Survey on the current management of rapid sequence induction in Germany

BACKGROUND

The practice of rapid sequence induction (RSI) differs widely within and between countries. We undertook this web-based survey to assess the variability in the practice of RSI amongst German anesthetists. We hypothesized that considerable variability exists.

METHODS

In 2009, we electronically asked all anesthetists listed in the corporate e-mail directory of the German professional anesthesia societies to participate in a web-based survey consisting of 26 questions related to various management aspects of RSI.

RESULTS

Of 12180 listed anesthetists, 4259 opened the website (35%). Of those, 2906 answered all questions (website response rate 68.2%; overall 23.9%). The survey revealed considerable differences in the practice of RSI with regard to patient positioning, preoxygenation, use of neuromuscular blocking drugs, handling of nasogastric tube, and application of cricoid pressure. With the exception of cricoid pressure, such differences were unrelated to the anesthetist's qualification, work experience, and type and size of hospital. A majority considered preoxygenation (95%), a stylet inserted in the endotracheal tube (86%), no mask ventilation before intubation (80%), and an additional suctioning device (62%) essential components of a RSI.

CONCLUSION

This to date largest survey undertaken in the context of RSI documents large management differences in the practice of RSI amongst German anesthetists. These differences are unrelated to qualification, years of work experience and type of institution. This survey emphasizes the need for solid scientific evidence regarding all interventions undertaken in the context of RSI.

Interplay between Kondo suppression and Lifshitz transitions in YbRh2Si2 at high magnetic fields

We investigate the magnetic field dependent thermopower, thermal conductivity, resistivity, and Hall effect in the heavy fermion metal YbRh2Si2. In contrast to reports on thermodynamic measurements, we find in total three transitions at high fields, rather than a single one at 10 T. Using the Mott formula together with renormalized band calculations, we identify Lifshitz transitions as their origin. The predictions of the calculations show that all experimental results rely on an interplay of a smooth suppression of the Kondo effect and the spin splitting of the flat hybridized bands.

Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma

AIM

To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively.

MATERIALS AND METHODS

Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose-length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann-Whitney U and Wilcoxon's test were used.

RESULTS

In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p < 0.001) and scan length (p = 0.01). There was no significant difference in the subjective image quality (p > 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR).

CONCLUSION

The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma.

[Epidemiology, risk stratification and outcome of severe pediatric trauma]

Accidents and trauma are the leading cause of hospital admissions and major contributors to mortality in children and adolescents. There are age-specific injury patterns and differences in the clinical presentation of pediatric trauma and treatment both at the scene and in the emergency department can be observed. In general, pediatric trauma-scores to appreciate injury severity are adapted from the adult population.The most important factor to increase mortality in the severely injured pediatric population is the extent of a concomitant traumatic brain injury (TBI). In addition, the acute trauma-associated coagulopathy, which is triggered multifactorial, is an independent prognostic marker for mortality in severe trauma. The complexity of all currently available trauma-scores for the pediatric population is one reason why these scores are not unequivocal recommended for the early use in pediatric trauma care. The pediatric BIG-Score was developed to allow an early prognostic stratification for pediatric trauma patients and includes with base excess (BE), INR (International Normalized Ratio) and GCS (Glasgow Coma Scale) relevant prognostic factors for poor outcome. Early risk stratification is crucial in pediatric trauma due to mortality rates ranging between 9% and 15% and with 50% of all fatalities to occur within the first 24 h of hospital admission.

Structural investigations on YbRh2Si2: from the atomic to the macroscopic length scale

YbRh2Si2 has advanced to a prototype material for investigating physics related to the Kondo effect. An optimization of the synthesis resulted in single crystals of extraordinary crystalline quality. At the atomic scale, we utilize scanning tunneling microscopy to study the topography of cleaved single crystals. A structural and chemical analysis was conducted by highly accurate x-ray diffraction and wavelength dispersive x-ray spectroscopy measurements. The latter indicate a homogeneity range of the YbRh2Si2 phase between approximately 40.0–40.2 at.% Rh. For our high-quality samples the number of defects found on the atomic scale (of the order of 0.3% of the visible lattice sites) is in quantitative agreement with a very small off-stoichiometry within this homogeneity range. Comparing our results for these samples allows an assignment of the structural defects observed at the cleaved surfaces to Rh occupying Si sites and, even less numerous Si in Rh sites. Such an analysis is hampered for samples of lesser quality, but there seem to be numerous empty Si-sites. Based on these observations the results of scanning tunneling spectroscopy can be analyzed in further detail and provide insight into the Kondo physics.

Magnetism, f-electron localization and superconductivity in 122-type heavy-fermion metals

Both CeCu2Si2 and YbRh2Si2 crystallize in the tetragonal ThCr2Si2 crystal structure. Recent neutron-scattering results on normal-state CeCu2Si2 reveal a slowing down of the quasielastic response which complies with the scaling expected for a quantum critical point (QCP) of itinerant, i.e., three-dimensional spin-density-wave (SDW), type. This interpretation is in full agreement with the non-Fermi-liquid behavior observed in transport and thermodynamic measurements. The momentum dependence of the magnetic excitation spectrum reveals two branches of an overdamped dispersive mode whose coupling to the heavy charge carriers is strongly retarded. These overdamped spin fluctuations are considered to be the driving force for superconductivity in CeCu2Si2 (Tc = 600 mK). The weak antiferromagnet YbRh2Si2 (TN = 70 mK) exhibits a magnetic-field-induced QCP at BN = 0.06 T (B⊥c). There is no indication of superconductivity down to T = 10 mK. The magnetic QCP appears to concur with a breakdown of the Kondo effect. Doping-induced variations of the average unit-cell volume result in a detachment of the magnetic and electronic instabilities. A comparison of the properties of these isostructural compounds suggests that 3D SDW QCPs are favorable for unconventional superconductivity. The question whether a Kondo-breakdown QCP may also give rise to superconductivity, however, remains to be clarified.

Frequency of symptomatic zinc deficiency in very low birth weight infants

Current concepts on zinc requirements for premature infants rely on studies dating back more than 20 years. Given that nowadays more premature infants frequently survive we aimed to obtain recent frequency data on zinc deficiency in very low birth weight (VLBW) infants.226 VLBW infants born between July 2005 and December 2009 were retrospectively included in this study. Mean gestational age (GA) was 28.7 weeks (range 23+0 to 38+0) and mean birth weight 1120g (range 354-1495). All infants received zinc supplementation according to the ESPGHAN guidelines. 26 (11.5%) patients showed clinical signs for zinc deficiency of whom 15 had serum zinc concentrations < 50µg/dl, 9 between 50 and 70 µg/dl and 2 > 70 µg/dl. Infants presenting with dermatitis had significantly lower concentrations (mean 26.7 µg/dl, range 19-31) when compared to infants with diarrhoea or isolated peripheral oedema (35.3 µg/dl and 51.8 µg/dl respectively). Strongest independent risk factors were low GA, being small for GA and suffering from intestinal resection due to necrotizing enterocolitis. Frequency of zinc concentrations <50 µg/dl were calculated to be 6.6% in VLBW infants.Even though current guidelines for zinc supplementation were followed the frequency of zinc deficiency was found to be unexpectedly high in ELBW and SGA infants. Despite the retrospective nature of this single centre study, our data strongly suggest that recommendations on zinc supplementation in ELBW and SGA infants should be reviewed.