Tesi: "Traumatic brain injury; intracranial pressure"

1

Donnelly, Joseph. "Intracranial monitoring after severe traumatic brain injury". Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/271422.

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Intracranial monitoring after severe traumatic brain injury offers the possibility for early detection and amelioration of physiological insults. In this thesis, I explore cerebral insults due raised intracranial pressure, decreased cerebral perfusion pressure and impaired cerebral pressure reactivity after traumatic brain injury. In chapter 2, the importance of intracranial pressure, cerebral perfusion pressure and pressure reactivity in regulating the cerebral circulation is elucidated along with a summary of the existing evidence supporting intracranial monitoring in traumatic brain injury. In chapter 4, intracranial pressure, cerebral perfusion pressure, and pressure reactivity insults are demonstrated to be common, prognostically important, and responsive to long-term changes in management policies. Further, while these insults often occur independently, coexisting insults portend worse prognosis. In chapter 5, I examine possible imaging antecedents of raised intracranial pressure and demonstrate that initial subarachnoid haemorrhage is associated with the subsequent development of elevated intracranial pressure. In addition, elevated glucose during the intensive care stay is associated with worse pressure reactivity. Cortical blood flow and brain tissue oxygenation are demonstrated to be sensitive to increases in intracranial pressure in chapter 6. In chapter 7, a method is proposed to estimate the cerebral perfusion pressure limits of reactivity in real-time, which may allow for more nuanced intensive care treatment. Finally, I explore a recently developed visualisation technique for intracranial physiological insults and apply it to the cerebral perfusion pressure limits of reactivity. Taken together, this thesis outlines the scope, risk factors and consequences of intracranial insults after severe traumatic brain injury. Novel signal processing applications are presented that may serve to facilitate a physiological, personalised and precision approach to patient therapy.

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2

Rohlwink, Ursula Karin. "Paediatric traumatic Brain Injury: The relationship between Intracranial Pressure and Brain Oxygenation". Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/2889.

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Introduction: Intracranial pressure (ICP) monitoring is a cornerstone of care for patients with severe traumatic brain injury (TBI). The primary goal of ICP treatment is to preserve brain oxygenation, and since brain oxygenation is usually not measured, the control of ICP is used as a surrogate marker. However studies indicating that cerebral hypoxia/ischemia may occur in the face of adequate ICP and cerebral perfusion pressure (CPP) suggest that the interaction between ICP and brain oxygenation is poorly understood and warrants further investigation. This is of particular importance in the context of children in whom the interpretation of relationships between intracranial factors is even more complex due to changing physiological norms with age. To date little scientific data exists in children and treatment threshold values are often extrapolated from adult guidelines. This study aims to better understand the relationship between ICP and brain oxygenation measured as brain tissue oxygen tension (PbtO2) in a large paediatric cohort suffering from severe TBI. Specifically analysis 1) investigated ICP and PbtO2 profiles over time following TBI, 2) examined the relationship between ICP and PbtO2 from time-linked paired observations, 3) explored various critical thresholds for ICP and PbtO2, and 4) interrogated digital data trends depicting the relationship between ICP and PbtO2. The level of agreement between hourly recorded and high frequency electronic data for ICP and PbtO2 was also evaluated. Method: Paired ICP and PbtO2 data from 75 children with severe TBI were tested with correlation and regression. Additional analyses controlled for mean arterial pressure (MAP), arterial partial pressure of oxygen (PaO2), CPP, arterial partial pressure of carbon dioxide (PaCO2) and haemoglobin (Hb) using multivariate logistic regression analysis and general estimating equations. Various thresholds for ICP were examined; these included age-related thresholds to account for the potential influence of age. Receiver-operating curves (ROCs) were used to graphically demonstrate the relationships between various thresholds of ICP and various definitions of low PbtO2. These were constructed for pooled and individual patient data. Interrogation of electronically recorded data allowed for case illustrations examining the relationship between ICP and PbtO2 at selected time points. Hourly and electronic data were compared using Bland and Altman plots and by contrasting the frequency of ICP and PbtO2 perturbations recorded with each system. 5 Result: Analyses using over 8300 hours of paired observations revealed a weak relationship between ICP and PbtO2, with an initially positive but weak slope (r = 0.05) that trended downwards only at higher values of ICP. Controlling for inter-individual differences, as well as MAP, CPP, PaO2, PaCO2 and Hb did not strengthen this association. This poor relationship was further reflected in the examination of threshold ICP values with ROCs, no singular critical ICP threshold for compromised brain oxygenation was discernible. Using age-based thresholds did not improve this relationship and individual patient ROCs demonstrated inter-individual heterogeneity in the relationship between ICP and PbtO2. However, it was clear that in individual patients ICP did exhibit a strong negative relationship with PbtO2 at particular time points, but various different relationships between the 2 variables were also demonstrated. A high level of agreement was found between hourly and electronic data. Conclusion: These results suggest that the relationship between ICP and PbtO2 is highly complex. Although the relationship in individual children at specific time points may be strong, pooled data for the entire cohort of patients, and even for individual patients, suggest only a weak relationship. This is likely because several other factors affect PbtO2 outside of ICP, and some factors affect both independently of each other. These results suggest that more study should be directed at optimising ICP thresholds for treatment in children. The use of complimentary monitoring modalities may assist in this task. Depending on the adequacy of measures of brain perfusion, metabolism or oxygenation, it is possible that targeting a range of ICP values in individual patients may be appropriate; however this would require detailed investigation.

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3

Elf, Kristin. "Secondary Insults in Neurointensive Care of Patients with Traumatic Brain Injury". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4837.

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4

Fan, Jun-Yu. "Intracranial pressure waveform analysis in traumatic brain injury : an approach to determining parameters capable of prediction decreased intracranial adaptive capacity /". Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/7312.

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5

Wu, Zhizhen. "Flexible Microsensors based on polysilicon thin film for Monitoring Traumatic Brain Injury (TBI)". University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1512045589967871.

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6

Pahren, Laura. "PHM for Biomedical Analytics: A Case Study on Neurophysiologic Data from Patients with Traumatic Brain Injury". University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1490352193060328.

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7

Nyholm, Lena. "Quality systems to avoid secondary brain injury in neurointensive care". Doctoral thesis, Uppsala universitet, Neurokirurgi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-253005.

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Outcome after traumatic brain injury (TBI) depends on the extent of primary cell death and on the development of secondary brain injury. The general aim of this thesis was to find strategies and quality systems to minimize the extent of secondary insults in neurointensive care (NIC). An established standardized management protocol system, multimodality monitoring and computerized data collection, and analysis systems were used. The Uppsala TBI register was established for regular monitoring of NIC quality indexes. For 2008-2010 the proportion of patients improving during NIC was 60-80%, whereas 10% deteriorated. The percentage of ‘talk and die’ cases was < 1%. The occurrences of secondary insults were less than 5% of good monitoring time (GMT) for intracranial pressure (ICP) > 25 mmHg, cerebral perfusion pressure (CPP) < 50 mmHg and systolic blood pressure < 100 mmHg. Favorable outcome was achieved by 64% of adults. Nurse checklists of secondary insult occurrence were introduced. Evaluation of the use of nursing checklists showed that the nurses documented their assessments in 84-85% of the shifts and duration of monitoring time at insult level was significantly longer when secondary insults were reported regarding ICP, CPP and temperature. The use of nurse checklist was found to be feasible and accurate. A clinical tool to avoid secondary insults related to nursing interventions was developed. Secondary brain insults occurred in about 10% of nursing interventions. There were substantial variations between patients. The risk ratios of developing an ICP insult were 4.7 when baseline ICP ≥ 15 mmHg, 2.9 when ICP amplitude ≥ 6 mmHg and 1.7 when pressure autoregulation ≥ 0.3. Hyperthermia, which is a known frequent secondary insult, was studied. Hyperthermia was most common on Day 7 after admission and 90% of the TBI patients had hyperthermia during the first 10 days at the NIC unit. The effects of hyperthermia on intracranial dynamics (ICP, brain energy metabolism and BtipO2) were small but individual differences were observed. Hyperthermia increased ICP slightly more when temperature increased in the groups with low compliance and impaired pressure autoregulation. Ischemic pattern was never observed in the microdialysis samples. The treatment of hyperthermia may be individualized and guided by multimodality monitoring.

