Acta neurochirurgica. Supplement
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This paper briefly reviews some basic principles of neurosurgical intensive care of patients with aneurysmal subarachnoid hemorrhage. The importance of early identification of secondary insults are underlined. Special attention is paid to the newly introduced method for neurochemical monitoring by means of intracerebral microdialysis. It is concluded that a well functioning neurointensive care unit constitutes an important organisational frame for the detection, prevention and treatment of secondary insults, after aneurysmal subarachnoidal hemorrhage and that improved results can be expected by applying a modern neurointensive care strategy also for patients with aneurysmal subarachnoid hemorrhage.
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Acta Neurochir. Suppl. · Jan 1999
Case Reports Comparative StudyContinuous monitoring of cerebrospinal fluid acid-base balance and oxygen metabolism in patients with severe head injury: pathophysiology and treatments for cerebral acidosis and ischemia.
Continuous monitoring of cerebral acid-base balance and oxygen metabolism has been introduced in neurointensive care settings. The hypothesis of this study utilizing multimodal neuromonitoring modalities is that hyperventilation and hypothermia improve cerebral acidosis through prevention of cerebral ischemia aggravation in patients with severe head injury. ⋯ CSF acidosis caused by increased CSF PCO2, La and Py, and/or decreased HCO3- tended to associate with abnormal ICP and CPP, and desaturation indicated by CSF SO2, rSO2, and/or SjO2. Hypothermia rather than hyperventilation tends to improve cerebral acidosis and ischemia.
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Acta Neurochir. Suppl. · Jan 1999
ReviewThe role of transcranial Doppler in the management of patients with subarachnoid haemorrhage--a review.
Introduced 15 years ago, transcranial Doppler (TCD) recordings of blood-velocity in patients with recent subarachnoid haemorrhage (SAH) have two objectives: to detect elevated blood velocities suggesting cerebral vasospasm (VSP) and to identify patients at risk for delayed cerebral ischemic deficits (DID). The pathophysiological cascade causing DID is complex. Discrepancies between blood velocities and DID (presuming that there actually is an "ischemic threshold" for blood velocity in absolute terms, which seems most unlikely) have been demonstrated, particularly in patients with elevated intracranial pressure (ICP) levels. ⋯ This probably explains why the clinical value of TCD is still debated. There is still uncertainty as to the best method to prevent and to treat VSP, and the overall outcome after SAH depends on so many factors besides VSP. Conclusive evidence may therefore be hard to obtain, and it appears sound to conclude that even with advanced investigation technology available, proper selection, pre- peri- and postoperative care and timing of surgery remain cornerstones in the management of these patients,--equal in importance to their treatment in the operating room or in the interventional angiography suite.
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Acta Neurochir. Suppl. · Jan 1999
Case Reports Comparative StudyMonitoring by subcutaneous microdialysis in neurosurgical intensive care.
Microdialysis is an in vivo sampling technique which provides a powerful approach to monitoring metabolic events. We have performed a study to determine the feasibility and effectiveness of subcutaneous microdialysis in monitoring patients on the Neurosurgical Intensive Care Unit (NICU). A microdialysis probe was placed in the subcutaneous fat of the anterior abdominal wall and perfused with Ringer's solution. ⋯ In one patient, following an apparently brief period of hypoxia, there was a prolonged disturbance of tissue chemistry. Another patient with obesity had significantly higher concentrations of dialysate glucose, lactate and glutamate. Monitoring by subcutaneous microdialysis on intensive care units is feasible, reveals unexpected changes in tissue metabolism and might be an important adjunct for the interpretation of intracerebral data.
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Acta Neurochir. Suppl. · Jan 1999
Glucose and lactate metabolism after severe human head injury: influence of excitatory neurotransmitters and injury type.
The survival of traumatized brain tissue depends on energy substrate delivery and consumption. Excitatory amino acids produce a disturbance of ion homeostasis and thus, increase energy demand. In head-injured patients, massive release of glutamate has been reported, especially in patients with focal contusions. ⋯ The interrelationship was more pronounced in diffusely injured brain (normal CT appearance) compared to the contused tissue. The results demonstrate that glutamate clearly influences the release of lactate following injury, supporting the hypothesis that glutamate "drives" glycolysis in astrocytes. The strong positive correlation between glutamate and glucose might indicate an effect of glutamate upon glucose uptake by cells which differs according to the type of injury.