The effect of norepinephrine on estimated cerebral perfusion pressure and critical closing pressure in healthy volunteers

2001 ◽  
Vol 18 (Supplement 21) ◽  
pp. 66 ◽  
Author(s):  
J. A. Latter ◽  
R. W. Sherman ◽  
P. E. Armory ◽  
M. R. Wild ◽  
R. P. Mahajan
Keyword(s):  
Healthy Volunteers ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Critical Closing Pressure ◽  
Closing Pressure

scholarly journals A noninvasive estimation of cerebral perfusion pressure using critical closing pressure

2015 ◽  
Vol 123 (3) ◽  
pp. 638-648 ◽  
Author(s):  
Georgios V. Varsos ◽  
Angelos G. Kolias ◽  
Peter Smielewski ◽  
Ken M. Brady ◽  
Vassilis G. Varsos ◽  
...  
Keyword(s):  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Estimation Error ◽  
Cohort Analysis ◽  
Area Under The Curve ◽  
Impedance Method ◽  
Arterial Blood ◽  
Critical Closing Pressure ◽  
Closing Pressure

OBJECT Cerebral blood flow is associated with cerebral perfusion pressure (CPP), which is clinically monitored through arterial blood pressure (ABP) and invasive measurements of intracranial pressure (ICP). Based on critical closing pressure (CrCP), the authors introduce a novel method for a noninvasive estimator of CPP (eCPP). METHODS Data from 280 head-injured patients with ABP, ICP, and transcranial Doppler ultrasonography measurements were retrospectively examined. CrCP was calculated with a noninvasive version of the cerebrovascular impedance method. The eCPP was refined with a predictive regression model of CrCP-based estimation of ICP from known ICP using data from 232 patients, and validated with data from the remaining 48 patients. RESULTS Cohort analysis showed eCPP to be correlated with measured CPP (R = 0.851, p < 0.001), with a mean ± SD difference of 4.02 ± 6.01 mm Hg, and 83.3% of the cases with an estimation error below 10 mm Hg. eCPP accurately predicted low CPP (< 70 mm Hg) with an area under the curve of 0.913 (95% CI 0.883–0.944). When each recording session of a patient was assessed individually, eCPP could predict CPP with a 95% CI of the SD for estimating CPP between multiple recording sessions of 1.89–5.01 mm Hg. CONCLUSIONS Overall, CrCP-based eCPP was strongly correlated with invasive CPP, with sensitivity and specificity for detection of low CPP that show promise for clinical use.

Relationship between Intracranial Pressure and Critical Closing Pressure in Patients with Neurotrauma

2002 ◽  
Vol 96 (3) ◽  
pp. 595-599 ◽  
Author(s):  
Christof Thees ◽  
Martin Scholz ◽  
Carlo Schaller ◽  
Annette Gass ◽  
Christos Pavlidis ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Linear Correlation ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Trauma Patients ◽  
Critical Closing Pressure ◽  
The Difference ◽  
Closing Pressure ◽  
Zero Flow

Background The driving pressure gradient for cerebral perfusion is the difference between mean arterial pressure (MAP) and critical closing pressure (CCP = zero flow pressure). Therefore, determination of the difference between MAP and CCP should provide an appropriate monitoring of the effective cerebral perfusion pressure (CPP(eff)). Based on this concept, the authors compared conventional measurements of cerebral perfusion pressure by MAP and intracranial pressure (CPP(ICP)) with CPP(eff). Methods Simultaneous synchronized recordings of pressure waveforms of the radial artery and blood flow velocities of the middle cerebral artery were performed in 70 head trauma patients. CCP was calculated from pressure-flow velocity plots by linear extrapolation to zero flow. Results Intracranial pressure measured by intraventricular probes and CCP ranged from 3 to 71 and 4 to 70 mmHg, respectively. Linear correlation between ICP and CCP was r = 0.91. CPP(ICP) was 77 +/- 20 mmHg and did not differ from CPP(eff); linear correlation was r = 0.92. However, limits of agreement were only +/- 16.2 mmHg. Therefore, in 51.4% of the patients, CPP(ICP) overestimated CPP(eff) by 19.8 mmHg at most. Conclusion Assuming that CPP(eff) (MAP - CCP) takes into account more determinants of cerebral downstream pressure, in individual cases, the actual gold standard of CPP determination (MAP - ICP) might overestimate the CPP(eff) of therapeutic significance.

Transcranial Doppler ultrasonography in raised intra-cranial pressure and in intracranial circulatory arrest

1988 ◽  
Vol 68 (5) ◽  
pp. 745-751 ◽  
Author(s):  
Werner Hassler ◽  
Helmuth Steinmetz ◽  
Jan Gawlowski
Keyword(s):  
Intracranial Pressure ◽  
Brain Death ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Transcranial Doppler ◽  
Cerebral Perfusion ◽  
Doppler Ultrasonography ◽  
Perfusion Pressure ◽  
Circulatory Arrest ◽  
Transcranial Doppler Ultrasonography

✓ Transcranial Doppler ultrasonography was used to monitor 71 patients suffering from intracranial hypertension with subsequent brain death. Among these, 29 patients were also assessed for systemic arterial pressure and epidural intracranial pressure, so that a correlation between cerebral perfusion pressure and the Doppler ultrasonography waveforms could be established. Four-vessel angiography was also performed in 33 patients after clinical brain death. With increasing intracranial pressure, the transcranial Doppler ultrasonography waveforms exhibited different characteristic high-resistance profiles with first low, then zero, and then reversed diastolic flow velocities, depending on the relationship between intracranial pressure and blood pressure (that is, cerebral perfusion pressure). This study shows that transcranial. Doppler ultrasonography may be used to assess the degree of intracranial hypertension. This technique further provides a practicable, noninvasive bedside monitor of therapeutic measures.

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