title: Optimizing oxygen delivery in the critically ill: the utility of lactate and central venous oxygen saturation (ScvO2) as a roadmap of resuscitation in shock.
abstract: BACKGROUND
  Resuscitation of any critically ill patient is aimed at restoration of oxygen delivery to maintain aerobic metabolism. Thus, "endpoints" of resuscitation have been sought after as a measure of evaluating the adequacy of resuscitation. This review article describes the most commonly used endpoints, central venous oxygen saturation (ScvO2) and lactate, and provides a clinically useful paradigm for utilizing these endpoints during resuscitation of critically ill patients in the emergency department (ED).
  
  
  OBJECTIVE
  This review article will summarize the pathophysiology of cellular shock, describe the available research regarding lactate and ScvO2, and provide an approach to utilizing these endpoints during resuscitation in the ED.
  
  
  CONCLUSIONS
  ScvO2 and lactate each have been shown to be useful for the assessment of shock, yet each has inherent limitations. When used together, ScvO2 and lactate provide the emergency physician with a glimpse of the underlying pathophysiologic state, allowing targeted therapy to restore oxygen delivery.
  
  
  CONCLUSIONS
  ScvO2 and lactate are useful endpoints of resuscitation, and when used together, provide a metabolic framework for guiding targeted therapy for critically ill patients in the ED with shock.
authors.affiliation: Department of Emergency Medicine, University of Arizona, Tucson, Arizona.
authors.forename: Raj
authors.initials: R
authors.lastname: Joshi
authors.affiliation: Department of Emergency Medicine, University of Arizona, Tucson, Arizona.
authors.forename: Benjamin
authors.initials: B
authors.lastname: de Witt
authors.affiliation: Department of Emergency Medicine, University of Arizona, Tucson, Arizona; Department of Medicine, Section of Pulmonary, Critical Care, Allergy and Sleep, University of Arizona, Tucson, Arizona.
authors.forename: Jarrod M
authors.initials: JM
authors.lastname: Mosier
mesh_terms: D015415:Biomarkers / Q000097:blood; D001784:Blood Gas Analysis; D016638:Critical Illness / Q000628:therapy*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D010100:Oxygen / Q000097:blood*; D017410:Practice Guidelines as Topic; D012151:Resuscitation / Q000379:methods*; D012772:Shock, Septic / Q000097:blood*
chemical_list: D015415:Biomarkers; D019344:Lactic Acid; D010100:Oxygen
keywords: central venous oxygen saturation; lactate; microcirculation; oxygen delivery; shock