title: Portable head CT scan and its effect on intracranial pressure, cerebral perfusion pressure, and brain oxygen.
abstract: OBJECTIVE
  Follow-up head CT scans are important in neurocritical care but involve intrahospital transport that may be associated with potential hazards including a deleterious effect on brain tissue oxygen pressure (PbtO(2)). Portable head CT (pHCT) scans offer an alternative imaging technique without a need for patient transport. In this study, the investigators examined the effects of pHCT scans on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and PbtO(2) in patients with severe brain injury.
  
  
  METHODS
  Fifty-seven pHCT scans were obtained in 34 patients (mean age of 42 ± 15 years) who underwent continuous ICP, CPP, and PbtO(2) monitoring in the neuro intensive care unit at a university-based Level I trauma center. Patient ICU records were retrospectively reviewed and physiological data obtained during the 3 hours before and after pHCT scans were examined.
  
  
  RESULTS
  Before pHCT, the mean ICP and CPP were 14.3 ± 7.4 and 78.9 ± 20.2 mm Hg, respectively. Portable HCT had little effect on ICP (mean ICP 14.1 ± 6.6 mm Hg, p = 0.84) and CPP (mean CPP 81.0 ± 19.8 mm Hg, p = 0.59). The mean PbtO(2) was similar before and after pHCT (33.2 ± 17.0 mm Hg and 31.6 ± 15.9 mm Hg, respectively; p = 0.6). Ten episodes of brain hypoxia (PbtO(2) < 15 mm Hg) were observed before pHCT; these episodes prompted scans. Brain hypoxia persisted in 5 patients after pHCT despite treatment. No new episodes of brain hypoxia were observed during or after pHCT.
  
  
  CONCLUSIONS
  These data suggest that pHCT scans do not have a detectable effect on a critically ill patient's ICP, CPP, or PbtO(2).
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania 19107, USA.
authors.forename: Kaitlin
authors.initials: K
authors.lastname: Peace
authors.forename: Eileen
authors.initials: E
authors.lastname: Maloney-Wilensky
authors.forename: Suzanne
authors.initials: S
authors.lastname: Frangos
authors.forename: Marianne
authors.initials: M
authors.lastname: Hujcs
authors.forename: Joshua
authors.initials: J
authors.lastname: Levine
authors.forename: W Andrew
authors.initials: WA
authors.lastname: Kofke
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Peter D
authors.initials: PD
authors.lastname: Le Roux
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D001921:Brain / Q000098:blood supply*; D001930:Brain Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D002534:Hypoxia, Brain / Q000000981:diagnostic imaging / Q000503:physiopathology; D007362:Intensive Care Units; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010101:Oxygen Consumption / Q000502:physiology*; D019095:Point-of-Care Systems; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D014193:Trauma Centers