title: Incidence and outcome from adult cardiac arrest occurring in the intensive care unit: a systematic review of the literature.
abstract: BACKGROUND
  Significant amount of data on the incidence and outcome of out-of-hospital and in-hospital cardiac arrest have been published. Cardiac arrest occurring in the intensive care unit has received less attention.
  
  
  OBJECTIVE
  To evaluate and summarize current knowledge of intensive care unit cardiac arrest including quality of data, and results focusing on incidence and patient outcome.
  We conducted a literature search of the PubMed, CINAHL and Cochrane databases with the following search terms (medical subheadings): heart arrest AND intensive care unit OR critical care OR critical care nursing OR monitored bed OR monitored ward OR monitored patient. We included articles published from the 1st of January 1990 till 31st of December 2012. After exclusion of all duplicates and irrelevant articles we evaluated quality of studies using a predefined quality assessment score and summarized outcome data.
  
  
  RESULTS
  The initial search yielded 794 articles of which 780 were excluded. Three papers were added after a manual search of the eligible studies' references. One paper was identified manually from the literature published after our initial search was completed, thus the final sample consisted of 18 papers. Of the studies included thirteen were retrospective, two based on prospective registries and three were focused prospective studies. All except two studies were from a single institution. Six studies reported the incidence of intensive care unit cardiac arrest, which varied from 5.6 to 78.1 cardiac arrests per 1000 intensive care unit admissions. The most frequently reported initial cardiac arrest rhythms were non-shockable. Patient outcome was variable with survival to hospital discharge being in the range of 0-79% and long-term survival ranging from 1 to 69%. Nine studies reported neurological status of survivors, which was mostly favorable, either no neurological sequelae or cerebral performance score mostly of 1-2. Studies focusing on post cardiac surgery patients reported the best long-term survival rates of 45-69%.
  
  
  CONCLUSIONS
  At present data on intensive care unit cardiac arrest is quite limited and originates mostly from retrospective single center studies. The quality of data overall seems to be poor and thus focused prospective multi-center studies are needed.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, Finland. Electronic address: pilulkin@gmail.com.
authors.forename: Ilmar
authors.initials: I
authors.lastname: Efendijev
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Nurmi
authors.affiliation: Karolinska Institutet, Department of Clinical Science and Education, Södersjukhuset and Section of Emergency Medicine, Södersjukhuset, Stockholm, Sweden; Department of Emergency Medicine, University of Turku, Finland.
authors.forename: Maaret
authors.initials: M
authors.lastname: Castrén
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, Finland.
authors.forename: Markus B
authors.initials: MB
authors.lastname: Skrifvars
mesh_terms: D000328:Adult; D006323:Heart Arrest / Q000453:epidemiology* / Q000628:therapy*; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D063868:Patient Outcome Assessment
keywords: Cardiac arrest; Intensive care unit; Resuscitation