title: Lactate clearance as a useful biomarker for the prediction of all-cause mortality in critically ill patients: a systematic review study protocol.
abstract: BACKGROUND
  Arterial lactate is a reflection of balance between lactate production and clearance. Accumulating lactate may be a marker of global hypoxia or hypoperfusion. Lactate clearance is the reduction of lactate concentrations with interventional strategies, and it has been associated with increased risk of death in critically ill patients. However, conflicting results exist, which mandates a systematic review to clarify the association between lactate clearance and clinical outcome.
  
  
  METHODS
  Critically ill adult patients will be included in our analysis. This population will include heterogeneous study participants, including patients with sepsis or severe sepsis, trauma, surgical intensive care unit (ICU) patients, and so on. We will search four databases including EBSCO, PubMed, Scopus and ISI Web of knowledge from inception to February 2014. There will be no language restrictions in the electronic search for studies. Newcastle Ottawa Scale for cohort study will be employed to assess the reporting quality of included original studies. We will report pooled relative risk of death for those with lactate clearance and those without. The diagnostic performance of lactate clearance in predicting mortality will be explored by using the hierarchical summary receiver operating characteristic model.
  
  
  BACKGROUND
  The protocol for the systematic review has been registered in PROSPERO. The study will be disseminated electronically and in print. It will also be presented to conferences related to critical care medicine.
  
  
  BACKGROUND
  CRD42013006511.
authors.affiliation: Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Zhejiang, People's Republic of China.
authors.forename: Zhongheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Zhejiang, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Zhejiang, People's Republic of China.
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002423:Cause of Death; D015331:Cohort Studies; D016638:Critical Illness / Q000401:mortality*; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism*; D011379:Prognosis; D012107:Research Design; D000078202:Systematic Reviews as Topic
chemical_list: D015415:Biomarkers; D019344:Lactic Acid
keywords: lactate clearance; mortality; systematic review