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
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.
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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
Relationship of neuron specific enolase and protein S-100 concentrations in systemic and jugular venous serum to injury severity and outcome after traumatic brain injury.
Neuron specific enolase (NSE) and protein S-100 have previously been described as markers of brain injury. We aimed to discover whether concentrations of either were raised in arterial and jugular venous serum after traumatic brain injury, and whether serum profiles were related to injury severity and neurological outcome. We recruited 22 patients with a traumatic brain injury who were admitted to the intensive care unit. ⋯ There was a small, but significant difference between jugular venous and arterial concentrations of S-100 (p = 0.022). High NSE and S-100 concentrations were significantly related to poor neurological outcome (p = 0.004 and p < 0.001 respectively). Both serum NSE and S-100 may be of some value in helping to predict outcome after a traumatic brain injury.
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Acta Neurochir. Suppl. · Jan 1998
Interhemispheric pressure gradients in severe head trauma in humans.
Interhemispheric pressure gradients may occur following severe head trauma in patients even in the absence of intracranial space occupying lesions. A higher ICP of the contralateral hemisphere may escape routine unilateral ICP monitoring. ⋯ According to our data with a limited number of patients, interhemispheric pressure gradients seem to occur in the initial posttraumatic phase in some patients, and they seem to resolve following adequate ICP treatment after several hours. Therefore, simultaneous bilateral ICP measurement may be warranted in the initial posttraumatic phase.