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8

Dodge, Lydia. "Investigating the effects of acute intracranial pressure and brain oxygenation on neuropsychological outcomes 12 months after severe pediatric traumatic brain injury". Master's thesis, Faculty of Humanities, 2019. http://hdl.handle.net/11427/30832.

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Traumatic brain injury (TBI) is one of the major causes of mortality and morbidity among children and adolescents all over the world and studies suggest a higher incidence of pediatric TBI (pTBI), as well as poorer post-TBI outcomes, in countries with extreme levels of socioeconomic inequality such as South Africa. pTBI leads to a multitude of long-term adverse outcomes in a wide range of domains and in general, a dose-response pattern is evident. Multiple acute and post-acute stage predictors of outcome have been investigated, however acute stage neurological and neurosurgical variables are relatively absent from this knowledge base. This study was conducted to better understand the heterogeneity in outcomes of pTBI: it aimed to investigate the nature and severity of neuropsychological deficits in pTBI patients one year after injury and to investigate the association between acute stage physiological changes in intracranial pressure (ICP) and brain tissue oxygenation (PbtO2) and neuropsychological outcomes one year after pTBI. Results of the study indicated that children who sustained TBI performed significantly poorer than healthy, matched controls on multiple cognitive, behavioural and quality of life domains, however, neither acute ICP nor PbtO2 reliably predicted within-TBI group performance. The results of the study emphasise the poor relationship of ICP and PbtO2, and the complexity of the relationship between acute physiological variables and outcomes after pTBI. Further studies of this kind should be done on large sample sizes and include multiple physiological variables.

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9

Tume, Lyvonne Nicole. "The effect of intensive care nursing interventions on the intracranial pressure in children with moderate to severe traumatic brain injury". Thesis, Liverpool John Moores University, 2009. http://researchonline.ljmu.ac.uk/5951/.

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Objective The aim of this study was to examine the effects of selected routine nursing interventions - endotracheal suctioning and manual ventilation (ETSMV), log-rolling, eye care, mouth care and washing - on the intracranial pressure (ICP) in children with traumatic brain injury. Design Prospective observational study over three years. Setting Single tertiary paediatric intensive care unit in the North West of England. Patients Twenty five children with moderate to severe closed traumatic brain injury and intraparenchymal intracranial pressure monitoring in intensive care (2 -17 years of age). Interventions Routine nursing care interventions. Measurements and main results ICP measured one minute before the procedure, at the maximal value during the procedure and five minutes after the procedure was recorded for the purpose of this study. Time to recovery was also recorded, in minutes. A total of 25 measurements (the first one in each child) in the first 36 hours of the child's PICU admission were analysed. Both ETSMV and log-rolling were associated with clinically and statistically significant changes in ICP from baseline to maximal ICP (p=0.005) and maximal to 5-minute post ICP (p=0.001) for ETSMV and (p < 0.001) baseline to maximal ICP and (p=0.002) for maximal to post-procedure ICP for log-rolling. During ETSMV and logrolling 70% of children exceeded the 20mmHg clinical treatment threshold during the interventions. During both ETSMV and log-rolling children with higher baseline ICPs ( > 15mmHg) showed higher maximal ICPs (but not ICP rise), suggesting a linear relationship between baseline and maximal ICP, although this was more pronounced during turning. One third of the children had not returned to their baseline ICP by 5 minutes after ETSMV, compared with 60% children after log-rolling. Neither eye care nor mouth care showed any clinically significant effects on ICP in these children, suggesting these procedures are not noxious and are tolerated very well. However, there was only a small number of washing episodes reported in this study therefore the observations are not conclusive. Conclusions Endotracheal suctioning and log-rolling in moderate to severe traumatic brain injured children can cause significant intracranial instability and should only be performed as required and with careful planning and execution. Eye and mouth care and washing appear to be well tolerated interventions and could be performed when necessary.

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10

Flynn, Liam Martin Clint. "Physiological responses to brain tissue hypoxia and blood flow after acute brain injury". Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31268.

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This thesis explores physiological changes occurring after acute brain injury. The first two chapters focus on traumatic brain injury (TBI), a significant cause of disability and death worldwide. I discuss the evidence behind current management of secondary brain injury with emphasis on partial brain oxygen tension (PbtO2) and intracranial pressure (ICP). The second chapter describes a subgroup analysis of the effect of hypothermia on ICP and PbtO2 in 17 patients enrolled to the Eurotherm3235 trial. There was a mean decrease in ICP of 4.1 mmHg (n=9, p < 0.02) and a mean decrease in PbtO2 (7.8 ± 3.1 mmHg (p < 0.05)) in the hypothermia group that was not present in controls. The findings support previous studies in demonstrating a decrease in ICP with hypothermia. Decreased PbtO2 could partially explain worse outcomes seen in the hypothermia group in the Eurotherm3235 trial. Further analysis of PbtO2 and ICP guided treatment is needed. The third chapter focuses on delayed cerebral ischaemia (DCI) after aneurysmal subarachnoid haemorrhage (aSAH), another form of acute brain injury that causes significant morbidity and mortality. I include a background of alpha-calcitonin gene-related peptide (αCGRP), a potential treatment of DCI, along with results from a systematic review and meta-analysis of nine experimental models investigating αCGRP. The meta-analysis demonstrates a 40.8 ± 8.2% increase in cerebral vessel diameter in those animals treated with αCGRP compared with controls (p < 0.0005, 95% CI 23.7 to 57.9). Neurobehavioural scores were reported in four publications and showed a Physiological responses to brain tissue hypoxia and blood flow after acute brain injury standardised mean difference of 1.31 in favour of αCGRP (CI -0.49 to 3.12). I conclude that αCGRP reduces cerebral vessel narrowing seen after SAH in animal studies but note that there is insufficient evidence to determine its effect on functional outcomes. A review of previous trials of αCGRP administration in humans is included, in addition to an original retrospective analysis of CSF concentrations of αCGRP in humans. Enzyme-linked immunosorbent assay of CSF (n = 22) was unable to detect αCGRP in any sample, which contrasts with previous studies and was likely secondary to study methodology. Finally, I summarise by discussing a protocol I designed for a dose-toxicity study involving the intraventricular administration of αCGRP to patients with aSAH and provide some recommendations for future research. This protocol was based upon the systematic review and was submitted to the Medical Research Council's DPFS funding stream during the PhD.

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11

Grinkevičiūtė, Dovilė. "Vaikų sunkios galvos smegenų traumos baigčių prognoziniai veiksniai". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080926_132024-82969.

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Atliktas perspektyvusis stebėjimo tyrimas, kurio metu buvo tirti sunkią galvos smegenų traumą patyrę vaikai, gydyti KMUK Vaikų intensyviosios terapijos skyriuje. Pacientų būklė pagal GBS vertinta išvykstant iš gydymo įstaigos ir po šešių mėnesių. Darbo tikslas Nustatyti sunkią galvos smegenų traumą patyrusių vaikų ligos baigčių prognozinius veiksnius. Darbo uždaviniai 1. Įvertinti ankstyvas ir vėlyvas sunkią galvos traumą patyrusių vaikų ligos baigtis. 2. Nustatyti sunkią galvos traumą patyrusių vaikų vidinio kaukolės slėgio ir smegenų perfuzinio slėgio ryšį su ligos baigtimis. 3. Nustatyti sunkią galvos traumą patyrusių vaikų traumos pobūdžio ryšį su ligos baigtimis. 4. Nustatyti paciento būkės vertinimo skalių ir laboratorinių tyrimų kritines reikšmes ir jų prognozinę vertę. 5. Nustatyti laboratorinių tyrimų kritines reikšmes ir jų prognozinę vertę. Išgyveno 80,5 proc. sunkią galvos smegenų traumą patyrusių vaikų. Išvykstant iš gydymo įstaigos 50 proc. pacientų, o po šešių mėnesių – 24,2 proc. pacientų traumos baigtis buvos bloga. Įtakos traumos baigtims turėjo kraujavimas po kietuoju smegenų dangalu, smegenų edema, kaukolės kaulų lūžiai. Nustatytos laktatų, gliukozės kiekio kraujo serume, vaikų traumų skalės, Glazgo komų skalės ir vaikų mirštamumo indekso 2 kritinės reikšmės, prognozuojančios mirtį, blogą baigtį išvykstant iš gydymo įstaigos ir po šešių mėnesių. Dekompresinė kraniotomija, atlikta, kai VKS = 24,5 mmHg,o SPS = 46.5 mmHg ligos baigčių nepakeitė.
The prospective observational study involved children after severe traumatic brain injury treated in Pediatric Intensive Care Unit of Kaunas University of Medicine Hospital. The outcome according to Glasgow Outcome Scale was assessed on discharge and after six months The aim of the study was to determine the prognostic factors in children after severe traumatic brain injury. The objectives of the study: 1. To evaluate early and late outcomes in children after severe traumatic brain injury 2. To evaluate the relation of intracranial pressure and cerebral perfusion pressure with outcome in children after severe traumatic brain injury. 3. To evaluate the relation between type of injury and outcome. 4. To determine the threshold values for trauma scoring scales and to evaluate their prognostic significance. 5. To determine the threshold values for laboratory findings and to evaluate their prognostic significance. The survival rate was 80.5 %.half of patients had bad outcome on discharge and 24.4 % – had bad outcome after six months. The prognostic factors of outcome for children after severe traumatic brain injury were subdural hemorrhage, cerebral edema and skull fracture. Threshold values of Pediatric Trauma Score, Glasgow Coma Score and Pediatric index of Mortality 2 for death and bad outcomes on discharge and after six months were ascertained. Decompressive craniectomy performed at ICP ≥ 24.5 mmHg, CPP ≤ 46.5 mmHg had no impact on outcome in children after severe traumatic... [to full text]

