Systems and method for homeostatic blood states

A method of administering a calculated volume of packed red blood cells (PRBC) to achieve a therapeutically appropriate post-transfusion Hct (ptHct) in a patient requiring such treatment, comprising the steps of:

• (a) determining baseline venous blood hematocrit (tHct) in the patient's blood sample just before starting PRBC transfusion and about 20 minutes after stopping maintenance rate intravenous crystalloid infusion for equilibration;
• (b) determining tRCM of patient based on tHct;
• (c) determining the ideal blood volume (IBV) of the patient;
• (d) calculating a therapeutically effective amount of packed red blood cells (PRBC) for transfusion into the patient to achieve the post-transfusion hematocrit (ptHct), wherein the therapeutically effective amount is directly proportional to k, where k is equivalent to about 30% of the IBV value, further wherein the therapeutically effective amount of packed red blood cells (PRBC) is defined by the mathematical formula:
• PRBC=(ptHct×tBV)−tRCM;
• (e) administering to the patient the calculated therapeutically effective amount of packet red blood cells to achieve a therapeutically appropriate post-transfusion Hct in the patient's blood.

A method for determining an ideal intravascular fluid replacement strategy in a patient requiring such strategy, comprising:

• a. determining hemoglobin concentration (Hb) in the patient's blood sample;
• b. determining the ideal blood volume (IBV) of the patient;
• c. determining the ideal plasma volume (IPV) according to the mathematical formula:
• IPV=0.6 IBV;
• d. determining a target red cell mass (tRCM) corresponding to the patient's hemoglobin concentration based on a predetermined mean cell hemoglobin concentration (MCHC) parameter, wherein steps (a) to (d) can occur in any order;
• and
• e. determining tBV according to the mathematical formula:
• tBV=0.5(IBV+IPV+tRCM),
• whereby, the physiologic target blood volume (tBV) can be achieved by appropriate fluid replacement.

A method for diagnosing and treating dehydration in a patient requiring such treatment, comprising:

• (a) obtaining a first blood sample from the patient at time T1 and determining a first blood hematocrit (Hct) value;
• (b) estimating the patient's ideal blood volume (IBV) to determine volume loading test-plasma (VLT) and volume expansion (PVE) values for calculating Hct values;
• (c) administering to the patient an infusion and begin collection of patient's urine, wherein the infusion is a high rate intravenous bolus of isotonic crystalloid infusion, wherein the volume for infusion into the patient is read off a plasma volume expansion (PVE) column, wherein the plasma expansion column forms part of a nomogram;
• (d) inducing blood equilibration by stopping the infusion and waiting for sufficient time to allow the patient's blood to equilibrate;
• (e) obtaining a second blood sample from the patient at time T2 and determining a second Hct value;
• and
• (f) determining the hydration state of the patient, wherein the patient had mild dehydration immediately prior to step (a) if blood Hct decreases more than 1% isoosmotically between the first and second Hct values, wherein the patient had severe isoosmotic dehydration prior to step (a) if blood Hct decreases more than 1% isoosmotically between the T1 and T2 blood samples in which case the patient is provided with another infusion in accordance with step (c), which is repeated until target hydration is achieved,
• wherein if Hct decreases by less than 1% isoosmotically between the T1 and T2 blood samples and if urine output of the patient during steps (c) and (d) exceeded 20 ml/hour, the patient's plasma has achieved a target level of hydration and no further medical intervention required,
• wherein if Hct decreases by less than 1% isoosmotically between the T1 and T2 blood samples and if urine output of the patient during steps (c) and (d) was approximate to or less than 20 ml/hour, the patient's plasma is suspected of over-target state plasma dilution and patient is administered an I.V. diuretic and hydration level of the patient is monitored until target hydration is achieved, and
• wherein if Hct increases by more than 1% and if urine output of the patient during steps (c) and (d) exceeded 20 ml/hour then patient is administered an I.V. diuretic and state of hydration of the patient is monitored until stabilization.

An apparatus for increasing blood hemoglobin concentration in a patient requiring such treatment, comprising:

• (a) one or more processors;
• and
• (b) a memory communicatively coupled to the one or more processors, the memory including one or more sequences of one or more instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:
• (i) acquiring hemoglobin concentration (Hb) and hematocrit (Hct) in a patient's blood sample;
• (ii) acquiring the ideal blood volume (IBV) of the patient;
• (iii) determining a first red cell mass value corresponding to the patient's hemoglobin concentration based on a predetermined mean cell hemoglobin concentration (MCHC) parameter;
• (iv) determining a target red cell mass (tRCM-B) of the patient based on the predetermined MCHC;
• (v) calculating a therapeutically effective amount of packet red blood cells for transfusion into a patient to increase the patient's red cell mass to approximately the tRCM-B level, wherein the therapeutically effective amount is directly proportional to k, wherein k is equivalent to about 30% of the IBV value, further wherein the therapeutically effective amount of packet red blood cells (PRBC) is defined by the mathematical formula:
• k((target red cell mass)−(first red cell mass)),
• wherein steps (i) to (v) can occur in any order;
• and
• (c) producing the calculated therapeutically effective amount of packet red blood cells that can be administered for increasing the hemoglobin concentration in the patient's blood.

An apparatus for determining a calculated volume of packed red blood cells (PRBC) to achieve a therapeutically appropriate post-transfusion Hct (ptHct) in a patient requiring such treatment, comprising:

• (a) one or more processors;
• and
• (b) a memory communicatively coupled to the one or more processors, the memory including one or more sequences of one or more instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:
• (i) acquiring baseline venous blood hematocrit (tHct) in the patient's blood sample just before starting PRBC transfusion and about 20 minutes after stopping maintenance rate intravenous crystalloid infusion for equilibration;
• (ii) determining tRCM of patient based on tHct;
• (iii) determining the ideal blood volume (IBV) of the patient;
• (iv) calculating a therapeutically effective amount of packed red blood cells (PRBC) for transfusion into the patient to achieve the post-transfusion hematocrit (ptHct), wherein the therapeutically effective amount is directly proportional to k, where k is equivalent to about 30% of the IBV value, further wherein the therapeutically effective amount of packed red blood cells (PRBC) is defined by the mathematical formula:
• PRBC=(ptHct×tBV)−tRCM;
• and
• (v) producing the calculated therapeutically effective amount of packet red blood cells to be administered to the patient to achieve a therapeutically appropriate post-transfusion Hct in the patient's blood.