Search Results
Results 451 - 500 of 2459
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Jaeger Matthias - - 2007
BACKGROUND AND PURPOSE: Disturbances of cerebrovascular autoregulation are thought to be involved in delayed cerebral ischemia and infarction after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that the continuous monitoring of brain tissue oxygen (PtiO(2)) pressure reactivity enables the detection of impaired autoregulation after SAH and that impaired autoregulation is associated ...
Sakowitz Oliver W - - 2007
BACKGROUND: Osmotic agents are widely used to lower elevated intracranial pressure (ICP). However, little data are available regarding cerebral oxygenation and metabolism in the traumatized brains studied under clinical conditions. The present prospective, open-labeled clinical study was designed to investigate whether administration of mannitol, with the aim of reducing moderate ...
Yanagawa Youichi - - 2007
BACKGROUND: Vasospasm caused by intracranial hypertension in head injury remains controversial. METHODS: Between 1996 and 2004, we prospectively and consecutively performed conventional cerebral angiography for six patients with head injuries who showed persistent intracranial hypertension (over 20 mm Hg for longer than 5 days) despite performing various treatments for intracranial ...
Tankisi Alp - - 2007
OBJECT: To the authors' knowledge, repeated measurements of intracranial pressure (ICP), cerebral perfusion pressure (CPP), and the degree of dural tension during different positions on the operating table (reverse Trendelenburg position [rTp]) have not been studied in patients undergoing craniotomy. METHODS: In the present study 53 patients with supratentorial cerebral ...
Lavinio Andrea A Department of Academic Neurosurgery, Box 167, Addenbrooke's Hospital, Cambridge, - - 2007
Mx is an index of cerebrovascular autoregulation. It is calculated as the correlation coefficient between slow spontaneous fluctuations of cerebral perfusion pressure (cerebral perfusion pressure=arterial blood pressure-intracranial pressure) and cerebral blood flow velocity. Mx can be estimated noninvasively (nMxa) with the use of a finger plethysmograph arterial blood pressure measurement ...
Lenfeldt N - - 2007
The accuracy of estimating intracranial pressure in brain tissue (ICP(BT)) via lumbar space was investigated using preset pressure levels in the interval 0 to 600 mm H(2)O in patients with communicating hydrocephalus. Lumbar space ICP correlated excellently to ICP(BT), demonstrated by a measured mean difference of 10 mm H(2)O (0.75 ...
Zanier Elisa Roncati - - 2007
INTRODUCTION: The presence of intracranial hypertension (HICP) after traumatic brain injury (TBI) affects patient outcome. Intracranial pressure (ICP) data from electronic monitoring equipment are usually calculated and recorded hourly in the clinical chart by trained nurses. Little is known, however, about how precisely this method reflects the real patterns of ...
Cormio Manuela - - 2007
INTRODUCTION: Aim of this randomized prospective clinical trial is to compare two methods of antipyretics and evaluate their efficacy in controlling fever during the acute phase of brain damage. METHODS: Twenty-two febrile comatose patients: 12 severe traumatic brain injury and 10 subarachnoid hemorrhage divided in 2 groups: Diclofenac low-dose infusion ...
Czarnik Tomasz - - 2007
BACKGROUND: Some publications suggest a strong correlation between the intracranial pressure and the intraocular pressure. Other studies claim no correlation between these two physiologic variables. Our aim was to study whether the tonometry could be a useful method to evaluate intracranial pressure in patients with suspected intracranial abnormality. METHODS: We ...
Muehlschlegel Susanne - - 2007
INTRODUCTION: Hypertensive, hypervolemic, and hemodilutional (HHH) therapy for vasospasm in subarachnoid hemorrhage (SAH) refractory to phenylephrine requires high doses of catecholamines, leading to adverse adrenergic effects. Arginine vasopressin (AVP) has been shown to stabilize advanced shock states while facilitating reduction of catecholamine doses, but its use has never been reported ...
Natale JoAnne E - - 2007
OBJECTIVE: Magnesium sulfate is neuroprotective in preclinical models, but there are limited safety data regarding its clinical use for pediatric traumatic brain injury. We conducted a pilot study in children with severe traumatic brain injury to a) examine if magnesium sulfate decreases mean arterial pressure, decreases cerebral perfusion pressure, increases ...
Wauters J - - 2007
Elevated intra-abdominal pressure (IAP) exerts effects not only on intra-abdominal organs, but also on organs distant to the abdominal compartment. Abdomino-thoracic interaction during intra-abdominal hypertension (IAH) or abdominal compartment syndrome (ACS) interferes with pulmonary, cardiovascular and cerebral function. In accordance with recent guidelines, IAH is defined as IAP above 12 ...