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12

Li, Xiaogai. "Finite Element and Neuroimaging Techniques toImprove Decision-Making in Clinical Neuroscience". Doctoral thesis, KTH, Neuronik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-72345.

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Our brain, perhaps the most sophisticated and mysterious part of the human body, to some extent, determines who we are. However, it’s a vulnerable organ. When subjected to an impact, such as a traffic accident or sport, it may lead to traumatic brain injury (TBI) which can have devastating effects for those who suffer the injury. Despite lots of efforts have been put into primary injury prevention, the number of TBIs is still on an unacceptable high level in a global perspective. Brain edema is a major neurological complication of moderate and severe TBI, which consists of an abnormal accumulation of fluid within the brain parenchyma. Clinically, local and minor edema may be treated conservatively only by observation, where the treatment of choice usually follows evidence-based practice. In the first study, the gravitational force is suggested to have a significant impact on the pressure of the edema zone in the brain tissue. Thus, the objective of the study was to investigate the significance of head position on edema at the posterior part of the brain using a Finite Element (FE) model. The model revealed that water content (WC) increment at the edema zone remained nearly identical for both supine and prone positions. However, the interstitial fluid pressure (IFP) inside the edema zone decreased around 15% by having the head in a prone position compared with a supine position. The decrease of IFP inside the edema zone by changing patient position from supine to prone has the potential to alleviate the damage to axonal fibers of the central nervous system. These observations suggest that considering the patient’s head position during intensive care and at rehabilitation should be of importance to the treatment of edematous regions in TBI patients. In TBI patients with diffuse brain edema, for most severe cases with refractory intracranial hypertension, decompressive craniotomy (DC) is performed as an ultimate therapy. However, a complete consensus on its effectiveness has not been achieved due to the high levels of severe disability and persistent vegetative state found in the patients treated with DC. DC allows expansion of the swollen brain outside the skull, thereby having the potential in reducing the Intracranial Pressure (ICP). However, the treatment causes stretching of the axons and may contribute to the unfavorable outcome of the patients. The second study aimed at quantifying the stretching and WC in the brain tissue due to the neurosurgical intervention to provide more insight into the effects upon such a treatment. A nonlinear registration method was used to quantify the strain. Our analysis showed a substantial increase of the strain level in the brain tissue close to the treated side of DC compared to before the treatment. Also, the WC was related to specific gravity (SG), which in turn was related to the Hounsfield unit (HU) value in the Computerized Tomography (CT) images by a photoelectric correction according to the chemical composition of the brain tissue. The overall WC of brain tissue presented a significant increase after the treatment compared to the condition seen before the treatment. It is suggested that a quantitative model, which characterizes the stretching and WC of the brain tissue both before as well as after DC, may clarify some of the potential problems with such a treatment. Diffusion Weighted (DW) Imaging technology provides a noninvasive way to extract axonal fiber tracts in the brain. The aim of the third study, as an extension to the second study was to assess and quantify the axonal deformation (i.e. stretching and shearing)at both the pre- and post-craniotomy periods in order to provide more insight into the mechanical effects on the axonal fibers due to DC. Subarachnoid injection of artificial cerebrospinal fluid (CSF) into the CSF system is widely used in neurological practice to gain information on CSF dynamics. Mathematical models are important for a better understanding of the underlying mechanisms. Despite the critical importance of the parameters for accurate modeling, there is a substantial variation in the poroelastic constants used in the literature due to the difficulties in determining material properties of brain tissue. In the fourth study, we developed a Finite Element (FE) model including the whole brain-CSF-skull system to study the CSF dynamics during constant-rate infusion. We investigated the capacity of the current model to predict the steady state of the mean ICP. For transient analysis, rather than accurately fit the infusion curve to the experimental data, we placed more emphasis on studying the influences of each of the poroelastic parameters due to the aforementioned inconsistency in the poroelastic constants for brain tissue. It was found that the value of the specific storage term S_epsilon is the dominant factor that influences the infusion curve, and the drained Young’s modulus E was identified as the dominant parameter second to S_epsilon. Based on the simulated infusion curves from the FE model, Artificial Neural Network (ANN) was used to find an optimized parameter set that best fit the experimental curve. The infusion curves from both the FE simulations and using ANN confirmed the limitation of linear poroelasticity in modeling the transient constant-rate infusion. To summarize, the work done in this thesis is to introduce FE Modeling and imaging technologiesincluding CT, DW imaging, and image registration method as a complementarytechnique for clinical diagnosis and treatment of TBI patients. Hopefully, the result mayto some extent improve the understanding of these clinical problems and improve theirmedical treatments.
QC 20120201

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13

Kroppenstedt, Stefan Nikolaus. "Die Bedeutung des zerebralen Perfusionsdruckes in der Behandlung des schweren Schädel-Hirn-Traumes". Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2003. http://dx.doi.org/10.18452/13898.

