Erythropoietin with iron supplementation for preoperative anaemia in non‐cardiac surgery

Erythropoietin plus iron versus control treatment including placebo or iron for preoperative anaemic adults undergoing non-cardiac surgery

BACKGROUND

Approximately 30% of adults undergoing non-cardiac surgery suffer from preoperative anaemia. Preoperative anaemia is a risk factor for mortality and adverse outcomes in different surgical specialties and is frequently the reason for blood transfusion. The most common causes are renal, chronic diseases, and iron deficiency. International guidelines recommend that the cause of anaemia guide preoperative anaemia treatment. Recombinant human erythropoietin (rHuEPO) with iron supplementation has frequently been used to increase preoperative haemoglobin concentrations in patients in order to avoid the need for perioperative allogeneic red blood cell (RBC) transfusion.

OBJECTIVES

To evaluate the efficacy of preoperative rHuEPO therapy (subcutaneous or parenteral) with iron (enteral or parenteral) in reducing the need for allogeneic RBC transfusions in preoperatively anaemic adults undergoing non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL, Ovid MEDLINE(R), Ovid Embase, ISI Web of Science: SCI-EXPANDED and CPCI-S, and clinical trial registries WHO ICTRP and ClinicalTrials.gov on 29 August 2019.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) that compared preoperative rHuEPO + iron therapy to control treatment (placebo, no treatment, or standard of care with or without iron) for preoperatively anaemic adults undergoing non-cardiac surgery. We used the World Health Organization (WHO) definition of anaemia: haemoglobin concentration (g/dL) less than 13 g/dL for males, and 12 g/dL for non-pregnant females (decision of inclusion based on mean haemoglobin concentration). We defined two subgroups of rHuEPO dosage: 'low' for 150 to 300 international units (IU)/kg body weight, and 'high' for 500 to 600 IU/kg body weight.

DATA COLLECTION AND ANALYSIS

Two review authors collected data from the included studies. Our primary outcome was the need for RBC transfusion (no autologous transfusion, fresh frozen plasma or platelets), measured in transfused participants during surgery (intraoperative) and up to five days after surgery. Secondary outcomes of interest were: haemoglobin concentration (directly before surgery), number of RBC units (where one unit contains 250 to 450 mL) transfused per participant (intraoperative and up to five days after surgery), mortality (within 30 days after surgery), length of hospital stay, and adverse events (e.g. renal dysfunction, thromboembolism, hypertension, allergic reaction, headache, fever, constipation).

MAIN RESULTS

Most of the included trials were in orthopaedic, gastrointestinal, and gynaecological surgery and included participants with mild and moderate preoperative anaemia (haemoglobin from 10 to 12 g/dL). The duration of preoperative rHuEPO treatment varied across the trials, ranging from once a week to daily or a 5-to-10-day period, and in one trial preoperative rHuEPO was given on the morning of surgery and for five days postoperatively. We included 12 trials (participants = 1880) in the quantitative analysis of the need for RBC transfusion following preoperative treatment with rHuEPO + iron to correct preoperative anaemia in non-cardiac surgery; two studies were multiarmed trials with two different dose regimens. Preoperative rHuEPO + iron given to anaemic adults reduced the need RBC transfusion (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.38 to 0.80; participants = 1880; studies = 12; I² = 84%; moderate-quality evidence due to inconsistency). This analysis suggests that on average, the combined administration of rHuEPO + iron will mean 231 fewer individuals will need transfusion for every 1000 individuals compared to the control group. Preoperative high-dose rHuEPO + iron given to anaemic adults increased the haemoglobin concentration (mean difference (MD) 1.87 g/dL, 95% CI 1.26 to 2.49; participants = 852; studies = 3; I² = 89%; low-quality evidence due to inconsistency and risk of bias) but not low-dose rHuEPO + iron (MD 0.11 g/dL, 95% CI -0.46 to 0.69; participants = 334; studies = 4; I² = 69%; low-quality evidence due to inconsistency and risk of bias). There was probably little or no difference in the number of RBC units when rHuEPO + iron was given preoperatively (MD -0.09, 95% CI -0.23 to 0.05; participants = 1420; studies = 6; I² = 2%; moderate-quality evidence due to imprecision).  There was probably little or no difference in the risk of mortality within 30 days of surgery (RR 1.19, 95% CI 0.39 to 3.63; participants = 230; studies = 2; I² = 0%; moderate-quality evidence due to imprecision) or of adverse events including local rash, fever, constipation, or transient hypertension (RR 0.93, 95% CI 0.68 to 1.28; participants = 1722; studies = 10; I² = 0%; moderate-quality evidence due to imprecision). The administration of rHuEPO + iron before non-cardiac surgery did not clearly reduce the length of hospital stay of preoperative anaemic adults (MD -1.07, 95% CI -4.12 to 1.98; participants = 293; studies = 3; I² = 87%; low-quality evidence due to inconsistency and imprecision).

AUTHORS' CONCLUSIONS

Moderate-quality evidence suggests that preoperative rHuEPO + iron therapy for anaemic adults prior to non-cardiac surgery reduces the need for RBC transfusion and, when given at higher doses, increases the haemoglobin concentration preoperatively. The administration of rHuEPO + iron treatment did not decrease the mean number of units of RBC transfused per patient. There were no important differences in the risk of adverse events or mortality within 30 days, nor in length of hospital stay. Further, well-designed, adequately powered RCTs are required to estimate the impact of this combined treatment more precisely.