HOMEOSTASIS ,blood

transfusion, and products Abdurrahman Sarisi

DEFINITION

Homeostasis is the physiological process by which the internal systems of the body (Eg. Blood pressure, Body temperature, Acid base balance) are maintained at equilibrium despite variations in the external conditions.

COMPONENTS OF HOMEOSTATIC SYSTEM

Homeostatic system in the body acts through self-regulating device, which operate in a cyclic manner.

This cycle includes four components.

1) Sensors or detectors , which recognize the deviation .

2) Transmission of this message to a control centre.

3) Transmission of information from the control centre to the effectors for correcting the deviation.

4) Effectors , which correct the deviation.

CONT..

Feedback is a process in which some proportion of the output signal of a system is passed back to the input

Whenever any changes occurs, system receives and react to two types of feedback

1. Negative feedback: more common, the system reacts in such a way to reverse the change

2. Positive feedback: less common, the system reacts in such a way to increase the intensity of the

change.

Regulation of thyroid hormone levels

Regulation of water balance

Regulation of blood glucose levels

Regulation of body temperature

Acid/base balance

POSITIVE FEEDBACK

Positive feedback is the one to which the system reacts in such a way as to increase the intensity of the change in the same direction.

The positive feedback is less common than the negative feedback. However , it has its own significance particularly during emergency condition.

COAGULATION OF BLOOD

One of the positive feedbacks occurs during the blood clotting.

Blood clotting is necessary to arrest the bleeding during injury and its occur in three stages;

1) Formation of prothrombin activator

2) Conversion of prothrombin into thrombin

3) Conversion of fibrinogen into fibrin.

Thrombin formed in the second stage stimulates the formation of more prothrombin activator in addiction to converting fibrinogen into fibrin.

It causes formation of more and more amount of prothrombin activator so that the blood clotting process is accelerated blood loss prevented quickly.

FINAL OUTCOME OF HOMEOSTAIC PROCESSES

Blood Transfusion & Blood Products

Type of Blood Transfusion Homologous Blood Transfusion: One person to another

Autologous: Derived from same individual

o Intra and Postoperative cell storage: Collection of blood shed from intraoperative wound & drain then process the blood to remove plasma constituents.

Use: Major orthopedic surgery

Cardiovascular Surgery

Hepatic Surgery, e.g. Liver transplantation

Contraindication: Dirty wound, Active Infection, Malignancy

o Normal normovolaemic hemodilution: Anesthetist withdraws several packs of Pt. blood replacing with Crystalloid or Colloid. Collected blood then reinfused during operation. This is useful when anticipated blood loss is >1L and Pt’s HCT is relatively high.

o Preoperative autologous deposit (PAD): Predonate Pt’s own blood 3 weeks prior surgery, around 2-4 units are collected. HB% kept >10gm/dl with oral iron supplementation .

Use: Major orthopedic & gynecological surgery

Contraindication: Active infection, Unstable Angina, AS, Severe HTN

Criteria of Ideal Donor Must have good health status

Unpaid volunteers

Age: Within18-65 years

Weight: >45 kg/ 100 lb.

Body Temperature: < 37.2 C

Pulse: 60-100 b/min

BP: Within normal range

Medical History:

• No H/O recent fever, tooth extraction within 3wks, Operation within 3months.

• Vaccination within 3 months

• At time of menstruation

• Any H/O heart disease or current pregnancy

Hematological History:

• Hb%: >12 gm/dl

• No H/O anemia, leukemia, coagulopathy

Screening before

Transfusion Compatibility Test:

a) Blood grouping

b) Cross matching

Screening Test:

a) Viral: HBsAg, Anti HCV strip test

b) Malaria Parasite

c) VDRL/Syphilis

d) HIV

Complication of Blood Transfusion Complications from a Single Transfusion

Complications from a single transfusion include: ● Incompatibility haemolytic transfusion

reaction ● Febrile transfusion reaction ● Allergic reaction ●Infection:

1. Bacterial infection (usually due to faulty storage) 2. Hepatitis 3. HIV 4. Malaria 5. Air embolism 6. Thrombophlebitis 7.Transfusion related acute lung injury (usually from FFP)

Complications from a Massive Transfusion

● Coagulopathy ● Hypocalcaemia ● Hyperkalaemia ● Hypokalaemia ● Hypothermia ● Iron overload (In repeated transfusion)

Management of Mismatched blood transfusion

Symptoms

Feeling of something wrong

Restlessness

Anxiety

Headache

Pain & Heaviness in chest, lumber region, Limbs

Pain venipuncture site

Fever

Rigors

Dyspnoea

Acute collapse

Rash, itch

Signs

Pallor

Raised Temperature

Rapid thread pulse

Low BP

Pulmonary Oedema (B/L Basal Creps)

Cervical vein engorgement

Cyanosis

Facial puffiness

Jaundice

Haemoglobunuria

Haemoglobinaemia

Oliguria F/B Uraemia

Management of Mismatched Blood Transfusion Immediate measures:

1. Stop blood transfusion immediately

2. Recheck Pt. identity against donor unit

3. Inj. Hydrocortisone Hemisuccinate (2vials I/V Stat)

4. Inj. Anti-Histamine

5. Maintain I/V access with 0.9% NaCl solution

6. Monitoring urine output by catheterization > if U/O is less than 1.5ml/kg/hour will insert CVP line and give fluid > If CVP adequate and U/O still less than 1.5ml/kg/hour then, frusemide (80-120mg)

7. If suspicion of bacterial contamination, broad spectrum antibiotic should started.

8. Contact senior Medical personnel for advice and inform transfusion department.

9. Contact blood transfusion laboratory before sending back blood pack and for advice on blood samples required for further investigation.

