Adverse events of iron and/or erythropoiesis-stimulating agent therapy in preoperatively anemic elective surgery patients: a systematic review.

BACKGROUND: Iron supplementation and erythropoiesis-stimulating agent (ESA) administration represent the hallmark therapies in preoperative anemia treatment, as reflected in a set of evidence-based treatment recommendations made during the 2018 International Consensus Conference on Patient Blood Management. However, little is known about the safety of these therapies. This systematic review investigated the occurrence of adverse events (AEs) during or after treatment with iron and/or ESAs. METHODS: Five databases (The Cochrane Library, MEDLINE, Embase, Transfusion Evidence Library, Web of Science) and two trial registries (ClinicalTrials.gov, WHO ICTRP) were searched until 23 May 2022. Randomized controlled trials (RCTs), cohort, and case-control studies investigating any AE during or after iron and/or ESA administration in adult elective surgery patients with preoperative anemia were eligible for inclusion and judged using the Cochrane Risk of Bias tools. The GRADE approach was used to assess the overall certainty of evidence. RESULTS: Data from 26 RCTs and 16 cohort studies involving a total of 6062 patients were extracted, on 6 treatment comparisons: (1) intravenous (IV) versus oral iron, (2) IV iron versus usual care/no iron, (3) IV ferric carboxymaltose versus IV iron sucrose, (4) ESA+iron versus control (placebo and/or iron, no treatment), (5) ESA+IV iron versus ESA+oral iron, and (6) ESA+IV iron versus ESA+IV iron (different ESA dosing regimens). Most AE data concerned mortality/survival (n=24 studies), thromboembolic (n=22), infectious (n=20), cardiovascular (n=19) and gastrointestinal (n=14) AEs. Very low certainty evidence was assigned to all but one outcome category. This uncertainty results from both the low quantity and quality of AE data due to the high risk of bias caused by limitations in the study design, data collection, and reporting. CONCLUSIONS: It remains unclear if ESA and/or iron therapy is associated with AEs in preoperatively anemic elective surgery patients. Future trial investigators should pay more attention to the systematic collection, measurement, documentation, and reporting of AE data.

Effectiveness of Iron Supplementation With or Without Erythropoiesis-Stimulating Agents on Red Blood Cell Utilization in Patients With Preoperative Anaemia Undergoing Elective Surgery: A Systematic Review and Meta-Analysis.

Patient Blood Management (PBM) is an evidence-based, multidisciplinary, patient-centred approach to optimizing the care of patients who might need a blood transfusion. This systematic review aimed to collect the best available evidence on the effectiveness of preoperative iron supplementation with or without erythropoiesis-stimulating agents (ESAs) on red blood cell (RBC) utilization in all-cause anaemic patients scheduled for elective surgery. Five databases and two trial registries were screened. Primary outcomes were the number of patients and the number of RBC units transfused. Effect estimates were synthesized by conducting meta-analyses. GRADE (Grades of Recommendation, Assessment, Development and Evaluation) was used to assess the certainty of evidence. We identified 29 randomized controlled trials (RCTs) and 2 non-RCTs comparing the effectiveness of preoperative iron monotherapy, or iron + ESAs, to control (no treatment, usual care, placebo). We found that: (1) IV and/or oral iron monotherapy may not result in a reduced number of units transfused and IV iron may not reduce the number of patients transfused (low-certainty evidence); (2) uncertainty exists whether the administration route of iron therapy (IV vs oral) differentially affects RBC utilization (very low-certainty evidence); (3) IV ferric carboxymaltose monotherapy may not result in a different number of patients transfused compared to IV iron sucrose monotherapy (low-certainty evidence); (4) oral iron + ESAs probably results in a reduced number of patients transfused and number of units transfused (moderate-certainty evidence); (5) IV iron + ESAs may result in a reduced number of patients transfused (low-certainty evidence); (6) oral and/or IV iron + ESAs probably results in a reduced number of RBC units transfused in transfused patients (moderate-certainty evidence); (7) uncertainty exists about the effect of oral and/or IV iron + ESAs on the number of patients requiring transfusion of multiple units (very low-certainty evidence). Effect estimates of different haematological parameters and length of stay were synthesized as secondary outcomes. In conclusion, in patients with anaemia of any cause scheduled for elective surgery, the preoperative administration of iron monotherapy may not result in a reduced number of patients or units transfused (low-certainty evidence). Iron supplementation in addition to ESAs probably results in a reduced RBC utilization (moderate-certainty evidence).