title: Intraoperative myocardial acidosis as a risk for hospital readmission after cardiac surgery.
abstract: BACKGROUND
  This study elucidates the relationship between intraoperative myocardial acidosis/ischemia and the risk of unplanned hospital readmissions within 30 days and 6 months after cardiac surgery.
  
  
  METHODS
  Myocardial tissue pH (corrected to 37 degrees C: pH(37C)) was monitored in 221 patients during cardiac surgery. Regional myocardial acidosis was defined in terms of specific pH thresholds.
  
  
  RESULTS
  Fourteen percent and 27% of the patients were readmitted within 30 days and 6 months postoperatively, respectively. The mean number of readmissions was 1.67 +/- 1.24; pH(37C) <6.85 at the end of cardiopulmonary bypass (CPB) was identified as the threshold most significantly associated with readmission. This threshold was associated with a 6-fold increased risk of readmission within 30 days and a 5-fold increased risk within 6 months.
  
  
  CONCLUSIONS
  Persistent regional myocardial acidosis after weaning from CPB independently determines unplanned readmission rates up to 6 months postoperatively. This study underscores the importance of avoiding myocardial tissue acidosis during cardiac surgery.
authors.affiliation: Surgical Service, VA Boston Healthcare System, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Dharam J
authors.initials: DJ
authors.lastname: Kumbhani
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Healey
authors.forename: Hemant S
authors.initials: HS
authors.lastname: Thatte
authors.forename: Vladimir
authors.initials: V
authors.lastname: Birjiniuk
authors.forename: Michael D
authors.initials: MD
authors.lastname: Crittenden
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Treanor
authors.forename: Shukri F
authors.initials: SF
authors.lastname: Khuri
mesh_terms: D000138:Acidosis / Q000401:mortality / Q000517:prevention & control*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000401:mortality; D002315:Cardiopulmonary Bypass; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007431:Intraoperative Complications / Q000401:mortality / Q000517:prevention & control*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000401:mortality / Q000517:prevention & control*; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012372:ROC Curve; D012307:Risk Factors