The ONTAI study - a survey on antimicrobial dosing and the practice of therapeutic drug monitoring in German intensive care units.

PURPOSE: Optimization of antibiotic therapy is still urgently needed in critically ill patients. The aim of the ONTAI survey (online survey on the use of Therapeutic Drug Monitoring of antibiotics in intensive care units) was to evaluate which strategies intensive care physicians in Germany use to improve the quality of antibiotic therapy and what role a Therapeutic Drug Monitoring (TDM) plays. METHODS: Among the members of the German Society for Anaesthesiology and the German Society for Medical Intensive Care Medicine and Emergency Medicine, a national cross-sectional survey was conducted using an online questionnaire. RESULTS: The questionnaire was completely answered by 398 respondents. Without TDM, prolonged infusion was judged to be the most appropriate dosing regimen for beta lactams. A TDM for piperacillin, meropenem and vancomycin was performed in 17, 22 and 75% of respondents, respectively. For all beta lactams, a TDM was requested more often than it was available. There was great uncertainty as to the optimal pharmacokinetic/pharmacodynamic index for beta-lactams. 86% of the respondents who received minimal inhibitory concentrations adapted the therapy accordingly. CONCLUSION: German intensive care physicians are convinced of TDM for dose optimization. However, practical implementation, the determination of MICs and defined target values are still lacking.

Therapeutic drug monitoring-guided high dose meropenem therapy of a multidrug resistant Acinetobacter baumannii - A case report.

BACKGROUND: Infections with multidrug resistant Acinetobacter baumannii in immunocompromised patients are life-threatening. Therapeutic options are rare in this context, but patients are dependent on an effective antibiotic therapy. Thus, new antibiotic strategies are deemed necessary. CASE PRESENTATION: This case report recounts the therapeutic drug monitoring-guided meropenem therapy of a 32 years old patient admitted with acute exacerbation of cystic fibrosis. Veno-venous extracorporeal membrane oxygenation was initiated on the first day of admission to the intensive care unit. The patient showed insufficient serum trough levels of meropenem despite the maximum approved dose (2g every 8h) was administered which was due to augmented renal clearance. Through continuous infusion of the same cumulative dose, target levels were reached. On day 17 of admission, the patient underwent successful double-lung-transplant surgery and extracorporeal membrane oxygenation was ended. Unfortunately, the donor's lung was colonized with a multidrug resistant Acinetobacter baumannii that was positive for OXA-23 carbapenemase. Hence a combination therapy of intravenous sulbactam, tigecycline, meropenem and inhalative colistin was established, with a known minimal inhibitory concentration for meropenem of 32 mg/l. Under continuous infusion of 8 g meropenem/day, serum levels exceeded 32 mg/l over 12 days. The patient was transferred from the intensive care unit to a general ward without any signs of infection. CONCLUSIONS: Therapeutic drug monitoring-guided meropenem may be a sound new therapeutic option in eradicating multidrug resistant Acinetobacter and offer a novel therapeutic option in the field of personalized medicine.

European survey on efficacy and safety of duty-cycled radiofrequency ablation for atrial fibrillation.

AIMS: Duty-cycled radiofrequency ablation (RFA) has been used for atrial fibrillation (AF) for around 5 years, but large-scale data are scarce. The purpose of this survey was to report the outcome of the technique. METHODS AND RESULTS: A survey was conducted among 20 centres from seven European countries including 2748 patients (2128 with paroxysmal and 620 with persistent AF). In paroxysmal AF an overall success rate of 82% [median 80%, interquartile range (IQR) 74-90%], a first procedure success rate of 72% [median 74% (IQR 59-83%)], and a success of antiarrhythmic medication of 59% [median 60% (IQR 39-72%)] was reported. In persistent AF, success rates were significantly lower with 70% [median 74% (IQR 60-92%)]; P = 0.05) as well as the first procedure success rate of 58% [median 55% (IQR 47-81%)]; P = 0.001). The overall success rate was similar among higher and lower volume centres and were not dependent on the duration of experience with duty-cycled RFA (r = -0.08, P = 0.72). Complications were observed in 108 (3.9%) patients, including 31 (1.1%) with symptomatic transient ischaemic attack or stroke, which had the same incidence in paroxysmal and persistent AF (1.1 vs. 1.1%) and was unrelated to the case load (r = 0.24, P = 0.15), bridging anticoagulation to low molecular heparin, routine administration of heparin over the long sheath, whether a transoesophageal echocardiogram was performed in every patient or not and average procedure times. CONCLUSION: Duty-cycled RFA has a self-reported success and complication rate similar to conventional RFA. After technical modifications a prospective registry with controlled data monitoring should be conducted to assess outcome.

