title: Validating a pragmatic definition of shock in adult patients presenting to the ED.
abstract: OBJECTIVE
  The importance of the early recognition of shock in patients presenting to emergency departments is well recognized, but at present, there is no agreed practical definition for undifferentiated shock. The main aim of this study was to validate an a priori clinical definition of shock against 28-day mortality.
  
  
  METHODS
  This prospective, observational, cross-sectional, single-center study was conducted in Hong Kong, China. Data were collected between July 1, 2012, and January 31, 2013. An a priori definition of shock was designed, whereby patients admitted to the resuscitation room or high dependency area of the emergency department were divided into 1 of 3 groups-no shock, possible shock, and shock. The primary outcome was 28-day mortality. Secondary outcomes were in-hospital mortality or admission to the intensive or coronary care unit.
  
  
  RESULTS
  A total of 111 patients (mean age, 67.2 ± 17.1 years; male = 69 [62%]) were recruited, of which 22 were classified as no shock, 54 as possible shock, and 35 as shock. Systolic blood pressure, mean arterial pressure, lactate, and base deficit correlated well with shock classifications (P < .05). Patients who had 3 or more positively defined shock variables had a 100% poor composite outcome rate (5 of 5). Patients with 2 shock variables had a 66.7% (4 of 6) poor composite outcome rate.
  
  
  CONCLUSIONS
  A simple, practical definition of undifferentiated shock has been proposed and validated in a group of patients presenting to an emergency department in Hong Kong. This definition needs further validation in a larger population and other settings.
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China; Emergency Department, The Second Affiliated Hospital of Guangzhou Medical University, China. Electronic address: lylgyey@126.com.
authors.forename: Yan-ling
authors.initials: YL
authors.lastname: Li
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: cangelchancc@gmail.com.
authors.forename: Cangel Pui-yee
authors.initials: CP
authors.lastname: Chan
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China. Electronic address: willissin@gmail.com.
authors.forename: King-keung
authors.initials: KK
authors.lastname: Sin
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: stewart_chan@hotmail.com.
authors.forename: Stewart S W
authors.initials: SS
authors.lastname: Chan
authors.affiliation: Emergency Department, The Second Affiliated Hospital of Guangzhou Medical University, China. Electronic address: linpeiyi@163.com.
authors.forename: Pei-yi
authors.initials: PY
authors.lastname: Lin
authors.affiliation: Emergency Department, The Second Affiliated Hospital of Guangzhou Medical University, China. Electronic address: cxhgz168@126.com.
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Chen
authors.affiliation: School of Biomedical Science, Charles Sturt University, Bathurst, New South Wales, Australia; Intensive Care Unit, Bathurst Base Hospital, Bathurst, New South Wales, Australia. Electronic address: brendanprivate@hotmail.com.
authors.forename: Brendan E
authors.initials: BE
authors.lastname: Smith
authors.affiliation: Anesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: gavinmjoynt@cuhk.edu.hk.
authors.forename: Gavin M
authors.initials: GM
authors.lastname: Joynt
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: cagraham@cuhk.edu.hk.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Graham
authors.affiliation: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: thrainer@cuhk.edu.hk.
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Rainer
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital; D005260:Female; D006723:Hong Kong; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012769:Shock / Q000145:classification* / Q000175:diagnosis / Q000401:mortality