Relationship of “dose” of intracranial hypertension to outcome in severe traumatic brain injury

Clinical article

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It has recently been suggested that the degree of intracranial pressure (ICP) above the treatment goal can be estimated by the area under the curve (AUC) of ICP versus time in patients with severe traumatic brain injury (TBI). The objective of this study was to determine whether the calculated “ICP dose”—the ICP AUC—is related to mortality rate, outcome, and Marshall CT classification.


Of 135 patients (age range 1–82 years) with severe TBI treated during a 5-year period at the authors' institution, 113 patients underwent ICP monitoring (84%). Ninety-three patients with a monitoring time > 24 hours were included for analysis of ICP AUC calculated using the trapezoidal method. Computed tomography scans were assessed according to the Marshall TBI classification. Patients with Glasgow Outcome Scale scores at 6 months and > 3 years were separated into 2 groups based on outcome.


Sixty patients (65%) had ICP values > 20 mm Hg, and 12 (13%) developed severe intracranial hypertension and died secondary to herniation. A multiple regression analysis adjusting for Glasgow Coma Scale score, age, pupillary abnormalities and Injury Severity Scale score demonstrated that the ICP AUC was a significant predictor of poor outcome at 6 months (p = 0.034) and of death (p = 0.035). However, it did not predict long-term outcome (p = 0.157). The ICP AUC was significantly higher in patients with Marshall head injury Categories 3 and 4 (24 patients) than in those with Category 2 (23 patients, p = 0.025) and Category 5 (46 patients, p = 0.021) TBIs using the worst CT scan obtained.


The authors found a significant relationship between the dose of ICP, the worst Marshall CT score, and patient outcome, suggesting that the AUC method may be useful in refining and improving the treatment of ICP in patients with TBI.

Abbreviations used in this paper: AUC = area under the curve; CPP = cerebral perfusion pressure; GCS = Glasgow Coma Scale; GOS = Glasgow Outcome Scale; ICP = intracranial pressure; ISS = Injury Severity Scale; TBI = traumatic brain injury.

Article Information

Address correspondence to: Anne Vik, M.D., Ph.D., Department of Neurosurgery, St. Olav University Hospital and Department of Neuroscience, Norwegian University of Science and Technology, 7489 Trondheim, Norway. email:

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Graphs of ICP above treatment goal (20 mm Hg) estimated by the trapezoidal method to calculate AUC for a patient with no dose (upper) and a patient with moderate dose (lower). Both patients had a mean ICP of 16 mm Hg.

  • View in gallery

    Graph representing the relationship between AUC of ICP and mean ICP in 60 patients with AUC > 0.

  • View in gallery

    Graph demonstrating the number of patients with favorable and poor outcomes at 6 months in 4 groups with different doses of ICP AUC: no dose (0 mm Hg*hour), low dose (> 0–75 mm Hg*hour), moderate dose (> 75–200 mm Hg*hour), and high dose (> 200 mm Hg*hour).


  • 1

    Balestreri MCzosnyka MHutchinson PSteiner LAHiler MSmielewski P: Impact of intracranial pressure and cerebral perfusion pressure on severe disability and mortality after head injury. Neurocrit Care 4:8132006

  • 2

    Barton CWHemphill JCMorabito DManley G: A novel method of evaluating the impact of secondary brain insults on functional outcomes in traumatic brain-injured patients. Acad Emerg Med 12:162005

  • 3

    Brain Trauma Foundation American Association of Neurological Surgeons Congress of Neurological Surgeons AANS/CNS Joint Section on Neurotrauma and Critical Care: Guidelines for the management of severe traumatic brain injury. VIII. Intracranial pressure thresholds. J Neurotrauma 24:SupplS55S582007

  • 4

    Elf KNilsson PRonne-Engström EHowells TEnblad P: Cerebral perfusion pressure between 50 and 60 mm Hg may be beneficial in head-injured patients: a computerized secondary insult monitoring study. Neurosurgery 56:962 9712005

  • 5

    Firsching RWoischneck DKlein SReissberg SDohring WPeters B: Classification of severe head injury based on magnetic resonance imaging. Acta Neurochir (Wien) 143:2632712001

  • 6

    Hemphill JC IIIBarton CWMorabito DManley GT: Influence of data resolution and interpolation method on assessment of secondary brain insults in neurocritical care. Physiol Meas 26:3733862005

  • 7

    Hiler MCzosnyka MHutchinson PBalestreri MSmielewski PMatta B: Predictive value of initial computerized tomography scan, intracranial pressure, and state of autoregulation in patients with traumatic brain injury. J Neurosurg 104:7317372006

  • 8

    Jones PAAndrews PJMidgley SAnderson SIPiper IRTocher JL: Measuring the burden of secondary insults in head injured patients during intensive care. J Neurosurg Anesthesiol 6:4141994

  • 9

    Juul NMorris GFMarshall SBMarshall LF: Intracranial hypertension and cerebral perfusion pressure: influence on neurological deterioration and outcome in severe head injury. The Executive Committee of the International Selfotel Trial. J Neurosurg 92:162000

  • 10

    Lee TTGalarza MVillanueva PA: Diffuse axonal injury (DAI) is not associated with elevated intracranial pressure (ICP). Acta Neurochir (Wien) 140:41461998

  • 11

    Maas AIDearden MTeasdale GMBraakman RCohadon FIannotti F: EBIC-guidelines for management of severe head injury in adults. European Brain Injury Consortium. Acta Neurochir (Wien) 139:2862941997

  • 12

    Marmarou AAnderson RLWard JDChoi SCYoung HFEisenberg HM: Impact of ICP instability and hypotension on outcome in patients with severe head trauma. J Neurosurg 75:SupplS59S661991

  • 13

    Marshall LFMarshall SBKlauber MRvan Berkum Clark MEisenberg HEJane JA: A new classification of head injury based on computerized tomography. J Neurosurg 75:SupplS14S201991

  • 14

    Miller KJSchwab KAWarden DL: Predictive value of an early Glasgow Outcome Scale score: 15-month score changes. J Neurosurg 103:2392452005

  • 15

    Narayan RKKishore PRBecker DPWard JDEnas GGGreenberg RP: Intracranial pressure: to monitor or not to monitor? A review of our experience with severe head injury. J Neurosurg 56:6506591982

  • 16

    Poca MASahuquillo JBáguena MPedraza SGracia RMRubio E: Incidence of intracranial hypertension after severe head injury: a prospective study using the Traumatic Coma Data Bank classification. Acta Neurochir Suppl 7127301998

  • 17

    Resnick DKMarion DWCarlier P: Outcome analysis of patients with severe head injuries and prolonged intracranial hypertension. J Trauma 42:110811111997

  • 18

    Servadei FMurray GDPenny KTeasdale GMDearden MIannotti F: The value of the “worst” computed tomographic scan in clinical studies of moderate and severe head injury. European Brain Injury Consortium. Neurosurgery 46:70752000

  • 19

    Stocchetti NRossi SBuzzi FMattioli CPaparella AColombo A: Intracranial hypertension in head injury: management and results. Intensive Care Med 25:3713761999

  • 20

    Taylor AButt WRosenfeld JShann FDitchfield MLewis E: A randomised trial of very early decompressive craniectomy in children with traumatic brain injury and sustained intracranial hypertension. Childs Nerv Syst 17:1541622001

  • 21

    Unterberg AKiening KSchmiedek PLanksch W: Longterm observations of intracranial pressure after severe head injury. The phenomenon of secondary rise of intracranial pressure. Neurosurgery 32:17241993


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