Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
BLOOD COMPONENT THERAPY 2002 EVAN G. PIVALIZZA, FFA Department of Anesthesiology University of Texas at Houston A. BLOOD PRODUCTS 22 x 106 components p.a. 50-70 % peri-operatively 18-57% inappropriate (NIH reviews in 80’s) Blood preservation and storage 75 % RBC’s in circulation @ 24 hrs Within 4 hrs, WB separated WB: 63 ml preservative (HCT 36-40%) – CPD- A (citrate, phosphate, dextrose, adenine) shelf-life 35 days @ 1-60 C PRBC: (HCT 60%) – CPD-A – ADSOL (adenine, dextrose, saline, mannitol) shelf-life 42 days Deglycerolized blood – Frozen with glycerol for storage, washed before transfusion (years) Leucocyte depleted blood (see later) Washed (IgA deficiency) DO2 / VO2 DO2 = CO x [(Hb x SaO2 x 1.34) + PaO2 x 0.003] Flow pressure, 1/R4, viscosity Balance hematocrit/ viscosity + 30% Compensations chronic anemia – viscosity = flow, venous return, SV – O2 extraction except cardiac and cerebral circulation – O2 DC shifted to right – DO2 adequate to Hct 18-25% Indications for PRBC transfusion ONLY: Increase O2 carrying capacity Use of single ‘trigger’ transfusion inappropriate TRICC: ? more conservative trigger in ICU (7-9 vs 10-12) – NOT apply to > 55, bleeding, cardiac surgery Determination transfusion based patient risks for complication of inadequate DO2 10 ml/kg Hct 10 % Indications for FFP transfusion 2 million units p.a. 200-260 ml: procoagulants (1U/ml) and fibrinogen (3-4 mg/ml) Urgent reversal of coumadin therapy (5-8 ml/ kg) Correction of known coagulation factor deficiencies (no concentrates available) to + 30% (10-15 ml/ kg) Microvascular bleeding with PT/ PTT > 1.5 normal Massive BT with microvascular bleeding – >1 BV/ 24 hours – > 50 % BV within 3 hrs – > 150 ml/min Plasmapheresis for TTP AT-III deficiency Succinylcholine apnea – S.D plasma – Pooled plasma, Rx solvent and detergent – Virus inactivated, bacteria, WBCs – Consistent coagulation factors (1 U 2-3%) BUT: – Cost – ? Transmission unknown particles Indications for cryoprecipitate transfusion 10 ml: fibrinogen (150-250 mg), VIII (80145 U), fibronectin, XIII 1U/ 10kg fibrinogen 50 mg/dL (usually a 6- pack) Hypofibrinogenemia (congenital or acquired) Microvascular bleeding with massive BT (fibrinogen < 80-100mg/dL) – 2 BVs = < 100 mg/dL Bleeding patients with vWD (or unresponsive to DDAVP) Indications for platelet transfusion 7 million units p.a. 50 ml: 0.5- 0.6 x 10 9 platelets (some RBC’s and WBC’s) Single donor apheresis OR Random donor (x 6) Decreased production Prophylactic for surgical patient with platelets < 50,000 Microvascular bleeding in surgical patient with platelets < 50,000 Neuro/ ocular surgery > 75,000 Massive transfusion with microvascular bleeding with platelets < 100,000 – 2 BVs = 50,000 Qualitative dysfunction with microvascular bleeding (may be > 100,000) Assessment of platelet function (TEG, Sonoclot) in O.R. B. TRANSFUSION REACTIONS RBC’s Nonhemolytic – 1-5 % transfusions: fever, chills, urticaria – Slow transfusion, diphenhydramine Hemolytic – Immediate: ABO incompatibility (1/ 1233,000) with fatality (1/ 500-800,000) – Majority are group O patients receiving type A, B or AB blood Anesthesiologist major trauma hospital: Transmit HIV once / 1,000 years Hep C 200 Hep B 100 Administer incorrect blood 30 – UK: 1996-99 – 97 life-threatening ABO incompatible transfusions Complement activation, RBC lysis, free Hb (+ direct Coombs Ab test) – Anesthesia: hypotension, urticaria, abnormal bleeding – Stop infusion, blood and urine to blood bank, coagulation screen (urine/plasma Hb, haptoglobin) – Fluid therapy and osmotic diuresis – Alkalinization of urine (increase solubility of Hb degradation products) – Delayed: (extravascular immune) – 1/ 5-10,000 – Hemolysis 1-2 weeks after transfusion (reappearance of Ab against donor Ag from previous exposure) – Fever, anemia, jaundice – Alloimmunization – Recipient produces Ab’s against RBC membrane Ag – Related to future delayed hemolytic reactions and difficulty crossmatching WBC’s Europe: All products leukodepleted USA: Initial FDA recommendation now reversed pending objective data (NOT length of stay for expense) Febrile reactions – Recipient Ab reacts with donor Ag, stimulates pyrogens (1-2 % transfusions) – 20 - 30% of platelet transfusions – Slow transfusion, antipyretic, meperidine for shivering TRALI (Transfusion related acute lung injury) – Donor Ab