title: Cognitive function after cardiac arrest and temperature management; rationale and description of a sub-study in the Target Temperature Management trial.
abstract: BACKGROUND
  Mild to moderate cognitive impairment is common amongst long-term survivors of cardiac arrest. In the Target Temperature Management trial (TTM-trial) comatose survivors were randomized to 33°C or 36°C temperature control for 24 hours after cardiac arrest and the effects on survival and neurological outcome assessed. This protocol describes a sub-study of the TTM-trial investigating cognitive dysfunction and its consequences for patients' and relatives' daily life.
  
  
  METHODS
  Sub-study sites in five European countries included surviving TTM patients 180 days after cardiac arrest. In addition to the instruments for neurological function used in the main trial, sub-study patients were specifically tested for difficulties with memory (Rivermead Behavioural Memory Test), attention (Symbol Digit Modalities Test) and executive function (Frontal Assessment Battery). Cognitive impairments will be related to the patients' degree of participation in society (Mayo-Portland Adaptability Inventory-4), health related quality of life (Short Form Questionnaire-36v2©), and the caregivers' situation (Zarit Burden Interview©). The two intervention groups (33°C and 36°C) will be compared with a group of myocardial infarction controls.
  
  
  CONCLUSIONS
  This large international sub-study of a randomized controlled trial will focus on mild to moderate cognitive impairment and its consequences for cardiac arrest survivors and their caregivers. By using an additional battery of tests we may be able to detect more subtle differences in cognitive function between the two intervention groups than identified in the main study. The results of the study could be used to develop a relevant screening model for cognitive dysfunction after cardiac arrest.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT01946932.
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden. gisela.lilja@med.lu.se.
authors.forename: Gisela
authors.initials: G
authors.lastname: Lilja
authors.forename: Niklas
authors.initials: N
authors.lastname: Nielsen
authors.forename: Hans
authors.initials: H
authors.lastname: Friberg
authors.forename: Janneke
authors.initials: J
authors.lastname: Horn
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaergaard
authors.forename: Tommaso
authors.initials: T
authors.lastname: Pellis
authors.forename: Malin
authors.initials: M
authors.lastname: Rundgren
authors.forename: Jørn
authors.initials: J
authors.lastname: Wetterslev
authors.forename: Matt P
authors.initials: MP
authors.lastname: Wise
authors.forename: Fredrik
authors.initials: F
authors.lastname: Nilsson
authors.forename: Tobias
authors.initials: T
authors.lastname: Cronberg
mesh_terms: D000328:Adult; D001831:Body Temperature / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy; D015331:Cohort Studies; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome