title: Therapeutic hypothermia after cardiac arrest: unintentional overcooling is common using ice packs and conventional cooling blankets.
abstract: OBJECTIVE
  Although therapeutic hypothermia for cardiac arrest survivors has been shown to improve neurologically intact survival, optimal methods to ensure controlled induction and maintenance of cooling are not clearly established. Precise temperature control is important to evaluate because unintentional overcooling below the consensus target range of 32-34 degrees C may place the patient at risk for serious complications. We sought to measure the prevalence of overcooling (<32 degrees C) in postarrest survivors receiving primarily noninvasive cooling.
  
  
  METHODS
  Retrospective chart review of postarrest patients.
  
  
  METHODS
  Three large teaching hospitals.
  
  
  METHODS
  Cardiac arrest survivors receiving therapeutic hypothermia.
  
  
  METHODS
  Charts were reviewed if primarily surface cooling was used with a target temperature goal between 32 degrees C and 34 degrees C.
  
  
  RESULTS
  Of the 32 cases reviewed, overcooling lasting for >1 hr was identified as follows: 20 of 32 patients (63%) reached temperatures of <32 degrees C, 9 of 32 (28%) reached temperatures of <31 degrees C, and 4 of 32 (13%) reached temperatures of <30 degrees C. Of those with overcooling of <32 degrees C, 6 of 20 (30%) survived to hospital discharge, whereas of those without overcooling, 7 of 12 (58%) survived to hospital discharge (p = not significant).
  
  
  CONCLUSIONS
  The majority of the cases reviewed demonstrated unintentional overcooling below target temperature. Improved mechanisms for temperature control are required to prevent potentially deleterious complications of more profound hypothermia.
authors.affiliation: Section of Emergency Medicine, University of Chicago Hospitals Emergency Resuscitation Center, Chicago, Illinois, USA.
authors.forename: Raina M
authors.initials: RM
authors.lastname: Merchant
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Abella
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Peberdy
authors.forename: Jasmeet
authors.initials: J
authors.lastname: Soar
authors.forename: Marcus E H
authors.initials: ME
authors.lastname: Ong
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Schmidt
authors.forename: Lance B
authors.initials: LB
authors.lastname: Becker
authors.forename: Terry L
authors.initials: TL
authors.lastname: Vanden Hoek
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature; D005260:Female; D006323:Heart Arrest / Q000628:therapy*; D006784:Hospitals, Teaching; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects* / Q000379:methods*; D007053:Ice; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D007053:Ice