Management of Mismatched Blood Transfusion

Investigation:

1. Blood grouping, cross matching of pt. and transfusion bag (donor)

2. S. Electrolytes

3. Blood Urea, S. Creatinine

4. Coagulation status – BT, CT, Platelet count, FDP, Fibrinogen

5. ECG – to see hyperkalaemia

Management of Complication:

1. DIC: Fresh blood, clotting factor, Inj. Hydrocortisone

2. Renal Failure: Treatment of renal failure.

WHOLE BLOOD

A 450 ml whole blood donation contains Up to 510 ml total volume

(volume may vary in accordance with local policies)

450 ml donor blood

63 ml anticoagulant-preservative solution

Haemoglobin approximately 12 g/ml

Haematocrit 35%–45%

No functional platelets

No labile coagulation factors (V and VIII)

Infection risk: capable of transmitting any agent which has not been

detected by routine screening including HIV-1 and HIV-2, hepatitis B and C ,

syphilis, malaria.

Storage is between +2°C and +6°C.

Shelf life ACD/CPD - 21 days CPDA-1: 35 days

Transfusion should be started within 30 minutes of removal from

refrigerator

Indications: Red cell replacement in acute blood loss with

hypovolaemia

Exchange transfusion

Patients needing red cell transfusions where red cell

concentrates or suspensions are not available

Contraindications:

-Risk of volume overload in patients with chronic anemia.

-Incipient cardiac failure

#It’s important to note:

Must be ABO and RhD compatible with the recipient

Complete transfusion within 4 hours of commencement

RED CELL CONCENTRATE (‘Packed red cells’, ‘plasma-reduced blood’)

150–200 ml red cells from which most of the plasma has been

removed

Hemoglobin approximately 20 g/100 ml (not less than 45 g

per unit)

Hematocrit 55%–75%

Infection risk & Storage: Same as whole blood

Indications:

-Replacement of red cells in anemic patients

-Use with crystalloid replacement fluids or colloid solution in

acute blood loss

RED CELL SUSPENSION

150–200 ml red cells with minimal residual plasma to which

±100 ml normal saline, adenine, glucose, mannitol solution (SAG-

M) or an equivalent red cell nutrient solution has been added

Haemoglobin approximately 15 g/100 ml (not less than 45 g

per unit)

Haematocrit 50%–70%

Infection risk, Storage: Same as whole blood

Shelf life – 42 days

Indications: Same as red cell concentrate

LEUCOCYTE-DEPLETED RED CELLS

A red cell suspension or concentrate containing

PLATELET CONCENTRATES

1) Random donor platelets (prepared from whole blood donations)

Single donor unit in a volume of 50–60 ml of plasma should contain: At least 55 x 109

platelets

FRESH FROZEN PLASMA

Pack containing the plasma separated from one whole blood donation within 6 hours of

collection and then rapidly frozen to –25°C or colder

FFP of 175-250 ml contains

70-80 units/dl of factor VIII, factor IX, vWF and other clotting factors. Fibrinogen 200-

400 mg

Infection risk : If untreated, same as whole blood

Very low risk if treated with methylene blue/ultraviolet light inactivation

Storage: At –25°C or colder for up to 1 year

Before use, should be thawed in the blood bank in water which is between 30°C to

37°C.

Dosage: Initial dose of 15 ml/kg.

Labile coagulation factors rapidly degrade; use within 6 hours of thawing

Indications:

- Replacement of multiple coagulation factor deficiencies: e.g.

- Liver disease

- Warfarin (anticoagulant) overdose

- Depletion of coagulation factors in patients receiving large volume transfusions

- Disseminated intravascular coagulation (DIC) Thrombotic thrombocytopenic

purpura (TTP)

CRYOPRECIPITATE

Prepared from fresh frozen plasma by collecting the precipitate formed during

controlled thawing at +4°C and resuspending it in 10–20 ml plasma

Infection risk: As for plasma, but a normal adult dose involves at least 6

donor exposures

Storage: At –25°C or colder for up to 1 year

Must be infused within 6 hours of thawing

Each unit of Cryo raises Factor VIII by 2%, to achieve plasma

factor VIII rise of 20%, 10units/kg have to be infused.