Pectus excavatum: echocardiography and cardiac MRI reveal frequent pericardial effusion and right-sided heart anomalies.

AIMS: In patients with pectus excavatum (PEX), echocardiographic assessment can be difficult. There are little data on the impact of the chest deformity on echocardiographic findings and comparison of data obtained by echocardiography (echo) with cardiac magnetic resonance imaging (CMR) in PEX. METHODS AND RESULTS: In a prospective study, cardiac anomalies in PEX were analysed by echo and compared with CMR in consecutive patients with PEX referred for echo. If they agreed to participate, the patients were referred for CMR and included if the pectus index was ≥3.0 by CMR. Also, clinical data and electrocardiogram tracings were analysed. There were 18 patients (13 females; 72%), with a mean age of 53±16 years; mean pectus index was 4.7 (range: 3-7.3). Echo showed haemodynamically insignificant pericardial effusion in six patients (33%), tricuspid valve prolapse in five (28%), right ventricular (RV) localized wall motion anomalies (WMA) in five (28%) and diminished RV systolic function in two (11%); no patient had RV dilatation. CMR demonstrated cardiac displacement to the left in 9 patients (50%); minimal pericardial effusion was seen in 10 patients (56%; P value=0.13 compared with echo), RV localized WMA in 6 (44%; P value=1.0), diminished RV systolic function in 8 (44%; P=0.07), and RV dilatation in 5 (28%; P=0.06). A completely normal cardiac examination was found in six patients by echo (33%) and in 2 (11%) using CMR. Although some signs of arrhythmogenic RV cardiomyopathy (ARVC) were present, no patient fulfilled the ARVC criteria. CONCLUSION: In severe PEX, haemodynamically insignificant pericardial effusion, tricuspid valve prolapse and other RV anomalies possibly due to RV displacement are frequent as demonstrated by both CMR and echo. The cardiac assessment by echo and CMR did show discrepancies; however, they were not significant.

Response analysis of stimulating efficacy of polihexanide in an in vitro wound model with respiratory ciliary epithelial cells.

In animal wound models, accelerated wound closure has been shown by use of polihexanide applied in antimicrobially effective concentrations. Additionally, an increased ATP production of keratinocytes in vitro induced by polihexanide was demonstrated and interpreted as a stimulatory effect on cell proliferation. Based on these results and the clinical reports on improved wound healing after introduction of polihexanide for preoperative antisepsis in the nasal cavity, polihexanide was tested in a wound model on respiratory ciliary epithelial cells allowing measurement of the healing process after artificial injury. 0.5 µg/ml polihexanide accelerated wound healing in terms of proliferation and migration significantly after an exposure time of 1 and 96 h. At a concentration of 1 µg/ml polihexanide, the stimulation of wound healing was significantly increased only after an exposure time of 96 h. This is the first study to demonstrate acceleration of wound healing in a standardized in vitro model using an epithelial cell line. Considering the present results and previous reports on the impact of polihexanide on wound healing, the conclusion is drawn that the positive effect of polihexanide on wound healing is a separate, dose-dependent effect independent of its antiseptic properties.

[Atrial flutter and fibrillation]. / Vorhofflimmern und Vorhofflattern.

This article summarizes current understandings and therapies for both arrhythmias. Atrial flutter is most often arising from a macroreentry circuit in the right atrium or around scar tissue in case or previous cardiothoracic surgery. As a macroreentrant tachycardia it is regular and can lead to higher heart rates, especially if occurring with 1:1 conduction. In contrast atrial fibrillation, especially when occurring paroxysmal at the beginning, is arising from triggers within the pulmonary veins. Ablation strategies to electrically isolate those triggers have a treatment success rate of 80%, which is much more than can be achieved with antiarrhythmic medication (success rates 30-50%). Emergency treatment of both arrhythmias include cardioversion and pacemaker implantation with AV node ablation if necessary.

