Thomas Kerz

Technical aids in the diagnosis of brain death: a comparison of SEP, AEP, EEG, TCD and CT angiography.

BACKGROUND The use of technical aids to confirm brain death is a controversial matter. Angiography with the intra-arterial administration of contrast medium is the international gold standard, but it is not allowed in Germany except in cases where it provides a potential mode of treatment. The currently approved tests in Germany are recordings of somatosensory evoked potentials (SSEP), brain perfusion scintigraphy, transcranial Doppler ultrasonography (TCD), and electroencephalography (EEG). CT angiography (CTA), a promising new alternative, is being increasingly used as well. METHODS In a prospective, single-center study that was carried out from 2008 to 2011, 71 consecutive patients in whom brain death was diagnosed on clinical grounds underwent recording of auditory evoked potentials (AEP) and SSEP as well as EEG, TCD and CTA. RESULTS The validity of CTA for the confirmation of brain death was 94%; the validity of the other tests was: 94% for EEG, 92% for TCD, 82% for SSEP, and 2% for AEP. In 61 of the 71 patients (86%), the EEG, TCD and CTA findings all accorded with the clinical diagnosis. The diagnosis of brain death was established beyond doubt in all patients. CONCLUSION In this study, the technical aids yielded discordant results in 14% of cases, necessitating interpretation by an expert examiner. The perfusion tests, in particular, can give false-positive results in patients with large cranial defects, skull fractures, or cerebrospinal fluid drainage. In such cases, electrophysiologic tests or a repeated clinical examination should be performed instead. CTA is a promising, highly reliable new method for demonstrating absent intracranial blood flow. In our view, it should be incorporated into the German guidelines for the diagnosis of brain death.

A case control study of statin and magnesium administration in patients after aneurysmal subarachnoid hemorrhage: incidence of delayed cerebral ischemia and mortality

Abstract Objective: To analyse the effect of the implementation of statin and magnesium treatment on delayed cerebral ischemia (DCI) and 14 day mortality in patients with subarachnoid hemorrhage (SAH). Methods: Retrospective, single-center, observational case control study. One hundred SAH patients received either simvastatin and magnesium, solely statin or no treatment. Results: Eighteen percent (n=5) of patients receiving statin and magnesium treatment developed a DCI whereas 24% (n=5) in the statin group and 16% (n=8) in the control group had DCI. Dead by day 14 was registered in 18% (n=5) of patients in the statin and magnesium group, in 10% (n=2) in the statin group and in 27% (n=14) in the control group. None of the results reached a statistical significance level of 0.05. Conclusion: A trend towards a lower mortality within 14 days in patients receiving solely simvastatin and those receiving statin and magnesium as compared with the control group was found. A higher incidence for DCI was found in the statin group, whereas patients without statin and magnesium tended to have less often DCI. None of the results was statistically significant.

Detection of intracranial circulatory arrest in brain death using cranial CT-angiography.

Computed tomographic‐angiography (CT‐A) is becoming more accepted in detecting intracranial circulatory arrest in brain death (BD). An international consensus about the use and the parameters of this technique is currently not established. We examined intracranial contrast enhancement in CT‐A after clinically confirmed BD, compared the results with electroencephalography (EEG) and Transcranial Doppler Ultrasonography (TCD) findings and developed a commonly applicable CT‐A protocol.

Effect of intraarterial papaverine or nimodipine on vessel diameter in patients with cerebral vasospasm after subarachnoid hemorrhage

Introduction. Papaverine (P) and nimodipine (N) are the most widely used vasodilators when angiographic and symptomatic vasospasm is present after subarachnoid aneurysmatic hemorrhage (SAH). Their effect is only short-lived and no direct comparisons have been undertaken to evaluate the action of both substances directly. We retrospectively assessed the effect of either P or N on angiographic diameter reduction and capillary blood flow. Methods. Fifteen SAH patients with secured aneurysms and cerebral vasospasm received intraarterial P, fifteen similar patients received N. As the primary endpoint, pre- and post-infusion arterial diameters and capillary blood flow were rated retrospectively on angiographies and compared by RM-ANOVA. Secondary endpoints were the difference in the modified Rankin Scale between the two groups on admission and at discharge, the occurrence of delayed cerebral ischemia, the separate effects on angiographic diameter and capillary blood flow and the overall response rate to the vasodilator infusion. Results. Angiographic resolution of diameter reduction and angiographically assessed capillary blood flow together differed not significantly between both groups. P infusion dilated all angiographic demonstrable vessels while N infusion was ineffective in 16% of the patients. Capillary flow on pre- and post-infusion angiographies was not different between the two groups. Conclusion. P and N seem to differ in the effect on cerebral diameter reduction in patients with vasospasm after SAH. The clinical implications remain to be established. A multimodal approach, perhaps combining different agents for intraarterial infusion in such patients, needs to be evaluated.

