title: Postoperative metabolic acidosis following the minimally invasive radiofrequency maze procedure.
abstract: OBJECTIVE
  Atrial fibrillation (AF) is the most common arrhythmia treated in the world. While medical treatment with antiarrhythmic drugs remains the primary treatment modality, symptomatic refractory AF often requires treatment with a catheter or surgical ablation. One minimally invasive therapy is the Mini-Maze procedure, which utilizes epicardial radiofrequency ablation via a subxiphoid approach to rid the heart of arrhythmogenic atrial foci without a median sternotomy or cardiopulmonary bypass. The goal of this retrospective cohort study was to identify clinical factors associated with metabolic acidosis following the Mini-Maze procedure.
  
  
  METHODS
  After Institutional Review Board approval, we studied patients undergoing the Mini-Maze procedure, off-pump coronary artery bypass grafting or patients conventional Cox-Maze on cardiopulmonary bypass. The first base deficit value obtained in the Intensive Care Unit was used as a measure of metabolic acidosis. Using logistic regression with Akaike information criteria, we analyzed preoperative, intraoperative, and postoperative data to determine the factors associated with changes in base deficit.
  
  
  RESULTS
  A multivariable model using stepwise selection demonstrated that diabetes mellitus and weight were associated with a decrease in the base deficit by 2.87 mEq/L (95% CI: -5.55--0.19) and 0.04 mEq/L (95%CI: -0.08, 0.004), respectively. Furthermore, creatinine was associated with a 1.57 mEq/L (95% CI: 0.14, 2.99) increase in the base deficit.
  
  
  CONCLUSIONS
  The Mini-Maze procedure was not associated with postoperative metabolic acidosis. Instead, nondiabetic patients and patients with higher creatinine were associated with greater base deficits after undergoing cardiac surgery.
authors.affiliation: Department of Anesthesiology, University of Michigan Cardiovascular Center, 1500 E. Medical Center Drive, CVC 4172, Ann Arbor, MI 48109 5861, USA.
authors.forename: Raymond Patrick
authors.initials: RP
authors.lastname: Hom
authors.forename: Anna
authors.initials: A
authors.lastname: Dubovoy
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Jewell
authors.forename: Milo
authors.initials: M
authors.lastname: Engoren
mesh_terms: D000138:Acidosis / Q000209:etiology* / Q000628:therapy*; D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000628:therapy; D001835:Body Weight; D002315:Cardiopulmonary Bypass; D017115:Catheter Ablation / Q000009:adverse effects*; D015331:Cohort Studies; D047549:Coronary Artery Bypass, Off-Pump; D003404:Creatinine / Q000097:blood; D048909:Diabetes Complications / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D011183:Postoperative Complications / Q000628:therapy*; D012189:Retrospective Studies
chemical_list: D003404:Creatinine