blood transfusion. topic modules 1.blood blank practices 2.indication to blood transfusion...

Blood transfusionBlood transfusion

Topic modules

1. Blood blank practices

2. Indication to blood transfusion

3. Complication

4. Alternative strategies for management of blood loss during surgery

Blood blank practices

1. Human red cell membrane : least 300 different antigen

2. fortunately, only the ABO and the Rh systems are important in the majority of blood transfusion

3. History Hct. Infection : Hepatitis B,C syphillis HIV-1,2

HTLV-I,II

#Crossmatching (50 min)

1) Confirms ABO and Rh typing

2) Detects antibodies to the other blood group systems

3) Detects antibodies in low titers or those that do not agglutinate easily



# Antibody screen : Indirect Coombs test

(45 mins)

the subject serum + red cells

( antigenic composition) ----- red cell agglutination

# Type&screen

# Emergency transfusion

T&S -determines ABO and Rh status and the presence of most commonly encountered antibodies – risk of adverse rxn is 1:1000

-takes about 5 mins

T&C -determines ABO and Rh status as well as adverse rxn to even low incidence antigens – risk of rxn is 1:10,000

-takes about 45 mins

Type and screen vs Type and crossmatch

Type and screen vs Type and crossmatch

T&S:Type O red cells are mixed with pt serum Antibody screen

T&C Type O red cells are mixed with pt serum Antibody screen

Donor red cells are then mixed with the pt’s serum to determine possible incompatibility

:


All units – RBC @ PRC 1unit (250 ml Hct.70%)

--platelet@ 1 unit (50-70 ml, stored at 20-24c for 5 days)

--plasma @ FFP

--cryoprecipitate @ high conc. Of factor VII, fibrinogen

Intraoperative transfusion practices1.1. PRCPRC Ideal for patients requiring red cells but not volume replacement

Only one – Increase O2 carrying capacity

AGE BLOOD VOLUME Neonates Premature 95 ml/kg Full-term 85 ml/kg Infants 80 ml/kg Adults Men 75 ml/kg Women 65 ml/kg Allowable blood loss = EBV*( Hctตั้��งตั้�น –Hctที่�ยอมรั�บได้�)/ Hctเฉลี่�

ย Hct. 30% not magic number Jehovah” s witness

Practice guideline

$$ case series : reports of Jehovah witness; some may tolerate very low Hb< 6-8 g/dl in the perioperative period without an incresae in mortality

Practice guideline

$$ In healthy, normovolemic individual, tissue oxygenation is maintained and anemia tolerated at Hct as low as 18-25%(Hb 6-8gm%)

$$ RBC transfusion is rarely indicated when Hb> 10 g/dl and is almost always indicated when Hb< 6 g/dl

American Society Anesthesiologist : 1996

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Intraoperative transfusion practices

2. FFPFFP ( initial therapeutic dose : 10-15 ml/kg )

isolated factor deficiencies

reverse warfarin therapy

correction of coagulopathy associated with liver disease

used in patients who are received massive blood transfusion with microvascular bleeding

Complications (PATCH) Platelets – dec,Potassium – inc., ARDS, Acidosis,Temp dec., Citrate intoxication, Hepatiti

>1 BV/ 24 HR> 50 % BV within 3 hrs > 150 ml/min

antithrombin III deficiency

TTP ( Thrombotic thrombocytopenic purpura )

Do not use for volume


3.3. PLATELETSPLATELETS

**thrombocytopenia or dysfunction platelets in the presence bleeding

* prophylactic : plt.counts below 10,000-20,000

* prophylactic preoperative : plt.counts below 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)



50 ml: 0.5- 0.6 x 10 9 platelets (some RBC’s and WBC’s)

Single donor apheresis OR

Random donor (x 6)


4.4. CRYOPRECIPITATE CRYOPRECIPITATE 10 ml: fibrinogen (150-250 mg), VIII (80-145 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)

Alternative strategies for management of blood loss during surgery

1) Autologous transfusion

2) Blood salvage & refusion

3) Normovolemic hemodilution

“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

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TRANSFUSION REACTIONSTRANSFUSION REACTIONS

• is any unfavorable transfusion-related event occurring in a patient during or after transfusion of blood components

TRANSFUSION REACTIONSTRANSFUSION REACTIONS

@RBC’s !• Nonhemolytic 1-5 % transfusions Causes -Physical or chemical destruction of

blood: freezing, heating, hemolytic drug -solution added to blood -Bacterial contamination

