title: Decompressive craniectomy for elevated intracranial pressure and its effect on the cumulative ischemic burden and therapeutic intensity levels after severe traumatic brain injury.
abstract: BACKGROUND
  Increased intracranial pressure (ICP) can cause brain ischemia and compromised brain oxygen (PbtO2 < or = 20 mm Hg) after severe traumatic brain injury (TBI).
  
  
  OBJECTIVE
  We examined whether decompressive craniectomy (DC) to treat elevated ICP reduces the cumulative ischemic burden (CIB) of the brain and therapeutic intensity level (TIL).
  
  
  METHODS
  Ten severe TBI patients (mean age, 31.4 +/- 14.2 years) who had continuous PbtO2 monitoring before and after delayed DC were retrospectively identified. Patients were managed according to the guidelines for the management of severe TBI. The CIB was measured as the total time spent between a PbtO2 of 15 to 20, 10 to 15, and 0 to 10 mm Hg. The TIL was calculated every 12 hours. Mixed-effects models were used to estimate changes associated with DC.
  
  
  RESULTS
  DC was performed on average 2.8 days after admission. DC was found to immediately reduce ICP (mean [SEM] decrease was 7.86 mm Hg [2.4 mm Hg]; P = .005). TIL, which was positively correlated with ICP (r = 0.46, P < or = .001), was reduced within 12 hours after surgery and continued to improve within the postsurgical monitoring period (P </= .001). The duration and severity of CIB were significantly reduced as an effect of DC in this group. The overall mortality rate in the group of 10 patients was lower than predicted at the time of admission (P = .015).
  
  
  CONCLUSIONS
  These results suggest that a DC for increased ICP can reduce the CIB of the brain after severe TBI. We suggest that DC be considered early in a patient's clinical course, particularly when the TIL and ICP are increased.
authors.affiliation: Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Weiner
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Lacey
authors.forename: Larami
authors.initials: L
authors.lastname: Mackenzie
authors.forename: Darshak P
authors.initials: DP
authors.lastname: Shah
authors.forename: Suzanne G
authors.initials: SG
authors.lastname: Frangos
authors.forename: M Sean
authors.initials: MS
authors.lastname: Grady
authors.forename: Andrew
authors.initials: A
authors.lastname: Kofke
authors.forename: Joshua
authors.initials: J
authors.lastname: Levine
authors.forename: James
authors.initials: J
authors.lastname: Schuster
authors.forename: Peter D
authors.initials: PD
authors.lastname: Le Roux
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D003399:Craniotomy / Q000379:methods* / Q000592:standards; D019299:Decompression, Surgical / Q000379:methods / Q000592:standards; D005260:Female; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery*; D019586:Intracranial Hypertension / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D011184:Postoperative Period; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D010100:Oxygen