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Die Höhe des optimalen zerebralen Perfusionsdruckes nach schwerem Schädel-Hirn-Trauma wird kontrovers diskutiert. Während im sogenannten Lund-Konzept ein niedriger Perfusionsdruck angestrebt und die Gabe von Katecholaminen aufgrund potentieller zerebraler vasokonstringierender und weiterer Nebeneffekte vermieden wird, befürwortet das CPP-Konzept nach Rosner eine Anhebung des zerebralen Perfusionsdruckes, wenn notwendig unter intravenöser Gabe von Katecholaminen. Vor diesem Hintergrund galt es, in einem experimentellen Schädel-Hirn-Trauma- Modell der Ratte (Controlled Cortical Impact Injury) den Bereich des optimalen zerebralen Perfusionsdruckes nach traumatischer Hirnkontusion zu ermitteln und den Effekt von Katecholaminen auf den posttraumatischen zerebralen Blutfluss und die Entwicklung des sekundären Hirnschadens zu untersuchen. Die wesentlichen Ergebnisse dieser Arbeit lassen sich wie folgt zusammenfassen: In der Akutphase nach Hirnkontusion liegt der Bereich des zerebralen Perfusionsdruckes, welcher die Entwicklung des Kontusionsvolumens nicht beeinflusst, zwischen 70 und 105 mm Hg. Eine Senkung des Perfusionsdruckes unterhalb bzw. Anhebung oberhalb dieser Schwellenwerte vergrößert das Kontusionsvolumen. Die Anhebung des Blutdruckes mittels intravenöser Infusion von Dopamin oder Noradrenalin führt sowohl in der Frühphase als auch in der Spätphase nach Trauma (4 Stunden bzw. 24 Stunden nach kortikaler Kontusion) zu einem signifikanten Anstieg im kortikalen perikontusionellen Blutfluss und in der Hirngewebe-Oxygenierung. Die durch Anhebung des zerebralen Perfusionsdruckes auf über 70 mm Hg induzierte Verbesserung des posttraumatischen zerebralen Blutflusses bewirkte jedoch keine Reduzierung der Hirnschwellung. Für eine Katecholamin-induzierte zerebrale Vasokonstriktion nach kortikaler Kontusion gibt es keinen Anhalt. Um die Entwicklung des sekundären Hirnschadens nach kortikaler Kontusion zu minimieren, sollte der zerebrale Perfusionsdruck nach traumatischem Hirnschaden nicht unterhalb 70 mm Hg liegen. Eine Anhebung des Perfusionsdruckes auf über 70 mm Hg erscheint nicht notwendig oder vorteilhaft zu sein. Wenn notwendig, kann sowohl in der Früh- als auch Spätphase nach Trauma der zerebrale Perfusionsdruck mittels intravenöser Gabe von Katecholaminen angehoben werden.
The optimum cerebral perfusion pressure after severe traumatic brain injury remains to be controversial. In the Lund concept a relatively low cerebral perfusion pressure is preferred, and administration of catecholamines is avoided due to potential catecholamine-mediated cerebral vasoconstriction and other side effects. In contrast, the CPP concept of Rosner recommends elevation of cerebral perfusion pressure, if needed by intravenous administration of catecholamines. Based on this, in an experimental model of traumatic brain injury of the rat (Controlled Cortical Impact Injury) the optimum range of cerebral perfusion pressure after traumatic brain contusion and the effects of catecholamines on posttraumatic cerebral perfusion and development of secondary brain injury were investigated. The most significant results can be summarized as follows: In the acute phase after brain contusion the range of cerebral perfusion pressure that does not affect the development of posttraumatic contusion volume was found to be between 70 and 105 mm Hg. Reduction of the cerebral perfusion pressure below or elevation above these thresholds increases contusion volume. Elevation of blood pressure by intravenous infusion of dopamine or norepinephrine during the early (4 hours) as well as late (24 hours) phase after trauma results in a significant increase in pericontusional blood flow and brain tissue oxygenation. The increase in cerebral blood flow by elevating cerebral perfusion pressure above 70 mm Hg did not decrease cerebral edema formation. There was no evidence of a catecholamine-induced cerebral vasoconstriction after cortical contusion. In order to minimize secondary brain injury after cortical contusion, cerebral perfusion pressure should not fall bellow 70 mm Hg. However, a further active elevation of cerebral perfusion pressure does not appear necessary or beneficial. If needed cerebral perfusion pressure can be elevated by administration of catecholamines in the early as well late phase after trauma.

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14

Rodling, Wahlström Marie. "Severe cerebral emergency : aspects of treatment and outcome in the intensive care patient". Doctoral thesis, Umeå universitet, Anestesiologi och intensivvård, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-21065.

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Severe Traumatic Brain Injury (TBI) and aneurysmal Subarachnoid Hemorrhage (SAH) are severe cerebral emergencies. They are common reasons for extensive morbidity and mortality in young people and adults in the western world. This thesis, based on five clinical studies in patients with severe TBI (I-IV) and SAH (V), is concentrated on examination of pathophysiological developments and of evaluation of therapeutic approaches in order to improve outcome after cerebral emergency. The treatment for severe TBI patients at Umeå University Hospital, Sweden is an intracranial pressure (ICP)-targeted therapy according to “the Lund-concept”. This therapy is based on physiological principles for cerebral volume regulation, in order to preserve a normal cerebral microcirculation and a normal ICP. The main goal is to avoid development of secondary brain injuries, thus avoiding brain oedema and worsened microcirculation. Study I is evaluating retrospectively 41 children with severe TBI, from 1993 to 2002. The boundaries of the ICP-targeted protocol were obtained in 90%. Survival rate was 93%, and favourable outcome (Glasgow Outcome Scale, score 4+5) was 80%. Study II is retrospectively analysing fluid administration and fluid balance in 93 adult patients with severe TBI, from 1998 to 2001.The ICP-targeted therapy used, have defined fluid strategies. The total fluid balance was positive day one to three, and negative day four to ten. Colloids constituted 40-60% of total fluids given/day. Severe organ failure was evident for respiratory insufficiency and observed in 29%. Mortality within 28 days was 11%. Study III is a prospective, randomised, double-blind, placebo-controlled clinical trial in 48 patients with severe TBI. In order to improve microcirculation and prevent oedema formation, prostacyclin treatment was added to the ICP-targeted therapy. Prostacyclin is endogenously produced, by the vascular endothelium, and has the ability to decrease capillary permeability and vasodilate cerebral capillaries. Prostacyclin is an inhibitor of leukocyte adhesion and platelet aggregation. There was no significant difference between prostacyclin or placebo groups in clinical outcome or in cerebral microdialysis markers such as lactatepyruvate ratio and brain glucose levels. Study IV is part of the third trial and focus on the systemic release of pro-inflammatory mediators that are rapidly activated by trauma. The systemically released pro-inflammatory mediators, interleukin-6 and CRP were significantly decreased in the prostacyclin group versus the placebo group. Study V is a prospective pilot study which analyses asymmetric dimethylarginine (ADMA) concentrations in serum from SAH patients. Acute SAH patients have cerebral vascular, systemic circulatory and inflammatory complications. ADMA is a marker in vascular diseases which is correlated to endothelial dysfunction. ADMA concentrations in serum were significantly elevated seven days after the SAH compared to admission and were still elevated at the three months follow-up. Our results show overall low mortality and high favourable outcome compared to international reports on outcome in severe TBI patients. Prostacyclin administration does not improve cerebral metabolism or outcome but significantly decreases the levels of pro-inflammatory mediators. SAH seems to induce long-lasting elevations of ADMA in serum, which indicates persistent endothelial dysfunction. Endothelial dysfunction may influence outcome after severe cerebral emergencies.

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15

Salci, Konstantin. "Intracranial Compliance and Secondary Brain Damage. Experimental and Clinical Studies in Traumatic Head Injury". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7214.

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16

Kirkness, Catherine Jean. "Complexity as an indicator of cerebrovascular adaptive capacity in individuals with acute brain injury /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/7218.

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17

Bobinski, Lukas. "On evolution of intracranial changes after severe traumatic brain injury and its impact on clinical outcome". Doctoral thesis, Umeå universitet, Klinisk neurovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-124069.

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Severe traumatic brain injury (sTBI) is a cause of death and disability worldwide and requires treatment at specialized neuro-intensive care units (NICU) with a multimodal monitoring approach. The CT scan imaging supports the monitoring and diagnostics. The level of S100B and neuron specific enolase (NSE) reflects the severity of the injury. The therapy resistant intracranial hypertension requires decompressive craniectomy (DC). After DC, the cranium must be reconstructed to recreate the normal intracranial physiology as well as to address cosmetic issues. The evolution of the pathological intracranial changes was analyzed in accordance with the three CT classifications: Marshall, Rotterdam and Morris-Marshall. The Rotterdam scale was best in describing the dynamics of the pathological evolution. Both the Rotterdam score and Morris- Marshall classification showed strong correlation with the clinical outcome, a finding that suggests that they could be used for prognostication. We demonstrated a clear correlation between the CT classifications and concentrations of S100B and NSE. The results revealed a concomitant correlation between NSE and S100B and clinical outcome. We found that the interaction between the ICP, Rotterdam CT classification, and concentrations of biochemical biomarkers are all associated with DC. We found a high percentage of complications following cranioplasty. Our results call into question whether custom-made allograft should be considered the best material for cranioplasty. It is concluded that both the Rotterdam and Morris-Marshall classification contribute to clinical evaluation of intracranial dynamics after sTBI, and might be used in combination with biochemical biomarkers for better assessment. The decision to perform DC should include a re-assesment of ICP evolution, CT scan images and concentration of the biochemical biomarkers. Furthermore, when determining whether DC treatment should be used, surgeon should also consider the risks of the following cranioplasty.

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18

Stahel, Philip F. [Verfasser]. "Neuroinflammation in traumatic brain injury – the role of cytokines, chemokines, and intracranial complement activation. / Philip F Stahel". Aachen : Shaker, 2005. http://d-nb.info/1186582006/34.

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19

Andrews, Peter John Dawson. "An assessment of the systematic effects and the intracranial effects of intensive care manoeuvres following traumatic brain injury". Thesis, University of Aberdeen, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335660.

