Acta neurochirurgica. Supplement
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Severe head injury with and without peripheral trauma is the most frequent cause of death and of severe disability up to 45 years. Outcome is determined by two major factors, the extent and nature of the irreversible primary brain damage, and the evolving secondary sequelae, which contrary to the former are responsive in principle to therapeutic intervention. An improvement of outcome from severe head injury can be expected only from an increased efficiency of the measures to prevent secondary brain damage. ⋯ Current results and experiences with establishment of this comprehensive research organization are presented, where no less than 31 hospitals. Institutions and organizations, and a study group of more than 40 physicians, students and statisticians are collaborating. Emerging data appear to be suitable to further improve pertinent aspects of the patient management as a basis to lower the incidence of secondary brain damage from severe head injury.
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Acta Neurochir. Suppl. · Jan 1998
Complications and safety associated with ICP monitoring: a study of 542 patients.
In our institution ICP was monitored in patients with GCS < or = 8 and abnormal CT scan: 362 severely head injured and 180 subarachnoid hemorrhage. Mean duration of monitoring was 103.6 hours (SD 74.96). Among 542 patients, 440 showed at least one episode of ICP above the threshold of 20 mm Hg. ⋯ In 13 cases (2.2%) a ventricular infection has been diagnosed. In 1 case an intraparenchimal hemorrhage related to the presence of the catheter was detected. Elevated risk of HICP and low incidence of complications have been shown in this series.
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Acta Neurochir. Suppl. · Jan 1998
The relationship of pulsatile cerebrospinal fluid flow to cerebral blood flow and intracranial pressure: a new theoretical model.
An electrical-equivalent circuit model of the cerebrovascular system is proposed, components of which directly relate to cerebrospinal fluid (CSF) compartment compliance and the determination of intracranial pressure (ICP). The model is based on three premises: 1) Under normal, physiologic conditions, the conversion of pulsatile arterial to nonpulsatile venous flow occurs primarily as a result of arterial compliance. Nonpulsatile venous flow is advantageous because less energy is required to maintain constant flow through the venous system, which comprises 75-80% of total blood volume. 2) Dynamic CSF movement across the foramen magnum is the primary facilitator by which intracranial arterial expansion occurs. ⋯ An interference of transcranial CSF movement results in a decrease in cerebral blood flow (CBF) due to inertial effects impeding pulsatile venous flow. Feedback regulation in response to this decreased CBF leads to arteriolar vasodilatation (decreased resistance), thereby lowering the pressure difference between internal carotid and capillary pressures. Assuming no changes in the BBB potential, ICP increases linearly as capillary pressure increases.
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Acta Neurochir. Suppl. · Jan 1998
The use of near infrared spectroscopy (NIRS) in children after traumatic brain injury: a preliminary report.
Children commonly develop diffuse cerebral swelling after traumatic brain injury (TBI) which is believed due to a secondary response to the injury. Near infrared spectroscopy (NIRS), a continuous, direct, and noninvasive monitor of cerebral oxygenation and cerebral blood volume (CBV), could be helpful in understanding these secondary responses. The aims of our study were to determine whether NIRS used in children with severe TBI will provide insight into the pathophysiology of injury. ⋯ Often, high ICP correlated with increased THb and HbO2 indicating increased CBV and cerebrovascular dilatation. In two children, posttraumatic seizures were preceded by an unexplained rapid cerebral hyperoxygenation several hours prior to the onset of the clinical seizures. NIRS reliably detects changes in cerebral hemodynamics in children and may be used to further understand the etiology of the diffuse cerebral swelling seen in children after severe TBI.
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Acta Neurochir. Suppl. · Jan 1998
Effects on intracranial pressure of fentanyl in severe head injured patients.
Despite opioids are routinely used for analgesia in head injured patients, the effects of such drugs on ICP and cerebral hemodynamics remain controversial. Cerebrovascular autoregulation (CAR) could be an important factor in the ICP increases reported after opioid administration. In order to describe the effects on intracranial pressure of fentanyl and correlated such effects with autoregulation status, we studied 30 consecutive severe head injury patients who received fentanyl (2 micrograms/kg) intravenously over one minute. ⋯ In patients with preserved CAR (34.5%), opioid-induced ICP increase was greater (but not statistically significant) than in those with impaired CAR (65.5%). We conclude than fentanyl moderately increased ICP and decreased MAP and CPP. Our data suggests that in patients with preserved CAR, potent opioids could cause greater increases of ICP, probably due to activation of the vasodilatadory cascade.