scholarly journals Impaired cerebral autoregulation, cerebral perfusion pressure and intracranial pressure in eclampsia

2021 ◽  
Author(s):  
Nivedita Jha ◽  
Ajay Kumar Jha
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Autoregulation ◽  
Cerebral Perfusion ◽  
Perfusion Pressure

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.

Effects of positive end-expiratory pressure on intracranial pressure in dogs with intracranial hypertension

1981 ◽  
Vol 55 (5) ◽  
pp. 704-707 ◽  
Author(s):  
Jon S. Huseby ◽  
John M. Luce ◽  
Jeffrey M. Cary ◽  
Edward G. Pavlin ◽  
John Butler
Keyword(s):  
Intracranial Pressure ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Autoregulation ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Clinical Situation ◽  
Positive End Expiratory Pressure ◽  
Content Type ◽  
Neurosurgical Patients

✓ Positive end-expiratory pressure (PEEP) is used to improve oxygenation in patients with the adult respiratory distress syndrome. Nevertheless, this treatment may increase intracranial pressure (ICP) and be detrimental to certain neurosurgical patients. This clinical situation was simulated by administering PEEP to dogs with normal and elevated ICP. Increases in PEEP increased ICP in all animals. However, the presence of intracranial hypertension diminished the increase in ICP seen at a given level of PEEP. Cerebral perfusion pressure also fell less in the presence of intracranial hypertension than it did in its absence, although in the former situation cerebral perfusion pressure was at the lower limits of the range of cerebral autoregulation. These findings suggest that PEEP is no more detrimental to patients with elevated ICP than it is to patients whose ICP is normal, assuming that their cerebral autoregulation is not impaired.

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.

Intratracheal Suctioning in Sick Preterm Infants: Prevention of Intracranial Hypertension and Cerebral Hypoperfusion by Muscle Paralysis

PEDIATRICS ◽  
1987 ◽  
Vol 79 (4) ◽  
pp. 538-543
Author(s):  
Sergio Fanconi ◽  
Gabriel Duc
Keyword(s):  
Heart Rate ◽  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Preterm Infants ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Muscle Paralysis ◽  
Endotracheal Suctioning ◽  
Significant Difference ◽  
Transcutaneous Po2

In a prospective nonrandomized study, using each baby as his or her own control, we compared intracranial pressure (anterior fontanel pressure as measured with the Digilab pneumotonometer), cerebral perfusion pressure, BP, heart rate, transcutaneous Po2, and transcutaneous Pco2 before, during, and after endotracheal suctioning, with and without muscle paralysis, in 28 critically ill preterm infants with respiratory distress syndrome. With suctioning, there was a small but significant increase in intracranial pressure in paralyzed patients (from 13.7 [mean] ± 4.4 mm Hg [SD] to 15.8 ± 5.2 mm Hg) but a significantly larger (P < .001) increase when they were not paralyzed (from 12.5 ± 3.6 to 28.5 ± 8.3 mm Hg). Suctioning led to a slight increase in BP with (from 45.3 ± 9.1 to 48.0 ± 8.7 mm Hg) and without muscle paralysis (from 45.1 ± 9.4 to 50.0 ± 11.7 mm Hg); but there was no significant difference between the two groups. The cerebral perfusion pressure in paralyzed infants did not show any significant change before, during, and after suctioning (31.5 ± 9.1 mm Hg before v 32.0 ± 8.7 mm Hg during suctioning), but without muscle paralysis cerebral perfusion pressure decreased (P < .001) from 32.8 ± 9.7 to 21.3 ± 13.1 mm Hg. Suctioning induced a slight decrease in mean heart rate and transcutaneous Po2, but pancuronium did not alter these changes. There was no statistical difference in transcutaneous Pco2, before, during, and after suctioning with and without muscle paralysis. Our data demonstrate that muscle paralysis in sick preterm infants can significantly minimize the increase in intracranial pressure and can stabilize the cerebral perfusion pressure without having any effect on the BP increase during suctioning.

Management of raised intracranial pressure

2020 ◽  
pp. 3892-3897
Author(s):  
David K. Menon
Keyword(s):  
Intracranial Pressure ◽  
Cerebral Perfusion Pressure ◽  
Cerebral Perfusion ◽  
Brain Oedema ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Brain Perfusion ◽  
Normal Brain ◽  
Intracranial Volume ◽  
Nervous System Diseases

Normal intracranial pressure is between 5 and 15 mm Hg in supine subjects. Intracranial hypertension (ICP >20 mm Hg) is common in many central nervous system diseases and in fatal cases is often the immediate cause of death. Increases in intracranial volume and hence—given the rigid skull—intracranial pressure may be the consequence of brain oedema, increased cerebral blood volume, hydrocephalus, and space-occupying lesions. Brain perfusion depends on the cerebral perfusion pressure which is mean arterial pressure minus intracranial pressure. The normal brain autoregulates cerebral blood flow down to a lower limit of cerebral perfusion pressure of about 50 mm Hg in healthy subjects, and perhaps 60–70 mm Hg in disease. Cerebral perfusion pressure reduction to below these values results in cerebral ischaemia.

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