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Introduction. During the intensive care of patients with traumatic brain injury, intracranial pressure and arterial pressure are commonly measured to derive cerebral perfusion pressure. The assumption is that provided cerebral perfusion pressure is maintained within normal limits cerebral blood flow will autoregulate and therefore meet cerebral metabolic demand. In this thesis cerebral perfusion pressure and cerebral venous oxyhaemoglobin saturation (SjO2) data are presented. The latter indicates the balance between cerebral blood flow and metabolism and therefore adequacy of cerebral oxygen delivery. Methods. Fibre optic technology makes continuous measurement of oxyhaemoglobin saturation possible, however the equipmenthad not been assessed in the jugular bulb. After assessment of the device, a cohort of brain injured patients with a Glasgow Coma Score (GCS) of less than 13 and/or an Injury Severity Score (ISS) of greater than 16 were studied before, during and after intrahospital transport. 10 patients with a GCS of 8 or less, without eye opening, were studied after the administration of the intravenous anaesthetics, Thiopentone and Propofol. Physiological variables were recorded every minute by a personal computer and abnormal values (insults) graded on an increasing three point scale. Results. After in vivo calibration the Oximetrix 3 and Opticath 40cm catheter demonstrated clinically satisfactory agreement when compared with in vitro reflection oximetry, mean difference 0.85% (95% confidence interval -4.5% to 5.2%). Abnormal physiology before intrahospital transport was predictive of further insults during and after transport. An increase in the frequency of insults was seen, that was associated with an increasing ISS (P< 0.01). Slow infusion of intravenous anaesthetic agent was superior to rapid infusion. Propofol, by slow infusion, produced a more sustained reduction of intracranial pressure and a higher cerebral venous oxyhaemoglobin saturation. However Thiopentone produced a higher cerebral perfusion pressure.

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20

Dennis, Kadeem. "Mechanical Modification of Cells by Pressure Waves and Its Application to Traumatic Brain Injury". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/34067.

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Recently there has been interest in determining what happens to the human brain during a traumatic brain injury (TBI). The blast wave created by explosive devices, such as landmines, is one of the most common causes of TBI. The purpose of this study is to investigate the link between an explosion and a cells reaction to a blast wave on a time scale of a few hours. Three different types of cells were tested by pressure waves exposure, fibroblasts (3T3), epithelial cervical cancer (HeLa), and canine epithelial kidney cells (MDCK). Fluorescent images of the cells before and after pressure wave exposure were used to determine how much damage cells have suffered. 3T3 cells showed the most cellular modification while HeLa and MDCK were more resilient. A simple scaling model is proposed to relate the cellular modification to the shock strength.

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21

Johnson, Ulf. "Pressure autoregulation of cerebral blood flow in traumatic brain injury and aneurysmal subarachnoid hemorrhage". Doctoral thesis, Uppsala universitet, Neurokirurgi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-294190.

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The ability of the brain to keep a stable and adequate cerebral blood flow (CBF) independently of fluctuations in systemic blood pressure is referred to as cerebral pressure autoregulation (CPA). When the brain is injured by trauma or hemorrhage, this ability may be impaired, leaving the brain vulnerable to events of high or low blood pressure. The aims of this thesis were to study CPA in patients with severe traumatic brain injury (TBI) or subarachnoid hemorrhage (SAH), the relation between CPA and other physiological parameters, and the influence of CPA on outcome. Four retrospective studies are included in the thesis. All patients were treated at the neurointensive care unit, Uppsala University hospital. In paper I, 58 TBI patients were studied. In patients with impaired CPA, cerebral perfusion pressure between 50-60 mm Hg was associated with favorable outcome while CPP > 70 and >80 mm Hg was associated with unfavorable outcome. In patients with intact CPA there was no association between CPP and outcome. In paper II, 107 TBI patients were studied. High CPP was associated with unfavorable outcome in patients with focal injuries. In patients with diffuse injury and impaired CPA, CPP > 70 mm Hg was associated with favorable outcome. In paper III, 47 SAH patients were studied. CBF was measured bedside with Xenon-enhance CT (Xe-CT). Patients with impaired CPA had lower CBF, both in the early (day 0-3) and late (day 4-14) acute phase of the disease. In paper IV, 64 SAH patients were studied. Optimal CPP (CPPopt) was calculated automatically as the level of CPP where CPA works best for the patient, i.e., where PRx is lowest. Patients with actual CPP below their calculated optimum had higher amounts of low-flow regions (CBF < 10 ml/100g/min). The findings in this thesis emphasize the importance of taking CPA into account in the management of TBI and SAH patients, and suggest that treatment should be individualized depending on status of autoregulation. PRx and CPPopt may be used bedside to guide management according to status of autoregulation. In the future CPA-guided management should be tested in prospective studies

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Walters-Stewart, Coren Tiffany. "Non-linear Centre of Pressure Analysis During Quiet Stance: Application to Mild Traumatic Brain Injury". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36039.

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A quiet stance framework and a control system perspective were used to explore healthy balance and balance after mild traumatic brain injury. Linear and non-linear centre of pressure analyses were applied. The foundation was laid by reviewing literature to understand how balance is achieved, how it is represented as a control system, what factors are known to affect balance, and the cornerstone—how to choose appropriate measures to quantify balance. To understand how mild traumatic brain injury affects the brain, a scoping review of the evolution of symptoms and effects was used to form a conceptual description. Findings described phases of functional effects that resulted from neurometabolic cascade; consequently, balance and dual-task functional effects were determined to stem from widespread not focal changes in the brain. Subsequent studies were tailored to address gaps in knowledge. Linear and non-linear centre of pressure measures were first investigated in healthy young adults to determine what supplemental information could be provided by non-linear measures describing local stability and scaling. It was found that linear and non-linear measures were complementary in assessing balance system input-output, control, and integration. Furthermore, normative non-linear data were established for single leg and tandem stance. Subsequently, these measures were investigated in young adults and adolescents with recent mild traumatic brain injury based on the hypothesis that altered mechanisms affecting balance would be reflected by changes in these measures. In young adults, increased complexity of short-term scaling indicated subtle changes to balance control after injury. In adolescents, linear and non-linear measures also demonstrated changes to output, control, and temporal relations of balance. Altered balance was also demonstrated while concurrently performing a Stroop task. On the whole, changes to multiple aspects of balance supported the concept of widespread effects resulting from mild traumatic brain injury. Balance control in quiet stance was further explored using three-dimensional state space reconstruction of centre of pressure. Visual representations demonstrated that dynamic structure within centre of pressure reflected control characteristics. These control characteristics were still present after mild traumatic brain injury.

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23

Assari, Soroush. "BLAST-INDUCED CEREBROVASCULAR AND BRAIN INJURY: THE THORACIC MECHANISM". Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/480107.

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Mechanical Engineering
Ph.D.
The focus of this dissertation was the biomechanics of blast-induced traumatic brain injury (bTBI). This study had three specific aims. One of the specific aims was to investigate the thoracic mechanism of bTBI by characterizing the cerebral blood pressure change during local blast exposure to head or chest in a rat model. This model utilized a shock tube to simulate the blast wave. The results showed that there is a blood pressure rise with high amplitude and short duration during both Head-Only and Chest-Only exposure conditions. It was shown that cerebral blood pressure rise was significantly higher in Chest-Only exposure, and resulted in astrocyte reactivation, and infiltration of blood-borne macrophages into the brain. It was concluded that due to chest exposure to a blast wave, high amplitude pressure waves that transfer from thoracic large vessels to cerebrovasculature can lead to blood-brain barrier disruption or perivascular injury and consequently trigger secondary neuronal damage. The second and third aims were related to the viscoelasticity and heterogeneity of brain tissue respectively for blast rate loading conditions. For the second specific aim, a novel test method was developed to apply shear deformation to samples of brain tissue with strain rates in the range of 300 to 1000 s-1. The results of shear tests on cylindrical samples of bovine brain showed that the instantaneous shear modulus (about 6 kPa) increased about 3 times compared to the values reported in the literature. For the third specific aim, local viscoelastic behavior of rat brain was characterized using a micro-indentation setup with the spatial resolution of 350 mm. The results of micro-indentation tests showed that the heterogeneity of brain tissue was more pronounced in long-term shear moduli. Moreover, the inner anatomical regions were generally more compliant than the outer regions and the gray matter generally exhibited a stiffer response than the white matter. The results of this study can enhance the prediction of brain injury in finite element models of TBI in general and models of bTBI in particular. These results contribute to development of more biofidelic models that can determine the extent and severity of injury in blast loadings. Such predictions are essential for designing better injury mitigation devices for soldiers and also for improving neurosurgical procedures among other applications.
Temple University--Theses

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24

Samuelsson, Carolina. "Glutamate Turnover and Energy Metabolism in Brain Injury : Clinical and Experimental Studies". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8630.

