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Factor
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Before or During Infusion
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Blood Sample Handling
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freezing blood
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environmental or unregulated refrigerator
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environmental, specimen handling, or unregulated refrigerator
|
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overheating blood
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blood warmer or makeshift warmer; placing blood on a room heater
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specimen handling
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mixing with hypotonic or hypertonic solution
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infusion of blood with an IV solution; addition of a drug
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drawing from a peripheral line running an infusion
|
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small needle with high pressure
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use of pressure bag forcing flow through small needle
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difficult draw with large syringe
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Some causes of in vitro hemolysis:
(1) storing blood in an unregulated refrigerator, with undetected freezing
(2) using a microwave oven or other unregulated device to warm blood
(3) malfunction of a blood warmer
(4) traveling in an ambulance or helicopter during the winter
Both occurrences require a high index of suspicion, usually after the transfusion reaction workup turns up negative:
(1) A careful redraw of a new sample will usually detect a problem in specimen handling.
(2) Preinfusion hemolysis often requires exclusion of the different causes plus circumstantial evidence.
(2a) If the blood bag or infusion setup is still available then it should be examined.
(2b) If a blood warmer was used it should be tested.
(2c) All personnel involved in handling and transfusing the implicated blood product(s) should be debriefed.
