Iron-Deficiency Anaemia and the Use of Iron in Long-Term Parenteral Nutrition Therapy

Abstract

Background and aim: Published studies suggest that the prevalence of iron-deficiency anaemia (IDA) in patients requiring long-term parenteral nutrition (PN) ranges from 30 to 55%. Currently at Auckland District Health Board (ADHB), a trace element containing 20 μmol of iron is added to all PN bags, however, it is uncertain whether this is adequate in meeting the iron requirements of patients with intestinal failure on longterm PN. The aims of our study were to assess the prevalence of IDA in patients who require long-term PN at ADHB, the effect of iron replacement methods in these patients, and the use of iron in patient PN by health professionals associated with the New Zealand National Intestinal Failure Service (NZNIFS). Methods: A retrospective review was carried out on patients at ADHB between May 2009 and September 2018, who received long-term PN (≥20 days). An online questionnaire was sent to health professionals associated with NZNIFS to assess the use of iron in patient PN bags. Results: Of the 63 episodes of PN included in the retrospective review, iron status was assessed in 53 (84.1%) patients at baseline, during PN therapy and/or at treatment endpoint. Seven (13.2%) had haematological values indicative of IDA, and 11 (20.8%) were suspected to have IDA based on their haematological results. Patients who received intravenous (IV) iron infusions (n=4) had a significant increase in haemoglobin (p=0.019) and mean cell volume (p=0.019) in comparison to patients who received iron-supplemented PN (n=21) in varying total dosages of 20 to 40 μmol of iron per litre of PN. Changes in serum ferritin were not significantly different between the two groups (p=0.143). Responses from the questionnaire showed a significant difference in the amount of additional iron generally added to patient PN by dietitians compared to other health professionals involved in prescribing PN (p=0.015). Conclusions: Recipients of long-term PN therapy are susceptible to developing IDA. However, the true prevalence of IDA in these patients is difficult to determine due to underlying inflammation and a lack of data around iron status. Further prospective research may assist with shaping the recommendations around the use of iron in long-term PN therapy.