You might be surprised to learn that many of the patients who receive red cell transfusions in the emergency department don’t need them. A Canadian study looking at trends in transfusion practice in the emergency department found that about half of transfusions given were deemed unnecessary.

If we think of a blood transfusion as a “blood transplant” similar to an organ transplant, then the potential complications including transfusion-associated circulatory overload (TACO), transfusion-related lung injury (TRALI), and alloimmunization become, perhaps, a bit more understandable. When you give someone a blood transfusion, you’re changing the patient’s immune system for life. Red cell transfusions should not be thought of as a delivery system for iron! While IV iron has been used for years in hematology clinics across the country, the emergency medicine community has been largely unaware of this sensible alternative.

ACEP Now features one article each issue related to an ACEP eCME CME activity.

Log on to the ACEP eCME CME site to complete the activity for this article and earn free AMA PRA Category 1 Credit.

The literature is full of studies showing that morbidity and mortality outcomes with lower hemoglobin thresholds, such as 7 g/dL for transfusing ICU patients (in the TRICC [Transfusion Requirements in Critical Care] trial), patients in septic shock (in the TRISS [Transfusion Requirements in Septic Shock] trial), and patients with gastrointestinal bleeds, are similar to outcomes with traditional higher hemoglobin thresholds of 9 or 10 g/dL.

The American Association of Blood Banks, in conjunction with the American Board of Internal Medicine’s Choosing Wisely campaign, recognized that physicians were being overzealous with our transfusions. One of its five statements on medication overuse declared, “Don’t transfuse iron deficiency without hemodynamic instability.”

How Low Can You Go?

So how low can a patient’s hemoglobin go? In a remarkable study (for ethical reasons) of healthy subjects, hemoglobin concentrations were reduced from 13.1 g/dL to as low as 5 g/dL by replacing aliquots of blood (450–900 mL) with 5 percent human albumin and/or autologous plasma. The researchers found that systemic oxygen delivery was maintained as assessed by change of O2 and plasma lactate concentration. Holter monitor readings suggested that myocardial ischemia was extraordinarily rare in this resting healthy population. Based on this and similar studies, the American Society of Anesthesiologists recommends against red cell transfusions in young, healthy patients without ongoing blood loss and a hemoglobin level greater than 6.0 g/dL, unless they are symptomatic or hemodynamically unstable.

It isn’t only healthy subjects who can tolerate incredibly low hemoglobin levels. The FOCUS (Fluoxetine or Control Under Supervision) trial sought to determine whether a higher threshold for blood transfusion would improve recovery in patients who had undergone surgery for a hip fracture. Results showed that even among elderly patients with known coronary artery disease or multiple coronary risk factors, survival rates were higher postoperatively at 30 and 90 days among patients with a transfusion trigger of 8 g/dL compared to those with a higher transfusion trigger.

What Are the Indications for IV Iron?

Current knowledge suggests physicians shouldn’t be giving red cell transfusions to many patients who have severe anemia or blood loss. Nonetheless, these patients with severe anemia (Hb <9 g/dL) do require treatment for symptom management, and the fastest, most effective treatment is IV iron.

The concept of giving IV iron in a subset of ED patients with iron-deficiency anemia might seem foreign to most emergency physicians, but there are indications that should be considered when faced with a patient with iron-deficiency anemia or blood loss in the ED. They include:

• Severe iron-deficiency anemia (Hb <9 g/dL) especially if there is ongoing bleeding
• Rate of bleeding too brisk for oral iron
• Time-sensitive pressures (eg, an urgent surgical procedure; observational studies of the use of IV iron preoperatively for patients with anemia have shown a reduced rate of red cell transfusion being required)
• Severe anemia of chronic disease and evidence of iron deficiency (eg, ferritin <30 ug/L)
• Oral iron being poorly tolerated or the failure of an oral trial
• Poor oral absorption (due to conditions including gastric bypass, celiac disease, and gastritis)

Is IV Iron Safe?

The main contraindications to IV iron are active systemic infection (eg, suspected sepsis), as iron is a good microbial nutrient, and known allergic or hypotensive reactions in the past. Risks of administration include hypotension (1 to 2 percent) and serious allergic reactions including fatal anaphylaxis in fewer than one in 1 million. In patients with chronic kidney disease, IV iron may result in more infections and cardiovascular complications than oral iron. More common adverse reactions, which generally resolve spontaneously within 24 hours of administration of IV iron, include joint aches, muscle cramps, headache, chest discomfort, nausea, vomiting, and diarrhea.

How Do You Give IV Iron?

IV iron is given as iron sucrose (brand name Venofer) in an infusion of 300 mg in 250 mL of normal saline over two hours. After IV iron, and with ongoing oral supplementation, a patient’s hemoglobin will start to rise in three to seven days. You can expect a 0.1- to 0.2-point rise in the hemoglobin per day; after two to four weeks, the hemoglobin will have risen 2 to 3 g/dL. Ferrous sulfate (300 mg) contains 60 mg of elemental iron, and one tablet can be taken each night on an empty stomach at least two hours after meals with 500 mg of vitamin C to improve absorption. Patients should be counseled to avoid taking iron with calcium or magnesium supplements as they decrease iron absorption.

Resources from Emergency Medicine Cases Website

Podcast: Episode 65–IV Iron for Anemia in Emergency Medicine

PDF Summary: Episode 65–IV Iron for Anemia in Emergency Medicine

A special thanks to Dr. Watler Himmel, Dr. Jeannie Callum, and Dr. Katerina Pavenski for their participation in the EM Cases podcast from which this article is based.

Dr. Helman is an emergency physician at North York General Hospital in Toronto. He is an assistant professor at the University of Toronto, Division of Emergency Medicine, and the education innovation lead at the Schwartz/Reisman Emergency Medicine Institute. He is the founder and host of Emergency Medicine Cases podcast and website.

Resources for Further Review

1. Mozaffarian D, Benjamin EJ, Go AS, et al. Heart Disease and Stroke Statistics—2015 Update. Circulation website.
2. Highlights of the 2015 American Heart Association Guidelines Update for CPR and ECC. American Heart Association website. Accessed June 12, 2016.
3. The ‘Top Five Changes’ Project: 2015 AHA guidelines on CPR + ECC update infographic series. CanadiEM website. Accessed 6/12/2016.
4. Milne K. SGEM#152: Movin’ on Up – Higher Floors, Lower Survival for OHCA. The Skeptics’ Guide to EM website. Accessed June 12, 2016.