Tests and Prevention for Low Red Blood Cell Count
Why is there more than one test for red blood cell counts?
There are several ways that doctors commonly measure red blood counts:
- Red blood cell count. This test counts the number of red blood cells in a single drop (a microliter) of blood. As a general guideline, consider the normal range to be 4.5 to 6.2 million for men; 4.2 to 5.4 million for women.
- Hemoglobin. This test measures the red-pigmented protein that carries oxygen. Normal range for red blood count is 14 to 18 grams per deciliter in men; 12 to 16 grams per deciliter in women. When someone's hemoglobin drops below 10 grams per deciliter, he's considered anemic.
- Hematocrit. This test measures the percentage of total blood volume made up of red blood cells. Normal range is 40 to 52 percent for men; 35 to 47 percent for women.
A complete red blood count usually includes additional measures of the size, capacity, and number of red blood cells. The doctor will usually order a battery of tests to get a complete picture of the health of a patient's red blood cells. For example, a low hematocrit in combination with low hemoglobin may indicate iron deficiency, while a high hematocrit can indicate dehydration.
Can I help prevent someone's red blood count from dropping?
There are medications called cell growth factors (also called colony stimulating factors) that can be given along with chemo or radiation to prevent red blood counts from dropping. The growth factor that boosts production of red blood cells is epoetin or darbepoetin (brand names Procrit, Epogen, Aranesp). Growth factors can take between two and eight weeks to work, so they're not a solution for dramatic red blood cell loss. There's also a risk of side effects, so a patient's doctor will decide whether to prescribe cell growth factors based on her assessment of the patient's risk of developing a low red blood count.
Get as much information as you can from the doctor about the chemo regimen of the person you're caring for and the effect you can expect it to have on his red blood count. "Some drugs reduce the red blood cell count by 25 percent immediately; some drugs take a week before the count start to drop. Every drug and regimen is different," says Terry Anders, an oncology nurse at the Zangmeister Cancer Center in Columbus, Ohio. Because side effects include fluid retention and heart palpitations -- both of which can worsen heart conditions -- the doctor will take into account whether the patient has heart problems when deciding whether to prescribe Procrit or other growth factors. Other side effects include diarrhea, vomiting, fever, and upper respiratory infection. In addition, Procrit can cause shortness of breath and edema, so if the person you're caring for already has these problems, the doctor may be conservative about prescribing it.