title: Monitoring of serum lactate level during cardiopulmonary resuscitation in adult in-hospital cardiac arrest.
abstract: BACKGROUND
  Serum lactate level may correlate with no-flow and low-flow status during cardiac arrest. Current guidelines have no recommended durations for cardiopulmonary resuscitation (CPR) before transition to the next strategy. We hypothesized that the lactate level measured during CPR could be associated with the survival probability and accordingly be useful in estimating the optimal duration for CPR.
  
  
  METHODS
  We conducted a retrospective observational study in a single medical centre and included adult patients who had suffered an in-hospital cardiac arrest between 2006 and 2012. We used multivariable logistic regression analysis to study the association of lactate level measured during CPR and outcomes. We used generalized additive models to examine the nonlinear effects of continuous variables and conditional effect plots to visualize the estimated survival probability against CPR duration.
  
  
  RESULTS
  Of the 340 patients included in our analysis, 50 patients (14.7 %) survived to hospital discharge. The mean lactate level was 9.6 mmol/L and mean CPR duration was 28.8 min. There was an inverse near-linear relationship between lactate level and probability of survival to hospital discharge. A serum lactate level <9 mmol/L was positively associated with patient survival to hospital discharge (odds ratio 2.00, 95 % confidence interval 1.01-4.06). The optimal CPR duration may not be a fixed value but depend on other conditions.
  
  
  CONCLUSIONS
  Serum lactate level measured during CPR could correlate with survival outcomes. A lactate level threshold of 9 mmol/L may be used as a reference value to identify patients with different survival probabilities and determine the optimal CPR durations.
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan. ogenkidesga@gmail.com.|Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. ogenkidesga@gmail.com.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No.7, Zhongshan S. Rd., Zhongzheng Dist., Taipei City, 100, Taiwan, R.O.C.. chhuang730@ntu.edu.tw.
authors.forename: Chien-Hua
authors.initials: CH
authors.lastname: Huang
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No.7, Zhongshan S. Rd., Zhongzheng Dist., Taipei City, 100, Taiwan, R.O.C.. wtchang@ntu.edu.tw.
authors.forename: Wei-Tien
authors.initials: WT
authors.lastname: Chang
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No.7, Zhongshan S. Rd., Zhongzheng Dist., Taipei City, 100, Taiwan, R.O.C.. mshanmshan@gmail.com.
authors.forename: Min-Shan
authors.initials: MS
authors.lastname: Tsai
authors.affiliation: Department of Emergency Medicine, Taipei Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan. ambigus39@gmail.com.
authors.forename: Ping-Hsun
authors.initials: PH
authors.lastname: Yu
authors.affiliation: Departments of Internal Medicine and Nuclear Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. wuyw0502@gmail.com.|Department of Nuclear Medicine and Cardiology Division of Cardiovascular Medical Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan. wuyw0502@gmail.com.|National Yang-Ming University School of Medicine, Taipei, Taiwan. wuyw0502@gmail.com.
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Wu
authors.affiliation: Division of Nephrology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. kyhung@ntu.edu.tw.
authors.forename: Kuan-Yu
authors.initials: KY
authors.lastname: Hung
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No.7, Zhongshan S. Rd., Zhongzheng Dist., Taipei City, 100, Taiwan, R.O.C.. wjchen1955@ntu.edu.tw.|Department of Emergency Medicine, Lotung Poh-Ai Hospital, Yilan, Taiwan. wjchen1955@ntu.edu.tw.
authors.forename: Wen-Jone
authors.initials: WJ
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000401:mortality*; D005260:Female; D006323:Heart Arrest / Q000097:blood / Q000401:mortality* / Q000628:therapy; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data*; D011336:Probability; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D019344:Lactic Acid