Management of raised intracranial pressure

2020 ◽  
pp. 3892-3897
Author(s):  
David K. Menon

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.

Author(s):  
David K. Menon

Normal intracranial pressure (ICP) is between 5 and 15 mmHg in supine subjects. Intracranial hypertension (ICP >20 mmHg) is common in many central nervous system diseases and in fatal cases is often the immediate cause of death. Aetiology and pathogenesis—increases in intracranial volume and hence—given the rigid skull—ICP may be the consequence of (1) brain oedema, (2) increased cerebral blood volume, (3) hydrocephalus, and (4) space-occupying lesions. Brain perfusion depends on the difference between mean arterial pressure and ICP, termed cerebral perfusion pressure (CPP). The normal brain autoregulates cerebral blood flow down to a lower limit of CPP of about 50 mmHg in healthy subjects, and perhaps 60 to 70 mmHg in disease. CPP reduction to below these values results in cerebral ischaemia....


1975 ◽  
Vol 43 (4) ◽  
pp. 385-398 ◽  
Author(s):  
Robert L. Grubb ◽  
Marcus E. Raichle ◽  
Michael E. Phelps ◽  
Robert A. Ratcheson

✓ The relationship of cerebral blood volume (CBV) to cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and the cerebral metabolic rate for oxygen (CMRO2) was examined in rhesus monkeys. In vivo tracer methods employing radioactive oxygen-15 were used to measure CBV, CBF, and CMRO2. Cerebral perfusion pressure was decreased by raising the intracranial pressure (ICP) by infusion of artificial cerebrospinal fluid (CSF) into the cisterna magna. The production of progressive intracranial hypertension to an ICP of 70 torr (CPP of 40 torr) caused a rise in CBV accompanied by a steady CBF. With a further increase in ICP to 94 torr, CBV remained elevated without change while CBF declined significantly. Cerebral metabolic rate for oxygen did not change significantly during intracranial hypertension. For comparison, CPP was lowered by reducing mean arterial blood pressure in a second group of monkeys. Only CBF was measured in this group. In this second group of animals, the lower limit of CBF autoregulation was reached at a higher CPP (CPP ∼ 80 torr) than when an increase in ICP was employed (CPP ∼ 30 torr).


1988 ◽  
Vol 68 (5) ◽  
pp. 745-751 ◽  
Author(s):  
Werner Hassler ◽  
Helmuth Steinmetz ◽  
Jan Gawlowski

✓ 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.


PEDIATRICS ◽  
1987 ◽  
Vol 79 (4) ◽  
pp. 538-543
Author(s):  
Sergio Fanconi ◽  
Gabriel Duc

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.


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