When a person receives blood in the hospital, the average person would think that they received whole blood with all of its components in it. This is not case. There are many different parts to the "blood" that we give to patients. They usually receive one or multiple parts of the blood depending on the reasoning for their transfusion. These include red blood cells, plasma, platelets, albumin, or cryoprecipitate.
Packed Red Blood Cells (PRBCs)
This is what you think of when talking about "blood." A unit of PRBCs is red blood cells centrifuged out from whole blood. The hematocrit of PRBCs is approximately 55%. This type of blood product is often given in the case of acute bleeding. In the ICU, it seems like the majority of patients receiving PRBCs are GI bleeders or patients with complications from surgery. *TIP: Each unit of PRBCs should raise a patient's hematocrit by 3 points and their hemoglobin by 1 point. The hematocrit is about three times the amount of the hemoglobin. So, if you give a unit of blood and the hematocrit does not change with your post-infusion blood draw, the patient is still bleeding! It should have raised the hematocrit by 3 points.
Fresh Frozen Plasma (FFP)
One unit of FFP is taken all of the plasma from a unit of whole blood. It contains many factors necessary for clotting and is often given to reverse a patient's INR. When patients receive multiple units of FFP, they are often given Vitamin K to aid in increasing the patient's ability to coagulate.
Platelets are are an essential part of the clotting mechanism of the body. In my experience, I do not see platelets given near as frequently as PRBCs or FFP. Usually our doctors order them if the patient is extremely thrombocytopenic (low platelets) and they are continuing to drop. Sometimes they will also order platelets prior to doing an invasive procedure like inserting a central line. It seems like usually patients do not have an overwhelming response to receiving platelets. Some of the nurses call one unit of platelets a "six-pack of platelets." They are referring to just one bag of them.
Albumin is a protein that helps to draw fluid back into the vasculature through osmotic pressure. The albumin protein pulls more volume into the veins. This can be especially helpful with patients who are in shock or who are in acute renal failure. When patients have decreased urine output, I have seen that the doctors try one of two things: a fluid bolus challenge or albumin administration. Sometimes they will do both. They are hoping that the patient's kidneys respond to the increase in fluid within the vasculature. If this is the case, the patient will start producing more urine and you will know that they are volume depleted. Doctors may order albumin q6 or q8 hours for a certain number of doses.
Cryoprecipitate is prepared from plasma and contains fibrinogen, factor VIII, von Willebrand factor, factor XIII and fibronectin. It is also called cryoprecipitate antihaemophiliac factor. This is used for patients with severely depleted fibrinogen levels. This is the blood product I have given the least. Patients requiring massive transfusions of other blood products often need an additional transfusion of cryoprecipitate.
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