title: Therapeutic intravascular normothermia reduces the burden of metabolic crisis.
abstract: BACKGROUND
  We aim to investigate whether therapeutic-induced normothermia (TIN) ≤ 37.5 °C, by means of intravascular cooling devices is more efficacious than standard medical therapy (MED) in alleviating metabolic crisis (MC) acutely following traumatic brain injury (TBI).
  
  
  METHODS
  We retrospectively analyzed data from 62 patients with severe TBI, GCS ≤ 8. We divided the cohort into two groups. (1) Patients who had temperature controlled via standard medical therapies (n = 52), (2) TIN group (n = 10). For each group, we analyzed the percent time spent in normothermia, and in MC. Furthermore, we focused the investigation on pre-TIN versus post-TIN comparing temp, intracranial pressure (ICP), sedation, and MC before and after intravascular cooling.
  
  
  RESULTS
  TIN patients had a better temperature control than MED group (60.72 ± 19.53 vs 69.75 ± 24.98 %, p < 0.001) and spent shorter time in MC (22.60 ± 20.45 vs 32.17 ± 27.25 %, p < 0.001). Temperature control was associated with reduced incidence of MC in TIN (OR 0.51, CI 0.38-0.67, p < 0.001, p < 0.001) but not in MED (OR 0.97, CI 0.87-1.1, p = 0.63). Within TIN group analysis, following TIN both temperature and incidence of MC improved from 37.62 ± 0.34 versus 36.69 ± 0.90 °C (p < 0.005) and 41.95 ± 27.74 % before to 8.35 ± 9.78 % (p = 0.005) after, respectively. ICP was well controlled both before and after intravascular cooling (13.07 vs 15.83 mmHg, p = 0.20).
  
  
  CONCLUSIONS
  Therapeutic normothermia, using intravascular cooling, results in a reduction in the burden of MC. This differential effect occurs despite equivalent control of ICP in both TIN and MED treatments. These results demonstrate proof of concept of normothermia, when applied in a controlled manner, being neuroprotective.
authors.affiliation: Department of Neurosurgery, David Geffen School of Medicine at UCLA, 757 Westwood Blvd, RR 6236A, Los Angeles, CA, 90095, USA, mchmayssani@yahoo.com.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Chmayssani
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Stein
authors.forename: David L
authors.initials: DL
authors.lastname: McArthur
authors.forename: Paul M
authors.initials: PM
authors.lastname: Vespa
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature / Q000502:physiology*; D001928:Brain Diseases, Metabolic / Q000517:prevention & control*; D001930:Brain Injuries / Q000378:metabolism* / Q000628:therapy*; D017679:Cryotherapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies