Continuous Monitoring of Middle Cerebral Arterial Blood Velocity and Cerebral Perfusion Pressure

1989 ◽  
pp. 101-105 ◽  
Author(s):  
T. Lundar ◽  
K.-F. Lindegaard ◽  
H. Nornes
Keyword(s):  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Continuous Monitoring ◽  
Perfusion Pressure ◽  
Blood Velocity ◽  
Arterial Blood

scholarly journals Comparison of static and dynamic cerebral autoregulation under anesthesia influence in a controlled animal model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245291
Author(s):  
Alexander Ruesch ◽  
Deepshikha Acharya ◽  
Samantha Schmitt ◽  
Jason Yang ◽  
Matthew A. Smith ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Animal Model ◽  
Blood Flow ◽  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Autoregulation ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Phase Lag ◽  
Arterial Blood

The brain’s ability to maintain cerebral blood flow approximately constant despite cerebral perfusion pressure changes is known as cerebral autoregulation (CA) and is governed by vasoconstriction and vasodilation. Cerebral perfusion pressure is defined as the pressure gradient between arterial blood pressure and intracranial pressure. Measuring CA is a challenging task and has created a variety of evaluation methods, which are often categorized as static and dynamic CA assessments. Because CA is quantified as the performance of a regulatory system and no physical ground truth can be measured, conflicting results are reported. The conflict further arises from a lack of healthy volunteer data with respect to cerebral perfusion pressure measurements and the variety of diseases in which CA ability is impaired, including stroke, traumatic brain injury and hydrocephalus. To overcome these differences, we present a healthy non-human primate model in which we can control the ability to autoregulate blood flow through the type of anesthesia (isoflurane vs fentanyl). We show how three different assessment methods can be used to measure CA impairment, and how static and dynamic autoregulation compare under challenges in intracranial pressure and blood pressure. We reconstructed Lassen’s curve for two groups of anesthesia, where only the fentanyl anesthetized group yielded the canonical shape. Cerebral perfusion pressure allowed for the best distinction between the fentanyl and isoflurane anesthetized groups. The autoregulatory response time to induced oscillations in intracranial pressure and blood pressure, measured as the phase lag between intracranial pressure and blood pressure, was able to determine autoregulatory impairment in agreement with static autoregulation. Static and dynamic CA both show impairment in high dose isoflurane anesthesia, while low isoflurane in combination with fentanyl anesthesia maintains CA, offering a repeatable animal model for CA studies.

Continuous Monitoring and Recording of Cerebral Perfusion Pressure

1993 ◽  
pp. 57-60 ◽  
Author(s):  
I. R. Chambers ◽  
A. Clark ◽  
P. J. Kane ◽  
D. A. Allcutt ◽  
A. D. Mendelow
Keyword(s):  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Continuous Monitoring ◽  
Perfusion Pressure

scholarly journals What is the optimal cerebral perfusion pressure in children suffering from traumatic coma?

2003 ◽  
Vol 15 (6) ◽  
pp. 1-8 ◽  
Author(s):  
Iain R. Chambers ◽  
Fenella J. Kirkham
Keyword(s):  
Intensive Care ◽  
Head Injury ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Clinical Signs ◽  
Clinical Practices ◽  
Physiological Variables ◽  
Arterial Blood ◽  
Surgical Trial

Head injury is a major cause of death and disability in children. Despite advances in resuscitation, emergency care, intensive care monitoring, and clinical practices, there are few data demonstrating the predictive value of certain physiological variables regarding outcome in this patient population. Mean arterial blood pressure (MABP), intracranial pressure (ICP), and cerebral perfusion pressure (CPP = MABP − ICP) are routinely monitored in patients in many neurological intensive care units throughout the world, but there is little evidence indicating that advances in care have been matched with corresponding improvements in outcome. Nonetheless, there is evidence that hypotension immediately following head injury is predictive of early death, and many patients with these features die with clinical signs of brain herniation caused by intracranial hypertension. Furthermore, available data indicate that a minimal and a mean CPP measured during intensive care are good predictors of outcome in survivors, but a target threshold to improve outcome has yet to be defined. Some medical management strategies can have detrimental effects, and there is now a good case for undertaking a controlled trial of immediate or delayed craniectomy. Independent outcome in children following severe head injury is associated with higher levels of CPP. The ability to tolerate different levels of CPP may be related to age, and therefore any such surgical trial would need a carefully defined protocol so that the potential benefit of such a treatment is maximized.

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.

Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma

2005 ◽  
Vol 102 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Tim Howells ◽  
Kristin Elf ◽  
Patricia A. Jones ◽  
Elisabeth Ronne-Engström ◽  
Ian Piper ◽  
...  
Keyword(s):  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Regression Line ◽  
Brain Trauma ◽  
Treatment Protocols ◽  
Content Type ◽  
Arterial Blood ◽  
Pressure Reactivity ◽  
Fine Print

Object. The aim of this study was to compare the effects of two different treatment protocols on physiological characteristics and outcome in patients with brain trauma. One protocol was primarily oriented toward reducing intracranial pressure (ICP), and the other primarily on maintaining cerebral perfusion pressure (CPP). Methods. A series of 67 patients in Uppsala were treated according to a protocol aimed at keeping ICP less than 20 mm Hg and, as a secondary target, CPP at approximately 60 mm Hg. Another series of 64 patients in Edinburgh were treated according to a protocol aimed primarily at maintaining CPP greater than 70 mm Hg and, secondarily, ICP less than 25 mm Hg for the first 24 hours and 30 mm Hg subsequently. The ICP and CPP insults were assessed as the percentage of monitoring time that ICP was greater than or equal to 20 mm Hg and CPP less than 60 mm Hg, respectively. Pressure reactivity in each patient was assessed based on the slope of the regression line relating mean arterial blood pressure (MABP) to ICP. Outcome was analyzed at 6 months according to the Glasgow Outcome Scale (GOS). The prognostic value of secondary insults and pressure reactivity was determined using linear methods and a neural network. In patients treated according to the CPP-oriented protocol, even short durations of CPP insults were strong predictors of death. In patients treated according to the ICP-oriented protocol, even long durations of CPP insult—mostly in the range of 50 to 60 mm Hg—were significant predictors of favorable outcome (GOS Score 4 or 5). Among those who had undergone ICP-oriented treatment, pressure-passive patients (MABP/ICP slope ≥ 0.13) had a better outcome. Among those who had undergone CPP-oriented treatment, the more pressure-active (MABP/ICP slope < 0.13) patients had a better outcome. Conclusions. Based on data from this study, the authors concluded that ICP-oriented therapy should be used in patients whose slope of the MABP/ICP regression line is at least 0.13, that is, in pressure-passive patients. If the slope is less than 0.13, then hypertensive CPP therapy is likely to produce a better outcome.

Cerebral perfusion pressure, intracranial pressure, and head elevation

1986 ◽  
Vol 65 (5) ◽  
pp. 636-641 ◽  
Author(s):  
Michael J. Rosner ◽  
Irene B. Coley
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Pressure Waves ◽  
Content Type ◽  
Arterial Blood ◽  
Head Elevation ◽  
Adequate Hydration ◽  
Fine Print

✓ Previous investigations have suggested that intracranial pressure waves may be induced by reduction of cerebral perfusion pressure (CPP). Since pressure waves were noted to be more common in patients with their head elevated at a standard 20° to 30°, CPP was studied as a function of head position and its effect upon intracranial pressure (ICP). In 18 patients with varying degrees of intracranial hypertension, systemic arterial blood pressure (SABP) was monitored at the level of both the head and the heart. Intracranial pressure and central venous pressure were assessed at every 10° of head elevation from 0° to 50°. For every 10° of head elevation, the average ICP decreased by 1 mm Hg associated with a reduction of 2 to 3 mm Hg CPP. The CPP was not beneficially affected by any degree of head elevation. Maximal CPP (73 ± 3.4 mm Hg (mean ± standard error of the mean)) always occurred with the head in a horizontal position. Cerebrospinal fluid pressure waves occurred in four of the 18 patients studied as a function of reduced CPP caused by head elevation alone. Thus, elevation of the head of the bed was associated with the development of CPP decrements in all cases, and it precipitated pressure waves in some. In 15 of the 18 patients, CPP was maintained by spontaneous 10- to 20-mm Hg increases in SABP, and pressure waves did not occur if CPP was maintained at 70 to 75 mm Hg or above. It is concluded that 0° head elevation maximizes CPP and reduces the severity and frequency of pressure-wave occurrence. If the head of the bed is to be elevated, then adequate hydration and avoidance of pharmacological agents that reduce SABP or prevent its rise are required to maximize CPP.

Blood Pressure Variability and Optimal Cerebral Perfusion Pressure—New Therapeutic Targets in Traumatic Brain Injury

Neurosurgery ◽  
2019 ◽  
Vol 86 (3) ◽  
pp. E300-E309 ◽  
Author(s):  
Teodor Svedung Wettervik ◽  
Timothy Howells ◽  
Anders Lewén ◽  
Per Enblad
Keyword(s):  
Blood Pressure ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cerebral Perfusion Pressure ◽  
Arterial Blood Pressure ◽  
Blood Pressure Variability ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Arterial Blood ◽  
Optimal Cerebral Perfusion Pressure

Abstract BACKGROUND Optimal cerebral perfusion pressure (CPPopt) is an autoregulatory-oriented target in the neurointensive care (NIC) of patients with traumatic brain injury (TBI), and deviation from CPPopt is associated with poor outcome. We recently found that blood pressure variability (BPV) is associated with deviation from CPPopt. OBJECTIVE To evaluate BPV and other variables related to deviation from CPPopt and to evaluate challenges and strategies for autoregulatory-oriented treatment in TBI. METHODS Data including arterial blood pressure and intracranial pressure (ICP) from 362 TBI patients treated at the NIC unit, Uppsala University Hospital, Sweden, between 2008 and 2016, were retrospectively analyzed day 2 to 5. RESULTS Higher BPV was a strong predictor of both CPP deviation below and above CPPopt after multiple regression analyses. There was no other explanatory variable for CPP deviation above CPPopt, whereas also higher ICP and worse autoregulation (higher pressure reactivity index) were associated with CPP deviation below CPPopt. A higher BPV was, in turn, explained by older age, lower ICP, higher mean arterial blood pressure, and higher slow arterial blood pressure amplitude (0.018-0.067 Hz). CONCLUSION BPV was strongly associated with deviation from CPPopt. High age is a risk factor for high BPV and hence CPP insults. Our treatment protocol is focused on avoiding CPP below 60 mm Hg. It is possible that a more restrictive upper level could generate more stable blood pressure and less deviation from CPPopt.

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