The Effect of Perioperative Iron Therapy in Acute Major Non-cardiac Surgery on Allogenic Blood Transfusion and Postoperative Haemoglobin Levels: A Systematic Review and Meta-analysis

Abstract

Background

Perioperative anaemia in relation to surgery is associated with adverse clinical outcomes. In an elective surgical setting, it is possible to optimize patients prior to surgery, often by iron supplementation with correction of anaemia. Possibilities for optimization prior to and during acute surgical procedures are limited. This review investigates whether iron treatment initiated perioperatively improves outcomes in patients undergoing major acute non-cardiac surgery.

Method

This systematic review was performed using PubMed, EMBASE (Ovid) and Scopus to identify current evidence on iron supplementation in acute surgery. Primary outcomes were allogenic blood transfusion (ABT) rate and changes in haemoglobin. Secondary outcomes were postoperative mortality, length of stay (LOS), and postoperative complications. Iron was administered at latest within 24 h after end of surgery.

Results

Of the 5413 studies screened, four randomized controlled trials and nine observational cohort studies were included. Ten studies included patients with hip fractures. A meta-analysis of seven studies showed a risk reduction of transfusion (OR = 0.35 CI 95% (0.20–0.63), p = 0.0004, I² = 66%). No influence on plasma haemoglobin was found. Postoperative mortality was reduced in the iron therapy group in a meta-analysis of four observational studies (OR 0.50 (CI 95% 0.26–0.96) p = 0.04). No effect was found on LOS, but a reduction in postoperative infection was seen in four studies.

Conclusions

This review examined perioperative iron therapy in acute major non-cardiac surgery. IV iron showed a lower 30-day mortality, a reduction in postoperative infections and a reduction in ABT largely due to the observational studies. The review primarily consisted of small observational studies and does not have the power to formally recommend this practice.

Appendices

Appendix 1

Search strategy

(((((((((((((((((((Abdomen) OR abdominal) OR Surgery) OR Abdomen, Acute) OR Digestive System Surgical Procedures) OR General Surgery) OR Specialties, Surgical) OR ((Bloodless Medical and Surgical Procedures)))) OR Abdominal Cavity/surgery)) OR Blood Loss, Surgical)))) AND (((((((((Postoperative) OR Perioperative) OR Perioperative period) OR Postoperative care) OR Preoperative Care) OR Emergency) OR Emergencies)) OR acute))) AND ((((((((iron) OR Iron therapeutic) OR Iron administration) OR Ferric Compounds) OR Ferrous Compounds)) OR hematinics)))) AND (((((((((Perioperative outcomes) OR Postoperative complications) OR Long term outcomes) OR Short term outcomes) OR Mortality) OR Treatment outcome) OR Blood transfusion) OR Length of Stay))

Appendix 2

References	Prasad et al. [27]	Parker [28]	Karkouti et al. [30]	Serrano-Trenas et al. [29]
Random sequence generation	Low	Low	Low	Low
Allocation concealment	Low	Low	Low	Low
Selective reporting	Unclear	Low	Unclear	Low
Other bias	Low	Low	Unclear	Low
Blinding of participants and personnel	Low	High	Low	Low
Blinding of outcome assessment	Low	Unclear	Low	Low
Incomplete outcome data	Low	Low	Low	Low
Quality	High	Fair	High	High

1. Quality assessment of randomized clinical trials, using Cochrane risk of bias assessment tool [25]

Appendix 3

References	Panarese et al. [38]	Blanco-Rubio et al. [31]	Izuel-Rami et al. [32]	Muñoz et al. [18]	Cuenca Espiérrez et al. [33]	Cuenca et al. [34]	Cuenca et al. [35]	Garcla-Erce et al. [36]	Armand-Ugón et al. [37]
Selection (max 4)	*	***	***	****	***	**	**	***	**
Comparability (max 2)		*	*					**	*
Outcome (max 3)	**	*	*	***	***	**	**	***	**
Total (max 9)	***	*****	*****	*******	******	****	****	********	*****

1. Quality assessment of observational studies, Newcastle–Ottawa Scale [26]