[Show abstract][Hide abstract] ABSTRACT: The probability of treating patients with valvular heart disease during non-cardiac surgery increases with the age of the patient. The prevalence of valvular heart disease is approximately 2.5% and increases further in the patient group aged over 75 years old. Patients with valvular heart disease undergoing non-cardiac surgery have an increased perioperative cardiovascular risk depending on the severity of the disease. Knowledge of the hemodynamic alterations and compensation mechanisms which accompany diseases of the valve apparatus is essential for a suitable treatment of patients with such pre-existing diseases. The most common valvular heart diseases lead to volume (mitral valve insufficiency) or pressure load (aortic stenosis) of the left ventricle and in the case of mitral stenosis to a pressure load on the left atrium. Depending on the underlying disease and the type of surgery planned a corresponding choice of anesthesia procedure and medication must be made. In the present review article the pathophysiology of the relevant valvular heart diseases and the implications for perioperative anesthesia management will be presented. An individually tailored extended perioperative monitoring allows hemodynamic alterations to be rapidly recognized and adequately treated.
Der Anaesthesist 09/2011; 60(9):799-813. · 0.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Invasive airway management techniques are still challenging even for skilled anesthesiologists, intensivists and emergency physicians. All current percutaneous tracheostomy techniques are based on Seldinger's principle. Using the recent introduced Blue Dolphin Kit is feasible and safe, but without clear advantage compared to other kits. There is no data available to generally support performing early (<8 days) tracheostomy in intensive care patients requiring mechanical ventilation. Experimental data show promising results of supporting expiration through a small bore catheter using ejectors based on Bernoulli's principle in terms of minimizing risk of barotrauma during emergency transtracheal high frequency jet ventilation.
[Show abstract][Hide abstract] ABSTRACT: Early identification of patients at risk of space-occupying "malignant" middle cerebral artery (MCA) infarction (MMI) is needed to enable timely decision for potentially life-saving treatment such as decompressive hemicraniectomy. We tested the hypothesis that acute stroke magnetic resonance imaging (MRI) predicts MMI within 6 hours of stroke onset.
In a prospective, multicenter, observational cohort study patients with acute ischemic stroke and MCA main stem occlusion were studied by MRI including diffusion-weighted imaging (DWI), perfusion imaging (PI), and MR-angiography within 6 hours of symptom onset. Multivariate regression analysis was used to identify clinical and imaging predictors of MMI.
Of 140 patients included, 27 (19.3%) developed MMI. The following parameters were identified as independent predictors of MMI: larger acute DWI lesion volume (per 1 ml odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02-1.06; p < 0.001), combined MCA + internal carotid artery occlusion (5.38, 1.55-18.68; p = 0.008), and severity of neurological deficit on admission assessed by the National Institutes of Health Stroke Scale score (per 1 point 1.16, 1.00-1.35; p = 0.053). The prespecified threshold of a DWI lesion volume >82 ml predicted MMI with high specificity (0.98, 95% CI 0.94-1.00), negative predictive value (0.90, 0.83-0.94), and positive predictive value (0.88, 0.62-0.98), but sensitivity was low (0.52, 0.32-0.71).
Stroke MRI on admission predicts malignant course in severe MCA stroke with high positive and negative predictive value and may help in guiding treatment decisions, such as decompressive surgery. In a subset of patients with small initial DWI lesion volumes, repeated diagnostic tests are required.
Annals of Neurology 10/2010; 68(4):435-45. · 11.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Drogenintoxikationen sind v.a. in Großstädten mit einer aktiven Drogen- und Partyszene häufig. Bis auf Opiate und Benzodiazepine
stehen keine spezifischen Antidote für die üblichen Rauschgifte zur Verfügung und die (oft lebensrettende) Therapie kann nur
rein symptomatisch erfolgen. Die klassische Symptomatik einer Heroinintoxikation besteht aus Koma, Atemdepression und Miosis,
diese kann durch Mischintoxikationen mit anderen Substanzen jedoch maskiert werden. Der Einsatz des Optiatantagonisten Naloxon
ist in Gebieten mit einer überproportional aktiven i.v.-Drogenszene und „Fixerstuben“ mit praktischen und medikolegalen Problemen
verbunden, da der medizinische Anspruch an eine ausreichend lange Überwachungszeit nach Antagonisierung oft im krassen Gegensatz
zur fehlenden Einsicht und Vorstellung der Drogenkonsumenten steht. Der Konsum von neuen Substanzen wie 4-Hydroxybutansäure
(Liquid Ecstasy, GHB) findet v.a. auf Partys statt und kann in hohen Dosierungen unspezifische Intoxikationssymptome mit
Koma und Myoklonien hervorrufen, welche durch zusätzlichen Konsum von Alkohol lebensbedrohlich werden können. Daher sollten
die in dieser Fortbildung dargestellten Aspekte insbesondere in Ballungsräumen tätigen Notärzten und Rettungshelfern geläufig
Intoxication due to drug abuse is common in big cities with an active drug and party scene. Antidotes are only available for
opioids and benzodiazepines, thus only supportive (often lifesaving) care can be done in other cases. The classical symptoms
of intoxication with heroin are coma, respiratory arrest, and miosis. Use of naloxone in areas with over-proportional numbers
of drug users goes along with some medico-legal und practical limitations. The proposed monitoring of patients after drug
reversal is often not possible due to incompliance of drug abusers. New drugs like 4-hydroxybutyric acid (liquid ecstasy,
GHB) are mainly abused at party events. High doses can cause unspecific symptoms with coma and myoclonus. Additional ingestion
of alcohol can lead to life threatening situations. Emergency physicians and paramedics should have the knowledge presented
in this article, especially if working in big city areas.
