title: Effect of shivering on brain tissue oxygenation during induced normothermia in patients with severe brain injury.
abstract: BACKGROUND
  We analyzed the impact of shivering on brain tissue oxygenation (PbtO(2)) during induced normothermia in patients with severe brain injury.
  
  
  METHODS
  We studied patients with severe brain injury who developed shivering during induced normothermia. Induced normothermia was applied to treat refractory fever (body temperature [BT] > or =38.3 degrees C, refractory to conventional treatment) using a surface cooling device with computerized adjustment of patient BT target to 37 +/- 0.5 degrees C. PbtO(2), intracranial pressure, mean arterial pressure, cerebral perfusion pressure, and BT were monitored continuously. Circulating water temperature of the device system was measured to assess the intensity of cooling.
  
  
  RESULTS
  Fifteen patients (10 with severe traumatic brain injury, 5 with aneurysmal subarachnoid hemorrhage) were treated with induced normothermia for an average of 5 +/- 2 days. Shivering caused a significant decrease in PbtO(2) levels both in SAH and TBI patients. Compared to baseline, shivering was associated with an overall reduction of PbtO(2) from 34.1 +/- 7.3 to 24.4 +/- 5.5 mmHg (P < 0.001). A significant correlation was found between the magnitude of shivering-associated decrease of PbtO(2) (DeltaPbtO(2)) and circulating water temperature (R = 0.82, P < 0.001).
  
  
  CONCLUSIONS
  In patients with severe brain injury treated with induced normothermia, shivering was associated with a significant decrease of PbtO(2), which correlated with the intensity of cooling. Monitoring of therapeutic cooling with computerized thermoregulatory systems may help prevent shivering and optimize the management of induced normothermia. The clinical significance of shivering-induced decrease in brain tissue oxygenation remains to be determined.
authors.affiliation: Department of Neurosurgery, University of Pennsylvania Medical Center, Philadelphia, PA, USA. mauro.oddo@chuv.ch
authors.forename: Mauro
authors.initials: M
authors.lastname: Oddo
authors.forename: Suzanne
authors.initials: S
authors.lastname: Frangos
authors.forename: Eileen
authors.initials: E
authors.lastname: Maloney-Wilensky
authors.forename: W
authors.initials: W
authors.lastname: Andrew Kofke
authors.forename: Peter D
authors.initials: PD
authors.lastname: Le Roux
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Levine
mesh_terms: D000293:Adolescent; D000328:Adult; D001833:Body Temperature Regulation / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D001930:Brain Injuries / Q000503:physiopathology*; D003422:Critical Care; D017679:Cryotherapy / Q000295:instrumentation*; D005260:Female; D005334:Fever / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D002534:Hypoxia, Brain / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D011379:Prognosis; D012768:Shivering / Q000502:physiology*; D055815:Young Adult