Anaemia in Renal Disease

Anaemia in CKD

Anaemia is a common complication of chronic kidney disease (CKD) and is associated with adverse outcomes. Investigation of anaemia for adults with CKD is recommended when haemoglobin falls below 110 g/L, or when symptoms attributable to anaemia develop (reference). For further information on the possible causes of anaemia in renal disease and suggested baseline investigations, click here.   EPO-replacement therapy with an erythropoiesis-stimulating agent (ESA) can be instigated for patients with CKD who have had other causes of anaemia investigated and excluded.

To download the Renal Association Clinical Practice Guideline (2017) on Anaemia of Chronic Kidney Disease, please click here.

Iron Deficiency and Supplementation

It is important to remember that CKD in itself is not a cause of iron deficiency, and patients with iron deficiency anaemia require appropriate investigation to determine the cause of this, usually involving investigation of the gastrointestinal tract.

Patients with CKD should be iron-replete irrespective of whether or not they are receiving ESA therapy. Assessing iron status is therefore mandatory. Doing so, however, is difficult and there is not a single fool-proof method. A ferritin of < 50μg/l is highly suggestive of iron deficiency, and <150μg/l is also likely to warrant supplementation. However, ferritin is an acute phase protein, and therefore higher levels may be found despite an underlying iron deficiency. Transferrin saturation (TSAT) is a measure of the ability to mobilise stored iron for red cell production. TSAT < 20% is indicative of a functional iron deficiency, even if the ferritin levels are normal / raised. This may respond to treatment with IV iron.

Iron supplementation for patients with CKD can be oral or intravenous. The choice between these routes largely depends upon the severity of iron deficiency, previous response to treatment, and tolerability of oral iron supplements. Many patients with CKD and iron-deficiency will maintain their haemoglobin with oral iron supplements in the early stages,  however, the absorption of oral preparations of iron often becomes insufficient as CKD advances, and therefore treatment with IV iron becomes increasingly necessary. 

In our department, we no longer routinely give test doses for IV iron as reactions, although serious, are rare. 

Diafer® is currently the IV iron preparation of choice for haemodialysis patients within NHS Lothian. Dosing is patient dependent, but most patients will receive 100mg on a weekly, fortnightly, or monthly basis during their dialysis sessions. Iron stores are checked once every 3 months, although more frequent monitoring may be necessary for some patients.

For conservative care patients, those on peritoneal dialysis, and those who have not yet commenced haemodialysis, Monofer® is currently the preferred IV preparation. Treatment of these patients are managed by our Anaemia Co-ordinators, who can be contacted on 0131 242 1204.

To download the current protocol for IV Monofer, please click here.  The protocol for IV Diafer is still under review.

Erythropoesis-Stimulating Agents

In their 2017 clinical practice guideline, the Renal Association recommend that Erythropoiesis-Stimulating Agents (ESAs) should be offered to patients with anaemia of CKD who are likely to benefit in term of quality of life and physical function and to avoid blood transfusion; especially in patients considered suitable for transplantation. The recommended target haemoglobin for adult patients receiving ESAs is between 100 and 120g/L1; the target without our department is 105 – 125g/L.

For patients receiving hospital-based haemodialysis therapy within NHS Lothian, ESAs are prescribed, dispensed and administered by the hospital under the supervision of a consultant nephrologist. This treatment is usually given intravenously during the haemodialysis session and our current ESA of choice in these patients is Neorecoromon®.

Community-based patients, such as those with advanced CKD, pre-dialysis patients and those on peritoneal dialysis, can receive ESAs from the hospital or their GP via a Shared Care Agreement. This type of ESA therapy is usually given subcutaneously, and the current ESA of choice is Mircera®.

ESA therapy in Haemodialysis Patients in NHS Lothian

 

Indication Haemoglobin consistently <105 g/L in an iron replete patient
Target Hb (g/l) Population target Hb range: 105 – 125 g/L. Hb should not be allowed to rise above 140g/L
Contraindications Uncontrolled hypertension (SBP >175mmHg, DBP >95mmHg)
Baseline Investigations (rationale)
  • Exclude occult blood loss
  • Reticulocyte count (to assess bone marrow responsiveness)
  • Iron studies (to ensure iron replete)
  • Vitamin B12 and Folate (to exclude nutritional deficiency)
  • PTH  (hyperparathyroidism can contribute to ESA resistance)
  • CRP (inflammation can contribute to ESA resistance)
  • TFTs (hypothyroidism can contribute to ESA resistance)
Initiation Dosing
The typical starting dose of Neorecoromon is 150 units/kg body weight/week. This is usually administered as 3 divided doses (but can be given as a single weekly dose), given intravenously during haemodialysis.
Monitoring Haemoglobin is checked monthly, although more frequent monitoring can be requested if clinically indicated.
Dose Adjustment (induction period) – If the rate of rise is <10 g/L/month, increase weekly ESA dose by 25%
– If the rate of rise of Hb is ≥ 15 g/l/month, decrease weekly dose by 25-50%
Dose Adjustment (stable period) – If Hb exceeds 125g/L, reduce weekly dose by 25-50% and consider period of discontinuation
– If Hb falls below 100g/l, increase weekly dose by 25-50%
Resistance If ESA doses ≥250units/kg/week are required to maintain haemoglobin, this should be discussed with senior staff and patients should be investigated for causes of ESA resistance (see below).
ESA Resistance

Some patients may require ever increasing doses of ESAs to result in an increment in haemoglobin, and a few will fail to respond to ESAs at all. There are a number of reasons for this so-called “ESA resistance” – for more information regarding causes of this and recommended investigations, please click (here).

Blood Transfusions

Blood transfusions should be avoided as far as possible in patients who are on, or who in the future may be on, the transplant list. All blood products given to patients with renal disease who may be future transplant candidates should be treated to remove white blood cells. Our Blood Transfusion Service now routinely provides leucocyte-depleted products for all patients. When blood transfusion is felt to be necessary for renal patients, careful consideration should be given to volume status. If blood is being given on haemodialysis, each unit is usually given over 1 hour and the equivalent fluid volume removed by ultrafiltration.

Education
References
  1. The Renal Association Clinical Practice Guideline for Anaemia of Chronic Kidney Disease, 2017. Available from Renal Assoc guidelines page

 

Acknowledgements: John Webster and Sue Mann were the original authors for this page, revised by Paddy Gibson and Wendy King. This page was reviewed and updated by Ashley Simpson in 2019. The date it was last modified is shown in the footer.

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