Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 1998
Subdural monitoring of ICP during craniotomy: thresholds of cerebral swelling/herniation.
It is possible to define thresholds for cerebral swelling or herniation during craniotomy. In 178 patients subjected to craniotomy for space occupying processes subdural ICP was measured before opening of dura. The subdural ICP was correlated to the degree of cerebral swelling or herniation after opening of dura. ⋯ These ICP thresholds are independent of the pathophysiology (SAH, cerebral tumor), the anaesthetic agent (isoflurane, propofol) and the PaCO2 level (< or = 4.0 kPa, > 4.0 kPa). Generally, a good correlation between the tactile estimation of dural tension and the tendency to cerebral swelling or herniation after opening of dura was found. However, in 8.5% the surgeons were unable to predict swelling/herniation.
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Acta Neurochir. Suppl. · Jan 1998
External lumbar drainage in uncontrollable intracranial pressure in adults with severe head injury: a report of 7 cases.
The retrospective results of external lumbar drainage in 7 adult patients with severe closed head injury and intracranial pressure (ICP) refractory to aggressive management strategies are presented. All patients had Glasgow Coma Scale (GCS) scores of 8 or less within 24 hours after admission and were treated by a staircase protocol including sedation, ventricular drainage, hyperventilation and mannitol. In three cases barbiturate drugs and an artificially induced hypothermia were used. ⋯ Three patients made a good functional recovery, 2 were severely disabled and 2 patients died. In none of the patients clinical signs of cerebral herniation occurred. We recommend additional external lumbar drainage in adults with severe head injury unresponsive to aggressive ICP control with open basilar cisterns and absent focal mass lesions on computerized-tomography scan before drainage.
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Acta Neurochir. Suppl. · Jan 1998
Determining cerebral perfusion pressure thresholds in severe head trauma.
Laboratory studies suggest the pulsatile component of the transcranial doppler (TCD) waveform may be useful in determining lower autoregulatory threshold. This study aimed to assess the effect of increasing CPP on jugular bulb oximetry (SjO2) and middle cerebral artery (MCA) TCD flow velocities in the early management of severe head injury. 16 severely head injured patients (GCS < or = 8), had intracranial pressure (ICP), mean arterial pressure, SjO2 and MCA Doppler velocity monitored continuously. CPP was increased by intravenous fluids (right atrial pressure approximately equal to 10) and supplemented with adrenaline infusion until TCD pulsatility (Gosling pulsatility index [PI] reached a plateau. ⋯ We conclude that a critically low level of SjO2 is a late indicator of failed autoregulation. CPP values associated with intact autoregulation identified by TCD assessment of MCA flow are significantly higher than those indicated by SjO2 monitoring. MCA Doppler flow assessment may be useful in determining the level of CPP at which therapy should be aimed in the early resuscitation of head trauma.
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Acta Neurochir. Suppl. · Jan 1998
Continuous monitoring of cerebrovascular pressure-reactivity in head injury.
Cerebrovascular vasomotor reactivity reflects changes in smooth muscle tone in the arterial wall in response to changes in transmural pressure or concentration of carbon dioxide in blood. We have investigated whether slow waves in ABP and ICP may be used to derive an index which reflects reactivity of vessels to changes in arterial blood pressure. ⋯ Computer analysis of slow waves in ABP and ICP is able to provide a continuous index of cerebrovascular reactivity to changes in arterial pressure, which is of prognostic significance.
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Acta Neurochir. Suppl. · Jan 1998
Continuous intracranial multimodality monitoring comparing local cerebral blood flow, cerebral perfusion pressure, and microvascular resistance.
Maintaining cerebral perfusion pressure (CPP) above 70 mmHg is currently a mainstay of neurosurgical critical care. Shalmon, et al. recently showed poor correlation between CPP and regional cerebral blood flow (CBF) [1]. To study the relationship between CPP and CBF, at a microvascular level, we retrospectively analyzed multimodality digital data from 12 neurosurgical critical care patients in whom a combined intracranial pressure (ICP)--laser Doppler flowmetry (LDF) probe (Camino, San Diego) had been placed. ⋯ Autoregulation was impaired or absent in all monitored patients. We conclude that with disrupted autoregulation, CPP above 70 mmHg does not necessarily insure adequate levels of cerebral perfusion. Restoration and maintenance of adequate cerebral perfusion should be performed under the guidance of direct CBF monitoring.