title: Sodium bicarbonate and renal function after cardiac surgery: a prospectively planned individual patient meta-analysis.
abstract: BACKGROUND
  The effect of urinary alkalinization in cardiac surgery patients at risk of acute kidney injury (AKI) is controversial and trial findings conflicting. Accordingly, the authors performed a prospectively planned individual patient data meta-analysis of the double-blind randomized trials in this field.
  
  
  METHODS
  The authors studied 877 patients from three double-blind, randomized controlled trials enrolled to receive either 24 h of intravenous infusion of sodium bicarbonate or sodium chloride. The primary outcome measure was a postoperative increase in serum creatinine concentration of greater than 25% or 0.5 mg/dl (> 44 μM/L) within the first five postoperative days. Secondary outcomes included the raw change in serum creatinine, greater than 50% and greater than 100% rises in serum creatinine, developing AKI (Acute Kidney Injury Network criteria), initiation of renal replacement therapy, morbidity, and mortality.
  
  
  RESULTS
  Patients were similar in demographics, comorbidities, and cardiac procedures. Sodium bicarbonate increased plasma bicarbonate (P < 0.001) and urine pH (P < 0.001). There were no differences in the development of the primary outcome (Bicarbonate 45% [39-51%] vs. Saline 42% [36-48%], P = 0.29). This result remained unchanged when controlling for study and covariates (odds ratio [OR], 99% confidence interval [CI]: Bicarbonate vs. Control, 1.11 [0.77-1.60], P = 0.45). There was, however, a significant study-adjusted benefit in elective coronary artery bypass surgery patients in terms of renal replacement therapy (Bicarbonate vs. Control, OR: 0.38 [99% CI: 0.25-0.58], P < 0.0001) and the development of an Acute Kidney Injury Network grade = 3 (Bicarbonate vs. Control, OR: 0.45 [99% CI: 0.43-0.48], P < 0.0001).
  
  
  CONCLUSIONS
  Urinary alkalinization using sodium bicarbonate infusion is not associated with an overall lower incidence of AKI; however, it reduces severe AKI and need for renal replacement therapy in elective coronary artery bypass patients.
authors.affiliation: From the Department of Epidemiology and Preventive Medicine, The Australian and New Zealand Intensive Care Research Center, Monash University, Melbourne, Australia (M.B., C.L.H., A.F., R.B.); Cardiothoracic and Vascular Intensive Care Unit, Auckland City Hospital, Auckland, New Zealand (S.M., R.P.); Department of Nephrology and Hypertension, Diabetes, and Endocrinology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany (M.H., A.H.-F.); and Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (S.M.B.).
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.forename: Shay
authors.initials: S
authors.lastname: McGuinness
authors.forename: Michael
authors.initials: M
authors.lastname: Haase
authors.forename: Anja
authors.initials: A
authors.lastname: Haase-Fielitz
authors.forename: Rachael
authors.initials: R
authors.lastname: Parke
authors.forename: Carol L
authors.initials: CL
authors.lastname: Hodgson
authors.forename: Andrew
authors.initials: A
authors.lastname: Forbes
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
mesh_terms: D058186:Acute Kidney Injury / Q000188:drug therapy* / Q000209:etiology; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007668:Kidney / Q000187:drug effects*; D007677:Kidney Function Tests; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000188:drug therapy; D011446:Prospective Studies; D017693:Sodium Bicarbonate / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D017693:Sodium Bicarbonate