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25

Olivecrona, Magnus. "On severe traumatic brain injury : aspects of an intra cranial pressure-targeted therapy based on the Lund concept". Doctoral thesis, Umeå universitet, Farmakologi och klinisk neurovetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1908.

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Severe Traumatic Brain Injury (sTBI) is a major cause of mortality and morbidity. At the Department of Neurosurgery Umeå University Hospital subjects with sTBI are treated with an intracranial pressure (ICP) guided therapy based on physiological principles, aiming to optimise the microcirculation of the brain so avoiding secondary brain injuries. The investigations in this thesis are unique in the sense that all patients with sTBI were treated according to the guidelines of an ICP targeted therapy based on the “Lund concept”. As the treatment is based on normalisation of the ICP, the accuracy and reliability of the measuring device is of outmost importance. Therefore the accuracy, drift, and complications related to the measuring device was prospectively studied (n=128). The drift was 0,9 ± 0,2 mmHg during a mean of 7,2 ± 0,4 days and the accuracy high. No clinical significant complications were noted. In 1997 uni- or bilateral decompressive hemi-craniectomy (DC) was introduced into the treatment guidelines. The effect of DC on the ICP and outcome was retrospectively analysed for subjects with sTBI treated 1998-2001. In the subjects who underwent DC the ICP was 36,4 mmHg immediately before and 12,6 mmHg immediately after the DC. The ICP then levelled out at just above 20 mmHg. The ICP was significant lower during the 72 hours following DC. The outcome did not differ between subjects who had undergone DC or not. Subclinical electroencephalographic seizures and status epilepticus have been reported to be common in subjects treated for traumatic brain injury (TBI). This can negatively influence the outcome giving rise to secondary brain injuries. The occurrence of seizures in subjects treated for TBI using continuous EEG monitoring was therefore prospectively studied. During 7334 hours of EEG recording in 47 patients no electroencephalographic seizures were observed. Theoretically, and based on animal studies, prostacyclin (PGI2) can improve the microcirculation of the brain, decreasing the risk for secondary ischaemic brain injury. PGI2 was introduced to the treatment in a prospective randomised double blinded study (epoprostenol 0,5 ng/kg/min). The effect of PGI1 pkt was analysed using the lactate/pyruvate ratio (L/P) measured by cerebral microdialysis in order to study the energy metabolism in the brain. The outcome was measured as Glasgow Outcome Scale (GOS) at 3 months follow-up. Forty-eight subjects were included. The L/P was pathological high during the first day, thereafter decreasing. There was no significant difference in L/P or outcome between the treated and non-treated group. At 3 months the mortality was 12,5% (95,8% was discharged alive from the ICU), and favourable outcome (GOS 4-5) was 52%. In the same study the brain injury biomarkers S-100B and NSE were followed twice a day for five days to evaluate brain injury and investigate the possible use of these biomarkers for outcome prediction. Initially the biomarkers were elevated to pathological levels which decreased over time. The biomarkers were significant elevated in subjects with Glasgow Coma Scale 3 (GCS) and GOS 1 compared with subjects with GCS 4-8 and GOS 2–5, respectively. A correlation to outcome was found but this correlation could not be used to predict clinical outcome. It is concluded that the ICP measurements are valid and the treatment protocol is a safe and solid protocol, yielding among the best reported results in the world, in regard to favourable outcome as well as in regard to mortality. Epoprostenol in the given dose was not shown to have any effects on the microdialysis parameters nor the clinical outcome. In sTBI L/P and brain injury biomarkers can not be used to predict the final outcome.

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Lindgren, Christina, e Jenny Reimers. "Identifiering och omvårdnadsåtgärder vid intrakraniell hypertension. En observationsstudie". Thesis, Uppsala universitet, Institutionen för folkhälso- och vårdvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-255684.

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SAMMANFATTNING Bakgrund Traumatisk skallskada drabbar relativt många och leder till personligt lidande och finansiell belastning för individ och samhälle då majoriteten får en svår till medelsvår funktionsnedsättning efter vårdtiden. På 1970-talet påvisades ett signifikant samband mellan högt ICP och sekundära hjärnskador. I studier där ICP >20 mmHg har förekommit kunde signifikant sämre utfall ses. Syfte Syftet med studien var att med hjälp av omvårdnadsprocessen observera intensivvårdssjuksköterskans identifiering och vidtagande av omvårdnadsåtgärder vid ett högt ICP samt utvärdera de utförda omvårdnadsåtgärderna. Metod Prospektiv tvärsnittsundersökning, där sju intensivvårdssjuksköterskor och fem patienter observerades med hjälp av ett observationsformulär. Resultat 51(73 %) av de höga ICP normaliserades inom en minut och intensivvårdssjuksköterskan uppskattades ha observerat högt ICP i 50(71 %) av tillfällena inom en minut. 19(27 %) tillfällen observerades inte och 11(65 %) av omvårdnadsåtgärderna skedde inom en minut. Omvårdnadsåtgärder som utfördes var administrering av bolusdos med läkemedel (35 %) eller dränera likvor (35 %). Efter utförd omvårdnadsåtgärd normaliserades högt ICP inom en till två minuter, 7(41 %), och 4(24 %) normaliserades inom två till tre minuter. Slutsats Majoriteten av tillfällena med högt ICP uppmärksammades inom en minut och vanligast förkommande omvårdnadsåtgärderna var administrering av bolusdos sederande läkemedel eller dränera likvor. Av de tillfällen med intrakraniell hypertension som inte blev observerade var enbart ett par tillfällen ihållande i längre än en minut och samtliga normaliserades spontant inom två minuter. Intensivvårdssjuksköterskorna identifierade och effektivt åtgärdade intrakraniell hypertension snabbt, vilket kan bidra till ett bättre utfall för patienterna.
ABSTRACT Background Due to traumatic brain injury a financial burden is placed on the individual as well as the society and personal suffering also occurs. A significant correlation between elevated ICP and secondary injury was found in the 1970s. Significantly worse outcome was found in a numerous of studies where ICP >20mmHg occurred. Objective The aim of this study was to observe intensive care nurses nursing interventions and its efficiency to decrease ICP by using Orem’s Self-care deficit theory. Methods A prospective observational study. Seven intensive care nurses and five patients were observed. Results 51(73%) of the observed ICP >20mmHg were normalized within the minute. The intensive care nurses were estimated to have observed an on-going intracranial hypertension in 50(71 %) within the minute. 19(27 %) went unnoticed and 11(65 %) of the nursing interventions were executed within the minute. Nursing interventions executed were administration of a sedative (35 %), drainage of cerebrospinal fluid (35 %). Elevated ICP was normalized in 7(41 %) within two minutes and 4(24 %) within three minutes due to the nursing intervention. Conclusion Intensive care nurses noticed the majority of occasions with elevated ICP within one minute. The most commonly used nursing intervention was to administrate a sedative or to drain cerebrospinal fluid. All of the elevated ICP that went unnoticed normalized spontaneously within two minutes. The fast identification of and treated intracranial hypertension are likely to have contributed positively in the patient’s outcome.

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Pokela, M. (Matti). "Predictors of brain injury after experimental hypothermic circulatory arrest:an experimental study using a chronic porcine model". Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:951427105X.

