Improved recall of handover information in a simulated emergency - A randomised controlled trial

Background

Handovers during medical emergencies are challenging due to time-critical, dynamic and oftentimes unorderly and distracting situations. We evaluated the effect of distraction-reduced clinical surroundings during handover on (1) the recall of handover information, (2) the recall of information from the surroundings and (3) self-reported workload in a simulated in-hospital cardiac arrest scenario.

Methods

In a parallel group design, emergency team leaders were randomly assigned to receive a structured handover of a cardio-pulmonary resuscitation (CPR) either inside the room ("inside group") right next to the ongoing CPR or in front of the room ("outside group") with no audio-visual distractions from the ongoing CPR. Based on the concept of situation awareness, the primary outcome was a handover score for the content of the handover (0-19 points) derived from the pieces of information given during handover. Furthermore, we assessed team leaders' perception of their surroundings during the scenario (0-5 points) and they rated their subjective workload using the NASA Task Load Index.

Results

The outside group (n = 30) showed significant better recall of handover information than the inside group (n = 30; mean difference = 1.86, 95% CI = 0.67 to 3.06, p = 0.003). The perception of the surroundings (n = 60; mean difference = -0.27, 95% CI = -0.85 to 0.32, p = 0.365) and the NASA Task Load Index (n = 58; mean difference = 1.1; p = 0.112) did not differ between the groups.

Conclusions

Concerning in-hospital emergencies, a structured handover in a distraction reduced environment can improve information uptake of the team leader.

Guiding Attention via a Cognitive Aid During a Simulated In-Hospital Cardiac Arrest Scenario: A Salience Effort Expectancy Value Model Analysis

OBJECTIVE

To investigate the effect of a cognitive aid on the visual attention distribution of the operator using the Salience Effort Expectancy Value (SEEV) model.

BACKGROUND

Cognitive aids aim to support an operator during the execution of a task. The effect of cognitive aids on performance is frequently evaluated but whether a cognitive aid improved, for example, attention distribution has not been considered.

METHOD

We built the Expectancy Value (EV) model version which can be considered to indicate optimal attention distribution for a given event. We analyzed the eye tracking data of emergency physicians while using a cognitive aid application versus no application during a simulated in-hospital cardiac arrest scenario.

RESULTS

The EV model could fit the attention distribution in such a simulated emergency situation. Partially supporting our hypothesis, the cognitive aid application group showed a significantly better EV model fit than the no application group in the first phases of the event, but a worse fit in the last phase.

CONCLUSION

We demonstrated that a cognitive aid affected attention distribution and that the SEEV model provides the means of capturing these effects. We suggest that the aid supported and improved visual attention distribution in the stressful first phases of a cardiopulmonary resuscitation but may have focused attention on objects that are relevant for lower priority goals in the last phase.

APPLICATION

The SEEV model can provide insights into expected and unexpected effects of cognitive aids on visual attention distribution and may help to design better artifacts.

Conventional versus video-assisted laryngoscopy for perioperative endotracheal intubation (COVALENT) - a randomized, controlled multicenter trial

BACKGROUND

Data on the routine use of video-assisted laryngoscopy in peri-operative intubations are rather inconsistent and ambiguous, in part due to small populations and non-uniform outcome measures in past trials. Failed or prolonged intubation procedures are a reason for relevant morbidity and mortality. This study aims to determine whether video-assisted laryngoscopy (with both Macintosh-shaped and hyperangulated blades) is at least equal to the standard method of direct laryngoscopy with respect to the first-pass success rate. Furthermore, validated tools from the field of human factors will be applied to examine within-team communication and task load during this critical medical procedure.

METHODS

In this randomized, controlled, three-armed parallel group design, multi-centre trial, a total of more than 2500 adult patients scheduled for perioperative endotracheal intubation will be randomized. In equally large arms, video-assisted laryngoscopy with a Macintosh-shaped or a hyperangulated blade will be compared to the standard of care (direct laryngoscopy with Macintosh blade). In a pre-defined hierarchical analysis, we will test the primary outcome for non-inferiority first. If this goal should be met, the design and projected statistical power also allow for subsequent testing for superiority of one of the interventions. Various secondary outcomes will account for patient safety considerations as well as human factors interactions within the provider team and will allow for further exploratory data analysis and hypothesis generation.

DISCUSSION

This randomized controlled trial will provide a solid base of data in a field where reliable evidence is of major clinical importance. With thousands of endotracheal intubations performed every day in operating rooms around the world, every bit of performance improvement translates into increased patient safety and comfort and may eventually prevent significant burden of disease. Therefore, we feel confident that a large trial has the potential to considerably benefit patients and anaesthetists alike.

TRIAL REGISTRATION

ClincalTrials.gov NCT05228288.

PROTOCOL VERSION

1.1, November 15, 2021.

The Validity of the SEEV Model as a Process Measure of Situation Awareness: The Example of a Simulated Endotracheal Intubation

OBJECTIVE

In the context of anesthesiology, we investigated whether the salience effort expectancy value (SEEV) model fit is associated with situation awareness and perception scores.

BACKGROUND

The distribution of visual attention is important for situation awareness-that is, understanding what is going on-in safety-critical domains. Although the SEEV model has been suggested as a process situation awareness measure, the validity of the model as a predictor of situation awareness has not been tested.