Computed tomographic angiography as a useful adjunct in the diagnosis of brain death.

BACKGROUND: Because of its widespread accessibly, computed tomographic angiography (CT‐A) is a promising technique in the detection of intracranial circulatory arrest in brain death (BD). Several studies assessed this tool, but neither have standardized evaluation parameters been developed nor has information about specificity become available. METHODS: We conducted a prospective study between January 2008 and April 2012. Thirty patients were admitted to our University Hospital (16 men and 14 women; age, 18–88 years) and underwent CT‐A scanning at two occasions: immediately after the first signs of loss of brain stem reflexes and after definitive determination of brain. The results of CT‐A were compared with transcranial Doppler ultrasonography and electroencephalogram. RESULTS: In 3 of 30 patients, we observed a termination of contrast flow at the level of the skull base and foramen magnum in arterial scanning series before the clinical determination of BD. After the clinical determination of BD, the opacification of all vascular territories in arterial phase scanning was found in one case, but venous phase scanning revealed no blood return in internal cerebral veins. In all other cases, contrast filling ceased at level of skull base or below. The specificity of CT‐A in the detection of intracranial circulatory arrest was 90%, and sensitivity was 97%. CONCLUSION: CT‐A is reliable and appropriate technical investigation to detect intracranial circulatory arrest in BD. The evaluation of contrast enhancement in arterial phase scanning seems to be more reliable than that in venous phase. An international consensus about a uniformly applied CT‐A protocol for the evaluation of BD should be established. LEVEL OF EVIDENCE: Diagnostic study, level V.

CT Angiography as a Confirmatory Test in Brain Death

OBJECTIVE From recent studies, it remains unclear whether CT angiography could be an alternative to other established ancillary tests for the diagnosis of brain death. We examined intracranial contrast enhancement in CT angiography after clinically established brain death and compared the results with EEG and TCD findings. MATERIALS AND METHODS Prospective study between April 2008 and January 2010. EEG, TCD and CT angiography were performed in 40 patients aged between 18 and 88 years (mean 56 years) who fulfilled the clinical criteria of brain death. RESULTS In all cases, the common carotid artery, cervical internal carotid artery, cervical vertebral artery and superficial temporal artery opacified in an arterial CT angiography series. 37 out of 40 cases demonstrated no opacification of both MCA-M4, ACA-A3, PCA-P2 segments, and BA. CONCLUSION CT angiography is a promising method of evaluating intracranial circulatory arrest in brain death with a high spatial and temporal resolution, superior to all other established technical procedures. The examination is easily accessible in most hospitals, operator independent, minimally invasive and inexpensive. Therefore, CT angiography has the potential to enlarge the existing armamentarium of confirmatory brain death tests.

Contrast-enhanced transcranial Doppler ultrasonography in the diagnosis of brain death

The diagnosis of brain death (BD) is based on clinical criteria including deep coma, brain stem areflexia and apnoea. Depending on different local guidelines, confirmatory technical tests are sometimes mandatory.1 Since the 1990s, transcranial Doppler sonography (TCD) has found its place in these circumstances and fulfils most of the criteria of an ‘ideal test’ in confirming BD. To confirm intracranial circulatory arrest (CA) with Doppler sonography, typical flow patterns must be recorded in bilateral intracranial and extracranial brain-supplying arteries.2 A completely absent intracranial flow signal is not a reliable sign to determine CA because this can be due to transmission problems. Inadequate ultrasound penetration of the temporal bone is a major drawback of this technique, making definitive assessment of intracranial flow patterns impossible. Stabilised microbubble ultrasonic contrast agents (UCA) are routinely used in neurological clinical routine when intracranial insonation is difficult. The application of UCAs may also be helpful during BD declaration, but to our knowledge, only one publication evaluated UCAs to detect intracranial CA in BD.3 Retrospective analysis of 102 patients (46 women, 56 men), aged between 8 years and 88 years (mean: 53 years±17 years), between January 2008 and December 2011, were examined by our department. Patients were found brain dead in clinical examination and were scheduled for …