Indications: As an alternative to Factor VIII concentrate in the treatment of

inherited deficiencies of:

— von Willebrand Factor (von Willebrand’s disease)

— Factor VIII (haemophilia A)

— Factor XIII

As a source of fibrinogen in acquired coagulopathies:

e.g. disseminated intravascular coagulation (DIC)

PLASMA DERIVATIVES

ALBUMIN: Preparations

Albumin 5%: contains 50 mg/ml of albumin

Albumin 20%: contains 200 mg/ml of albumin

Albumin 25%: contains 250 mg/ml of albumin

Indications: -nephrotic syndrome

-liver disease with fluid overload

IMMUNOGLOBULINS

Concentrated solution of the IgG antibody component of plasma

Indications

-Idiopathic autoimmune thrombocytopenic purpura

-Treatment of immune deficiency states

-Hypogammaglobulinaemia

-Prevention of specific infections

FACTOR VIII CONCENTRATE

Factor VIII ranges from 0.5–20

iu/mg of protein.

Vials of freeze-dried protein

labelled with content, usually

about 250 iu of Factor VIII.

+2°C to +6°C up to stated expiry

date

Indications:

• Treatment of haemophilia A

Treatment of von Willebrand’s

disease: use only preparations

that contain von Willebrand

Factor

Factor IX

• Vials of freeze-dried protein

labelled with content, usually

about 350–600 iu of Factor IX

• +2°C to +6°C up to stated

expiry date

Indications

• Treatment of haemophilia B

(Christmas disease)

Immediate correction of prolonged ✔

prothrombin time

MASSIVE OR LARGE VOLUME BLOOD

TRANSFUSIONS Replacement of one entire blood volume within 24h

Transfusion of >10 units of packed red blood cells (PRBCs) in

24 h

Transfusion of >3 units of PRBCs in 1 h when on-going need is

foreseeable (uptodate)

Replacement of 50% of total blood volume (TBV) within 3 h.

MASSIVE TRANSFUSION PROTOCOL

designed to interrupt the ―lethal triad”

HYPOTHE

-RMIA

ACIDOSIS

COAGULO

-PATHY

Massive transfusion protocols are activated by a clinician in

response to massive bleeding.

Generally this is activated after transfusion of 4-10 units.

Massive transfusion protocols have a predefined ratio of RBCs,

FFP/cryoprecipitate and platelets units (random donor platelets) (e.g. 1:1:1 or

2:1:1 ratio) for transfusion.

COMPLICATIONS OF MASSIVE TRANSFUSION

Problems secondary to volume resuscitation

Inadequate resuscitation: Hypoperfusion leads to lactic acidosis,

systemic inflammatory response syndrome (SIRS), disseminated

intravascular coagulation and multiorgan dysfunction.

Transfusion Associated Circulatory Overload: This is a well- known condition

that occurs due to rapid transfusion of blood or blood products.

Dilutional coagulopathy:

During haemorrhagic shock, there is fluid shift from the interstitial to the

intravascular compartment that leads to dilution of the coagulation factors. This

is further accentuated when the lost blood is replaced with fluids.

Citrate toxicity:

•80 ml of citrate phosphate dextrose adenine solution present in each blood bag

contains approximately 3 g citrate. A healthy adult can metabolize this load in 5

min.

•Hypo perfusion or hypothermia associated with massive blood loss can

decrease this rate of metabolism leading to citrate toxicity.

•Unmetabolised citrate can then lead to hypocalcaemia,

hypomagnesemia and worsen the acidosis.

• Hypocalcaemia can lead to myocardial depression that

• Calcium supplementation is thus required in most cases.

Hyperkalaemia:

Potassium concentrations in PRBCs can range from 7 to 77 mEq/L

depending on age of stored blood.

Development of hyperkalaemia will depend on the underlying renal

function, severity of tissue injury and rate of transfusion.

At transfusion rates exceeding 100-150 ml/min, transient hyperkalaemia

is frequently seen.

Hypothermia:

Factors contributing to hypothermia include infusion of cold fluids and

blood and blood products.

Hypothermia leads to decreased citrate metabolism and decreased

platelet function contributing coagulopathy.

Hypomagnesemia: Citrate also binds to magnesium and can lead to hypomagnesaemia which can further accentuate effects of hypocalcaemia

Acidosis

Acidosis directly reduces activity of both extrinsic and intrinsic

coagulation pathways.

A pH decrease from 7.4 to 7.0 reduces the activity of FVIIIa and

FVIIa by over 90% and 60% respectively.

Late complications

Respiratory failure

Transfusion related acute lung injury (TRALI): The risk of TRALI

increases with the number of blood and blood products transfused.

SIRS

Sepsis

Thrombotic complications

Targets of resuscitation in massive blood loss

Mean arterial pressure (MAP) around 60 mmHg, systolic

arterial pressure 80-100 mmHg (in hypertensive patients one

may need to target higher MAP)

Hb 7-9 g/dl

INR 50 × 10 /L

pH 7.35-7.45

Core temperature >35.0°C