[Show abstract][Hide abstract] ABSTRACT: Management of ischemic stroke is challenging. No prehospital treatment option exists, and the only approved pharmacologic therapy, that is, systemic thrombolysis, requires brain imaging and initiation of therapy within a narrow therapeutic window. This review provides an overview of recent efforts to optimize management of suspected stroke patients by reducing the interval from symptom onset to reperfusion therapy.
There is clear evidence that stroke patients have a favorable outcome when treated with thrombolysis in specialized stroke centers. Data from the European Cooperative Acute Stroke Study-III trial, coupled with improved patient selection by advanced imaging technologies will expand future therapeutic options. However, major obstacles remain in consistently translating scientific advances into clinical practice with only a small percentage of potentially eligible patients receiving thrombolysis. Integrated systems of prehospital management and clinical pathways are necessary to reduce this treatment gap.
The dogma 'time is brain' is as relevant now as it was at the inauguration of recombinant tissue plasminogen activator for acute stroke treatment in 1996. Knowledge of stroke symptoms and treatment options by the public and first responders, along with integrated stroke systems of care are crucial to ensure rapid access to stroke expertise and treatment.
Current opinion in critical care 07/2009; 15(4):295-300. · 2.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pretreatment lesion size on diffusion-weighted imaging (DWI) is a risk factor for symptomatic intracerebral hemorrhage (sICH) associated with thrombolytic treatment. Here, we investigated whether the Alberta Stroke Programme Early CT Score (ASPECTS) applied to DWI images (DWI-ASPECTS) predicts sICH risk accurately.
In this retrospective multicenter study, prospectively collected data of 217 patients with anterior circulation stroke treated with intravenous or intraarterial thrombolysis within 6 hours after symptom onset were analyzed. Pretreatment DWI-ASPECTS scores were assessed by 2 independent investigators. For bleeding risk analysis, DWI-ASPECTS scores were either categorized into 0 to 7 (n=105) or 8 to 10 (n=112) or in 3 groups of similar sample size (DWI-ASPECTS 0 to 5 [n=69], 6 to 7 [n=70], and 8 to 10 [n=78]).
DWI-ASPECTS scores correlated well with the DWI lesion volume (r=0.77, P<0.001, Spearman Rank test). Interobserver reliability for the assessment of DWI-ASPECTS was moderate (weighted kappa 0.441 [95% CI 0.373 to 0.509]). Twenty-three (10.6%) patients developed sICH. The sICH rate was significantly higher in patients with DWI-ASPECTS scores 0 to 7 (n=21, 15.1%) as compared to patients with DWI-ASPECTS scores 8 to 10 (n=2, 2.6%, P=0.004). sICH risk was 20.3%, 10%, and 2.6% in the 0 to 5, 6 to 7, and 8 to 10 DWI-ASPECTS groups, respectively. DWI-ASPECTS remained an independent prognostic factor for sICH after adjustment for clinical baseline variables (age, NIHSS, time to thrombolysis).
DWI-ASPECTS predicts sICH risk after thrombolysis and may be helpful to contributing to quick sICH risk assessment before thrombolytic therapy.
[Show abstract][Hide abstract] ABSTRACT: The consequences of poor insonation conditions on autoregulation parameters assessed with transcranial Doppler (TCD) are unclear.
