Transfusion Medicine LECT Flashcards
what fatal disorder does giving Rhogam prevent?
hemolytic disease of the newborn
what are spur cells?
acanthocytes (abnormal RBC’s) seen in chronic compensated hemolytic anemia
what is the McLeod phenotype?
X-linked anomaly of the Kell blood group system in which Kell antigens are poorly detected by laboratory tests
when would you see chronic compensated hemolytic anemia or chronic granulomatous disease?
McLeod phenotype (Kell system)
lack Kx Ag on membrane of neutrophil and monocytes
- deficiency of NADH-oxidase -> no H2O2 to destroy microbes
chronic granulomatous disease (CGD)
what is the Fy(a-,b-) phenotype of the Duffy system resistant to?
plasmodium vivax
what must blood specimen be labeled with at the patients bedside?
time, date, initial of phlebotomist
- gives a permanent and unique ID of each pt
what is a type and screen?
only ABO, Rh and Ab screen performed (no crossmatch)
what is a crossmatch?
actual testing of pts serum compatibility with donor cells
what is an indirect Coombs test?
aka indirect antiglobulin test (IAT)
- detects antibodies in pts SERUM against foreign RBC’s
- Ab must NOT be bound to RBCs (either pts own or transfused) to enable detection
helps to prevent problems (before a transfusion and prenatal testing)
what is a direct Coombs test? (DAT)
detects antibodies (or complement proteins) that attached to pts RBCs.
- helps to diagnose things already going on in your blood
- detects autoimmune hemolytic anemia -> **transfusion rxn workup*
what is an antigen detection test?
commercial anti-sera mixed with patient cells
- confirmation pt +/- Ag on own cells
- usually done in conjunction with Ag typing/screening donor cells for compatibility
what does initial combination of patient sera at room temp with “commercial” suspension of RBCs detect?
“cold” antibodies, IgM
- not usually clinically significant
what is detected at 37 degrees?
“warm” Abs, IgM-IgG mixture and IgG
what are the warm antibodies?
Rh, Kell, Kidd, Duffy systems
detection of warm Abs, IgG coats the RBC membrane
AHG
Ab directed against individuals own RBC Ag
autoantibody
- can cause RBC destruction when pts RBC coated with Ab and serum contains Ab reactive to most donor cells
- difficult to interpret ABO, Rh, AbID and compatibility tests
what type of anemia:
- increase in reticulocytes, increased unconj. bilirubin, decrease haptoglobin
autoimmune hemolytic anemia (AIHA)
- if INTRAvascular hemolysis: hemoglobinemia and -uria
what do you confirm (AIHA)?
confirm with DAT and characterization of autoAb as cold or warm reactive
what is the most common autoAb?
benign cold agglutinin (4C)
- low titer, occ agglutinate cells at room temp, IgM can activate complement in vitro
what can happen if self RBC is heavily coated with Ab?
it can spontaneously agglutinate (false positive)
what can you do to prevent cold Ab from obscuring alloAbs?
prewarm the serum
what is the most common autoAb?
autoAb-I most common, also found on most donor units
- prewarm or autoabsorp serum
what type of anemia shows 70% warm rx, 16% cold?
AIHA
- idiopathic, SLE-associated, or drug induced
- positive DAT is characteristic (IgG, IgG+complement, or complement coated cells)
intravascular hemolysis that may be associated with m. pneumoniae or infectious mononucleosis
- hemolysis increases as pt exposed to cold and complement gets activated
cold agglutinin disease
- avoid cold weather!
- recipient ABO Rh type: forward and reverse typing + weak D
- RBC screening cells for unexpected antibodies in recipient serum, followed to Ab ID if necessary
- mix recipient serum with donor RBCs to detect agglutination
- if no agglutination or hemolysis -> compatible!!
crossmatch/compatibility testing
when would you see fever as an adverse effect of transfusion?
- febrile transfusion rxn
- acute or delayed hemolytic transfusion rxn
- septic shock/rxn
what does transfusion related acute lung injury (TRALI) resemble?
ARDS
- is d/t donor leukocyte Abs
what are the immediate steps that Martin wants us to know in the management of acute transfusion rxns?
- STOP transfusion***
- keep IV open with 0.9% NaCl (normal saline)***
- verify correct unit was given
- notify attending and blood bank
what types of transfusion reactions are due to RBC incompatibility?
- actue hemolytic
- delayed hemolytic
what causes febrile NON-hemolytic rxn?
Ab to donor leukocyte Ag
what causes allergic transfusion rxns?