De laet I - - 2007
INTRODUCTION: Intra-abdominal hypertension (IAH) and abdominal compartment syndrome are a common occurrence in ICU patients. The deleterious effects of IAH on organ function are well known and increasingly appreciated in recent years, especially where renal and respiratory function are concerned. METHODS: This review will focus on the available literature from ...
Agarwal Madhu R - - 2007
Idiopathic intracranial hypertension, also known as pseudotumor cerebri, is a condition of increased intracranial pressure without the presence of mass lesions and with normal cerebrospinal fluid composition. Patients may experience papilledema and vision loss. Optic nerve sheath fenestration (ONSF) is one method of stabilizing visual function and decreasing optic nerve ...
Jetzki S - - 2007
In the therapy of hydrocephalus the dynamic course of the intracranial pressure (ICP) is rarely considered, although it may contain valuable diagnostic information. Several models for intracranial pressure and fluid dynamics are described. Assuming a simplified model and deriving the intracranial pressure wave relationships, this model could be partially confirmed ...
Choi James J - - 2007
The feasibility of blood-brain barrier (BBB) opening in the hippocampus of wild-type mice using focused ultrasound (FUS) through the intact skull and skin was investigated. Needle hydrophone measurements through ex vivo skulls revealed minimal attenuation ( approximately 18% of the pressure amplitude), a well-focused beam pattern and minute focus displacement ...
Furgała Agata - - 2007
Most of the disturbances of autonomic system (AS) activity seen in clinical practice result from head injury are due to development of increased intracranial pressure (ICP). It has been described that cerebral lesions produce hypersympathetic states mediated mostly by sympatho-adrenal discharge. Aim of the study was to evaluate effects of ...
Takahashi T - - 2007
The purpose of this paper is to discuss the basic study of mechanism of brain injury analytically and experimentally, in respect to the frequency analysis of the pressure changes. First, a three-dimensional FEM model for impact analysis was presented. The pressure changes inside a brain agar phantom and its frequency ...
Czosnyka Marek M Academic Neurosurgical Unit, University of Cambridge Clinical School, Cambridge, United Kingdom. MC141@medschl.cam.ac.uk - - 2007
Many doctors involved in the critical care of head-injured patients understand intracranial pressure (ICP) as a number, characterizing the state of the brain pressure-volume relationships. However, the dynamics of ICP, its waveform, and secondarily derived indices portray useful information about brain homeostasis. There is circumstantial evidence that this information can ...
Zhang Jiangyue - - 2007
Biomechanical quantification of projectile penetration using experimental head models can enhance the understanding of civilian ballistic brain injury and advance treatment. Two of the most commonly used handgun projectiles (25-cal, 275 m/s and 9 mm, 395 m/s) were discharged to spherical head models with gelatin and Sylgard simulants. Four ballistic ...
Yannopoulos Demetris - - 2006
OBJECTIVE: To evaluate the potential to use subatmospheric intrathoracic pressure to regulate intracranial pressure (ICP) in normovolemic and hypovolemic animals, we tested the hypothesis that mechanical devices designed to reduce intrathoracic pressure will decrease ICP in a dose-related manner. An inspiratory impedance threshold device was used in spontaneously breathing animals ...
Geddes J F - - 2006
Unexplained subdural and retinal haemorrhages in an infant are commonly attributed to 'shaking', the mechanism of which is believed to be traumatic venous rupture. However, the haemorrhagic retinopathy reported as a result of Valsalva manoeuvres and the subdural bleeding that is a rare complication of pertussis together demonstrate that if ...
Gondim Jackson A - - 2006
OBJECTIVE: To determine if there was a relationship between intrassellar pressure (ISP) and pituitary tumor volume. METHOD: Between August 2002 and May 2004, 60 patients aged between 13 and 75 years old (39 males), having a pituitary adenoma were submitted to an endoscope transseptal approach. During the surgery and before ...
Lescot Thomas - - 2006
OBJECTIVE: The aim of this study was to quantify the effect of hypertonic saline solution on contused and noncontused brain tissue in patients with traumatic brain injury. We hypothesize that hypertonic saline would increase the volume of brain contusion while decreasing the volume of noncontused hemispheric areas. DESIGN: Prospective observational ...
Eide P K - - 2006
The aim of this study was to explore how the lumbar cerebrospinal fluid pressure (CSFP) waves recorded during lumbar infusion compared with the intracranial pressure (ICP) waves recorded, either during lumbar infusion or during long-term, overnight monitoring. For this purpose, we assessed 27 simultaneous lumbar CSFP/ICP recordings made during lumbar ...
