What you need to know about blood transfusions

Let's look at some of the factors that doctors look at when deciding to give a blood transfusion.  Assuming that this is not an emergency situation, and the patient  is having elective or a non-emergency surgery, the doctor wants to get a look at your lab work.  The information that will follow pertains specifically to your CBC.    This information tells the doctor about the: hemoglobin, hematocrit, white blood cells, red blood cells and platelets, specifically as related to transfusion decision making. Not to simplify a really complex decision such as transfusion because obviously, a lot of factors are involved. Let's look a little closer.

CBC - what information does it yield?

Hemoglobin is the protein in the red blood cell that carries oxygen to the body's cells and tissues. Normal ranges are roughly 13 - 18 grams of hemoglobin in every 100 cubic centimeters of blood for a male, and 12 -16 grams of hemoglobin in every 100 cubic centimeters of blood for a female.  So, just to make lab results jargon clearer, if your doctor were to say that you (a male)  have a hemoglobin of 2, well, you know that this is a cause for concern. You're probably bleeding somewhere.   In the past, hemoglobin (hgb) of 10 was the golden standard for transfusion for surgery.  It has now been found that this is not true.

Another thing that the doctor looks at is the hematocrit which is the concentration of red blood cells in a given amount of blood.  This is usually expressed as a per cent.  Normal ranges are roughly 45-62% for a male and 37-48% for a female. The hematocrit is the proportion by volume of the blood that consists of red blood cells.  Example, 25% means that 25 milliliters of blood per 100 ml consists of RBC. Again, the further the number is from normal, the more the cause for concern.

Platelets are another factor that can influence transfusions. Platelets are the smallest cell-like structures in the blood and are important for clotting. They are expressed as 150,000 - 450,000 per microliter.

Red blood cells are very important as these are the oxygen containing cells of the blood. Normal ranges are 4.2 - 6.9 million/cu mm. Packed red blood cells would most likely be used in traumatic blood loss.

White blood cells are usually involved in fighting infection.  Transfusions are rarely given for these.  Normal ranges are 4,300 -10,800 cells per cu mm. ("Blood transfusions" www.medicinenet.com/hematocrit/article.htm)

Types of transfusions

Whole Blood Transfusion Reasons - This is rare now.  This is blood with all of its components - red blood cells, platelets, plasma, etc.

Packed red blood cells are given to increase the oxygen-carrying capacity of the patient's blood.  This could be low due to loss of blood during trauma, surgery or bleeding internally.

Platelets are transfused when there are problems with clotting.

Fresh frozen plasma may be used to treat an overdose of coumadin, warfarin or other blood thinners.  These problems are diagnosed in the PT (Prothrombin time) or APTT (Activated partial thromboplastin time).

Cryoprecipitate Transfusions are usually given to replace specific clotting factors such as Factor VIII or Factor XIII deficiency.

White blood cell transfusion are given when the body does not respond to appropriate antibiotic treatment.  This is very rare though. ("Blood transfusions" http://www.medicinenet.com/

Summarizing it all

The next article will be discussing some of the basic types of volume replacement as a subsitute for blood.