Question

You measured the following information on a patient.
Blood volume = 5 liters, Hematocrit = 47%
Hemoglobin concentration = 12.3 g/dL whole blood
Total amount of oxygen carried in blood prior to incident = 1020 mL O2
Arterial plasma PO2 = 100 mm Hg
You know that when the patient’s PO2 is 100 mm Hg, the patient’s plasma contained 0.3 mL O2/dL and that hemoglobin was 98% saturated. Unfortunately, the patient reacted poorly to a treatment and a subsequent blood test revealed a hematocrit of 40%. Estimate what hemoglobin concentration (g/dL whole blood) would be needed to maintain the same level of total oxygenation measured prior to the reaction assuming no change in Hb carrying capacity before and after the incident? PLEASE UPLOAD A PDF OF YOUR WORK.

Answer 1

The amount of oxygen combined with Hb divided by the oxygen-binding capacity of the blood is defined as the fractional oxygen saturation of Hb. Therelationship between the bound oxygen content and hematocrit are:

[O2]bound = SO2[Hb]CHb

Arithmetically, blood hemoglobin concentration and hematocrit are related by,

[Hb] = Hct [Hb]RBC

where,

[Hb] - blood hemoglobin concentration.

Hct -  hematocrit .

[Hb]RBC - average hemoglobin concentration of a single RBC

Prior to incident: [Hb] 1 = Hct1 [Hb]RBC1

After the incident: [Hb]2 = Hct2 [Hb]RBC2

From the above relation hemoglobin concentration is deduced by

([Hb] 1)/Hct1 [Hb]RBC1  =    ( [Hb]2) /Hct2 [Hb]RBC2

By assuming no change in Hb carrying capacity of RBC

([Hb] 1)/Hct1) = ( [Hb]2) /Hct2 )

Hb1 =  12.3 g/dL

Hct 1= 47%

Hct2= 40%

By applying,

12.3/47 = x/40

x= (12.7 * 40)/47 = 10.80g/dL

Volume concentration relationship is:

C=(M/V)

Mass of hemoglobin si constant.

Comparing hematocrit percentage before and after

v2/v1 = 40/47 = 0.85 = 85%

There should be 85% increase in the hemoglobin concentration,

85 % increase of 10.80 is 19.98g/dL