BLOOD PRODUCTS AND ADMINISTRATION Flashcards
what is the normal Hg of men vs. women?
what is the normal Hct of men vs. women?
Hg: men ≥ 14gm/dL women ≥ 12gm/dL
(Hct = 3X Hg)
Hct: men ≥ 42% women ≥ 38%
define hematocrit
the volume percentage of RBCs in blood; also known as PCV (packed cell volume)
when was whole blood first given in US?
1960s
when was component therapy given?
1970s-1980s
during what period were infectious concerns/transfusion triggers debated?
1970s-1990s
during what period did (reconstituted) whole blood return as component transfusion ratios?
1990-2005
how long have we seen reduced infectious risks, revision of transfusion triggers and computerization of blood banks?
since 2005
name two types of blood products
packed RBCs, fresh whole blood
in what instances should PRBCs be administered?
severe anemia
define anemia
reduced oxygen carrying capacity
define severe anemia
Hg
define splanchnic
term used to describe organs in the abdominal cavity (visceral organs)
what risks are associated with severe anemia and perioperative anemia (hence the need for PRBC administration)?
inadequate splanchnic and preportal oxygen delivery – acute kidney injury (AKI) and mortality
how does the 1988 NIH consensus conference define perioperative determinants for PRBC necessity?
Hg > 10gm/dL – rarely requires PRBCs
Hg
how are the liberal vs. conservative/restrictive threshold camps defined?
liberal transfusion threshold ≤ 9-10gm/dL
conservative/restrictive transfusion threshold ≤ 7-8gm/dL
according to 2006 ASA recommendations, define transfusion indications
Hg > 10gm/dL – transfusion rarely indicated
Hg
according to 2006 ASA recommendations, the determination of whether intermediate Hg concentrations (6-10gm/dL) justify or require RBC transfusion should be based on what?
should be based on pt’s risk for complications of inadequate oxygenation
define allogeneic
tissues or cells that are genetically dissimilar and hence immunologically incompatible, although from individuals of the same species
what is in PRBCs?
(contains as much Hg as) whole blood with most of plasma removed, CPDA/CPDA-1
what are the components/functions of CPDA
citrate – anticoagulant
phosphate – pH buffer
dextrose – nutrition
adenine – for ATP synthesis (extends storage time from 21-35 days)
what are the nutritional components of CPDA-1 that increase shelf life?
CPDA-1/AS-1 – adsol (adenine, glucose, mannitol and NaCl)
CPDA-1/AS-3 – nutricel (adenine, glucose, citrate and phoshpate)
CPDA-1/AS-5 – optisol (adenine, dextrose, mannitol and NaCl)
what percentage of transfused RBCs must remain in circulation for 24hr after infusion?
70%. RBCs that survive 24hr after transfusion disappear from the circulation at a normal rate
what is the Hct of whole blood?
40%
what is the Hct/total volume/plasma volume of CPDA?
Hct 65%, total volume 250ml, plasma volume, 70ml
what is the Hct/total volume/storage sln volume of CPDA-1
Hct 40%, total volume 310ml, storage sln volume 100ml
which crystalloid are PRBCs normally reconstituted with and why?
NS; Ca2+ in LR activates clotting factors
how does the pH of PRBCs change with time?
become more acidic: pH from 7.55 to 6.71 over 35d
how does the plasma Hg (mg/dl) of PRBCs change with time?
increases from 0.5mg/dl to 246mg/dl over 35d
how does the plasma potassium (mEq/L) of PRBCs change with time?
increases from 4.2mEq/L to 76mEq/L over 35d
how does the plasma sodium (mEq/L) of PRBCs change with time?
decreases from 169mEq/L to 122mEq/L over 35d
how does the blood dextrose (mg/dl) of PRBCs change with time?
decreases from 440mg/dl to 84mg/dl over 35d
how does the 2,3-diphosphoglycerate (µM/ml) of PRBCs change with time?
decreases from 13.2µM/ml to 1.0µM/ml over 35d
how does the survival percentage of PRBCs change with time?
decreases from 100% to 71% over 35d
how do ‘blood type’ and surface antigens/plasma antibodies relate?
blood type = surface antigen expressed; has opposite plasma antibody
type A blood: A surface antigen, B plasma antibody
type B blood: B surface antigen, A plasma antibody
type AB blood: A&B surface antigens, no plasma antibodies
type O blood: no surface antigens, A&B plasma antibodies
describe the negative effect of giving ABO incompatible blood
if plasma antibodies target the surface antigen expressed on transfused RBCs, the antibodies activate complement agglutination (clumping), leading to hemolysis
what percentage of the population is Rh(D)-positive (express surface antigen D)?
