HOW CAN BLOOD SAVE YOUR LIFE?

Conclusion of: QUALITY ALTERNATIVES TO TRANSFUSION

While adults accommodate a low hemoglobin level, what of children?  Dr. James A. Stockman III says:  "With few exceptions, infants born prematurely will experience a decline in hemoglobin in the first one to three months . . . The indications for transfusion in the nursery setting are not well defined.  Indeed, many infants seem to tolerate remarkably on low levels of hemoglobin concentration with no apparent clinical difficulties." -Pediatric Clinics of North America, February 1986.

Such information does not mean that nothing need be done when a person loses a lot of blood in an accident or during surgery.  If the loss is rapid and great, a person's blood pressure drops, and he may go into shock. What is primarily needed is that the bleeding be stopped and the volume in his system be restored. That will serve to prevent shock and keep the remaining blood cells  and other components in circulation. 

Volume replacement can be accomplished without using whole blood or plasma. Various non-blood fluids are effective volume expanders.  The simplest is saline (salt) solution, which is both inexpensive and compatible with our blood. There are also fluids with special properties, such as dextran, Haemaccel, and lactated  Ringer's solution.  Hetastarch (HES)  is a newer volume expander, and it can be safely recommended for those [burn] patients who object to blood products." (Journal of Burn & Care Rehabilitation, January/February 1989) Such fluids  have definite advantages .  "Crystalloid solutions (such as normal saline and lactated Ringer's solution], Dextran and HES are relatively nontoxic and inexpensive, readily available, can be stored at room temperature, requiring no compatibility testing and are free of the risk of transfusion-transmitted disease." -Blood Transfusion Therapy -A Physician's Handbook, 1989. 

You may ask , though, 'Why do nonblood replacement fluids work well, since I need red cells to get oxygen throughout my body? As mentioned, you have oxygen carrying reserves. If you lose blood, marvelous compensatory mechanisms start up.  Your heart pumps more blood with each beat. Since the lost blood was replaced with  a suitable fluid, the now diluted blood flows more easily, even in the small vessels.  As a result of chemical changes, more oxygen is released to the tissues. These adaptations are so effective that if only half of your red cells remain, oxygen delivery may be about 75 percent of normal.  A patients at rest uses only 25 percent of the oxygen available in his blood. And most general anesthetics reduce the body's need for oxygen. 

Next time: HOW CAN BLOOD SAVE YOUR LIFE?/HOW CAN DOCTORS HELP? 

From the Watchtower magazine