Akuttherapie lebensbedrohlicher tachykarder Rhythmusstörungen

Life-threatening supraventricular tachyarrhythmias include atrial fibrillation, atrial flutter, AV-nodal reentrant tachycardia with rapid ventricular response and preexcitation syndromes combined with atrial fibrillation. Ventricular tachyarrhythmias still remain one of the leading causes of death; these arrhythmias include monomorphic and polymorphic ventricular tachycardia, torsade de pointes tachycardia, ventricular fibrillation and ventricular flutter. In all patients with tachycardias, an attempt should be made to differentiate between narrow (QRS duration < 0.12 s) or wide QRS complex (QRS duration ≥ 0.12 s) tachycardias. In the assessment of patients (pts) with supraventricular/ventricular tachyarrhythmias, attention should be given to identify whether the tachycardia is associated with worsening angina or low cardiac output. In pts with narrow QRS complex tachycardias or pts with atrial fibrillation and preexcitation syndromes immediate synchronized cardioversion should be performed if signs or symptoms of instability (hypotension, evidence of end-organ dysfunction, worsening angina) exist. In pts with a stable hemodynamic situation, vagal maneuvers, adenosine or calcium channel blockers can be used. Management of atrial flutter usually centers on cardioversion or rapid atrial pacing to normal sinus rhythm. In the treatment of patients with deemed unstable ventricular tachycardia (VT), electrical cardioversion is the treatment of choice. In more stable patients, ajmaline is the preferred agent after myocardial infarction and lidocaine if myocardial ischemia is present. In pts with torsade de pointes tachycardias aggressive steps must be taken to prevent degeneration of this rhythm to ventricular fibrillation (VF). Magnesium sulfate has recently been demonstrated efficacious and is currently considered first-line drug therapy. Transcutaneous overdrive pacing should be attempted if magnesium is unsuccessful. The pt with pulseless VT or VF demands early electrical countershock.     

The Bright Side of Grit in Burnout-Prevention: Exploring Grit in the Context of Demands-Resources Model among Chinese High School Students

This study contributes to understanding students’ emotional responses to academic stressors by integrating grit into the well-established Job Demands-Resources Model and by examining the relationship between academic demands, grit (consistency of interests, perseverance of effort), burnout, engagement, academic achievement, depression, and life satisfaction in Chinese students. We conducted a self-report study with N?=?1527 Chinese high school students (M_age?=?16.38 years, SD?=?1.04). The results of structural equation modeling showed that after controlling for gender, socio-economic status, and school types, demands positively related to burnout and negatively related to engagement. Both facets of grit negatively related to exhaustion, whereas only perseverance of effort positively related to engagement. Burnout positively related to depression and negatively related to life satisfaction, whereas engagement positively related to life satisfaction. However, neither burnout nor engagement was related to academic achievement. Our findings indicate that grit may be protective against school burnout.

     

Neutrophil Extracellular Trap-Related Extracellular Histones Cause Vascular Necrosis in Severe GN

Severe GN involves local neutrophil extracellular trap (NET) formation. We hypothesized a local cytotoxic effect of NET-related histone release in necrotizing GN. In vitro, histones from calf thymus or histones released by neutrophils undergoing NETosis killed glomerular endothelial cells, podocytes, and parietal epithelial cells in a dose-dependent manner. Histone-neutralizing agents such as antihistone IgG, activated protein C, or heparin prevented this effect. Histone toxicity on glomeruli ex vivo was Toll-like receptor 2/4 dependent, and lack of TLR2/4 attenuated histone-induced renal thrombotic microangiopathy and glomerular necrosis in mice. Anti–glomerular basement membrane GN involved NET formation and vascular necrosis, whereas blocking NET formation by peptidylarginine inhibition or preemptive anti-histone IgG injection significantly reduced all aspects of GN (i.e., vascular necrosis, podocyte loss, albuminuria, cytokine induction, recruitment or activation of glomerular leukocytes, and glomerular crescent formation). To evaluate histones as a therapeutic target, mice with established GN were treated with three different histone-neutralizing agents. Anti-histone IgG, recombinant activated protein C, and heparin were equally effective in abrogating severe GN, whereas combination therapy had no additive effects. Together, these results indicate that NET-related histone release during GN elicits cytotoxic and immunostimulatory effects. Furthermore, neutralizing extracellular histones is still therapeutic when initiated in established GN.     

