title: Sodium bicarbonate infusion to reduce cardiac surgery-associated acute kidney injury: a phase II multicenter double-blind randomized controlled trial.
abstract: OBJECTIVE
  Cardiac surgery-associated acute kidney injury occurs in up to 50% of patients and is associated with increased mortality and morbidity. This study aimed to discover if perioperative urinary alkalinization with sodium bicarbonate infusion reduces the prevalence of cardiac surgery-associated acute kidney injury.
  
  
  METHODS
  This study was a phase IIb multicenter double-blind randomized controlled trial.
  
  
  METHODS
  This study was conducted in three tertiary hospitals in New Zealand and Australia.
  
  
  METHODS
  A total of 427 patients scheduled to undergo elective cardiac surgery, who were at increased risk of development of cardiac surgery-associated acute kidney injury using recognized risk factors.
  
  
  RESULTS
  Patients were randomly allocated to receive either sodium bicarbonate (n = 215) or sodium chloride (n = 212) infusion, commencing at the start of anesthesia, in a dose of 0.5 mEq/kg/hr for the first hour and then 0.2 mmol/kg/hr for 23 hours. The primary outcome measure was the number of patients with development of cardiac surgery-associated acute kidney injury, defined as an increase in creatinine greater than 25% or 0.5 mg/dL (44 µmol/L) from baseline to peak value within the first five postoperative days. Significant differences among the groups in both plasma and urinary biochemistry were achieved 6 hours after commencement of the infusion, and these changes persisted for more than 24 hours. A total of 100 out of 215 patients (47% [95% CI, 40%-53%]) in the sodium bicarbonate group and 93 of 212 patients (44% [95% CI, 37%-51%]) in the sodium chloride group with development of acute kidney injury within the first five postoperative days (p = 0.58). There were also no significant differences in ventilation hours, ICU or hospital length of stay, or mortality.
  
  
  CONCLUSIONS
  Perioperative alkalinization of blood and urine using an infusion of sodium bicarbonate did not result in a decrease in the prevalence of acute kidney injury in patients following cardiac surgery.
authors.affiliation: Cardiothoracic and Vascular Intensive Care Unit, Auckland City Hospital, Auckland, New Zealand. shaymc@adhb.govt.nz
authors.forename: Shay P
authors.initials: SP
authors.lastname: McGuinness
authors.forename: Rachael L
authors.initials: RL
authors.lastname: Parke
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
authors.forename: Frank M P
authors.initials: FM
authors.lastname: Van Haren
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000517:prevention & control*; D000368:Aged; D000369:Aged, 80 and over; D001774:Blood Chemical Analysis; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D015897:Comorbidity; D003404:Creatinine / Q000652:urine; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D017693:Sodium Bicarbonate / Q000008:administration & dosage*; D012965:Sodium Chloride / Q000008:administration & dosage
chemical_list: D012965:Sodium Chloride; D017693:Sodium Bicarbonate; D003404:Creatinine