We present two new complementary methods to assess the quality of a TCD signal. Inserting a thin aluminium foil between TCD probe and skin makes a simple model to artificially worsen a good insonation window. Validation studies are presented. We assessed insonation quality and cerebral autoregulation parameters with transfer function analysis and cross correlation in 46 healthy volunteers with and without the aluminium foil model. The same studies were operated on 45 patients with good insonation windows, naïve, after worsening the bone window and during constant infusion of an ultrasound contrast agent. For studying reproducibility, we assessed autoregulation twice in 30 patients with poor bone windows, with and without constant contrast infusion.
Both methods to measure insonation quality are valid and reproducible. The aluminium foil model realistically simulates a natural poor bone window, reducing the signal quality (e.g. energy of the signal spectrum from 33.4+/-3.5 to 26.2+/-2.5 dB, p<0.001). Thereby, the autoregulation parameters are systematically biased (e.g. phase difference from 37.3+/-10.1 degrees to 25.9+/-15.1 degrees , p<0.001); while with the use of an ultrasound contrast agent this can be largely compensated (phase difference 35.7+/-10.7 degrees , p<0.001). The reproducibility is significantly improved (ICC from 0.76 to 0.90, p<0.05).
Poor bone windows can cause considerable bias in TCD autoregulation parameters. This bias might be avoided by the use of ultrasound contrast agents, which may greatly improve the credibility of TCD autoregulation assessment in elderly patients.
Journal of the neurological sciences 03/2009; 283(1-2):49-56. · 2.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cerebral autoregulation is an important pathophysiological and prognostic parameter for a variety of neurologic conditions. It can be assessed quickly and safely using transcranial Doppler sonography (TCD). In elderly patients, poor insonation conditions decrease the number of examinable patients and can cause a systematic bias in autoregulation parameters. The aim of this study was to investigate whether a constant infusion of an ultrasound contrast agent (Levovist((R))) can counteract these effects. We examined two cohorts of unselected neurologic patients. In 45 patients with good insonation windows (cohort 1), we used a thin aluminium foil between the skin and the TCD probe to artificially decrease the insonation quality. We determined two parameters of cerebral autoregulation (phase difference [PD] and a cross-correlation coefficient [Mx]) in native patients, with aluminium foil and with aluminium foil and a constant infusion of Levovist. In 30 patients with poor insonation windows (cohort 2), we measured the autoregulation twice, with and without an infusion of Levovist, to assess the reproducibility of the autoregulation parameters. In cohort 1, the foil model significantly decreased the Doppler signal quality, i.e., the mean spectrum energy decreased from 33.9 +/- 2.7 dB to 26.3 +/- 2.4 dB (p < 0.001). This introduced a significant bias to all autoregulation parameters (PD: decreased from 38.2 +/- 10.0 degrees to 27.9 +/- 12.5 degrees (p < 0.001); Mx: decreased from 0.308 +/- 0.170 to 0.254 +/- 0.162 (p < 0.01)). Both effects were compensated largely by a constant infusion of Levovist (300 mg/min). In cohort 2, infusion of the contrast agent at the same rate increased insonation quality, too, but to a lesser degree (27.4 +/- 2.4 dB to 32.0 +/- 3.7 dB, p < 0.001). This smaller increase did not cause a significant change in the autoregulation parameters, but the reproducibility of the PD was significantly improved (intraclass coefficient coefficient [ICC] 0.76, 95% confidence interval [0.59-0.87] in native poor bone window compared with ICC 0.90, 95% confidence interval [0.81-0.95] with infusion of the contrast agent). Our data show that constant infusion of an ultrasound contrast agent during the assessment of cerebral autoregulation can avoid potential bias introduced by poor insonation conditions. Furthermore, infusion of the contrast agent can improve reproducibility and contribute to the credibility of autoregulation assessment in the elderly. (E-mail: email@example.com).
Ultrasound in Medicine & Biology 03/2008; 34(3):345-53. · 2.46 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The risk for symptomatic intracerebral hemorrhage (sICH) associated with thrombolytic treatment has not been evaluated in large studies using diffusion-weighted imaging (DWI). Here, we investigated the relation between pretreatment DWI lesion size and the risk for sICH after thrombolysis.
In this retrospective multicenter study, prospectively collected data from 645 patients with anterior circulation stroke treated with intravenous or intraarterial thrombolysis within 6 hours (<3 hours: n = 320) after symptom onset were pooled. Patients were categorized according to the pretreatment DWI lesion size into three prespecified groups: small (< or =10 ml; n = 218), moderate (10-100 ml; n = 371), and large (>100 ml; n = 56) DWI lesions.
