ARE BLOOD TRANSFUSIONS SAFE IN THE HOSPITALIZED PATIENT?
By: Dr. Joan Pellegrini
Ever since we were able to offer blood transfusions (about the 1940’s), it has been common wisdom that higher red blood cell counts are good for you. We know that red blood cells carry oxygen and some athletes use this to their advantage when they train at higher altitudes in order to increase their red blood cell level (or engage in the illegal activity of “blood doping”). If you come into the hospital hemorrhaging and your life is in danger, you may receive a life-saving blood transfusion.
What is less clear is whether a patient who is in the hospital and has a low blood count but who is not bleeding to death should be transfused. Physicians started questioning the conventional wisdom of transfusion in the 1990’s. Back then, if you were a patient in the hospital and your blood count dropped below a certain level (a hemoglobin level of “10”), your physician would order a blood transfusion even if you were feeling and doing well. Starting in the 1990’s physicians began studying the question of whether blood transfusion might actually be hurting patients. They were observing that patients who were transfused had worse outcomes after cancer surgery and had more infections. Since then, a few important trials were done to show that it is safe to let patients have lower blood cell levels (below “10” and even as low as “7”). We are not sure why blood may be harmful. The current theory is that it affects the immune system is causes an immunocompromised state that is less able to fight off infection.
This week in JAMA (Journal of the American Medical Association) another study has come out showing that patients who are transfused have a higher risk of health care associated infections (HCAI). This study was a meta-analysis that looked at 18 studies and combined the results. They compared a “restrictive” transfusion policy (transfusion only if the blood count is low) versus a “liberal” transfusion policy (transfuse at the physicians’ discretion). There were fewer infections (such as pneumonia and wound infections) in the restrictive group. Patients undergoing hip or knee surgery appeared to benefit the most from the restrictive policy. However, patients with cardiac disease did not show any difference.
These studies did not look at mortality, heart attack, or other outcomes. Clearly, there is a lot more work to be done. It does not do us any good to prevent an infection but have the patient not do well anyway. We also do not know “how low is too low” for the red blood cell level.
What do you need to know as a patient or family member? You need to know that a low blood count may not be reason enough for a transfusion. If your physician orders a transfusion, you should understand why it is being ordered or ask questions to understand. Are there alternative treatment strategies? What else is being done to prevent infections? What is your blood level and what is being done to prevent it from going lower? If your blood level is low and you need surgery, should you postpone your surgery in order to get treatment to raise your blood level? On the one hand, if your blood level is low and your physician states they are not recommending a transfusion, there is good evidence that this may be an excellent recommendation. On the other hand, there is still a very need for blood transfusions and transfusion still save lives in some instances.