Routine Blood Draw during Chemotherapy Does Not Cause Significant Iron Deficiency.

Chemotherapy-related anemia in cancer patients can be significant. Frequent blood draws prior to and during chemotherapy treatment may result in a loss of iron (Fe) that could exacerbate or cause anemia. Therefore, phlebotomy for diagnostic testing has the potential to lead to significant Fe loss. We conducted a retrospective case study on 40 randomly selected patients currently undergoing chemotherapy. A CBC and routine chemistry resulted in blood losses of 9 ml and 13 ml respectively. If an infusaport was used, an additional 10 ml was drawn and discarded. Blood loss was recorded for each visit during a chemotherapy course of some 4–6 cycles. Approximately 1 ml of compacted red blood cells is equivalent to 1 mg of Fe. Therefore, by multiplying the hematocrit (HCT) by the blood loss (ml), the amount of iron loss (mg) was determined for each patient visit. Fe losses for the patients in this study were compiled and averaged by gender (M/F), by method of access (port/IV), per cycle of chemotherapy and overall. The average overall loss of Fe during a course of chemotherapy was 45.7 mg. Female patients lost an average of 39.9 mg Fe, while male patients lost an average of 53.7 mg Fe, probably because of higher average HCTs in men. As expected, patients with infusaports lost more Fe (76.9 mg Fe/course) than patients with peripheral intravenous access (30.7 mg Fe/course). Correcting for variability in the number of cycles per course of chemotherapy revealed an average loss of 10.3 mg Fe per cycle of chemotherapy. The impact of Fe loss on a patient’s overall hematological condition is dependent on many factors. If a patient is initially Fe deficient, an additional loss of Fe will have a greater effect than if the patient has sufficient iron stores. For example, an Fe loss of 50 mg in an Fe replete patient (approx. 3000 mg Fe) versus an Fe deficient patient (approx. 1500 mg Fe) would only account for a 1.67% or 3.33% loss respectively. This loss is not likely to result in Fe restricted erythropoiesis. Therefore, the Fe loss due to diagnostic phlebotomy in chemotherapy patients is unlikely to cause significant Fe deficiency.