Blood management Flashcards
exam 1
Blood transfusion are given to:
Increase
1. CaO2 (blood carrying capacity
2. DO2 (delivery of O2)
Maximum allowable blood loss equation:
starting hct
DO2 is
Oxygen delivery
oxygen needs to be delivered to the tissues
DO2 (oxygen delivery) is dependent on
- oxygen content (CaO2) of blood
- blood flow of tissue (CO)
CaO2 is
Oxygen content
Oxygen content (CaO2) =
O2 dissolved in blood + O2 carried or bound by hemoglobin
DO2 =
(equation)
CaO2 x CO
VO2 is
oxygen consumption
DO2 (what is it and equation)
Oxygen delivery
CaO2 x CO
Oxygen content (CaO2) equation:
Oxygen bound to Hgb + oxygen dissolved in blood
(1.34 x Hgb x O2 sat/100) + (0.003 x PO2)
Oxygen bound to hgb calculation
1.34 x Hgb x O2sat/100)
Oxygen dissolved in blood calculation
0.003 x PO2
Normal oxygen consumption (VO2)
250 mL/min or
3.5 mL/kg/min
Mixed venous measurement reflects:
balance of O2 delivery (DO2) and consumption (VO2)
Normal SVO2 (mixed venous saturation)
65-75%
Normal PvO2
35-45 mmHg`
tachycardia and decreased SVO2 (mixed venous saturation) are suggestive of
anemia in the setting of intraoperative hemorrhage
DO2 integrates
- cardiac index
- oxyhemoglobin saturation
- hgb concentration
(rather just using hgb to decide on transfusion)
Survival in high-risk patients is associated with a DO2 greater than or equal to
600 mL O2/min/m2
DO2 (oxygen delivery) calculation:
CO (L/min) x CaO2 (mL O2/dL)
when calculating DO2, remember to
convert CO (L/min) to dL/min (end value should be O2/min)
ASA task force concludes that transfusion is usually unecessary for hgb
hgb>10
ASA task force conlucdes that transfusion is usually necessary for hgb
hgb<6
1 united of blood = (hgb)
1 unit blood = increase hgb by 1
PRBC administration: blood loss ratio
1:1 or 1:2 PRBCs: mL blood loss
One unit of PRBC will increase hct
increase hct 2-3%
Mass transfusion is defined as:
- > =10 unites over 24 hours
- Loss of 50% of blood volume within 3 hours or less
RBCs given with crystalloids and colloids issue:
Does not provide coagulation factors and can lead to dilutional coagulopaty of dilutional thrombocytopenia
Banked blood is commonly anticoagulated by
citrate
citrate issue
inhibits coagulation -> hypocalcemia,hyperglycemia (dextrose containing)
Very rapid infusion of blood can (ionized calcium and results)
reduce ionized calcium –> hypocalcemia and hyperkalemia
The lethal triad with mass transfusion
- Hypoperfusion/acidosis
- Hypothermia
- coagulopathy
FFP contains
all coagulation factors
Reversal of warfarin
FFP 5-8mL/kg
Platelet transfusion is indicated for
platelet count less than 50,000
Cryo contains
- factor VII
- con Willebrand factor
- fibrinogen (highest concentration)
Universsal RBC donor
O negative
Universal Plasma donor
AB positive
Universial RBC recipient
AB positive
Universal plasma recipient
O negative
know blood group antigen, antibody, compatability
apex
Order of prevalence of viral diseases in. banked blood
cytomegalovirus > hepatitis B > Hepatitis C > HIV