: fever, chills, urticaria– Slow transfusion, diphenhydramine , antipyretic for fever

• Hemolytic– Immediate: ABO incompatibility (1/ 12-33,000) with fatality (1/

500-800,000)

Majority are group O patients receiving type A, B or AB blood

Complement activation, RBC lysis, free Hb (+ direct Coombs Ab test)

Acute Hemolytic Transfusion Reaction

Ab (in recipient serum) + Ag (on RBC donor)

-Neuroendocrine responses

-Complement Activation

-Coagulation Activation

- Cytokines Effects

Acute hemolytic transfusion reaction

Pathophysiology

Acute Hemolytic Transfusion Reactions

Acute onset within minutes or 1-2 hours

after transfuse incompatible blood

Most common cause is ABO-incompatible

transfusion

Signs and Symptoms of AHTR

• Chills , fever• Facial flushing• Hypotension• Renal failure• DIC• Chest pain• Dyspnea• Generalized bleeding

• Hemoglobinemia• Hemoglobinuria• Shock• Nausea• Vomitting• Back pain• Pain along infusion

vein

– 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)– Correct bleeding, Rx. DIC

Laboratory investigation for AHTR

• sample from blood bag Repeat ABO, Rh, Ab screening

• Patient sample

Pre Tx sample Repeat ABO, Rh, Ab screening

Post Tx sample Repeat ABO, Rh, Ab screening, DAT,

CBC, UA, Bilirubin, BUN, Cr,

Coagulation screening

• Repeat compatibility test

- Pre Tx sample & Donor unit

- Post Tx sample & Donor unit

– 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!@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) – noncardiogenic pulmonary edema– Supportive therapy

Transfusion-related Acute Lung Injury (TRALI)

Pathophysiology Leukocyte Ab in donor react with pt. leukocytes

Activate complements

Adherence of granulocytes to pulmonary endothelium with release of proteolytic enz.&

toxic O2 metabolites

Endothelial damage

Interstitial edema and fluid in alveoli


Acute and severe type of transfusion reaction

Symptoms and signs• Fever• Hypotension• Tachypnea• Dyspnea• Diffuse pulmonary infiltration on X-rays• Clinical of noncardiogenic pumonary edema


Therapy and Prevention• Adequate respiratory and hemodynamic

supportive treatment• If TRALI is caused by pt. Ab use LPB• If TRALI is caused by donor Ab no special

blood components

• Transfusion-associated Graft-versus-Host Disease ( TA-GVHD)

– Rare: immunocompromised patients – Suggestion that more common with

designated donors– BMT, LBW neonates, Hodgkin's disease,

exchange Tx in neonates

Transfusion-associated Graft-versus-Host

Disease ( TA-GVHD) Pathophysiology

Infusion of Immunocompetent Cells

(Lymphocyte)

Patient at risk

proliferation of donor T lymphocytes

attack against patient tissue

Graft-versus-Host Reaction

Signs & Symptoms

Onset ~ 3 to 30 days after transfusion Clinical significant – pancytopenia Other effects include fever, liver enzyme,

copious watery diarrhea,

erythematous skin erythroderma

and desquamation

@Platelets!@Platelets!

Alloimmunization– 50 % of repeated platelet transfusions– Ab-dependent elimination of platelets with lack of response– Use single donor apheresis – Signs & Symptoms

• mild slight fever and Hb• severe platelet refractoriness with bleeding

Post-transfusion purpura– Recipient Ab leads to sudden destruction of platelets

1-2 weeks after transfusion (sudden onset)– Rare complication

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

INFECTIOUS COMPLICATIONSINFECTIOUS 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, 10-20

% develop cirrhosis

HIV

• 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

CJD (and variant CJD)

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

II. Bacterial• Contamination unlikely in products stored for > 72

hours at 1-6 0 C • gram –ve, gram +ve bacteria most frequent – Yersinia enterocolitica

Produced endotoxin Platelets stored at room temperature for 5 days, with

infection rate of 0.25%

III. Protozoal• Trypanosoma cruzi (Chaga’s disease) • Malaria• Toxoplasmosis• Leishmaniasis

Serological Testingfor Infectious markers

• HIV – Ag

• Anti – HIV

• HBsAg

• Anti – HCV

• Test for syphilis

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. topic modules 1.blood blank practices 2.indication to blood transfusion...

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