Endovascular therapy for vasospasm after aneurysmatic subarachnoid hemorrhage

Abstract Introduction: Balloon angioplasty and/or selective intra-arterial vasodilator therapies are treatment options in patients with vasospasm after subarachnoid hemorrhage (SAH). We analyzed the effect of balloon angioplasty and/or selective intra-arterial vasodilator therapy in our patients. Methods: Twenty-six patients (vasodilation group, VDT) were treated with intra-arterial nimodipine. The balloon angioplasty with nimodiopine-group (BAP-N group) comprised 21 patients. The primary endpoint of this study was successful angiographic vessel dilation in vasospastic vessels after balloon angioplasty, together with nimodipine (BAP-N group), compared to intra-arterial vasodilator therapy (VDT group) with nimodipine alone. Results: A significant effect of angioplasty plus nimodipine was found in the central arteries (composite endpoint) with an OR of 2.4 (95% CI: 1.4–4.2], p = 0.002), indicating a chance of improvement of the BAP-N group of more than twice compared to nimodipine infusions alone. Significant advantages for BAP-N-therapy were also encountered in the internal carotid artery (OR 5.4, p < 0.001) and basilar artery (OR 29.7, p = 0.003). A joint analysis of all arteries combined failed to show significant benefit of BAP-N therapy (OR 1.5, p = 0.079), which was also true for cerebral peripheral arteries (OR 0.77, p = 0.367). There was no difference in clinical outcome between both groups. Conclusions: In SAH patients with vasospasm, a combination therapy of balloon angioplasty and intra-arterial nimodipine resulted in a more than doubled vasodilative effect in the central cerebral arteries compared to the sole infusion of nimodipine. Regarding the ICA and BA arteries, this beneficial effect was even more pronounced. Although there was a tendency of better effects of the BAP-N group, regarding the overall effect in all territories combined, this failed to reach statistical evidence. In cerebral peripheral arteries, no differences were observed, and there was no difference in clinical outcome, too.

Direct effects of Facio-Oral Tract Therapy® on swallowing frequency of non-tracheotomised patients with acute neurogenic dysphagia

Objectives: The aim of this study was to investigate the direct effect of Facio-Oral Tract Therapy® on swallowing frequency of non-tracheotomised patients with acute neurogenic dysphagia. Methods: Within a pre-, post-/during and follow-up study design, 19 non-tracheotomised dysphagic patients were included consecutively and treated according to three specific preselected Facio-Oral Tract Therapy stimulation techniques. Results: The primary outcome was the direct effect of the three different Facio-Oral Tract Therapy stimulation techniques on the number of swallows. We found a significant effect of Facio-Oral Tract Therapy on swallowing frequency as compared to baseline with an increase by 65.63% and medium effect size of D = 0.62. No significant difference could be demonstrated when comparing baseline to follow-up. Conclusion: For the first time, this positive therapy effect could be demonstrated on a population of non-tracheotomised patients. Facio-Oral Tract Therapy seems to be an appropriate means for improving effectiveness and safety of swallowing. Since improvement was not long lasting, it appears to be reasonable to apply therapy frequently during the day with the plausible result of minimising the amount of aspirated saliva and thereby reducing the risk of aspiration pneumonia. Further studies may consider choosing a randomised controlled trial design to demonstrate that change in swallow frequency is related to the target intervention only.

Germany: Where Have We Been?

Germany’s health system organization is based on three major principles: compulsory insurance, compulsory contributions from both employers and employees and solidarity. A vast majority of German citizens follow the idea that health risks should be shared collectively by the community of all insured persons [9]. Irrespective of the amount each person had paid into the social system, all have access to comprehensive coverage. In order to understand Germany’s peculiarities in health policy, this chapter provides an introduction into Germany’s model of health care and then discusses which kinds of resource allocation strategies already have evolved. The second chapter deals with prospects for Germany’s health care system in the near future and future. Both chapters do not discuss future developments in the area of medical technology.