title: The effect of bicarbonate administration via continuous venovenous hemofiltration on acid-base parameters in ventilated patients.
abstract: BACKGROUND
  Acute kidney injury (AKI) and metabolic acidosis are common in the intensive care unit. The effect of bicarbonate administration on acid-base parameters is unclear in those receiving continuous venovenous hemofiltration (CVVH) and mechanical ventilatory support.
  
  
  METHODS
  Metabolic and ventilatory parameters were prospectively examined in 19 ventilated subjects for up to 96 hours following CVVH initiation for AKI at an academic tertiary care center. Mixed linear regression modeling was performed to measure changes in pH, partial pressure of carbon dioxide (pCO2), serum bicarbonate, and base excess over time.
  
  
  RESULTS
  During the 96-hour study period, pCO2 levels remained stable overall (initial pCO2 42.0±14.6 versus end-study pCO2 43.8±16.1 mmHg; P=0.13 for interaction with time), for those with initial pCO2≤40 mmHg (31.3±5.7 versus 35.0±4.8; P=0.06) and for those with initial pCO2>40 mmHg (52.7±12.8 versus 53.4±19.2; P=0.57). pCO2 decreased during the immediate hours following CVVH initiation (42.0±14.6 versus 37.3±12.6 mmHg), though this change was nonsignificant (P=0.052).
  
  
  CONCLUSIONS
  We did not detect a significant increase in pCO2 in response to the administration of bicarbonate via CVVH in a ventilated population. Additional studies of larger populations are needed to confirm this finding.
authors: Division of Nephrology, Department of Medicine, Massachusetts General Hospital, 7 Whittier Place, Suite 106, Boston, MA 02114, USA.
authors: Andrew S
authors: AS
authors: Allegretti
authors: Division of Nephrology and Hypertension, Department of Medicine and Genetics, UNC School of Medicine, UNC Kidney Center, 7024 Burnett-Womack, CB No. 7155, Chapel Hill, NC 27599-7155, USA.
authors: Jennifer E
authors: JE
authors: Flythe
authors: Renal Division, Department of Medicine, Brigham and Women's Hospital, 75 Francis Street, MRB4, Boston, MA 02115, USA.
authors: Vinod
authors: V
authors: Benda
authors: Renal Division, Department of Medicine, Brigham and Women's Hospital, 75 Francis Street, MRB4, Boston, MA 02115, USA.
authors: Emily S
authors: ES
authors: Robinson
authors: Renal Division, Department of Medicine, Brigham and Women's Hospital, 75 Francis Street, MRB4, Boston, MA 02115, USA.
authors: David M
authors: DM
authors: Charytan
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D001639:Bicarbonates / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006440:Hemofiltration / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial
chemical_list: D001639:Bicarbonates; D002245:Carbon Dioxide
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