title: Increased Thyroxin During Therapeutic Hypothermia Predicts Death in Comatose Patients After Cardiac Arrest.
abstract: BACKGROUND
  The course and prognostic value of pituitary-thyroid axis hormones is not well studied after cardiac arrest. We aimed to study the prognostic role of the pituitary-thyroid axis response to resuscitation from cardiac arrest before, during and after therapeutic hypothermia.
  
  
  METHODS
  We conducted a retrospective cohort study in consecutive comatose patients after out-of-hospital cardiac arrest who were sampled before, during and up to 48 h after a 24-h period of therapeutic hypothermia in the intensive care unit (ICU). Thyroid-stimulating hormone, total and free thyroxine (T4) and triiodothyronine (T3) were determined and compared between ICU outcome groups.
  
  
  RESULTS
  We included twenty-nine patients. TSH levels were comparable in non-survivors (n = 17) and survivors (n = 12). The free T4 levels were higher in non-survivors than in survivors (P = 0.001), whereas the free T3 levels were comparable. All samples' results similarly declined in both outcome groups up to 72 h after start of 24 h hypothermia. ROC curves analyses showed a maximum AUC of 0.83 (P = 0.003) for free T4 at the end of hypothermia with an optimal cut off ≥17.8 pmol/L to obtain 100 % specificity and positive predictive value for non-survival.
  
  
  CONCLUSIONS
  Non-survival after cardiac arrest, coma, and therapeutic hypothermia following successful resuscitation is associated with a transient increase in free T4, most probably due to inhibition of free T4 to T3 conversion. However, before routine clinical application, external validation of our finding to assess generalizability is warranted.
authors: Department of Intensive Care of Erasmus Medical Center, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands, m.vanderjagt@erasmusmc.nl.
authors: Mathieu
authors: M
authors: van der Jagt
authors: Saskia
authors: S
authors: Knoops
authors: Margriet F C
authors: MF
authors: de Jong
authors: Martin J
authors: MJ
authors: de Jong
authors: Robin P
authors: RP
authors: Peeters
authors: A B Johan
authors: AB
authors: Groeneveld
mesh_terms: D000328:Adult; D000368:Aged; D003128:Coma / Q000097:blood / Q000401:mortality / Q000628:therapy; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000097:blood / Q000401:mortality / Q000628:therapy; D013974:Thyroxine / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D013974:Thyroxine