Influence of different trigger techniques on twitch mouth pressure during bilateral anterior magnetic phrenic nerve stimulation

BACKGROUND: The trigger has a key role when assessing the twitch mouth pressure (Tw Pmo), since a "gentle" inspiratory or expiratory effort is needed for triggering to ensure an open glottis during twitch, but which also guarantees only very mild changes of transdiaphragmatic pressure following changes in lung volume. STUDY OBJECTIVES: To test if different trigger mechanisms cause different Tw Pmo values, if the predefined trigger criteria were accomplished, and if the breathing maneuver during triggering can influence the Tw Pmo. DESIGN: Experimental study. SETTING: Respiratory muscle and lung function laboratory of a university hospital. PARTICIPANTS: Twenty healthy men (mean age, 25.6 +/- 1.2 years [+/- SD]; mean FEV(1), 105.9 +/- 11.5% of predicted). MEASUREMENTS: Tw Pmo produced by bilateral anterior magnetic phrenic nerve stimulation was measured using an inspiratory flow trigger (40 mL/s), an inspiratory pressure trigger, and an expiratory pressure trigger (3.75 mm Hg). All trigger criteria were controlled. RESULTS: Unusable pressure-time curves occurred in 40% during expiratory triggering, but not during inspiratory triggering. For inspiratory pressure (flow) triggering, 10% (30%) of the predefined trigger criteria were exceeded by 50%, indicating that a "gentle" inspiratory effort was not warranted. The Tw Pmo was higher during inspiratory compared to expiratory triggering (analysis of variance, p < 0.05). The Tw Pmo during inspiratory pressure and flow triggering were comparable and significantly correlated (r = 0.70, p < 0.0001). The time between start of inspiration and trigger release, and the pressure-time product during that period ranged widely, but this could not predict the Tw Pmo (multiple linear regression). CONCLUSIONS: The trigger technique influences the Tw Pmo with higher values during inspiratory compared to expiratory triggering. Expiratory triggering more often produced unusable pressure-time curves. Inspiratory flow and pressure triggering is comparably useful in healthy subjects, but this might be different in patients. The trigger criteria need to be controlled to warrant a gentle breathing effort.     

Using Vascular Closure Devices Following Out-Of-Hospital Cardiac Arrest?

Objectives and Background: Despite a generally broad use of vascular closure devices (VCDs), it remains unclear whether they can also be used in victims from out-of-hospital cardiac arrest (OHCA) treated with mild therapeutic hypothermia (MTH).Methods: All victims from OHCA who received immediate coronary angiography after OHCA between January 1^st 2008 and December 31^st 2013 were included in this study. The operator decided to either use a VCD (Angio-Seal™) or manual compression for femoral artery puncture. The decision to induce MTH was based on the clinical circumstances.Results: 76 patients were included in this study, 46 (60.5%) men and 30 (39.5%) women with a mean age of 64.2 ± 12.8 years. VCDs were used in 26 patients (34.2%), and 48 patients (63.2%) were treated with MTH. While there were significantly more overall vascular complications in the group of patients treated with MTH (12.5% versus 0.0%; p=0.05), vascular complications were similar between patients with VCD or manual compression, regardless of whether or not they were treated with MTH.Conclusion: In our study, the overall rate of vascular complications related to coronary angiography was higher in patients treated with mild therapeutic hypothermia, but was not affected by the application of a vascular closure device. Therefore, our data suggest that the use of VCDs in victims from OHCA might be feasible and safe in patients treated with MTH as well, at least if the decision to use them is individually carefully determined.     

Neuroendocrine Changes in Patients with Spontaneous Supratentorial Intracerebral Hemorrhage

Background

Neuroendocrine changes have been reported after ischemic stroke, subarachnoid hemorrhage, and brain trauma. As there are no corresponding data in patients with intracerebral hemorrhage (ICH) we analyzed various neuroendocrine parameters to investigate possible alterations in hormone profiles of patients with ICH.

Methods

Twenty patients with ICH were prospectively enrolled in the study. Patients were a priori parted into two groups: Ten non-ventilated patients treated on the stroke-unit (hemorrhage volumes <20 ml, “small ICH”), and 10 ventilated patients treated on the neurocritical care unit (hematoma volumes >20 ml with possible additional ventricular involvement (“large ICH”). Neuroendocrine parameters were compared between both groups referring to reference values. The following parameters were obtained over a period of 9 days in 20 patients with spontaneous supratentorial ICH: thyrotropin, free thiiodothyronine and thyroxine, human growth hormone, insulin-like growth factor 1, luteinizing hormone, follicle-stimulating hormone, testosterone, prolactin, adrenocorticotropic hormone, and cortisol.

Results

Small ICH patients were in a median 71 (54–88) years old and had a mean ICH volume of 9.5 ± 6.5 ml, whereas large ICH patients were 65 (47–80) years old and showed a mean volume of 56 ± 30.2 ml. None of the patients revealed pathological alterations for thyrotropin, free thiiodothyronine, thyroxine, human growth hormone, insulin-like growth factor 1, and testosterone. There was only a mild decrease of adrenocorticotropic hormone and cortisol on day 3 in large ICH patients. Small ICH patients showed pathologically elevated levels of luteinizing and follicle-stimulating hormone throughout the observation period. Large ICH patients showed a marked increase of prolactin that developed during the course.

Conclusions

Overall, neuroendocrine changes in ICH patients are not as profound as reported for ischemic stroke or subarachnoid hemorrhage. The clinical significance of increased LH and FSH levels in small ICH is unclear, whereas elevation of prolactin in large ICH was anticipated. Future randomized controlled trials should also focus on neuroendocrine parameters to clarify the impact of possible hormonal alterations on functional outcome.