Critical closing pressure: Comparison of three methods

Jorge A. López-Magaña, Hugh K. Richards, Danila K. Radolovich, Dong Joo Kim, Peter Smielewski, Peter J. Kirkpatrick, John D. Pickard, Marek Czosnyka

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Critical closing pressure (CCP) is an arterial pressure threshold below which small arterial vessels collapse. Our aim was to compare different methods to estimate CCP in the cerebrovascular circulation using the relationships between transcranial Doppler flow velocity (FV), laser-Doppler flux (LDF), and arterial blood pressure (ABP). A total of 116 experiments in rabbits were analyzed retrospectively. At the end of each recording, cardiac arrest (CA) was induced. Arterial blood pressure in femoral artery, basilar artery FV, cortical blood LDF, intracranial pressure (ICP) was recorded. Critical closing pressure was estimated using linear regression between decreasing mean ABP values, FV, and LDF during CA. In addition, CCP was calculated from FV waveform just before CA. The correlation between CCP evaluated using LDF and FV during CA was 0.98 (P0.0001). The correlation between CCP measured during CA and CCP estimated from the transcranial Doppler ultrasonography (TCD) waveform was weaker (R0.39; P0.001), with CCP calculated from waveform being significantly greater than CCP from CA (median difference 9mmHg; P0.003). Critical closing pressures obtained from FV waveform and CA correlated with mean ICP before CA (R0.40; P0.001). In conclusion strong correlation exists between CCP values obtained by means of FV and LDF during cardiac arrest. However, predictions of CCP using TCD waveform analysis show substantial differences from values of CCP recorded during cardiac arrest.

Original languageEnglish
Pages (from-to)987-993
Number of pages7
JournalJournal of Cerebral Blood Flow and Metabolism
Issue number5
Publication statusPublished - 2009 May
Externally publishedYes


  • Cerebral hemodynamic
  • Critical closing pressure
  • Experiment
  • Ultrasonography
  • laser-Doppler flowmetry

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine


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