Use of ICM+ software for on-line analysis of intracranial and arterial pressures in head-injured patients

  • K. Guendling
  • P. Smielewski
  • M. Czosnyka
  • P. Lewis
  • J. Nortje
  • I. Timofeev
  • P. J. Hutchinson
  • J. D. Pickard
Part of the Acta Neurochirurgica Supplementum book series (NEUROCHIRURGICA, volume 96)



To summarize our experience from the first 2 years of use of the ICM+ software in our Neurocritical Care Unit (NCCU).

Materials and methods

Ninety-five head-injured patients (74 males, 21 females), average age 36 years, were managed in the NCCU. Intracranial pressure (ICP) was monitored using Codman intraparenchymal probes and arterial blood pressure (ABP) was measured from the radial artery. Signals were monitored by ICM+ software calculating mean values of ICP, ABP, cerebral perfusion pressure (CPP) and various indices describing pressure reactivity, compensation and vascular waveforms of ICP (pulse amplitude, respiratory, and slow waves), etc.


Mean ICP was 17 mmHg, mean CPP was 73 mmHg. Seven patients showed permanent disturbance of cerebral autoregulation (mean pressure reactivity index above 0.3). Pressure reactivity index demonstrated significant U-shape relationship with CPP, suggesting loss of pressure reactivity at too low (CPP < 55 mmHg) and too high CPPs (CPP > 95 mmHg). Mean ICP was inversely correlated with respiratory rate (R 0.46; p < 0.0001; reciprocal model).


The new version of ICM+ software proved to be useful clinically in the NCCU. It allows continuous monitoring of pressure reactivity and exploratory analysis of factors implicating intracranial hypertension.


Head injury intracranial pressure cerebral perfusion pressure autoregulation computer monitoring 


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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • K. Guendling
    • 2
    • 1
  • P. Smielewski
    • 2
    • 3
  • M. Czosnyka
    • 2
  • P. Lewis
    • 4
  • J. Nortje
    • 5
  • I. Timofeev
    • 2
  • P. J. Hutchinson
    • 2
  • J. D. Pickard
    • 2
  1. 1.Academic NeurosurgeryAddenbrooke’s HospitalCambridgeUK
  2. 2.Academic Department of Clinical NeuroscienceAddenbrooke’s HospitalCambridgeUK
  3. 3.Department of NeurosurgeryUniversity of GiessenGiessenGermany
  4. 4.Prince Alfred HospitalMelbourneAustralia
  5. 5.Department of AnesthesiologyAddenbrooke’s HospitalCambridgeUK

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