Role of diagnostic, predictive, and prognostic biomarkers in preoperative iron-deficiency – scoping review

Abstract
Objective: The objective of this scoping review is to map the existing evidence regarding type and cut-off values for diagnostic, predictive, and prognostic biomarkers in patients with preoperative iron-deficiency, with or without anemia (ID(A)).
Introduction: Preoperative anaemia is associated with poor postoperative outcomes. The detection and treatment of ID(A) is an essential part of Patient Blood Management (PBM) programs. For the diagnosis, prediction or prognosis of ID(A) haemoglobin, transferrin, and transferrin saturation (TSAT) are commonly used. Also newer biomarkers such as reticulocyte hemoglobin (Ret-He) or zinc protoporphyrin have been considered recently. Although these biomarkers are used routinely to diagnose ID(A) a variety of guideline-recommended cut-off values exists.
Inclusion criteria: This review will focus on patients ≥18 years in which blood-based or non-invasive biomarkers are used 1) to diagnose ID(A), 2) to predict efficacy or safety of iron supplementation with or without erythropoietin (EPO), and 3) to prognose adverse intra- / postoperative outcomes (until hospital discharge) in patients with preoperative ID(A). Only surgical patients will be included. Patients without confirmed iron-deficiency are excluded. Experimental studies containing exclusively animal or cell culture data will be excluded.
Methods: MEDLINE (via Ovid) and the Cochrane Central Register of Controlled Trials (CENTRAL) (via Cochrane Library) will be systematically searched for published studies. Language will be limited to English and German without restrictions of publication date. Results will be imported to EndNote Reference manager and duplicates will be removed. The review process will involve two reviewers with a third reviewer resolving disagreements. The Covidence software will be used for the review process. Data will be extracted and organised with subsequent analysis.
Ethics: This scoping review does not require research ethics approval.

摘要
目标：本次范围综述旨在梳理现有关于术前铁缺乏症（ID(A)）患者中诊断、预测和预后生物标志物的类型和截止值的相关证据。引言：术前贫血与不良术后结果相关。铁缺乏症（ID(A)）的检测和治疗是患者血液管理（PBM）计划的重要组成部分。对于ID(A)的诊断、预测或预后，常用的生物标志物包括血红蛋白、转铁蛋白和转铁蛋白饱和度（TSAT）。近期，还考虑了如网织红细胞血红蛋白（Ret-He）或锌原卟啉等新型生物标志物。尽管这些生物标志物在诊断ID(A)方面被常规使用，但存在多种指南推荐的截止值。纳入标准：本综述将聚焦于≥18岁的患者，其中血液或非侵入性生物标志物被用于以下目的：1）诊断ID(A)，2）预测铁剂补充（含或不含有红细胞生成素（EPO））的疗效或安全性，以及3）预测术前ID(A)患者的不良围手术期或术后结果（直至出院）。仅包括手术患者，排除未确认的铁缺乏症患者。仅包含动物或细胞培养数据的实验研究将被排除。方法：将系统地检索MEDLINE（通过Ovid）和Cochrane中央对照试验注册库（CENTRAL）（通过Cochrane图书馆）已发表的文献。语言限制为英语和德语，无关于出版日期的限制。结果将被导入EndNote参考文献管理器，并去除重复项。综述过程将由两位审稿人完成，如有分歧，将由第三位审稿人解决。将使用Covidence软件进行综述过程。数据将被提取和整理，随后进行数据分析。伦理：本次范围综述无需进行伦理审查。