title: Characterising the Role of Perioperative Erythropoietin for Preventing Acute Kidney Injury after Cardiac Surgery: Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  The role of perioperative erythropoietin (EPO) for preventing cardiac surgery associated acute kidney injury (CSA-AKI) remains uncertain with published trials producing conflicting results. Perspective into the factors at work is needed, due to ongoing uncertainty.
  
  
  METHODS
  We undertook the systematic review and meta-analysis of randomised-controlled trials (RCTs) using random-effects modelling. The primary outcome was safety and efficacy of perioperative EPO to prevent CSA-AKI and the secondary outcomes were change in serum creatinine, urinary neutrophil gelatinase-associated lipocalin, time in ICU, rates of postoperative transfusions, haemodialysis, and mortality. Subgroup analysis explored the effect of the timing of the EPO dose in relation to surgery, the dose response, and the impact of the preoperative risk for CSA-AKI for the patient group.
  
  
  RESULTS
  Six RCTs were included, which totalled 473 participants. Erythropoietin administration did not reduce the incidence of CSA-AKI compared with controls (OR: 0.69, 95% CI: 0.35 to 1.36, P=0.28; I2=64%, P=0.001), however, subgroup analysis suggested administrating EPO before anaesthesia was correlated with a reduction in CSA-AKI (OR: 0.27, 95% CI: 0.13 to 0.54, P=0.0002; I2=0%, P=0.98). Additionally, in low risk populations, perioperative EPO administration correlated with significant reduction in CSA-AKI when compared to controls (OR: 0.25, 95% CI: 0.11 to 0.56, P=0.0008; I2=0%, P=0.86).
  
  
  CONCLUSIONS
  Our findings suggest that administering EPO before anaesthesia is emerging as an important factor for efficacy. Erythropoietin may have a role in preventing CSA-AKI, however, additional high-quality prospective studies are warranted, particularly aimed at describing the methodological components, such as the timing and size of the dose, which potentiate the cytoprotective effect of EPO in the clinical setting.
authors: Department of Surgery (School of Clinical Sciences at Monash Health), Monash University and Department of Cardiothoracic Surgery, Monash Health, Melbourne, Vic., Australia. Electronic address: jcpen1@student.monash.edu.
authors: Jahan Che
authors: JC
authors: Penny-Dimri
authors: Department of Surgery (School of Clinical Sciences at Monash Health), Monash University and Department of Cardiothoracic Surgery, Monash Health, Melbourne, Vic., Australia.
authors: Andrew D
authors: AD
authors: Cochrane
authors: Department of Surgery (School of Clinical Sciences at Monash Health), Monash University and Department of Cardiothoracic Surgery, Monash Health, Melbourne, Vic., Australia.
authors: Luke A
authors: LA
authors: Perry
authors: Department of Surgery (School of Clinical Sciences at Monash Health), Monash University and Department of Cardiothoracic Surgery, Monash Health, Melbourne, Vic., Australia.
authors: Julian A
authors: JA
authors: Smith
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology / Q000517:prevention & control*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D004921:Erythropoietin / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D019990:Perioperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control*
chemical_list: C554270:EPO protein, human; D004921:Erythropoietin
keywords: Acute kidney injury; Cardiac surgery; Erythropoietin; Meta-analysis; Perioperative care; Pharmacology