In total, 44 (6.8%) patients experienced development of sICH. The sICH rate was significantly different between subgroups: 2.8, 7.8, and 16.1% in patients with small, moderate, and large DWI lesions, respectively (p < 0.05). This translates to a 5.8 (2.8)-fold greater sICH risk for patients with large DWI lesions as compared with patients with small (or moderate) DWI lesions. The results were similar in the large subgroup (n = 536) of patients treated with intravenous tissue plasminogen activator. DWI lesion size remained an independent risk factor when including National Institutes of Health Stroke Scale, age, time to thrombolysis, and leukoariosis in a logistic regression analysis.
This multicenter study provides estimates of sICH risk in potential candidates for thrombolysis. The sICH risk increases gradually with increasing DWI lesion size, indicating that the potential benefit of therapy needs to be balanced carefully against the risk for sICH, especially in patients with large DWI lesions.
Annals of Neurology 01/2008; 63(1):52-60. · 11.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pathological yawning can be a clinical sign in disorders affecting the brainstem. Here we describe seven patients with pathological yawning caused by acute middle cerebral artery stroke, indicating that pathological yawning also occurs in supratentorial stroke. We hypothesise that excessive yawning is a consequence of lesions in cortical or subcortical areas, which physiologically control diencephalic yawning centres.
Journal of neurology, neurosurgery, and psychiatry 12/2007; 78(11):1253-4. · 4.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intracerebral hemorrhage constitutes an often fatal sequela of thrombolytic therapy in patients with ischemic stroke. Early blood-brain barrier disruption may play an important role, and the astroglial protein S100B is known to indicate blood-brain barrier dysfunction. We investigated whether elevated pretreatment serum S100B levels predict hemorrhagic transformation (HT) in thrombolyzed patients with stroke.
We retrospectively included 275 patients with ischemic stroke (mean age of 69+/-13 years; 46% female) who had received thrombolytic therapy within 6 hours of symptom onset. S100B levels were determined from pretreatment blood samples. Follow-up brain scans were obtained 24 hours after admission, and HT was classified as either hemorrhagic infarction (1, 2) or parenchymal hemorrhage (1, 2).
HT occurred in 80 patients (29%; 45 hemorrhagic infarction, 35 parenchymal hemorrhage). Median S100B values were significantly higher in patients with HT (0.14 versus 0.11 mug/L; P=0.017). An S100B value in the highest quintile corresponded to an OR for any HT of 2.87 (95% CI: 1.55 to 5.32; P=0.001) in univariate analysis and of 2.80 (1.40 to 5.62; P=0.004) after adjustment for age, sex, symptom severity, timespan from symptom onset to hospital admission, vascular risk factors, and storage time of serum probes. A pretreatment S100B value above 0.23 mug/L had only a moderate sensitivity (0.46) and specificity (0.82) for predicting severe parenchymal bleeding (parenchymal hemorrhage 2).
Elevated S100B serum levels before thrombolytic therapy constitute an independent risk factor for HT in patients with acute stroke. Unfortunately, the diagnostic accuracy of S100B is too low for it to function in this context as a reliable biomarker in clinical practice.
[Show abstract][Hide abstract] ABSTRACT: Sex differences in the management of acute coronary symptoms are well documented. We sought to determine whether sex disparities exist in acute stroke management, particularly with regard to early hospital admission and thrombolytic therapy.
We analyzed a prospective, countywide, hospital-based stroke registry. Between 1999 and 2005, all cases with a final diagnosis of cerebral infarction (ICD-10 I63) or intracerebral hemorrhage (ICD-10 I61) were selected. Datasets with missing values for sex and time to admission, as well as datasets of patients transferred between hospitals in the acute phase, were excluded. Main outcome measures were the probability of being admitted within the first 3 hours of stroke onset and being treated with thrombolytic agents for both women and men, after adjustment for age, prestroke disability, severity of clinical symptoms, vascular risk factors, and final diagnosis.
Fifty-three thousand four hundred fourteen patients were included (49.3% female; mean+/-SD age, 72.1+/-12.5 years). Women had a 10% lower chance of being admitted within the first 3 hours than men (odds ratio=0.902, 95% CI=0.860 to 0.945, P<0.001). This chance further decreased in elderly women. Similarly, the chance of a female stroke patient being treated with thrombolysis was 13% lower than that of a male patient (odds ratio=0.867, 95% CI=0.782 to 0.960, P=0.006). For patients admitted within the 3-hour time window, the chance of being treated with thrombolysis was similar for women and men (odds ratio=0.915, 95% CI=0.809 to 1.035, P=0.156).