reacts with recipient Ag (1/ 10,000 but causes 15 % of mortality due to BT) – Noncardiogenic pulmonary edema – Supportive therapy – ? relation to multiparous donors (> 4 pregnancies) GVHD – Rare: immunocompromised patients – Suggestion that more common with designated donors – BMT, LBW neonates, Hodgkin's disease, exchange Tx in neonates Platelets Alloimmunization – 50 % of repeated platelet transfusions – Ab-dependent elimination of platelets with lack of response – Use single donor apheresis Post-transfusion purpura – Recipient Ab leads to sudden destruction of platelets 1-2 weeks after transfusion (sudden onset) Immunomodulatory effects of transfusion Wound infection: circumstantial evidence (? leukocyte filters for immunocompromised) Beneficial effects on renal graft survival (now < NB with CyA) – 97: 9% graft survival advantage after 5 years Nonspecific overload of RES – lymphocytes, APCs – Modification T helper/suppressor ratio – Allogeneic lymphocytes may circulate for years after transfusion Cancer recurrence (mostly retrospective) – Colon: 90 % studies suggest increased recurrence – Breast: 70 % studies – Head and neck: 75 % studies “Allogeneic blood products increase cancer recurrence after potentially curative surgical resection” - Landers Evidence circumstantial NOT causal However, 2 recent prospective, randomized studies: no effect on tumor related morbidity/mortality, but poorer outcomes Conservative trigger (< 3 units) Clinical judgment to weigh risk-benefit ratio C. INFECTIOUS COMPLICATIONS I. Viral (Hepatitis 88% of per unit viral risk) Hepatitis B Risk 1/ 200,000 due to HBsAg, antiHBc screening (7-17 % of PTH) Per unit risk 1/63-66,000 0.002% residual HBV remains in ‘negative’ donors (window 2-16 weeks) Anti-HBc testing retained as surrogate marker for HIV NANB and Hepatitis C Risk now 1/ 103,000 (NEJM 96) with 2nd/ 1/ 125,000 with 3rd generation HCV Ab/ HVC RNA tests Window 4 weeks 70 % patients become chronic carriers, 1020 % develop cirrhosis HIV 29 cases -transfusion recipients 93 7,800 by 12/ 95 Current risk 1/ 450- 660,000 (95) With current screening (Abs to HIV I, II and p24 Ag), window 6-8 weeks (third generation ELISA tests in Europe) sero -ve window to < 16 days HTLV I, II Only in cellular components (not FFP, cryo) Risk 1/ 641,000 (window period unknown) Screening for antibody I may not pick up II CMV Cellular components only Problem in immunocompromised, although 80 % adults have serum Ab WBC filtration decreases risk of transmission CMV -ve blood: – CMV -ve pregnant patients, LBW neonates, CMV -ve transplant recipient, – CMV-ve/ HIV +ve CJD (and variant CJD) BB implementing donor deferrals – 1980-96: > 3 months UK TF in UK > 5 years in France II. Bacterial Contamination unlikely in products stored for > 72 hours at 1-6 0 C (10 cases Yersinia) Platelets stored at room temperature for 5 days, with infection rate of 0.25% III. Protozoal Trypanosoma cruzi (Chaga’s disease) D. METABOLIC COMPLICATIONS Citrate toxicity Citrate (3G/ unit WB) binds Ca2+ / Mg+ Metabolized liver, mobilization bone stores Hypocalcemia ONLY if > 1 unit/ 5 min or hepatic dysfunction Hypotension more likely due to cardiac output/ perfusion than calcium (except neonates) Worse with hypothermia/ hepatic dysfunction Hyperkalemia After 3 weeks, K+ is 25- 30 mmol/l Only 8- 15 mmol per unit PRBC/ WB Concern with > 1 unit/5 min @ infants Acidosis Acid load after after 3 weeks 30-40 mmol/l (pH 6.6 - 6.9) Metabolic acidosis more likely due to decreased perfusion, hepatic impairment, hypothermia NaHCO3 or THAM if base deficit > 7-10 mEq/l 2, 3 DPG Depleted within 96 hours of storage O2 Hb DC to left Restored within 8- 24 hours of transfusion E. REFERENCES Practice Guidelines for Blood Component Therapy (ASA Task Force). Anesthesiology 1996; 84: 732-47. Safety of the Blood Supply. JAMA 1995; 274:1368--73. Infectious Disease Testing for Blood Transfusions (NIH Consensus Conference). JAMA 1995; 274: 1374-9. Blood Transfusion- Induced Immunomodulation. Anesth Analg 1996; 82: 187-204 ASA Questions and Answers about Transfusion Practices (3rd ed., 1997) Immunomodulatory aspects of transfusion. Anesthesiology 1999; 91: 861-5. “Blood is still the best possible thing to have in our veins” - Woody Allen “Blood transfusion is a lot like marriage. It should not be entered upon lightly, unadvisedly or wantonly, or more often than is absolutely necessary” - Beal