BLOOD TRANSFUSION
A standard unit of blood donated for
transfusion consists of 450 ml of blood mixed with 63 ml of solution which
contains citrate to prevent clotting and other additives for optimal
preservation of RBCs viability .
The Hazard of Blood Transfusion
Blood is a potentially dangerous drug .
(1) sensitisation
Blood is considered suitable for transfusion if it is shown to be of a compatible ABO and Rhesus D group , if no other transfusion is given , or if the foreign group is another one , the possibility of any subsequent ill –effect is small .
many cases of such sensitisation did , however , occur some years age before the Rhesus groups were known and some Rhesus – negative women developed antibodies after transfusion of Rhesus – positive blood . If the babies of such women were Rhesus –positive the first pregnancy after sensitisation .
(2) Incompatibility
Cases in which untoward destruction of red cells follows transfusion and this dose not occur in simple sensitisation .
Hemolytic reactions may also follow the transfusion of time – expired blood , or which has been infected or damaged by excessive heat or cold .
Most cases of hemolytic reaction are due to ABO
incompatibility and the accident is usually due to carelessness such as the
misreading of labels .
The symptoms vary according to the rate of
hemolysis ; the reaction is immediate follows the giving of a few ml of blood ,
but in others the transfusion may be given without apparent trouble and the
cells may be not be apparent .
Special care should always be taken during the
transfusion of anaesthetised patients for severe reactions may not be apparent
.
Sudden rise of temperature , rigors , intense
lumber pain is common a sense of intense constriction across the chest and
dyspnoea , severe headache is frequent .
In suspected cases
•
* Blood should be examined for hemoglobin ,
methaemalbumin , and the urine should be examined for the presence of
hemoglobin and breakdown products .
•
*If incompatibility is suspected the transfusion must be stopped
once . If the patients is shocked – he must be treated by transfusion of
compatible blood , plasma , or a substitute .
* Fluid balance and patient treated as any other case of
oliguria or anuria .
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(3) Overloading
there is a very great danger of overloading the circulation in chronic anemia and in patients with severe general disease .
Special care must be taken in the transfusion of elderly patients – here small volumes of concentrated cells are indicated and it may be necessary to repeat small transfusion at intervala of a day or two .
Febrile Reactions
A rise of temperature during or just after a blood transfusion may be due to some serious complication such as incompatibility .
A quite frequent cause is the presence of some bacterial product , a pyrogen , in the transfusion fluid or equipment .
These reaction are accompanied by chills headache , vomiting and flushing .
Their severity could be reduced by warming the patient well before hand and the symptoms could be relived to some extent by warmth , antihistamines , sedatives , and if necessary , morphine .
there is a very great danger of overloading the circulation in chronic anemia and in patients with severe general disease .
Special care must be taken in the transfusion of elderly patients – here small volumes of concentrated cells are indicated and it may be necessary to repeat small transfusion at intervala of a day or two .
Febrile Reactions
A rise of temperature during or just after a blood transfusion may be due to some serious complication such as incompatibility .
A quite frequent cause is the presence of some bacterial product , a pyrogen , in the transfusion fluid or equipment .
These reaction are accompanied by chills headache , vomiting and flushing .
Their severity could be reduced by warming the patient well before hand and the symptoms could be relived to some extent by warmth , antihistamines , sedatives , and if necessary , morphine .
(5) Allergic Reactions
These most commonly occur in patients who are already subject to allergic disorders
The reaction is due to the presence in the donated blood of some substance to which the recipient is sensitive .
The treatment is by administration of adrenaline , antihistamines , and sedatives .
(6) Air Embolism
It is very hazardous and every precaution must be taken against its occurrence .
It is very unlikely to occur now that plastic bags are used as containers for blood .
The patients should be placed on his left side to avoid air collecting in the right ventricle outflow tract , the head should be down and the feet up .
If these measures fail , and the outcome seems likely to be fatal , aspiration of air from the heart has been advocated .
(7) The Transmission of Infection
Serum hepatitis is especially to affect those handling large amounts of blood and multiply-transfused patients so that it is a great hazard in renal units .
Syphilis and malaria may be transmitted by transfusion and extensive precautions are taken to avoid such accidents .
Infectious mononucleosis and cytomegalovirus have also been transmitted and there have been several reports of their occurrence after open heart surgery . Potential donors who have jaundice are excluded .
It is very hazardous and every precaution must be taken against its occurrence .
It is very unlikely to occur now that plastic bags are used as containers for blood .
The patients should be placed on his left side to avoid air collecting in the right ventricle outflow tract , the head should be down and the feet up .
If these measures fail , and the outcome seems likely to be fatal , aspiration of air from the heart has been advocated .
(7) The Transmission of Infection
Serum hepatitis is especially to affect those handling large amounts of blood and multiply-transfused patients so that it is a great hazard in renal units .
Syphilis and malaria may be transmitted by transfusion and extensive precautions are taken to avoid such accidents .
Infectious mononucleosis and cytomegalovirus have also been transmitted and there have been several reports of their occurrence after open heart surgery . Potential donors who have jaundice are excluded .
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