin, Saturation fraction, and PaO2 using the definitions and units below so the result can be reproduced.

Hemoglobin

A finite measured or assumed value greater than or equal to 5e-324, expressed in g/dL.

Saturation fraction

A finite measured or assumed value from 0 through 1.

PaO2

A finite measured or assumed value greater than or equal to 0, expressed in mmHg.

The published tool contract uses this rule: Compute arterial oxygen content from hemoglobin, saturation, and PaO2.^[1]

Oxygen content

The calculated oxygen content in mL/dL.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small. It is informational and cannot diagnose a condition, select treatment, or replace professional interpretation of the original measurements. Saturation fraction must remain between 0 and 1.

Retain the original Hemoglobin, Saturation fraction, and PaO2 values and their units alongside the result. O2 Saturation Category is useful when you instead need to classify peripheral oxygen saturation as hypoxemic (below 90), borderline (90 to below 95) or normal (95 to 100). Bohr Effect Shift provides another view by helping you compute the Bohr effect shift of hemoglobin oxygen affinity as shiftLogP50 = phiBohrCoefficient x (pH2 - pH1), where phi is the signed Bohr coefficient, negative by convention and defaulting to -0.48 for human whole blood.

• O2 Saturation Category

  Classify peripheral oxygen saturation as hypoxemic (below 90), borderline (90 to below 95) or normal (95 to 100).

• Bohr Effect Shift

  Compute the Bohr effect shift of hemoglobin oxygen affinity as shiftLogP50 = phiBohrCoefficient x (pH2 - pH1), where phi is the signed Bohr coefficient, negative by convention and defaulting to -0.48 for human whole blood.

• Anthocyanin Content

  Compute anthocyanin content in micrograms per gram of dry mass as the corrected absorbance divided by the dry mass times an extinction scale factor that defaults to one hundred; apply any baseline correction to the absorbance upstream before passing it in.