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Abstract There is a lack of reliable methods of evaluation of brain ischemic injury in patients undergoing cardiac surgery. The present study was, therefore, planned to evaluate whether serum S100β protein (I), brain cortical microdialysis (II), intracranial pressure (III) and electroencephalography (EEG) (IV) are predictive of postoperative death and brain ischemic injury in an experimental surviving porcine model of hypothermic circulatory arrest (HCA). One hundred and twenty eight (128) female, juvenile (8 to 10 weeks of age) pigs of native stock, weighing 21.0 to 38.2 kg, underwent cardio-pulmonary bypass prior to, and following, a 75-minute period of HCA at a brain temperature of 18°C. During the operation, hemodynamic, electrocardiograph and temperature monitoring was performed continuously. Furthermore, metabolic parameters were monitored at baseline, end of cooling, at intervals of two, four and eight hours after HCA and before extubation. Electroencephalographic recording was performed in all animals, serum S100β protein measurement in 18 animals, cortical microdialysis in 109 animals, and intracranial pressure monitoring in 58 animals. After the operation, assessment of behavior was made on a daily basis until death or elective sacrifice on the seventh postoperative day. All four studies showed that these parameters were predictive of postoperative outcome. Animals with severe histopathological injury had higher serum S100β protein levels at every time interval after HCA. Analysis of cortical brain microdialysis showed that the lactate/glucose ratio was significantly lower and the brain glucose concentration significantly higher among survivors during the early postoperative hours. Intracranial pressure increased significantly after 75 minutes of HCA, and this was associated with a significantly increased risk of postoperative death and brain infarction. A slower recovery of EEG burst percentage after HCA was significantly associated with the development of severe cerebral cortex, brain stem and cerebellum ischemic injury. In conclusion, serum S100β protein proved to be a reliable marker of brain ischemic injury as assessed on histopathological examination. Cerebral microdialysis is a useful method of cerebral monitoring during experimental HCA. Low brain glucose concentrations and high brain lactate/ glucose ratios after HCA are strong predictors of postoperative death. Increased intracranial pressure severely affected the postoperative outcome and may be a potential target for treatment. EEG burst percentage as a sum effect of anesthetic agent and ischemic brain damage is a useful tool for early prediction of severe brain damage after HCA. Among these monitoring methods, brain cortical microdialysis seems to be the most powerful one in predicting brain injury after experimental hypothermic circulatory arrest.

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Patel, Maryam. "Cerebral autoregulation in children with traumatic brain injury: Comparing the autoregulatory index (ARI) to pressure reactivity index (PRx) and their associations with cerebral physiological parameters". Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27399.

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As an important hemodynamic mechanism, pressure autoregulation protects the brain against inappropriate fluctuations in cerebral blood flow subject to changing cerebral perfusion pressures. In acute neurological illnesses, including traumatic brain injury in children, impaired autoregulation is associated with a worse prognosis. It also has important clinical implications for managing blood pressure and intracranial pressure. Two common methods of measuring pressure autoregulation reported in the adult literature have been rarely reported in children. This pilot study aimed to examine the relationship between two autoregulatory indices, namely PRx (pressure reactivity index) and ARI (autoregulatory index) in children with severe TBI. The study also examined their relationship with the response of clinically relevant variables such as intracranial pressure (ICP), brain oxygenation (PbtO2) and local cerebral blood flow (loCBF) to dynamic testing. The study is a retrospective cohort study of prospectively collected data conducted at the Red Cross Children Hospital. We analyzed the results of 18 patients in 28 tests of autoregulation to determine the static state of autoregulation by calculating the autoregulatory index (ARI). These tests were done by controlled elevation of blood pressure to evaluate changes in transcranial Doppler-derived flow velocity of the middle cerebral artery. Concomitant recordings were made of ICP, PbtO2, and loCBF. Secondly, we also calculated the PRx as a moving correlation co-efficient between slow changes in blood pressure and ICP. Two time epochs of PRx were examined in relation to the static tests: 1 hour before and after the test, and 12 hours before and after the test. The results included 28 tests done for ARI and 27 calculations for PRx epochs; all tests had ICP and PbtO2 data and 23 had loCBF. PRx and ARI showed no significant relationship between them. However, there was a significant relationship between ARI and ΔICP (p=0.04), i.e. when autoregulation was weak the change in ICP with a change in blood pressure was greater; and between PRx and ΔPbtO2 (p=0.04). There was a trend in correlation analysis between loCBF and PRx but not in the linear mixed effects model In conclusion, the study showed no correlation between the two autoregulatory indices, PRx and ARI, probably because they assess different aspects of autoregulation. However, significant relationships exist between ARI and ΔICP as well as PRx and ΔPbtO2, which generate interesting hypotheses about autoregulation and have clinical implications. Both autoregulatory indices have benefits and limitations. Further studies on such relationships, taking into consideration a larger sample group, inclusion of unstable patients, and utilization of the same range in BP for calculating the indices, are recommended.

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Amato, Damian P. "Animal models for intracranial pressure monitoring in traumatic brain injury". Thesis, 2010. http://hdl.handle.net/2440/65143.

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The aim of this study was to identify appropriate animal models of raised intracranial pressure (ICP) and brain tissue oxygenation (P[subscript]btO₂) following traumatic brain injury (TBI) that would be suitable for the development of novel therapies for secondary brain injury. Monitoring of ICP and P[subscript]btO₂ are important for understanding the effects of altered cerebral perfusion pressure (CPP). Tissue oxygenation is determined by the interaction of these variables and is important in the prevention of secondary injury following TBI. Unfortunately, few animal models reproduce the ICP and P[subscript]btO₂ response that has been observed in the human condition. Previous studies at the University of Adelaide have used an ovine model of TBI in which the neuropathological response in these animals accurately mimics human TBI. However functional studies using sheep, at present are problematic. Development of an alternative small animal model with scope for functional studies would assist with development of clinical therapies. Aside from rats, which do not exhibit profound increases in ICP without the presence of a significant mass lesion, guinea pigs have been successfully used previously in studies of TBI. We therefore compared the ICP and P[subscript]btO₂ response in guinea pigs with those of sheep. Compared to sheep, the guinea pig proved unsuitable for the study of ICP. Their labile response to inhalational anaesthesia, which included significant hypotension and bradycardia, was a confounding factor. With careful review and alteration to the anaesthetic regime, this problem was reduced, albeit that reproducible increases in ICP were never shown after TBI. Although the reasons for a lack of ICP response in guinea pigs and rats are unknown, we note that sheep have a higher tentorial index than both species, and that the presence of an intact tentorium may restrict increases in pressure to a single compartment, thus increasing ICP. We propose that species with higher tentorial indexes may prove to be a more suitable than rodents for the study of ICP and functional outcome after TBI.
Thesis (M.S.) -- University of Adelaide, School of Medical Sciences, 2010

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Hsu, Yi-Fang, e 許宜芳. "Effects of Positive End-Expiratory Pressure (PEEP) on Intracranial Pressure in Acute Brain Injury Patients". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/96941825150246875212.

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碩士
中臺科技大學
護理系碩士班
102
Head injury is a major problem. It may even cause coma or death. When the intracranial pressure increased, the patient with head injury should be accepted the decompressive craniectomy. For preventing the emotion of patient after operation from influencing intracranial pressure (ICP), they will receive tranquilizers for several days to control the ICP changes. However, the anesthesia and tranquilization easily lead to alveolar collapse. Pulmonary complications will occur to 80% or so patients after surgery. Therefore, such patients’ care will be forcused on protecting not only the nerve function, but also the lung safety. The research was designed to be descriptive correlation. A consecutive series of 1042 patients with head injury were retrospectively reviewed to explore the effect of using positive end-expiratory pressure (PEEP) on ICP and related factor. The contents collected included basic data and physiological values from June 1 in 2006 to May 31 in 2012. The results were shown that (1)there were significant differences between gender and APACHE II score at admission or GCS within 3 days after surgery(P<0.05). (2)There were significant differences between smoking and APACHE II score at admission or ICP within 3 days after surgery or GCS within 3 days after surgery (P<0.05). (3)There were significant differences between patient follow-up development and APACHE II score at admission or ICP within 3 days after surgery or GCS within 3 days after surgery (P<0.05). (4)The PEEP set up from 0 to 5, to 6 to 10 and 11 to 15 did not affect ICP and GCS within 3 days after surgery (P＞0.05). But, the differences between PEEP and CCP at 1st day after surgery or heart rates (HR) within 3 days after surgery were proved (P<0.05). (5)During the 3 days after surgery, ICP initially increased and then decreased a little. A day-by-day decrease of CPP became stable and GCS increased daily. Furthermore, both APACHE II score and GCS were significantly related with ICP (P<0.001). The study results can supply the related medical knowledges for clinical staffs to take care of patients with head injury after surgery, and expect to be helpful in the process of such kind of patient care.

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31

Chen, Yu-Chih, e 陳昱至. "Partial Pressure Estimation of Brain Tissue Oxygen in Traumatic Brain Injury by Using Wireless Near Infrared Spectroscopy". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3j2866.

