Blood bank Unit 3

emergency release

release of blood components to a patient before pretransfusion compatibility testing is complement

the physician has determined the risk of delaying transfusion outweighs the risk of ________ tested blood

transfusing incompletely

when is emergency release used?

life-threatening hemorrhage where there is not time to complete routine pretransfusion testing (trauma, massive obstetric hemorrhage, ruptured aneurysm)

what is incomplete in emergency release?

recipient testing, donor testing

when does an incomplete cross match exist?

due to warm autoantibody or clinically significant alloantibody, and there is no time to resolve it before the patient needs blood

what blood should you use in emergency release if the ABO group is unknow or not yet confirmed?

group O red cells or low-titer group O whole blood

D-negative RBCs are reserved for

females of childbearing potential (under 50) and for children, since alloimmunization to D could cause HDFN in future pregnancy

Group O, D positive are acceptable for

males and post menopausal females

why do we give out O+ blood to males and post menopausal females?

to conserve the limited O-neg inventory for the patients who need it most

what should you do before starting emergency transfusion?

collect the patient’s pretransfusion (type and screen) sample

a current specimen always takes priority over _______ for ABO/ D determination

historical records

previous records are not ______ other than group O

acceptable for issuing type-specific RBCs

what must a physician do for emergency release?

must sign a release statement attesting that the clinical situation was emergent and that the benefits of immediate transfusion outweigh the risks of transfusion before testing is complete

-this signature can be obtained after the emergency, but it must be documented

what should the documentation of emergency release have?

• patient full name and unique identifiers

• patient’s ABO and D phenotype

• A list of all units issued

• name of the person who issued the units

• name of the physician who requested the emergency release

• a tag/label on each unit

• segments pulled from each unit for cross matching

once a current sample reaches the blood bank and ABO/D is determined →

switch to ABO (and D)- identical, type-specific units

once the antibody screen is complete →

switch to full crossmathc-compatible units

why is switching a patient who received group O cells back to their own ABO-identical type low risk?

group O RBCs units contain only minimal donor anti-A/anti-B

why should you watch for passively acquired anti-A/ anti-B on reverse grouping after large-volume group O trasnfusion?

can cause a positive DAT, and is seen in small children and infants

-consult the medical director before switching components

what happens if a patient dies during the emergency?

remaining compatibility testing may be waived or abbreviated at the medical director’s discretion, but testing should still be completed enough to determine whether the transfusion contributed to the death

massive transfusion protocol

replacement of a patient’s total blood volume within 24 hours (roughly >10 RBC units in an adult) or transfusion of more than 4 RBC units within 4 hours in actively hemorrhaging patient

an MTP may or may not be ___as apart of an a

intiated

MTP is a separate, protocol-driven process ordered by a physician when ____ is anticipated

massive, ongoing blood loss

Goals of MTP

deliver red cells, plasma, and platelets in a dixed, balanced ratio to avoid diluting the patient’s remaining coagulation factors and platelets as they lose and replace large volumes of blood

MTP target goal for hemoglobin

>7.0 g/dL

MTP target goal for INR

<1.5

MTP target goal for fibrinogen

>100 mg/dL

MTP target goal for platelet count

>50,000/ uL

fixed “ round” or “packs” of components for MPT

commonly delivered in a roughly 1:1 RBC to plasma ratio, with platelets and cryoprecipitate added at set intervals issued rather than waiting for lab results between round

products are needed before ABO/Rh typing is complete

start with group O RBC’s and group AB plasma then switch to type specific products as soon as possible

MTP formally initiated and terminated

with a documented date, time, and name of person giving/ ending the order

volume overload complication

from the sheer volume of fluid and blood components infused rapidly

hypocalcemia complication

citrate anticoagulant in RBC and plasma units chelates ionized calcium as it’s rapidly infused; citrate is normally metabolized by the liver to bicarbonate, but impaired metabolism lets citrate accumulate. depresses cardiac function and worsens the hypercoagulable state

acidosis complication

related to citrate metabolism; increases the risk of hyperkalemia as H+ enters cells and K+/Na+ shift out into the plasma

hyperkalemia complication

from rapid transfusion of RBC units nearing their outdate, which have leaked intracellular potassium into the supernatant during storage; premature infants/ newborns are especially at risk. can cause cardiac arrhythmias or death

dilutional coagulopathy complication

platelets and coagulation factors become diluted as large volumes of RBCs are transfused; this is the core rationale for alse transfusion plasma and platelets during MTP, not RBC’s alone

reduced tissue oxygenation complication

stored RBC units have low 2,3-DPG, so more units may be needed to than expected to fully restore oxygen-carrying capacity

decreased opsonic activity

plasma proteins that help defend against bacterial infection as diluted as well

ABO/ Rh management during MTP

if the patient has a known antibody history, RBC units must still be antigen-negative for the specificity

what happens if there is a D-negative patient who is actively, massively bleeding?

may be switched to D-positive RBC units as the medical director’s discretion, to preserve the limited D-neg inventory. once bleeding is the controlled, the patient is switched back to D-neg units, and RH-immune globulin administration should be considered to help prevent ant-D formation