title: Severity and Duration of Metabolic Acidosis After Deep Hypothermic Circulatory Arrest for Thoracic Aortic Surgery.
abstract: OBJECTIVE
  To determine the severity, duration, and contributing factors for metabolic acidosis after deep hypothermic circulatory arrest (DHCA).
  
  
  METHODS
  Retrospective observational study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Eighty-seven consecutive patients undergoing elective thoracic aortic surgery with DHCA.
  
  
  METHODS
  Regression analysis was used to test for relationships between the severity of metabolic acidosis and clinical and laboratory variables.
  
  
  RESULTS
  Minimum pH averaged 7.27±0.06, with 76 (87%) having a pH<7.35; 55 (63%), a pH<7.30; and 7 (8%), a pH<7.20. The mean duration of metabolic acidosis was 7.9±5.0 hours (range: 0.0 - 26.8), and time to minimum pH after DHCA was 4.3±2.0 hours (1.0 - 10.0 hours). Hyperchloremia contributed to metabolic acidosis in 89% of patients. The severity of metabolic acidosis correlated with maximum lactate (p<0.0001) and hospital length of stay (LOS) (r = 0.22, p<0.05), but not with DHCA time, DHCA temperature, duration of vasoactive infusions, or ICU LOS. Patient BMI was the sole preoperative predictor of the severity of postoperative metabolic acidosis.
  
  
  CONCLUSIONS
  This retrospective analysis involved short-term clinical outcomes related to pH severity and duration, which indirectly may have included the impact of sodium bicarbonate administration.
  
  
  CONCLUSIONS
  Metabolic acidosis was common and severe after DHCA and was attributed to both lactic and hyperchloremic acidosis. DHCA duration and temperature had little impact on the severity of metabolic acidosis. The severity of metabolic acidosis was best predicted by the BMI and had minimal effects on short-term outcomes. Preventing hyperchloremic acidosis has the potential to decrease the severity of metabolic acidosis after DHCA.
authors.affiliation: Anesthesiology and Critical Care. Electronic address: Kamrouz.Ghadimi@duke.edu.
authors.forename: Kamrouz
authors.initials: K
authors.lastname: Ghadimi
authors.affiliation: Anesthesiology and Critical Care.
authors.forename: Jacob T
authors.initials: JT
authors.lastname: Gutsche
authors.affiliation: Anesthesiology and Critical Care.
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Setegne
authors.affiliation: Anesthesiology and Critical Care.
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Jackson
authors.affiliation: Anesthesiology and Critical Care.
authors.forename: John G T
authors.initials: JG
authors.lastname: Augoustides
authors.affiliation: Anesthesiology and Critical Care.
authors.forename: E Andrew
authors.initials: EA
authors.lastname: Ochroch
authors.affiliation: Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Bavaria
authors.affiliation: Anesthesiology and Critical Care.
authors.forename: Albert T
authors.initials: AT
authors.lastname: Cheung
mesh_terms: D000138:Acidosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000601:surgery*; D050792:Circulatory Arrest, Deep Hypothermia Induced / Q000009:adverse effects* / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000453:epidemiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D019616:Thoracic Surgical Procedures / Q000009:adverse effects* / Q000639:trends; D013997:Time Factors; D014463:Ultrasonography; D055815:Young Adult
keywords: critical care; deep hypothermic circulatory arrest; hyperchloremia; lactate; metabolic acidosis; thoracic aortic surgery