title: Association of positive fluid balance and cardiovascular complications after thoracotomy for noncancer lesions.
abstract: OBJECTIVE
  The purpose of this study was to explore the influence of positive fluid balance on cardiovascular complications after thoracotomy for noncancer lesions.
  
  
  METHODS
  After approval from an institutional review board, a retrospective cohort study was conducted. All consecutive patients undergoing thoracotomy between January 1, 2005 and December 31, 2011 in a single medical center were recruited. The primary outcome of the study was the incidence of cardiovascular complications, which were defined as cardiac arrhythmia, cardiac arrest, heart failure, myocardial ischemia, and pulmonary embolism. Univariable and multivariable risk regression analyses were used to evaluate the association between positive fluid balance and cardiovascular complications.
  
  
  RESULTS
  A total of 720 patients were included in this study. The incidence of cardiovascular complications after thoracotomy for noncancer lesions was 6.7% (48 of 720). Patients with positive fluid balance >2,000 mL had a significantly higher incidence of cardiovascular complications than those with positive fluid balance ≤2,000 mL (22.2% versus 7.0%, P=0.005). Cardiac arrhythmias were the most common complication. Univariable risk regression showed that positive fluid balance >2,000 mL was a significant risk factor (risk ratio =3.15, 95% confident interval [CI] =1.44-6.90, P-value =0.004). After adjustment for all potential confounding variables during multivariable risk regression analysis, positive fluid balance >2,000 mL remained a strong risk factor for cardiovascular complications (risk ratio =2.18, 95% CI =1.36-3.51, P-value =0.001). Causes of positive fluid balance >2,000 mL included excessive hemorrhage (48%), hypotension without excessive hemorrhage (29.6%), and liberal fluid administration (22.4%).
  
  
  CONCLUSIONS
  Positive fluid balance was a significant risk factor for cardiovascular complications. Strategies to minimize positive fluid balance during surgery for patients at high risk of cardiovascular complications include preparing adequate blood and blood products, considering appropriate hemoglobin level as a transfusion trigger, and adjusting the optimal dose of local anesthetic for intraoperative thoracic epidural analgesia.
authors: Clinical Epidemiology Program, Chiang Mai University, Chiang Mai, Thailand ; Department of Anesthesiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Tanyong
authors: T
authors: Pipanmekaporn
authors: Department of Anesthesiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Yodying
authors: Y
authors: Punjasawadwong
authors: Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors: Somrat
authors: S
authors: Charuluxananan
authors: Department of Anesthesiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Worawut
authors: W
authors: Lapisatepun
authors: Department of Anesthesiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors: Pavena
authors: P
authors: Bunburaphong
authors: Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Somchareon
authors: S
authors: Saeteng
keywords: cardiac arrest; cardiac arrhythmias; heart failure; hemorrhage; myocardial ischemia