Intracranial aneurysms and subarachnoid hemorrhage: Clinical studies on diagnosis and treatment

Computerized tomography angiography (CTA) can be performed quicker, safer and cheaper than digital subtraction angiography (DSA) in patients after aneurysmal subarachnoid hemorrhage (SAH). However, DSA is still regarded as the gold standard in the diagnosis of intracranial ruptured aneurysms. No studies have specifically addressed the value of CTA in planning of endovascular treatment of ruptured aneurysms. Mathieu van der Jagt investigates the diagnostic value of CTA for endovascular treatment compared with DSA, in cooperation with Radiology. He hypothesizes is that, at least in a subset of patients, CTA suffices and DSA can be omitted in the planning of endovascular treatment. Another project concerns a systematic review on rupture rate of unruptured intracranial aneurysms (UIAs), estimating the rupture rate of UIAs based on the available observational studies. The statistical method used will allow for correction for methodological quality per study, lea! ding to an estimate of rupture rate that is based on less biased data. The PhD project also evaluates the localizing value of blood distribution on CTA for the location of ruptured intracranial aneurysm; it includes a cohort study on the impact of early surgery on overall outcome after aneurysmal SAH

Fluid management of the neurological patient: A concise review

Maintenance fluids in critically ill brain-injured patients are part of routine critical care. Both the amounts of fluid volumes infused and the type and tonicity of maintenance fluids are relevant in understanding the impact of fluids on the pathophysiology of secondary brain injuries in these patients. In this narrative review, current evidence on routine fluid management of critically ill brain-injured patients and use of haemodynamic monitoring is summarized. Pertinent guidelines and consensus statements on fluid management for brain-injured patients are highlighted. In general, existing guidelines indicate that fluid management in these neurocritical care patients should be targeted at euvolemia using isotonic fluids. A critical appraisal is made of the available literature regarding the appropriate amount of fluids, haemodynamic monitoring and which types of fluids should be administered or avoided and a practical approach to fluid management is elaborated. Although hypovolemia is bound to contribute to secondary brain injury, some more recent data have emerged indicating the potential risks of fluid overload. However, it is acknowledged that many factors govern the relationship between fluid management and cerebral blood flow and oxygenation and more research seems warranted to optimise fluid management and improve outcomes

Airfoil optimization by using the Manifold Mapping method

In this report it is investigated if the Manifold Mapping method can be used in airfoil optimization. Before the method can be implemented, a suitable airfoil parametrization must be chosen. Furthermore a coarse and fine model must be assigned. These models are the key to success for the Manifold Mapping method. If two models are chosen that are completely different from each other, the Manifold Mapping will not work properly. Furthermore, if two models are chosen that are very similar to each other, the benefit in reducing computational cost will be only marginal. In this report the Manifold Mapping method will be explained in detail and applied to airfoil design. The approach is validated by using a test case, which will also be explained in detail. Furthermore recommendations and extensions will be given in the last chapter

Relative versus absolute rises in T/QRS ratio by ST analysis of fetal electrocardiograms in labour:A case-control pilot study

INTRODUCTION: The additional value of ST analysis during labour is uncertain. In ST analysis, a T/QRS baseline value is calculated from the fetal electrocardiogram and successive T/QRS ratios are compared to this baseline. However, variation in the orientation of the electrical heart axis between fetuses may yield different T/QRS baseline values. In case of a higher T/QRS baseline value more ST events are encountered, although not always related to perinatal outcome. We hypothesised that we can partly correct for this effect by analysing T/QRS rises as a percentage from baseline (relative ST analysis). This study aimed to explore whether relative ST analysis has better diagnostic value for cord acidaemia compared to conventional ST analysis, where predefined fixed T/QRS ratios are used.METHODS AND MATERIALS: A case-control study was performed in 20 term human fetuses during labour; 10 cases (umbilical cord artery pH &lt;7.05 at birth, defining acidaemia) and 10 controls (pH &gt;7.20) were included. The fetal electrocardiogram was recorded using a STAN monitor. We electronically extracted all T/QRS values, baseline and episodic ST events from the STAN monitor and calculated the relative T/QRS changes. The cut-off for relative ST events was determined in a receiver operator characteristic (ROC) curve at optimal specificity for cord acidaemia. Parameters of interest were area under the curve (AUC) of the ROC curve for relative ST events and test performance of both conventional and relative ST analysis.RESULTS: Relative ST analysis showed an AUC of 0.99. The optimal cut-off value for relative T/QRS rise was determined at 0.70. Relative vs conventional (absolute) ST analysis showed a specificity of 100% vs 40% (p = 0.031); sensitivity 90% vs 90%; positive likelihood ratio infinity vs 1.5; negative likelihood ratio 0.10 vs 0.25, respectively.CONCLUSION: Relative ST analysis seems to be a promising method to detect impending fetal acidaemia during labour. Further studies are required to determine the diagnostic accuracy.</p