title: Observational study of the effects of traumatic injury, haemorrhagic shock and resuscitation on the microcirculation: a protocol for the MICROSHOCK study.
abstract: BACKGROUND
  The microcirculation is the physiological site of oxygen and substrate exchange. Its effectiveness during circulatory shock is vital for the perfusion of tissues, and has a bearing on subsequent organ function and prognosis. Microcirculatory dysfunction following traumatic haemorrhagic shock (THS) has been understudied compared with other pathologies such as sepsis. The aim of the MICROSHOCK study is to investigate changes seen in the microcirculation of patients following THS, and to assess its response to resuscitation. A greater understanding of the behaviour and mechanisms of microcirculatory dysfunction in this context may direct future avenues of goal-directed resuscitation for these patients.
  
  
  METHODS
  This multicentre prospective longitudinal observational study includes patients who present as an emergency with THS. Microcirculatory parameters are recorded using sublingual incident dark field microscopy alongside measurements of global flow (oesophageal Doppler and transthoracic echocardiography). Patients are enrolled into the study as soon as feasible after they arrive in hospital, and then at subsequent daily time points. Blood samples are taken for investigation into the mechanisms of microcirculatory dysfunction. Sequential Organ Failure Assessment scores will be analysed with microcirculatory parameters to determine whether they correlate with greater fidelity than more conventional, global circulatory parameters.
  
  
  BACKGROUND
  Research Ethics Committee approval has been granted for this study (Reference: 14/YH/0078). Owing to the nature of THS, capacity for informed consent will be absent on patient enrolment. This will be addressed according to the Mental Health Capacity Act 2005. The physician in charge of the patient's care (nominated consultee) may consent on behalf of the patient. Consent will also be sought from a personal consultee (close relative or friend). After capacity is regained, the participant will be asked for their consent. Results will be submitted for publication in peer-reviewed journal format and presented at relevant academic meetings.
  
  
  BACKGROUND
  NCT02111109; Pre-results.
authors.affiliation: Kings College Hospital, Denmark Hill, London, UK Kings College London, London, UK Royal Centre for Defence Medicine, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Hutchings
authors.affiliation: Royal Centre for Defence Medicine, Queen Elizabeth Hospital, Birmingham, UK University of Birmingham, Birmingham, UK University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: David N
authors.initials: DN
authors.lastname: Naumann
authors.affiliation: Barts Health NHS Trust and Queen Mary University of London, London, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Harris
authors.affiliation: Kings College Hospital, Denmark Hill, London, UK Kings College London, London, UK.
authors.forename: Julia
authors.initials: J
authors.lastname: Wendon
authors.affiliation: Royal Centre for Defence Medicine, Queen Elizabeth Hospital, Birmingham, UK University of Birmingham, Birmingham, UK University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Midwinter
mesh_terms: D002985:Clinical Protocols; D017548:Echocardiography, Transesophageal; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008833:Microcirculation; D018715:Microscopy, Video; D063305:Organ Dysfunction Scores; D011446:Prospective Studies; D012151:Resuscitation / Q000379:methods*; D012771:Shock, Hemorrhagic / Q000000981:diagnostic imaging*; D012772:Shock, Septic; D006113:United Kingdom
keywords: ACCIDENT & EMERGENCY MEDICINE; INTENSIVE & CRITICAL CARE; TRAUMA MANAGEMENT