ICU Patients With Iron Deficiency More Likely to Require Blood Transfusion

Receiving a blood transfusion in the intensive care unit (ICU) is not uncommon, but reliable predictors for patients that will require transfusion are not readily available. A new study published in the May issue of Anesthesiology seeks to reduce the occurrence of ICU transfusions, revealing a new marker for patients at higher risk for developing severe anemia and subsequently requiring transfusion in the ICU.

In this study, Rafael Fernandez, M.D., Ph.D. and colleagues set out to determine if patients with functional iron deficiency (called CHr) was associated with transfusion requirements in ICU patients.

“Previous studies have indicated that anemia is a common occurrence in ICU patients and is even associated with greater patient mortality while admitted to the hospital,” said Dr. Fernandez. “Our study was designed as an observational investigation looking for clues about anemia in critically ill patients and associations between iron deficiency, a common cause of anemia, at ICU admission and the requirement for transfusion.”

About the Study
Researchers examined patients admitted to a 16-bed ICU over a two month period. During that time period 75 patients were admitted. A total of 62 patients had an ICU stay of greater than 48 hours and were included in the study.

Of these patients, 23 were admitted with iron deficiency. Patients presenting with iron deficiency were found to be sicker and more likely to have sepsis. These patients were also found to be prone to complications in particular renal failure (37 percent) and ICU-acquired infection (30 percent).

Significantly the transfusion rate for patients was 22.6 percent, a rate that was higher in patients with low CHr levels signaling iron deficiency than in patients with normal-CHr (39.1 percent to 12.8 percent).

Next Steps
Dr. Fernandez commented on the significance of the study results: “The fact that iron deficiency was associated with a higher need for a transfusion and higher likelihood of mortality in this group should reinforce the impact iron levels can have on surgical outcomes. Whenever possible, iron levels should be well-managed prior to admission.”

Further research on the significance of iron deficiency and need for blood transfusion is required. Dr. Fernandez and colleagues recommend that critically ill patients with low CHr levels are included in future studies to determine if early treatment with intravenous iron after ICU admission could reduce the need for transfusions.

The American Society of Anesthesiologists
Anesthesiologists: Physicians providing the lifeline of modern medicine. Founded in 1905, the American Society of Anesthesiologists is an educational, research and scientific association with 44,000 members organized to raise and maintain the standards of the medical practice of anesthesiology and improve the care of the patient.