[Stress, depression and cardiac arrhythmias]. / Stress, Depression und kardiale Arrhythmien.

A relationship between behavioural factors and cardiac arrhythmogenesis in humans has been described. Three sets of conditions contribute to the occurrence of arrhythmias: myocardial electrical instability, most often due to coronary artery disease; an acute triggering event, frequently related to mental stress; and a chronic, pervasive, and intense psychological state, often including depression and hopelessness. The autonomic nervous system plays an important role in the occurrence of cardiac arrhythmias and it is well documented that mood alterations as mental stress and depression influence cardiac autonomic balance. There is an increasing body of evidence that patients with the greatest changes in cardiac neural regulation with decreased parasympathetic tone coupled with increased sympathetic activity are at the greatest risk for developing fatal ventricular arrhythmias. These patients have a reduced heart rate variability, increased QT-dispersion and a decreased baroreceptor sensitivity. The influence of stress and depression on the autonomic nervous system and the impact on the occurrence of both atrial and ventricular arrhythmias is being discussed.

[Cholestatic jaundice and pruritus]. / Cholestatischer Ikterus und Pruritus.

The 38 year old male patient was admitted to our clinic with jaundice and invalidating pruritus of unknown origin. The primary evaluation made by the practitioner of the patient and the initial examinations performed in the clinic revealed no diagnosis. In particular, an infectious liver disease could be excluded. Reevaluation of anamnestic data revealed then the in-take of Dianabol, an often used anabolic steroid as the most possible reason for the cholestatic hepatopathy.

Sudden cardiac death after coronary artery bypass grafting is not predicted by signal-averaged ECG.

BACKGROUND: Sudden cardiac death (SCD) is a major cause of death despite successful revascularization in patients with coronary artery disease. The signal-averaged ECG (SAECG) is a sensitive predictor of SCD and could be used in the screening strategy to select patients for prophylactic cardioverter implantation. METHODS: The SAECG was recorded in 561 patients (mean age: 60 +/- 8.8 years) within 10 days of coronary artery bypass grafting. Signal-averaged ECG was performed with a bandpass filtering of 40 to 250 Hz for more than 250 beats until a noise level of 0.6 microV was achieved. All patients were followed for 5.5 +/- 1.2 years after the procedure. RESULTS: Preoperative angiographic ejection fraction was at least 60% in 393 patients (72%), 40% to 60% in 126 patients (23%), and 40% or less in 28 patients (5%). There were 34 deaths, 10 of which were SCD. Late potentials were found in a total of 150 patients (27%) and were equally frequent preoperatively and postoperatively and among patients with (30%) and without (27%) SCD. The only predictors for overall mortality were age and a reduced ejection fraction. CONCLUSIONS: Signal-averaged ECG did not predict prognosis in low-risk patients undergoing coronary artery bypass grafting.

Tumour-related enzyme alterations in the clear cell type of human renal cell carcinoma identified by two-dimensional gel electrophoresis.

To identify tumour-related enzyme alterations we have used 2D-gels to analyse the proteome from dissected malignant and benign kidney areas from patients with clear-cell-type renal carcinoma. The expression of 12 proteins was diminished in tumour. Four proteins were characterized by mass spectrometry and were identified as enoyl-CoA hydratase, alpha-glycerol-3-phosphate dehydrogenase, aldehyde dehydrogenase 1 and aminoacylase-I.

A comprehensive two-dimensional map of cytosolic proteins of Bacillus subtilis.

Proteomics relying on two-dimensional (2-D) gel electrophoresis of proteins followed by spot identification with mass spectrometry is an excellent experimental tool for physiological studies opening a new perspective for understanding overall cell physiology. This is the intriguing outcome of a method introduced by Klose and O'Farrell independently 25 years ago. Physiological proteomics requires a 2-D reference map on which most of the main proteins were identified. In this paper, we present such a reference map with more than 300 entries for Bacillus subtilis proteins with an isoelectric point (pI) between 4 and 7. The most abundant proteins of exponentially growing cells were compiled and shown to perform mainly housekeeping functions in glycolysis, tricarboxylic acid cycle (TCC), amino acid biosynthesis and translation as well as protein quality control. Furthermore, putative post-translational modifications were shown at a large scale, with 47 proteins in total forming more than one spot. In a few selected cases evidence for phosphorylation of these proteins is presented. The proteome analysis in the standard pI range was complemented by either stretching the most crowded regions in a narrow pH gradient 4.5-5.5, or by adding other fractions of the total B. subtilis proteome such as alkaline proteins as well as extracellular proteins. A big challenge for future studies is to provide an experimental protocol covering the fraction of intrinsic membrane proteins that almost totally escaped detection by the experimental procedure used in this study.

