Systematic Reviews
Copyright ©The Author(s) 2020.
World J Gastroenterol. Dec 7, 2020; 26(45): 7242-7257
Published online Dec 7, 2020. doi: 10.3748/wjg.v26.i45.7242
Table 1 Characteristics of included original articles and meta-analyses
Study type
No of patients
GI etiology
No of males/females
Study period
Bager et al[5]2013Retrospective169Nonvariceal AUGIB86/8370 (22-95)12009
Bager et al[44]2014Double-blind, randomized, placebo-control97Nonvariceal AUGIB51/4670 (23-95)22010-2013
Bager et al[50]2014Double-blind, randomized, placebo-control97Nonvariceal AUGIB51/4670 (67.4-73.1)3-
Ballester et al[45]2019Retrospective, single-center84Acute GIB58/2668.0 (16.9)22012-2015
Bosch et al[51]2017Prospective cohort2818GI diseases known to cause GIB1398/142063.4 (15.7)22015-2016
Bosch et al[29]2017Prospective cohort4552Occult bleeding2266/228663.7 (17.6)22005-2015
Brooklyn et al[6]2003N/A153Occult bleeding51/10266 (45-96)22000
Cheng et al[52]2010Prospective390Ulcers263/12763 (16)2-
El-Halabi et al[7]2016Retrospective, chart review, single-center307Any GIB130/17766.2 (18.6)22011-2012
Geisser et al[46]2010Phase I/II, multicenter, open-label, multiple-dose46Bleeding due to GI disorder10/3642.9 (11.0)22003-2004
Jairath et al[35]2010Meta-analysis-AUGIB2731/1710Early RBC 67.9 (16.51)2; no early RBC 63.4 (19.19)22007
Jairath et al[36]2015Pragmatic, multicentric, open-label, randomized feasibility trial936AUGIB566/370Liberal 60.4 (20.0)2; restrictive 58.0 (20.3)22012-2013
Restellini et al[31]2013Observational, registry-based1677Nonvariceal AUGIB1035/64266.2 (16.8)21999-2002
Rockey et al[32]2017Prospective cohort1460Acute or chronic GIB899/56153 (14)22006-2011
Salvadori et al[47]2016Retrospective38GI chronic blood loss22/1678 (54-94)42014-2015
Schröder et al[48]2004N/A31GI blood loss12/1943.8 (18.0)2-
Subramaniam et al[30]2016Retrospective cohort2360Nonvariceal AUGIB1505/85270 (56-81)42008-2010
Villanueva et al[37]2013RCT889Severe AUGIB--2003-2009
Table 2 Characteristics of the included guidelines
Guideline organization/society/authors
GI etiology
Level of development
Iron-Deficiency Anemia Working Group Consensus Report[34]2017IBD and GIBTurkeyScientific committee/expert group
The International Consensus Upper Gastrointestinal Bleeding Conference Group[38]2010Nonvariceal UGIBInternationalScientific committee/expert group
Dahlerup et al[17] Guideline approved by the Danish Society of Gastroenterology and Hepatology2014GIB, various etiologiesDenmarkIndependent authors and approved by a professional organization/society
Baveno IV Consensus Workshop[43]2015Variceal bleedingInternationalScientific committee/expert group
European Crohn's and Colitis Organization[10]2015IBDEuropeProfessional organization/society
Gasche et al[11]2007IBDEuropeScientific committee/expert group
British Society of Gastroenterology[12] 2011-United KingdomProfessional organization/society
Hong Kong Society of Gastroenterology, the Hong Kong IBD Society, the Hong Kong Society of Digestive Endoscopy, and the Hong Kong Red Cross Blood Transfusion Service[13]2018Acute and chronic GIBHong KongProfessional organization
The 2018 Patient Blood Management International Consensus Conference[39]2019Acute GIBGermanyScientific committee/expert group
British Society of Gastroenterology[40]2019ALGIBUnited KingdomProfessional organization
National Institute for Health and Care Excellence[41]2015-United KingdomProfessional organization
Strate et al[42]2016ALGIBUnited States and IsraelIndependent authors
World Health Organization[33]2001-InternationalProfessional organization
Table 3 Erythrocyte transfusion: Guidelines for hemoglobin thresholds and targets
Professional association
GI etiology
Threshold Hb, g/dL
Threshold Hb cardiovascular disease, g/dL
Target Hb, g/dL
Target Hb cardiovascular disease, g/dL
The International Consensus Upper Gastrointestinal Bleeding Conference Group[38]Nonvariceal UGIB< 7---
Baveno IV Consensus Workshop[43]Variceal bleeding7-8---
European Crohn's and Colitis Organization[10]IDA in IBD< 7---
Hong Kong Society of Gastroenterology, the Hong Kong IBD Society, the Hong Kong Society of Digestive Endoscopy, and the Hong Kong Red Cross Blood Transfusion Service[13]Acute UGIB7-89-10--
The 2018 Patient Blood Management International Consensus Conference[39]Acute GIB7-8---
British Society of Gastroenterology[40]Acute LGIB< 787-910
National Institute for Health and Care Excellence[41]N/A< 787-98-10
Strate et al[42]Acute LGIB-9> 7 > 9
Table 4 Pharmacological characteristics, advantages and disadvantages of worldwide available oral and intravenous iron preparations
Type of preparation
Oral Safe; readily available (does not require a prescription); administered at home; inexpensive; effective when intestinal absorption is not impaired; no need for venous access and infusion monitoring; eliminates the risk of infusion reactionsSlower repletion of iron stores; Intestinal absorption is relatively low, and may be impaired by concomitant food and medications; gastrointestinal adverse events, including constipation, dyspepsia, bloating, nausea, diarrhoea, heartburn, reducing tolerance and adherence to treatment; compliance difficulted by high pill burden (typically three tablets/day) and gastrointestinal intolerance; diminished efficacy when the uptake is impaired (e.g., in celiac disease, autoimmune gastritis, anemia of chronic disease, or post–gastric or duodenal resection)
Ferric hydroxide polymaltose complex
Sodium ferric gluconate
Ferrous gluconate
Ferrous sulfate
Ferrous fumarate
Intravenous Fast repletion of iron stores; safe when avoiding preparations with dextran; very effective; gastrointestinal adverse events less frequent; ferric carboxymaltose, iron isomaltoside 1000, and ferumoxytol are considered more stableAdministration by a health care professional, requiring clinic visits; increased costs per dose, but fewer doses required; risk of iron overload and transient increase in oxidative stress; risk of anaphylactic reactions with dextran-containing preparations; risk of hypersensitivity reactions
Ferric gluconate
Iron sucrose
Low molecular weight iron dextran
Ferric carboxymaltose
Iron isomaltoside 1000
Table 5 Calculation of iron requirement according to patient body weight and hemoglobin level
Hemoglobin (g/dL)
Hemoglobin (mmoL/L)
Patient body weight (below 35 kg)
Patient body weight (35 kg to 70 kg)
Patient body weight (70 kg and above)
< 10< 6.2500 mg1500 mg2000 mg
10 to 146.2 to 8.7500 mg1000 mg1500 mg
≥ 14≥ 8.7500 mg500 mg500 mg