Ab to plasma protein
what causes anaphylactic transfusion rxns?
Ab to IgA**
what is the appropriate lab response to transfusion rxns?
- check for identification errors***
- visual check of unit and post-transfusion sample for hemolysis
- serologic test or incompatibility
- send donor unit for gram stain and culture***
- F/U H/H and urine for hemolysis***
- MUST RULE OUT TRALI***
symptoms of what transfusion rxn?
- HYPOtension, hemoglobinuria, DIC, flank pain or infusion site pain
acute hemolytic rxn
symptoms of what transfusion rxn?
- unexplained rise in unconjugated Hgb, drop in H/H
delayed hemolytic rxn
symptoms of what transfusion rxn?
- fever, chills, HYPERtension
febrile non-hemolytic
symptoms of what transfusion rxn?
- urticarial rxn
allergic transfusion rxn
symptoms of what transfusion rxn?
- non-cardiogenic pulmonary edema KNOW
TRALI
- associated with passive transfer of donor granulocyte Abs
- presentation resembles ARDS
symptoms of what transfusion rxn?
- fever, chills, rigors, shock
septic tranfusion rxn
- caused by contaminated blood component
- usually platelets (because they aren’t refrigerated!)
presents within 24 hours of transfusion
- pre-existing natural IgM Abs induce complement-mediated intravascular hemolysis -> hemoglobinuria and positive DAT
- fever, chills, N/V, pain (flank, back, chest, head, infusion site), dyspnea, tachycardia, hypotension, bleeding
- renal failure is LATE complication
acute hemolytic transfusion rxn (AHTR)
what is the tx for AHTR?
discontinue transfusion and verify ID
- if mild -> observe
- if severe -> CV support, fluid resuscitation, pressor support, avoid fluid overload, maintain urine output, sodium bicard to maintain urine pH>7
occurs >24 hrs post transfusion (usually 2-6 weeks)
- extravascular hemolysis
- IgG from prior transfusion/exposure (Rh, Kell, Kidd)
- sx: unexpected anemia, fever/chills, jaundice, pain, dyspnea, RARELY renal failure
- anemia, increase LDH, increase bili, decrease haptoglobin, leukocytosis, new RBC Ab, +DAT
delayed hemolytic transfusion rxn (DHTR)
- may precipitate Sickle Cell crisis in sickle pt
what is the tx for DHTR?
most tolerate well, follow carefully
- fluid loading and diuresis only active intravascular hemolysis
what is the key to prevention of DHTR?
serologic detection of RBC Ab
- select donor units negative for RBC Ag
rise in temp >1 degree C
- may not be evident up to 30 minutes, may be delayed up to 1 hr post transfusion
- fever +/- chills, cold or rigors
- secondary sx: HA, N/V
febrile non-hemolytic transfusion rxn
- NOT life threatening, but important to exclude other causes of fever
- associated with acquired Ab to leukocyte Ag in transfused products
- attributed to pyrogenic cytokines in units during storage
what is the tx of febrile non-hemolytic transfusion rn?
+/- antipyretics (acetaminophen)
- NO ASA, dt effect on platelet function
how do you prevent febrile non-hemolytic transfusion rxn?
pre-medicate with antipyretic
- pre-storage leukocyte reduces cytokines
- plasma reduction or wash PC
mild allergic rxns common
- any type of blood component, assoc with amount of plasma transfused
- sx: pruritis, urticaria, erythema, and cutaneous flushing
- laryngeal edema(upper airway)
- bronchoconstriction (lower airway)
allergic transfusion rxn
what do you need to rule out in a pt with allergic transfusion rxn and dyspnea?
TRALI and volume overload
what is the tx for allergic transfusion rxn? how can you prevent?
intubate, O2 prn
- pre-medicate with anti-histamine to prevent mild allergic rxns
cardiovascular instability, hypotension, tachycardia, LOC, arrhythmia, shock, cardiac arrest
severe allergic (anaphylactic) transfusion rxn
what is the tx for severe allergic transfusion rxn?
intubate, O2, **epinephrine*
- diphenhydramine (esp with cutaneous sx)
- aminophylline (with bronchospasm)
what is the prevention for severe allergic rxn?
