Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
50 Cards in this Set
- Front
- Back
|
Causes of hypotensive transfusion reaction
|
1. Vasogal reaction
2. sever allergic reaction to: - IgA or other plasma protein - Ig aggregates in donor unit - Drugs or other reagin in donor unit 3. Hemolytic transfusion reaction 4. bacterial contamination 5. Bradykinin-mediated reaction 6. massive citrate infusion 7. air embolus 8. unrelated to, but conincidental with, transfusion: - medication or latex allergy - dialysis membrane exposure (kinin elaboration by dialysis) - bleeding - cardiac arrhythmia - pulmonary embolus |
|
|
Anaphylactoid vs. anaphylactic reaction
|
1. Anaphylactic: involves sensitized patient with preformed IgE on basophils and mast cells with allergen binding leading to degranulation
2. Anaphylactoid - different mechanism: immune complexes involving Ig other than IgE can lead to complement activation and generation of anaphylotoxins (C3a, C5a, C4a) with subsequent activation of mast cell and basophils |
|
|
IgA deficiency is relatively common (1 in 1200), and IgA mediated anaphylactoid transfusion reactions are __
|
- still uncommon among IgA deficient people
- requires high titer, IgA-specific Ig |
|
|
____ signs and symptoms are helpful in distinguishing a hypotensive anaphylactic transfusion reaction from hemolytic transfusion reaction
|
cutaneous manifestations in anaphylactic/anaphylactoid reactions
|
|
|
Patients taking ACE inhibitors are at risk for __ transfusion reactions
|
hypotensive reactions due to excess bradykinin
- ACE inhibitors inhibit the main degradation pathway - negative surface contact activation of Hageman factor (factor XII) leads to release of bradykinin from HMWK |
|
|
ACE inhibitors in general have a half life of ___
|
12 hours
- stopping the drug 48-72 hours prior to apheresis or transfusion may eliminate risk of hypotension Note: leukoreduction filters can activate bradykinin system |
|
|
repeated use of a single donor to supply components for a single patient is okay?
|
- if approved by TM MD and ordered by pt's MD
- frequency of donation can be as often as every 3 days as long as donor Hb meets or exceeds minimum requirement for allogeneic donation |
|
|
Autologous donors: minimum Hb and HCT
|
Hb at least 11 g/dl
HCT at least 33% |
|
|
Contraindications for autologous blood donation
|
- infection and risk of bacteremia
- aortic valve surgery - unstable angina - uncontrolled seizure - MI or stroke in last 6 mos - significant cardiac or pulm dz and not cleared by MD - cyanotic heart dz - uncontrolled hypertension |
|
|
Ideally, the last autologous blood collection should be __ before surgery
|
at least 72 hours (3 days), preferably longer
|
|
|
Acute normovolemmic hemodilution, simultaneous infusion of __ml of crystalloid for each 1 ml of blood withdrawn
|
3ml crystalloid: 1ml blood
- blood is stored at RT until reinfusion (w/in 8 hours) - units are reinfused in the reverse order of withdrawal (last unit taken is first to go back in) - benefits: lower viscosity allows for decreased peripheral resistance and increased cardiac output (improved O2 delivery) and less red cell mass lost to the surgical field |
|
|
Acute normovolemic hemodilution units can be stored at RT for ___ or ___ in a monitored refrigerator
|
8 hrs at RT
24 hrs refrigerated |
|
|
Positive bacterial cx from blood recovered from surgical fields have been reported, but clinical infection is __
|
rare
|
|
|
Preop Hb requirement for acute normovolemic hemodilution
|
12mg/dl
|
|
|
intraoperative blood recovered with and without processing: storage time and temp
|
w/ processing:
- RT: 4 hours - 1-6 C: 24 hours w/out processing: - RT or 1-6 c: 4 hours only |
|
|
AABB standards require that __% of plateletpheresis units contain ____ plts
TM p140 |
90% have 3 x 10^11 plts
|
|
|
Plateletpheresis donors can donate __ frequently than whole blood donors
|
- more frequently
- interval at least 2 days, but no more that twice in one week and no more than 24 times in one year - must wait 8 weeks after whole blood donation |
|
|
Aspirin and plateletpheresis donation
TM p141 |
- must wait 36 hrs
(these units are often the sole source of plts for a recipient) |
|
|
Platelet count prior to plateletpheresis
|
- not required for first donation or if interval between donations is 4 weeks+
- if interval less than 4 weeks, plt > 150 required |
|
|
Total amount of plasma collected during plateletpheresis should not exceed __ mls
|
500mls maximum
- up to 600ml if donorr >175lbs |
|
|
When should a HCT be measured on an plateletpheresis unit?
