title: Peri-operative interventions, but not inflammatory mediators, increase risk of acute kidney injury after cardiac surgery: a prospective cohort study.
abstract: OBJECTIVE
  Cardiopulmonary bypass (CPB)-related inflammatory response might be one mechanism by which cardiac surgery associated acute kidney injury (CS-AKI) occurs. Interventions that may attenuate inflammation, including glucocorticoids or phosphodiesterase inhibitors, could therefore have a role in its prevention. We aimed to determine the role of inflammatory mediators in CS-AKI in children and the efficacy of commonly used peri-operative interventions to reduce CS-AKI risk.
  
  
  METHODS
  We prospectively studied 109 children undergoing heart surgery. Using regression modeling (adjusting for covariates), we (1) evaluated the association between inflammatory mediators [interleukin (IL)-6, IL-8, C-reactive protein, and tumor necrosis factor-α levels] and CS-AKI, and (2) evaluated risk/prevention factors for CS-AKI including glucocorticoid and milrinone administration. CS-AKI was defined based on pRIFLE methods.
  
  
  RESULTS
  CS-AKI occurred in 68% of children. No inflammatory mediator measured had an independent association with CS-AKI. Higher pre-operative glomerular filtration rate (GFR), sustained decrease in mean arterial pressure during CPB, post-operative single ventricle physiology, deep hypothermic circulatory arrest, and milrinone use at 24 h post-operatively were significant independent predictors of CS-AKI. Intra-operative steroid administration had no effect on the rate of CS-AKI.
  
  
  CONCLUSIONS
  Although inflammatory mediators are up-regulated following CPB, we found no association between levels of inflammatory cytokines and CS-AKI. CS-AKI has complex pathophysiology and the observation that milrinone was associated with increased AKI risk (and that higher GFR predicts more injury) suggests that mechanisms beyond inflammation play a significant role. Intra-operative administration of glucocorticoid does not appear to be an effective intervention for reducing the risk of CS-AKI.
authors: Department of Pediatrics, University of Alberta, Edmonton, Canada. cmorgan@ualberta.ca
authors: Catherine J
authors: CJ
authors: Morgan
authors: Peter J
authors: PJ
authors: Gill
authors: Simon
authors: S
authors: Lam
authors: Ari R
authors: AR
authors: Joffe
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology* / Q000517:prevention & control*; D062186:Arterial Pressure; D006348:Cardiac Surgical Procedures; D005260:Female; D005919:Glomerular Filtration Rate; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007036:Hypothermia, Induced; D007223:Infant; D007231:Infant, Newborn; D018836:Inflammation Mediators / Q000097:blood*; D016015:Logistic Models; D008297:Male; D020105:Milrinone / Q000627:therapeutic use; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D005938:Glucocorticoids; D018836:Inflammation Mediators; D014665:Vasodilator Agents; D020105:Milrinone