85%
if blood typing produces clumping, what does it mean?
administration of the antigen specific antibody has produced a positive result, meaning that the RBCs express the targeted antigen
what is the purpose of the type and screen?
determines ABO-Rh blood type and presence of most commonly found unexpected antibodies in the pt’s serum
how are serum antibodies screened?
donor serum is added to commercially supplied RBCs (with optimal number of antigens to react to most common antibodies to cause a hemolytic reaction)
how is a type and crossmatch performed?
a “test transfusion” in a test tube – donor RBCs mixed with recipient plasma to detect a potential for serious transfusion reaction
how long (total) do the three phases of type and crossmatch take?
45min
what are the three phases of the type and crossmatch?
- immediate – (room temp) major ABO rxns
- incubation – (37ºC) Rh and other major antibody rxns in albumin or low-ionic strength salt solution; no agglutination
- antiglobulin – addition of anti globulin sera to incubated test tubes; tests lesser antibody rxns; agglutination
why are the incubation and antiglobulin phases of T&C especially important?
the antibodies appearing in these phases are capable of causing serious hemolytic rxns
why not T&C every patient for surgery?
need 1-2d minimum for PRBCs to be removed from circulation and reserved for pt – leading to higher incidence of PRBC expiration
Is a T&C necessary for all pts?
*yes for ABO/Rh compatibility
what are the reaction prevention percentages of the three typing procedures?
blood typing (alone) prevents reactions in 99.8% of cases type and screen prevents serious reactions in 99.94% of cases type and cross prevents serious reactions in 99.95% of cases
what are the best, next best, and most often scenarios of blood transfusion in trauma and emergency cases?
Best: typed and partially crossed (ABO-Rh & immediate-phase (major ABO rxns)
Next best: typed and uncrossed (caution for those who have previously had transfusion or previously pregnant)
Most often: type O, Rh-negative uncrossed (PRBCs)
why is type O, Rh-negative most often given in trauma, emergency scenarios?
type O blood lacks A and B antigens; cannot be hemolyzed by anti-A or -B antibodies in the recipients blood
why are type O, Rh-negative PRBCs (vs. whole blood) given in trauma, emergency scenarios?
some type O donors produce high titers of hemolytic ommunoglobulin (IgG), IgM, anti-A and anti-B antibodies; use of PRBCs reduces risks associated with these
describe what is meant by the point of no return when administering O-negative blood in trauma, emergency situations
switching to correct T&C blood after administration of > 2-4 units O-negative PRBCs can cause major intravascular hemolysis of donor RBCs by increasing titers of anti-A and anti-B, thus increasing risk of immune system response
what are the positive effects of giving PRBCs?
1 unit PRBCs increases Hg by 1-2gm/dl, Hct by 3-5%
what are the four major negative effects of PRBCs?
- decreased 2,3-DPG levels (decreased O2 offloading)
- thrombocytopenia (low platelets decreased clotting/free bleeding)
- decreased factor V, fibrinogen, factor VII levels (decreased clot formation/coagulation)
- citrate intoxication (can lead to hypocalcemia => hypotension, decreased pulse pressure, arrhythmias)
how does blood loss change as the classification for acute hemorrhage increases?
blood loss increases from 750 to ≥ 2000ml from class I to class IV (from 15 to ≥ 40% of volume)
how does pulse, blood pressure, and pulse pressure change from class I to class IV acute hemorrhage?
pulse increases from 100 to ≥ 140 from class II to IV blood pressure decreases from class II to IV puls pressure remains normal (or increased) for class I, but decreases as the class of hemorrhage increases