Mitchell Patrick - - 2007
To determine the statistical characteristics of blood pressure (BP) readings from a large number of head-injured patients. The BrainIT group has collected high time-resolution physiological and clinical data from head-injured patients who require intracranial pressure (ICP) monitoring. The statistical features of this dataset of BP measurements with time resolution of ...
Eide P K - - 2006
OBJECT: To relate intracranial pressure (ICP) levels and single ICP wave amplitudes to the acute clinical state (Glasgow Coma Score, GCS) and final clinical outcome (Glasgow Outcome Score, GOS) in patients with subarachnoid haemorrhage (SAH). METHODS: Twenty-seven consecutive patients with severe SAH had their ICP and arterial blood pressure (ABP) ...
Dohmen Christian - - 2007
BACKGROUND AND PURPOSE: To study cerebrovascular autoregulation and its impact on clinical course in patients with impending malignant middle cerebral artery infarction, we used invasive multimodal neuromonitoring, including measurement of cerebral perfusion pressure, tissue oxygen pressure, and microdialysis. METHODS: Fifteen patients with a stroke that involved >50% of the middle ...
Latka, M.
We employ complex continuous wavelet transforms to develop a consistent mathematical framework capable of quantifying both cerebrospinal compensatory reserve and cerebrovascular pressure reactivity. The wavelet gain, defined as the frequency dependent ratio of time averaged wavelet coefficients of intracranial pressure (ICP) and arterial blood pressure (ABP) fluctuations, characterizes the dampening ...
Koźniewska E - - 2006
The main consequence of subarachnoid hemorrhage, for those who survive bleeding, is delayed, persistent vasospasm of intracranial conduit arteries which occurs between the third and seventh day after the insult and results in symptomatic brain ischemia in about 40% of cases. This vasospasm is considered to be a major cause ...
Enam Syed Ather - - 2006
Cerebral venous sinus thrombosis (CVST) usually is taken care of by medical management or neuro-interventional vascular techniques. Some cases of CVST may take a malignant course if the intracranial pressure increases excessively. This increase in pressure is because of oedema in brain tissue due to impediment in venous return and/or ...
Fodstad Harald - - 2006
Increasing systolic and pulse pressure with bradycardia and respiratory irregularity are signs of increased intracranial pressure, leading to cerebral herniation and fatal brainstem compression. This phenomenon, the vasopressor response, is generally known as the Cushing reflex based on Harvey Cushing's experimental work in Europe in 1901 and 1902. However, similar ...
Kirkness Catherine J - - 2006
BACKGROUND: Clinical bedside monitoring systems do not provide prominent displays of data on cerebral perfusion pressure (CPP). Immediate visual feedback would allow more rapid intervention to prevent or minimize suboptimal pressures. OBJECTIVE: To evaluate the effect of a highly visible CPP display on immediate and long-term functional outcome in patients ...
Splavski Bruno - - 2006
PRIMARY OBJECTIVE: To investigate the potential of transcranial Doppler ultrasonography in estimating post-traumatic intra-cranial pressure early after severe traumatic brain injury. RESEARCH DESIGN: The group of 24 patients was analysed for the observation of an early post-traumatic cerebral haemodynamic by middle cerebral artery blood velocity measuring. METHODS AND PROCEDURES: The ...
Foss Tonje - - 2007
BACKGROUND/AIMS: Previous research has shown improvements in the clinical triad (gait, incontinence and cognitive dysfunction) after shunt surgery in idiopathic normal pressure hydrocephalus (iNPH) patients with intracranial pulse pressure amplitudes >4-5 mm Hg, the pulse amplitudes being <4 mm Hg in the nonresponders. However, it is unknown whether similar differences ...
Stevens Scott A - - 2007
Idiopathic intracranial hypertension (IIH) is a syndrome of unknown etiology characterized by elevated intracranial pressure (ICP). Although a stenosis of the transverse sinus has been observed in many IIH patients, the role this feature plays in IIH is in dispute. In this paper, a lumped-parameter model is developed for the ...
Ang B T - - 2007
OBJECTIVE: To investigate the temporal relationship between cerebrovascular pressure reactivity and brain tissue oxygenation in patients with severe head injury. METHODS: In 40 patients, brain tissue oxygenation and intracranial pressure were monitored. Time-averaged values for intracranial pressure (ICP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP) and brain tissue oxygenation ...