[Ventricular tachycardia]. / Ventrikuläre Tachykardien.

In patients with ventricular tachycardias, various structural and functional conditions can be influenced by certain triggers, initiating the mechanism of the arrhythmia. Thorough understanding of these different factors is paramount for the appropriate choice of treatment. Several options are available for the management of ventricular tachycardias: antiarrhythmic drugs, ICD implantation and catheter ablation or a combination of the above. The prognosis of an individual patient is determined by the underlying disease, the mechanism of tachycardia and the selected therapy. The complexity of several conditions requires a specialized diagnostic approach and tailored medical management. Therefore the patients with the following diagnoses should be referred to a specialized electrophysiology center: survivors of sudden cardiac death old infarct scar, reduced ejection fraction and complex ectopy Cardiomyopathy with syncope or ventricular tachycardias Long QT-Syndrome Brugada Syndrome Right Ventricular Dysplasia recurrent syncopes of unclear etiology.

Characterization of the sigma(B) regulon in Staphylococcus aureus.

The sigma(B)-dependent stress regulon in gram-positive bacteria might fulfill a physiological role in stress response and virulence similar to that of the sigma(S) regulon in Escherichia coli and other gram-negative bacteria. In order to obtain evidence for the function of the sigma(B) regulon of Staphylococcus aureus, especially in virulence control, sigma(B)-dependent stress genes were identified. The two-dimensional protein pattern of wild-type cells of S. aureus COL was compared with that of an isogenic sigB mutant. By this approach, we found that the synthesis of about 27 cytoplasmic proteins seemed to be under the positive control of sigma(B). N-terminal sequencing of 18 proteins allowed the identification of their genes on the almost finished genome sequence of S. aureus COL and the analysis of the promoter structure. Transcriptional analyses of 11 of these genes confirmed their sigma(B) dependency, and moreover, about 7 additional sigma(B)-dependent genes were found which are cotranscribed with the newly detected genes, forming operons. Altogether, we identified 23 sigma(B)-dependent genes and their corresponding proteins. Among them are proteins probably involved in the generation of NADH or in membrane transport mechanisms. Furthermore, at least one clpC-homologous gene was localized on the S. aureus sequence solely transcribed by sigma(B). In contrast, a second clpC-homologous gene in S. aureus forming an operon with ctsR, yacH, and yacI was sigma(B) independently expressed.

Monitoring of genes that respond to overproduction of an insoluble recombinant protein in Escherichia coli glucose-limited fed-batch fermentations.

The cellular response of Escherichia coli to overproduction of the insoluble heterologous protein alpha-glucosidase of Saccharomyces cerevisiae during a glucose-limited fed-batch fermentation was analyzed on the transcriptional and the translational levels. After the induction of the tac-regulated overexpression of the recombinant model protein, a significant but transient increase of the mRNA levels of the heat shock genes lon and dnaK could be observed. The mRNA level of the gene coding for the inclusion body-associated protein IbpB showed the strongest increase and remained at a clearly higher level until the end of the fermentation. By contrast, the mRNA levels of htrA and ppiB were decreased after induction of the alpha-glucosidase overexpression. Analysis of the soluble cytoplasmic protein fraction 3 h after induction revealed increased levels of the chaperones GroEL, DnaK, and Tig and a decrease in the protein levels of the two ribosomal proteins S6 and L9, the peptidylprolyl-cis-trans-isomerase PpiB, and the sigma(38)-dependent protein Dps. Analysis of the aggregated protein fraction revealed a remarkably inhomogeneous composition of the alpha-glucosidase inclusion bodies. N-terminal sequencing and MALDI-TOF mass spectrometry identification showed that most of these spots are fragments of the heterologous alpha-glucosidase. Host stress proteins, like DnaK, GroEL, IbpA, IbpB, and OmpT, have been found to be associated with the alpha-glucosidase protein aggregates.