We identified sex disparities in acute stroke management in terms of early hospital admission and thrombolytic treatment. This is best explained by the sociodemographic fact that "surviving spouses" are more likely to be women than men. Attempts to overcome disadvantages in their access to acute stroke care should focus on increased social support.
[Show abstract][Hide abstract] ABSTRACT: The corpus callosum (CC) is commonly affected in multiple sclerosis (MS). The ipsilateral silent period (iSP) is a putative electrophysiological marker of callosal demyelination. The purpose of this study was to re-assess, under recently established optimised protocol conditions [Jung P., Ziemann U. Differences of the ipsilateral silent period in small hand muscles. Muscle Nerve in press.], its diagnostic sensitivity in MS, about which conflicting results were reported in previous studies.
ISP measurements (onset, duration, and depth) were obtained in the abductor pollicis brevis (APB) muscle of either hand in 49 patients with early relapsing-remitting MS (RRMS) (mean EDSS, 1.3). Standard central motor conduction times to the APB (CMCT(APB)) and tibial anterior muscles (CMCT(TA)), and magnetic resonance images (MRI) were also obtained.
ISP measurements showed a similar diagnostic sensitivity (28.6%) as CMCT(APB) (24.5%), while diagnostic sensitivities of CMCT(TA) (69.4%) and MRI of the CC (78.6%) were much higher. Prolongation of iSP duration was the most sensitive single iSP measure. ISP prolongation occurred more frequently when CMCT(APB) to the same hand was also prolonged (40.0% vs. 8.4%, p<0.0001). The correlation between iSP duration and CMCT(APB) was significant (Pearson's r=0.24, p<0.02), suggesting that iSP duration can be contaminated by demyelination of the contralateral corticospinal tract. ISP duration did not correlate with MRI abnormalities of the CC.
ISP measures are neither a sensitive nor a specific marker of callosal conduction abnormality in early RRMS.
Journal of the Neurological Sciences 12/2006; 250(1-2):133-9. · 2.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The authors studied clinical features and lesion patterns associated with conjugate eye deviation (CED) in acute stroke.
Consecutive patients with supratentorial stroke (<6 hours after symptom onset) were prospectively recruited. CED was classified according to the National Institute of Health Stroke Scale (NIHSS) item "gaze palsy" as being forced, partial, or absent. Lesion patterns on diffusion-weighted images (DWI) were analyzed in 46 patients using a normalization procedure for direct comparisons between patients. Perfusion data were analyzed for a subset of patients.
Partial CED was found in 7 (6%) and forced CED in 31 (26.7%) of 116 patients. Forced and partial CED were associated with higher initial NIHSS scores compared with patients without CED (16 and 10 versus 5; P<0.05). DWI lesion volume was larger in patients with CED (103.24+/-102.4 mL, mean+/-SD) as compared with patients without CED (17+/-34.98 mL, P<0.001). CED was more frequent in right hemispheric stroke (44.6% versus 23%, P<0.02). DWI pattern analysis in patients with CED with right hemispheric stroke revealed a network of affected regions, including basal ganglia and temporoparietal cortex. In left hemispheric CED, lesions were larger than in patients without CED, but no consistent pattern could be established. In a subset of selected patients with CED, a small temporoparietal perfusion deficit was sufficient to elicit CED.
Selective dysfunction of cortical areas involved in spatial attention and control of eye movements is sufficient to cause CED in patients with acute stroke. However, in the majority of cases, CED is an indicator of large infarcts involving more than one area, including both cortical and subcortical structures.
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was to evaluate whether leukoaraiosis (LA) is a risk factor for symptomatic intracerebral hemorrhage (sICH) in patients treated with thrombolysis for acute stroke.
In this retrospective, multicenter analysis, we evaluated data from acute anterior circulation stroke patients (n=449; <6 hours after symptom onset) treated with thrombolysis. All patients had received standard magnetic resonance imaging evaluation before thrombolysis, including a high-quality T2-weighted sequence. For the analysis, LA in the deep white matter was dichotomized into absent or mild versus moderate or severe (corresponding to Fazekas scores of 0 to 1 versus 2 to 3).
The rate of sICH was significantly more frequent in patients with moderate to severe LA of the deep white matter (n=12 of 114; 10.5%) than in patients without relevant LA (n=13 of 335; 3.8%), corresponding to an odds ratio of 2.9 (95% CI, 1.29 to 6.59; P=0.015). In a logistic-regression analysis (including age, National Institutes of Health Stroke Scale score at presentation, and type of thrombolytic treatment), LA remained a significant independent risk factor (odds ratio, 2.9; P=0.03).
LA of the deep white matter is an independent risk factor for sICH after thrombolytic treatment for acute stroke.