IgA deficient products, antihistamines, steroids
- can even give Epi if high risk anaphylactic
sx within hrs of transfusion
- Ab bind with MHC class 1 Ag, recognize Ag on neutrophils
- seen in multiparous women
- FFP and platelet transfusions (high levels of donor Abs)
- sx: dyspnea, hypoxemia, tachycardia, fever, hypotension, cyanosis
- **LACK of abnl breath sounds*
- NO signs of cardiac failure
TRALI
- look for NON-cardiogenic pulmonary edema**
- resolved 48-96 hrs from onset
what is the tx for TRALI?
fever and hypotension respond well to antipyretics and fluid
- supportive tx, O2
what is TRALI attributed to?
presence of Ab in the plasma of donor unit directed against HLA or granulocyte Ag on the recipient leukocytes
- also lipid inflammatory mediators
what kind of bacterial contamination is seen in blood products?
- yersinia entercolitica and pseudomonas in packed cells d/t ability to grow at low temp and high-iron environment
- staph, strep (gram-pos cocci), and salmonella, E.coli, serratia (gram-neg rods) in platelets
who should not donate blood?
- HIV+
- Hepatits since 11th birthday
- babesiosis or chagas dz
- taking tegison for psoriasis
- CJD
what is donated blood tested for?
- HepB/C
- HIV-1/2
- HTLV-1/2
- West nile virus
- syphilis
- trypanosoma cruzi
what are the components of plasma?
- leukocytes
- FFP
- albumin
- plasma protein fraction
- cryo
- plasma fraction concentration
what are the indications for RBC transfusion?
Hgb <7g/dL or Hct <21% in otherwise healthy individual with acute anemia
- Hgb 7-9g/dL in pt with cardiovascular or cerebrovascular risk factor
- HbS 30-50% in sickle cell pts to prevent stroke
what is the indication for PRBC transfusion?
symptomatic anemia
what is the contraindication for PRBC transfusion?
volume exansion, coagulation deficiency or drug treatable anemia
when are frozen/deglyced (washed) RBC indicated?
hypersensitivity to plasma proteins
what is the indication for washed RBCs?
recurrent severe allergic rxn to unwashed RBC
- can only keep stored for 24 hours after being thawed d/t risk of infection
what is the indication for irradiated RBCs?
risk of GVHD in immunocompromised pts
- gamma radiation inactivates donor lymphs
- leukocyte reduction filter utilized during administration of platelets
what is the indication for leukocyte reduced RBCs?
febrile rxns d/t leukocyte antibodies
what is the indication for platelet transfusion?
bleeding due to thrombocytopenia or prophylaxis
what is the threshold of platelet transfusion?
prophylaxis in absence of bleeding <10k platelets
- 20k to stop spontaneous bleed
- significant hemorrhage <50k
- risk of CNS bleed <100k
what is the contraindication of platelet transfusion?
plasma coagulation deficit, clinical conditions assoc with rapid platelet destruction (ITP or TTP)
what are the contents of FFP?
400mg fibrinogen
- very few RBC, WBC, or platelets
what is the indication for FFP?
deficiency of stabile plasma coagulation factors
- emergent reversal of warfarin
- is the tx for TTP
- 1 unit should increase the factor level 20-30%
what is the contraindication for FFP?
volume expansion
what are the contents of cryoprecipitate?
- 150-250 mg fibrinogen
- 80-120 units vWF
- 40-60 units factor 8
what are the indications for cryoprecipitate?
- hemophilia A
- von Willebran disease
- hypofibrinogenemia DIC
- bleeding uremia
- topical glue ingestion
what is the threshold for cryoprecipitate transfusion?
fibrinogen <80mg/dL with ongoing bleed
what is the kleinhaur-Betke test?
measures fetal Hgb in mothers circulation
what is the Rhogam dosing?
- full dose at 26-28 weeks gestation (or within 72hrs delivering), or mini dose for termination before 12 weeks
- full IM dose to prevent alloimmunization (15mL Rh + RBCs or 30mL whole blood)
pooled plasma from up to 2500 donors
- virus inactivated using solvent detergent
- inactivates enveloped viruses (HIV, HepB)
solvent detergent treated plasma (SDP)
what are the hazards of granulocyte-pheresis?
allergic and febrile reactions
- GVHD unless irradiated to inactive lymph
what does Martin want us to know about blood administration?
- ID patient
- unit verification
- * clerical verification
transfusion time must be completed within how many hours?
4
- unused units MUST be returned within 30 minutes of release from blood bank
what size needle is used for transfusion?
18 gauge needle
- ONLY normal saline can be transfused with blood!
what is the rule of thumb for transfusion management?
1 unit FFP per every 2-3 units of RBC
what two disorders is plasma pheresis indicated?
TTP and HUS
