Brain PtiO2

BACKGROUND: Prone position is a key component to treat hypoxemia in patients with severe acute respiratory distress syndrome. However, most studies evaluating it exclude patients with brain injuries without any medical evidence. METHODS: This study includes a systematic review to determine whether brain-injured patients were excluded in studies evaluating prone position on acute respiratory distress syndrome; a prospective study including consecutive brain-injured patients needing prone position...

Cerebral oxygenation represents the balance between oxygen delivery, consumption and utilization by the brain, and therefore reflects the adequacy of cerebral perfusion. Different factors can influence the amount of oxygen to the brain including arterial blood pressure, hemoglobin levels, systemic oxygenation, and transfer of oxygen from blood to the cerebral microcirculation. A mismatch between cerebral oxygen supply and demand results in cerebral hypoxia/ischemia, and is associated with secondary brain damage and worsened outcome after acute brain injury...

BACKGROUND: Delayed posthemorrhagic vasospasm remains among the major complications after aneurysmal subarachnoid hemorrhage (SAH) and can result in devastating ischemic strokes. As rescue therapy, neurointerventional procedures are used for selective vasodilatation. OBJECTIVE: To investigate the effects of intra-arterial papaverine-hydrochloride on cerebral metabolism and oxygenation. METHODS: A total of 10 consecutive patients, suffering from severe aneurysmal SAH were prospectively included...

PURPOSE: The use of epinephrine (EN) or vasopressin (VP) in hemorrhagic shock is well established. Due to its specific neurovascular effects, VP might be superior in concern to brain tissue integrity. The aim of this study was to evaluate cerebral effects of either EN or VP resuscitation after hemorrhagic shock. METHODS: After shock induction fourteen pigs were randomly assigned to two treatment groups. After 60 min of shock, resuscitation with either EN or VP was performed...

BACKGROUND: Brain injury is a leading cause of death and disabilities worldwide. The severity of brain damage is of course related to the primary injury. Secondary brain insults are the most powerful determinants of outcome from severe head injury. To improve the outcome, it needs to be well detected to be controlled. The detection of these factors can be difficult among numerous data. The objective of this work was to validate a monitoring matrix to help this screening. We hypothesise that a monitoring matrix will improve the detection rate of factors linked to secondary brain injury (SBI)...

BACKGROUND: A novel multiparameter brain sensor (MPBS) allows the simultaneous measurement of brain tissue oxygenation (ptiO2 ), cerebral blood flow (CBF), intracranial pressure (ICP), and brain temperature with a single catheter. This laboratory investigation evaluates the MPBS in an animal model in relation to established reference probes. METHODS: The study group consisted of 17 juvenile male pigs. Four MPBS and four reference probes were implanted per pig and compared simultaneously...

BACKGROUND: Critical care management of patients suffering from acute liver failure (ALF) continues to be challenging. Animal models studying the pathophysiological central nervous system alterations during the course of ALF provide an opportunity to improve diagnostic and therapeutic strategies. The aim of this study was to analyse the course of cerebral oxygenation in addition to conventional neuromonitoring during the course of acetaminophen-induced ALF. METHODS: ALF was induced by intrajejunal acetaminophen administration in 20 German landrace pigs...

Multiple trauma (MT) associated with hemorrhagic shock (HS) might lead to cerebral hypoperfusion and brain damage. We investigated cerebral alterations using a new porcine MT/HS model without traumatic brain injury (TBI) and assessed the neuroprotective properties of mild therapeutic hypothermia. Male pigs underwent standardized MT with HS (45% or 50% loss of blood volume) and resuscitation after 90/120 min (T90/T120). In additional groups (TH90/TH120) mild hypothermia (33°C) was induced following resuscitation...

GOAL: An important research area in biomedical signal processing is that of quantifying the relationship between simultaneously observed time series and to reveal interactions between the signals. Since biomedical signals are potentially nonstationary and the measurements may contain outliers and artifacts, we introduce a robust time-varying generalized partial directed coherence (rTV-gPDC) function. METHODS: The proposed method, which is based on a robust estimator of the time-varying autoregressive (TVAR) parameters, is capable of revealing directed interactions between signals...

OBJECTIVE: The main objective of the study is to obtain knowledge about the organisation of care for severe head trauma as well as the initial management of these patients in Neurosurgical Departments in Spain. MATERIAL AND METHOD: A 22-item questionnaire was designed and sent to 59 Neurosurgical Departments. The aim of the questionnaire was to collect data regarding the general profile of the patients with a severe head injury, the general characteristics of the hospitals, the initial care of these patients, the monitoring techniques used, and the measures used to control Intracranial pressure (ICP)...