When should a sample of plt donor blood accompany the apheresis plt unit? |
- if RBC are visible
- FDA requires that if a plateletpheresis unit contains >2ml RBC, a sample of the donor blood for compatibility testing should be attached to the container!! |
|
|
leukocyte reduced apheresis plts must have ___
|
less than 5 x 10^6 WBCs
TM p142 |
|
|
During plateletpheresis, if a donor loses >100ml of blood, then they must wait __ until next donation
|
8 weeks
|
|
|
occasional plasmapheresis donation vs serial plasmapheresis donation
|
> 4 weeks between donations
< 4 weeks between donation - serial donors have special requirements such as: - monitoring of serum or plasma total protein and Ig levels at initial plasmapheresis and at 4 month intervals - 2 days between donations - no more than twice in a 7 day period |
|
|
AABB and FDA requirements for two RBC apheresis units every ___ weeks
|
- 2 RBC apheresis units every 16 weeks
- requires a HCT of 40% (instead of 38%) |
|
|
a therapeutic dose of granulocyte infusion is __
|
1 x 10^10 granulocytes
- thus this is the yeild need for donations |
|
|
leukapheresis (granulocyte collection): drugs given include
|
1. hydroxyethyl starch (HES)
2. corticosteroids (can double the yield of granulocytes - marginal pool 3. G-CSF |
|
|
HES is used as a ___
HES hydroxyethyl starch can be detected in donors ___ after donation HES is a colloid, so its administration can lead to ___ |
- sedimenting agent: ehances RBC sedimentation to allow for better granulocyte harvesting with fewer RBC content
- up to a year after!! - expanded circulatory volume in the donor: HA or peripheral edema |
|
|
G-CSF and leukapheresis (granulocyte collection)
|
- can lead to yields as high as 4-8 x 10^10 granulocytes per apheresis collection
- typical dose: 5-10 ug/kg given 8-12 hrs before collection |
|
|
granuloctye units contain RBCs and should be ABO compatible with __
Should the unit be crossmatched |
- recipient plasma
- if > 2ml of RBC present, then the unit should be crossmatched |
|
|
Granulocyte units
|
- store at RT up to 24 hrs
- transfuse ASAP - no agitation - irradiation usually indicated due to nature of the typical recipient (immunocompromised) - no microaggregate or leukocyte reduction filters!!! |
|
|
Therapeutic apheresis is considered effective treatment for category ___ indications
|
category I and II
|
|
|
category I indications for therapeutic apheresis include
|
- anti-GBM disease (I)
- TTP - TPE(I) while HUS is (III) - familial hypercholesterolemia - selective absorption (I) or TPE (II) - polycythemia vera (I) - cytapheresis or phelbotomy - sickle cell disease - RBC exchange (I) - acute or chronic inflammatory demyelinating polyneuropathy - myasthenia gravis - TPE (I) |
|
|
For therapeutic apheresis, if the patient in critically ill or pediatric, vascular access should ideally be __
|
indwelling central or peripheral venous catheters
- rigid wall, large bore, doulbe lumen catheter |
|
|
During therapeutic apheresis, the efficacy of substance removal is ___ early in the procedure, and ___ progressively during the exchange
|
- greatest early on
- diminishes - TPE usually limited to 1-1.5 plasma volumes (40-60 ml plasma exchange per Kg body weight) 1.5 - 78% originial plasma exchanged |
|
|
rebound synthesis may complicate TPE treatment for autoimmune disease
|
- the removal of the autoAb leads to rapid production or more, maybe greater than pretreatment levels
- immunosuppressive therapy may help blunt this response |
|
|
In Waldenstrom's macroglobulinemia, the IgM is effective removed by TPE due to __
|
most of the IgM remains intravascular
|
|
|
Durin TPE: removal of normal plasma constituents occurs
- fibrinogen - other clotting factors - platelets |
- fibrinogen: 75-85% removed after 1.5 TPE (req 3-4 d to return to normal levels)
- other clotting factors (other than fibrinogen): return to nml levels within 24 hrs - platelets: expect 10%+ drop |
|
|
Draw blood samples for testing __ TPE
|
prior too!!
|
|
|
In TPE, hypocalcemia due to __ toxicity can usually be controlled by __
|
- citrate toxicity
- reducing proportion of citrate or slowing the reinfusion rate Mild: - perioral paresthesia - tingling - feeling of vibrations Can progress to: - muscle twitching - chills - pressure in the chest - nausea - vomiting - hypotension - cardiac arrhythmias - oral calcium carbonate or IV calcium can be given |
|
|
normal serum viscosity is ___ relative to __
|
1.4 to 1.8
relative to water - usually do not require treatment (such as TPE) until 4.0 to 5.0 |
|
|
Leukemics with extreme leukocytosis often have anemia, when do you transfuse RBCs?
|
- not until hyperviscosity crisis is resolved
- the anemia reduces viscosity |
|
|
leukapheresis is sometimes used to reduce the WBC count to less than ___ in acute leukemics, prior to CTX, to help prevent___
|
- <100K
- tumor lysis syndrome Note: not proven by RCT |
|
|
In pts with TTP, evidence of DIC is usually __
|
absent
|
|
|
TTP patients (fulminant) often present with plts counts less than ___ and elevated ___
|
- plts <50K
- LDH>1000 IU/ml - schistocytes |
|
|
TTP initiated by __
|
- usually unknown
- pregnancy - infection - drugs (ticlopidine, clopidogrel) |
|
|
TTP pathophys
|
- transient antibody to a protease (ADAMTS13) that normally cleaves large vWF multimers
- these large vWF multimers avidly aggregate circulatin platelets, triggering the syndrome |
|
|
HUS vs TTP
|
HUS:
- more renal dysfunction and less prominent neurologic and hematologic findings - most do NOT have antibody to vWF factor protease and have normal concentrations of vWF protease |
|
|
Sickle cell disease, after RBC exchange, the HCT should be less than __
|
30-35% and HbA should be 60-80%
|
|
|
Myasthenia gravis and TPE
|
- autoAb to postsynaptic motor endplate ACh receptor
- standard tx includes steroids and anticholinesterase - TPE used for exacerbations not controlled by meds and prior to thymectomy - recommend concurrent immunosuppression to prevent antibody rebound |