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碩士
國立交通大學
照明與能源光電研究所
102
Monitoring partial pressure of oxygen in the brain tissue (PbtO2) is an important standard for traumatic brain injury (TBI) patients in clinical. But it is an invasive measurement and inconvenient for real-time monitoring. Recently, Near-infrared spectroscopy (NIRS) is widely used in neuroscience, and can assess cerebral ischemia and hypoxia non-invasively. In this thesis, a novel wireless NIRS system, and the PbtO2 monitoring system were used to monitor the oxygenation of rat brains under different impact strengths. And all rats were randomly assigned to four different impact strength groups in the fluid percussion injury experiments. The relationships of the concentration changes of HbO2 and HbR, and PbtO2 under and after TBI with different impact strengths were also investigated. Triphenyltetrazolium chloride (TTC) staining was used for infarction volume evaluation. Results show that Δ[HbO2], Δ[HbR], and Δ[HbT] dropped immediately after the impact and increased gradually then maintain a stable status. And Δ[PbtO2] had a similar change tendency with the NIRS parameters. The result of the TTC staining showed the infarction volume was increased with the increased impact strength, and Δ[HbO2] and Δ[PbtO2] were decreased with the increased impact strength. The correlation coefficient between Δ[PbtO2] and Δ[HbO2] is 0.77, and between Δ[HbR] and Δ[HbO2] is 0.08. It can be discovered that Δ[HbO2] is highly and positively correlated to Δ[PbtO2]. That means the Δ[HbO2] may be available to be the reference parameter to estimate the partial pressure of oxygen in the brain tissue.

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32

Wang, Che-Chuan, e 王哲川. "A wireless near infrared spectroscopy (NIRS) used in traumatic brain Injury experimental animals for the intracranial physiological change evaluation". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/78188017105355965857.

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博士
國立交通大學
光電系統博士學位學程
105
cerebral perfusion pressure and brain tissue oxygen partial pressure is an important indicator of clinical monitoring of brain injury. In recent years, near-infrared spectroscopy is a non-invasive method to assess cerebral oxygenation and brain ischemia. We use wireless infrared spectroscopy and intracranial pressure monitor, brain tissue oxygen partial pressure monitor to access result of the injured mouse brain. The results showed that cerebral perfusion pressure and infrared spectrometer parameters changes with the increase of the force will be reduced. In addition, there was a high positive correlation between the change of oxygenated hemoglobin and the change of oxygen tension in brain tissue. Therefore, the near-infrared spectroscopy can be used to assess relative cerebral perfusion pressure in a noninvasive manner and can be used to estimate brain tissue oxygen partial pressure. In addition, we also use the concept of local brain cooling therapy in this experiment, the results show that oxygen concentration of hemoglobin and brain tissue oxygen partial pressure will increase at low temperature. Therefore, it is also proved that local cerebral hypothermia therapy does have a protective effect on the brain after trauma .

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33

Lin, Jia-Wei, e 林家瑋. "Application of Decreasing Brain Tissue Gliosis, Elevating Brain Tissue O2 Partial Pressure, and Maintaining Optimal Cerebral Perfusion Pressure in Treatment of Severe Traumatic Brain Injury". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/26240376282598094004.

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博士
臺北醫學大學
臨床醫學研究所
97
Before 1997, Taiwan was one of the areas with the highest incidence and mortality rate of traumatic brain injuries (TBI) in the world. This situation mainly resulted from a large number of motorcyclists, of whom only very few wore a helmet. In order to tackle this serious problem, we carried out several studies on TBI in the past few years. According to different subjects, material and methods, there were seven main topics of studies, which were:1. Epidemiological study of TBI: We initiated a nationwide brain injury survey. We found that incidence of TBI was higher in the rural area than in the urban area of Taiwan. Seventy percent of the TBI were due to motorcycle accidents and most of the motorcycle riders did not wear a helmet. So we asserted that the mandatory helmet use law would be the most important and effective policy to reduce and to prevent TBI in Taiwan. 2. Intervention study of TBI: We started a complete study comparing the trend of TBI before and that after the mandatory helmet use law. We found that after the helmet use law, there was a reduction of the rate of consciousness disturbance, skull fracture and intracranial hemorrhage in the motorcycle related accidents. We concluded that the helmet use law intervention was effective and the continue education for the use of helmet and re-enforcement of the helmet use law were essential to maintain a satisfactory rate of helmet use in motorcyclists. 3. Study of neurobehavioral: With the use of the neurobehavioral rating scale (NRS) of Levin et al. (1987), we investigated the relationship of neurobehavioral disturbances in TBI patients with the severity and duration of head injury. NRS factors “cognitive language” and “anxiety” were significantly different in head injury subgroups with different degree of brain injury. 4. Epidemiological study of spinal cord injury: After the helmet use law, the incidence of TBI in Taiwan was proved to be successfully declined, but the use of helmet might increase the risk of spinal cord injury. In order to investigate the correlation of helmet use with spinal cord injury, we collected the registered and telephone interview data from the “Head and Spinal Cord Injury Study Group, R.O.C” for important after injury evaluation. The result showed that the use of helmet would not cause cervical spine injury. 5. International collaborative program: TBI is a tough and complicated issue for developing countries. However, most of these countries have limited resources and facilities for TBI prevention and treatment. Kraus, Jennett and Frankowski reported in 1990 that the annual incidence rate of head injury was 132–430/105, and the annual morality rate was 9–32/105. Although every country has their own method, definition and strategies in their TBI databases collection, the comparative results between developing countries and developed countries showed that the developing countries faced a more serious problem of TBI. 6. Quality of life study of severe TBI: The main goal of the TBI patients care is to reduce the severity of disability, mortality rates, and their quality of life as much as possible. Since 1970, many researches showed that application of intensive care on severe TBI patients significantly decreased the severity and mortality rates. USA published the “Guidelines of management in severe head injury” in 1995, suggesting the use of intracranial pressure monitors to control not only the intracranial pressure, but also to maintain the cerebral perfusion pressure. That was a breakthrough concept that could clinically help to avoid cell necrosis due to ischemia of brain tissues and was now widely used in Europe and America after a 5 years evaluation. 7. Study of minor TBI: This is an international collaborative cohort study of six countries (Australia, Italy, India, USA, Argentina and Taiwan) with standardized method of study and forms. We aim to find out the risk and prognostic index of patients with minor traumatic brain injury, and provide patients with better quality of care. 8. Guidelines for management of severe TBI in Taiwan: We invited 32 neurosurgical experts from medical centers and local regional hospitals in different parts of Taiwan to join the Taiwan TBI guideline consensus meetings and conferences. We chose eight topics of guideline development: • Management in emergency room • ICP monitor • CPP and fluid management • Use of sedation • Nutrition • Management of intracranial hypertension • Seizure prophylaxis Second tier therapy Within this dissertation, 4 major basic and clinical researches for the severe traumatic brain injury were conducted. 4 major conclusions were summarized as following: (1) HA application could effectively reduce the gliosis in brain cortex not only on the thickness of the scarring and also in glia cell proliferation. All these change was believed to be related with the lesser chance of post traumatic or post operative seizure incidence. (2) HBOT could elevate the brain oxygenation; promote the GCS improvement, and also the 3 months outcome, esp. in GOS change. But the timing when the HOBT implement need further clarification. (3) Slower speed of hemodialysis, more frequently dialysis could reduce the severity of brain edema effective. These subtle changes for the patient who need dialysis could reduce IICP incidence and increase the survival rate for these patient also. And (4) Improved cerebral perfusion, esp. for the patient with extreme poor GCS after the brain trauma could be indicated for the better outcome and better survival rate. But the high complication rate should be also monitored closely to avoid the further disaster during the maintenance patient’s CPP. These entire 4 major topics was only the beginning of the clinical trial for the development of the treatment guideline of severe traumatic brain injury. We hope in the near future, some more researchers could join into this field of research. With all there efforts evidence-based guideline could be then setup and well accepted by the clinical practice.

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34

Castro, Alexandre Loureiro de. ""Optimal Cerebral Perfusion Pressure and the risk of Acute Respiratory Distress Syndrome in Traumatic Brain Injury Patients"". Master's thesis, 2019. https://hdl.handle.net/10216/120583.

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35

Castro, Alexandre Loureiro de. ""Optimal Cerebral Perfusion Pressure and the risk of Acute Respiratory Distress Syndrome in Traumatic Brain Injury Patients"". Dissertação, 2019. https://hdl.handle.net/10216/120583.

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