Clinical Conversations: Interpreting Iron Studies… Tips, Traps and Curly Cases | Part two
Iron deficiency, its identification and optimal management is more complex than many doctors realise. There are many exceptions to the interpretation of iron studies and patient co-morbidities become an important consideration. Dr Patrick Coleman leads us through this topic with practical examples, summaries of the guidelines and a discussion about relevant product information. This is part two, the final part of this article.
This is part two of this series. Read Part 1 >>
• You need to decide if the patient has an absolute iron deficiency, an absolute iron deficiency with chronic disease, or a functional iron deficiency with chronic disease.
• If the CRP is elevated, the ferritin would be elevated too, because both are acute phase reactants. A low ferritin implies low iron stores, but a high ferritin does not automatically imply normal iron stores, depending on the CRP.
• Patients who should have a secondary polycythaemia, but do not, may be iron deficient.
• Test patients for iron deficiency prior to major surgery and if they are iron deficient, they should receive an iron infusion ideally at least four weeks preoperatively.
• Investigate patients to establish what is causing the iron deficiency anaemia.
• Always choose a cannula for iron infusions to avoid skin staining from leakage.
• Hypophosphataemia is rare, but begins about seven days after an iron infusion and is worst at approximately fourteen days. Symptoms are fatigue, malaise, weakness, myalgia and bone pain. In extreme cases there may be ileus, bradycardia, hypotension and/or neurological symptoms. It tends to last over a period of months and unidentified patients can actually develop osteomalacia with pathological fractures.
• Patients at increased risk of hypophosphataemia include those with eating disorders, malnutrition, gastrointestinal disorders, who have had bariatric surgery, are deficient in vitamin D and in particular, patients who require recurrent iron infusions.
In 2022, you may think that we would have better tests, better parameters and more accurate ways of interpreting iron status in patients and we probably do. The problem is that most of these tests are really only being used in research and they are not widely available. They may become available in the future, but they are certainly not ...