Randell Tarja - - 2006
PURPOSE OF REVIEW: The recent literature on the perioperative maintenance of cerebral homeostasis was reviewed. RECENT FINDINGS: Several studies focused on the regulation of cerebral blood flow in patients without intracranial disease; therefore, further studies in neurosurgical patients are needed. High intracranial pressure and brain swelling can be controlled by ...
Engelhard Kristin - - 2006
PURPOSE OF REVIEW: In neurosurgery, anesthesiologists and surgeons focus on the same target - the brain. The nature of anesthetics is to interact with brain physiology, leading to favorable and adverse effects. Research in neuroanesthesia over the last three decades has been dedicated to identifying the optimal anesthetic agent to ...
Rangel-Castillo Leonardo - - 2006
Effective treatment of intracranial hypertension involves meticulous avoidance of factors that precipitate or aggravate increased intracranial pressure. When intracranial pressure becomes elevated, it is important to rule out new mass lesions that should be surgically evacuated. medical management of increased intracranial pressure should include sedation and paralysis, drainage of cerebrospinal ...
Tayal Vivek S - - 2007
STUDY OBJECTIVE: Our objective is to determine whether a bedside ultrasonographic measurement of optic nerve sheath diameter can accurately predict the computed tomographic (CT) findings of elevated intracranial pressure in adult head injury patients in the emergency department (ED). METHODS: We conducted a prospective, blinded observational study on adult ED ...
Leal-Noval Santiago Ramón - - 2006
OBJECTIVE: To investigate the long-term influence of erythrocyte transfusion on cerebral oxygenation in patients with severe traumatic brain injury. DESIGN: Prospective and observational study. SETTING: Neurotrauma intensive care unit of trauma center level I. PATIENTS: Sixty consecutive, hemodynamically stable patients with severe traumatic brain injury, pretransfusion hemoglobin<100g/l, non-bleeding and monitored ...
Thelandersson A - - 2006
BACKGROUND: Prone position has been used for several years to treat acute lung insufficiency, but in previous studies patients with unstable intracranial pressure (ICP) are mostly excluded. The aim of this study was to investigate if prone position is a safe and useful treatment in patients with reduced intracranial compliance. ...
Eigsti Janice - - 2006
The skull is a unique part of anatomy. It exists in a state of dynamic equilibrium. The components of the skull and their role in maintaining integrity and normal intracranial pressure will be reviewed in this article. Compensatory mechanisms that attempt to prevent the destructive effects of cerebral ischemia and ...
Nekludov M - - 2006
BACKGROUND: Treatment of patients in the prone position is a well-established method to improve oxygenation in general intensive care unit (ICU) practice. This method is rarely used in a neurosurgical ICU, considering the risk of intracranial hypertension. The aim of this study was to analyse the effect of prone position ...
Chavko Mikulas - - 2007
Exposure to blast wave that is generated during an explosion may result in brain damage and related neurological impairments. The aim of this study was to investigate pressure changes induced by exposure to blast inside the rat brain. For intracranial pressure measurement we used a miniature optic fiber sensor (o.d. ...
Shinder Roman - - 2006
A 54-year-old non-obese woman treated with amiodarone reported blurred vision and had bilateral optic disc edema with relative preservation of visual function. Neurologic examination, brain imaging, and lumbar puncture opening pressures were normal, effectively ruling out increased intracranial pressure. Amiodarone was discontinued and the optic disc edema completely resolved over ...
Roher Alex E - - 2006
OBJECTIVE: Recent post-mortem studies have reported that the severity of atheromatous deposits in the circle of Willis is significantly greater, relative to non-demented (ND) elderly persons, in subjects with neuropathologically diagnosed Alzheimer's disease (AD). Additionally, the severity of intracranial atherosclerosis correlates significantly with the densities of neuritic plaques and neurofibrillary ...
David M - - 2006
BACKGROUND: Current practice at high-frequency oscillatory ventilation (HFOV) initiation is a stepwise increase of the constant applied airway pressure to achieve lung recruitment. We hypothesized that HFOV would lead to more adverse cerebral haemodynamics than does pressure controlled ventilation (PCV) in the presence of experimental intracranial hypertension (IH) and acute ...
Yannopoulos Demetris - - 2006
BACKGROUND: The intrathoracic pressure regulator (ITPR) was created to improve hemodynamics by generating continuous negative airway pressure between positive pressure ventilations to enhance cardiac preload in apnoeic animals. In normovolemic and hypovolemic pigs, we tested the hypothesis that continuous negative intrathoracic pressure set at -5 or -10mmHg, interrupted only for ...
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