Background  Studies investigating multimodal cerebral monitoring including partial brain tissue oxygen monitoring (ptiO2) in neuro-intensive care patients during physiotherapy are completely lacking in the literature. Materials and Methods  We performed a post hoc analysis of prospectively collected data of patients on multimodal cerebral monitoring by intracranial pressure (ICP) and cerebral perfusion pressure (CPP) measurement as well as ptiO2. Patients with severe brain diseases were treated with passive range of motion (PROM)...

Low doses of the carbonic anhydrase inhibitor acetazolamide provides accelerated acclimatization to high-altitude hypoxia and prevention of cerebral and other symptoms of acute mountain sickness. We previously observed increases in cerebral O2 metabolism (CMRO2 ) during hypoxia. In this study, we investigate whether low-dose oral acetazolamide (250 mg) reduces this elevated CMRO2 and in turn might improve cerebral tissue oxygenation (PtiO2 ) during acute hypoxia. Six normal human subjects were exposed to 6 h of normobaric hypoxia with and without acetazolamide prophylaxis...

Near-infrared spectroscopy (NIRS) has gained acceptance for cerebral monitoring, especially during cardiac surgery, though there are few data showing its validity. We therefore aimed to correlate invasive brain tissue oxygen measurements (PtiO2) with the corresponding NIRS-values (regional oxygen saturation, rSO2). We also studied whether NIRS was able to detect ischemic events, defined as a PtiO2-value of <15 mmHg. Eleven patients were studied with invasive brain tissue oxygen monitoring and continuous-wave NIRS...

BACKGROUND: In contrast to other types of shock, anaphylactic shock decreases cerebral blood flow more than would be expected from severe arterial hypotension, thus potentially affecting survival through brain ischaemia/hypoxia. We hypothesised that epinephrine (EPI) used as a first-line treatment of anaphylactic shock and arginine vasopressin (AVP) proposed in case of EPI refractoriness may have different effects on brain oxygenation. OBJECTIVES: To compare the effect of EPI and AVP on brain oxygenation under similar macro-haemodynamic target values in an anaphylactic shock model...

BACKGROUND: In moyamoya disease (MMD), cerebral revascularization is recommended in patients with recurrent or progressive ischemic events and associated reduced cerebral perfusion reserve. Low-flow bypass with or without indirect revascularization is generally the standard surgical treatment. Intraoperative monitoring of cerebral partial pressure of oxygen (PtiO2) with polarographic Clark-type probes in cerebral artery bypass surgery for MMD-induced chronic cerebral ischemia has not yet been described...

AIM: Monitoring of intracranial pressure (ICP), local cerebral blood flow (CBF) and oxygen is part of modern intensive critical care medicine. Preclinical evaluation of newly developed catheters that should monitor several parameters simultaneously is reported poorly in the literature. The goal of our study was (1) to evaluate a new multi-parametric sensor in brain tissue and (2) to establish a testing protocol using pathophysiological challenges that target measured parameters of the sensor and autoregulatory boundaries and could be used as preclinical standard protocol in future studies...

PURPOSE: Preconditioning with low doses of monophosphoryl lipid A (MPL) has been shown to induce endotoxin tolerance and to reduce the metabolic and hemodynamic consequences of endotoxin shock. However, no data are available about the effects of endotoxin preconditioning on cerebral metabolism during endotoxemia. The study was designed to determine the effects of endotoxin preconditioning with MPL on cerebral metabolism via microdialysis compared to muscle tissue metabolism during experimental endotoxemia...

The main goal of exhaustively monitoring neurocritical patients is to avoid secondary injury. In the last few years we have witnessed an increase in brain monitoring tools, beyond the checking of intracranial and brain perfusion pressures. These widely used systems offer valuable but possibly insufficient information. Awareness and correction of brain hypoxia is a useful and interesting measure, not only for diagnostic purposes but also when deciding treatment, and to predict an outcome. In this context, it would be of great interest to use all the information gathered from brain oxygenation monitoring systems in conjunction with other available multimodal monitoring devices, in order to offer individualized treatment for each patient...

Brain injury results from ischemia, tissue hypoxia, and a cascade of secondary events. The cornerstone of neurocritical care management is optimization and maintenance of cerebral blood flow (CBF) and oxygen and substrate delivery to prevent or attenuate this secondary damage. New techniques for monitoring brain tissue oxygen tension (PtiO2) are now available. Brain PtiO2 reflects both oxygen delivery and consumption. Brain hypoxia (low brain PtiO2) has been associated with poor outcomes in patients with brain injury...

Evolving brain damage following traumatic brain injury (TBI) is strongly influenced by complex pathophysiologic cascades including local as well as systemic influences. To successfully prevent secondary progression of the primary damage we must actively search and identify secondary insults e.g. hypoxia, hypotension, uncontrolled hyperventilation, anemia, and hypoglycemia, which are known to aggravate existing brain damage. For this, we must rely on specific cerebral monitoring. Only then can we unmask changes which otherwise would remain hidden, and prevent adequate intensive care treatment...