Response to intravenous iron in a hospice population with anaemia

Background St Barnabas House provides intravenous iron (IVI) to patients with symptomatic iron deficiency anaemia (IDA). Interpreting iron studies is difficult; colleagues expressed concern they might miss IDA when combined with anaemia of chronic disease (ACD). Ferritin, typically low in IDA, is raised in malignancy. Low iron levels are unhelpful as occur in both IDA and ACD; total iron binding capacity (TIBC) and MCV can be used in diagnosis. We reviewed the notes of 16 patients who received IVI for presumed IDA over 12 months to assess type of anaemia and outcome.

Method We determined type of anaemia according to the following criteria - IDA: ferritin <30 mcg/l or TIBC >70; ACD: ferritin ≥30 + TIBC ≤ 70 + MCV ≥80; Mixed: ferritin ≥30 + TIBC ≤ 70 + MCV <80fl. Response was measured by an increase in Hb ≥ 5 g/dl/month and subjective symptom improvement.

Results Eight patients (50%) had IDA: Hb increase in 86% symptom benefit 43%. One patient had mixed IDA/ACD: Hb increase, no symptom benefit. Seven patients had ACD: Hb increase in 29% , symptom benefit 0%. 100% of patients experienced fatigue, 56% dyspnoea. 30% of patients died within 3 months of IVI.

Conclusion Defined criteria for cause of anaemia identifies patients most likely to benefit from IVI – those with haematological and biochemical markers of IDA. Patients with ACD had less benefit suggesting misplaced anxiety around missing mixed IDA and ACD. Collectively, less than 50% of patients had symptomatic benefit highlighting the multifactorial causes of fatigue, and dyspnoea and delay in response to IVI. This provides reassurance that defined diagnostic criteria enables access to IVI to those most likely to benefit whilst reducing non-beneficial interventions. Prognostic estimation should inform decision making as response to IVI can take several weeks.