METHOD

In a medical simulation, 31 senior and 30 junior anesthesiologists wore a mobile eye tracker and induced general anesthesia into a simulated patient. When inserting a breathing tube into the mannequin's trachea (endotracheal intubation), the scenario included several clinically relevant events for situation awareness and general events in the environment. Both were assessed using direct awareness measures.

RESULTS

The overall SEEV model fit was good with no difference between junior and senior anesthesiologists. Overall, the situation awareness scores were low. As expected, the SEEV model fits showed significant positive correlations with situation awareness level 1 scores.

CONCLUSION

The SEEV model seems to be suitable as a process situation awareness measure to predict and investigate the perception of changes in the environment (situation awareness level 1). The situation awareness scores indicated that anesthesiologists seem not to perceive the environment well during endotracheal intubation.

APPLICATION

The SEEV model fit can be used to capture and assess situation awareness level 1. During endotracheal intubation, anesthesiologists should be supported by technology or staff to notice changes in the environment.

The use of a cognitive aid app supports guideline-conforming cardiopulmonary resuscitations: A randomized study in a high-fidelity simulation

Aim

Cardiac arrests require fast, well-timed, and well-coordinated interventions delivered by several staff members. We evaluated a cognitive aid that works as an attentional aid to support specifically the timing and coordination of these interventions. We report the results of an experimental, simulation-based evaluation of the tablet-based cognitive aid in performing guideline-conforming cardiopulmonary resuscitation.

Methods

In a parallel group design, emergency teams (one qualified emergency physician as team leader and one qualified nurse) were randomly assigned to the cognitive aid application (CA App) group or the no application (No App) group and then participated in a simulated scenario of a cardiac arrest. The primary outcome was a cardiopulmonary resuscitation performance score ranging from zero to two for each team based on the videotaped scenarios in relation to twelve performance variables derived from the European Resuscitation Guidelines. As a secondary outcome, we measured the participants’ subjective workload.

Results

A total of 67 teams participated. The CA App group (n = 32 teams) showed significantly better cardiopulmonary resuscitation performance than the No App group (n = 31 teams; mean difference = 0.23, 95 %CI = 0.08 to 0.38, p = 0.002, d = 0.83). The CA App group team leaders indicated significantly less mental and physical demand and less effort to achieve their performance compared to the No App group team leaders.

Conclusions

Among well-trained in-hospital emergency teams, the cognitive aid could improve cardiopulmonary resuscitation coordination performance and decrease mental workload.

Why and How to Approach User Experience in Safety-Critical Domains: The Example of Health Care

OBJECTIVE

To highlight the importance of the personal experience of users who interact with technology in safety-critical domains and summarize three interaction concepts and the associated theories that provide the means for addressing user experience.

BACKGROUND

In health care, the dominant concepts of interaction are based on theories arising from classic cognitive psychology. These concepts focus mainly on safety and efficiency, with too little consideration being given to user experience.

METHOD

Users in complex socio-technical and safety-critical domains such as health care interact with many technological devices. Enhancing the user experience could improve the design of technology, enhance the well-being of staff, and contribute to modern safety management. We summarize concepts of "interaction" based on modern theories of human-computer interaction, which include the personal experience of users as an important construct.

RESULTS AND CONCLUSION

Activity theory, embodiment, and interaction as experience provide a theoretical foundation for considering user experience in safety-critical domains. Using an example from anesthesiology, we demonstrate how each theory provides a unique but complementary view on experience. Finally, the methodological possibilities for considering personal experience in design and evaluations vary among the theories.

APPLICATION

Considering user experience in health care and potentially other safety-critical domains can provide an additional means of optimizing interaction with technology, contributing to the well-being of staff, and improving safety.

Closing the gap - inclusion of ultrashort-chain perfluoroalkyl carboxylic acids in the total oxidizable precursor (TOP) assay protocol

An improved protocol of the total oxidizable precursor (TOP) assay was developed for precursors to C₂-C₁₄ perfluoroalkyl carboxylic acids (PFCAs) and C₄-C₈ and C₁₀ perfluoroalkyl sulfonic acids (PFSAs). The proposed protocol was tested and validated for contaminated soil samples. The perfluoroalkyl acids (PFAAs) present in the soil extract solutions after oxidation with persulfate were separated from the inorganic salts by vacuum-assisted drying of the digestion solution followed by solid-liquid extraction of the PFAAs with acetonitrile from the dry residue. Ion chromatography (for C₂-C₄ PFCAs) and reversed phase liquid chromatography (for all other PFASs), both coupled to tandem mass spectrometry, were used for quantification. High procedural recoveries of PFAAs between 68% and 123% with RSDs between 0.2% and 25% (n = 3) were achieved. The method was validated using selected polyfluoroalkyl phosphoric acid esters (PAPs) and bis-[2-(N-ethyl perfluorooctane-1-sulfonamido)ethyl] phosphoric acid ester (diSAmPAP) as model precursors in pure solutions and in the presence of soil matrix. The oxidation led to characteristic and reproducible PFCA patterns (in the case of PAPs) or PFOA (in the case of diSAmPAP) with total reaction yields between 92 ± 4% and 123 ± 13% (n = 3). The impact of the soil matrix on transformation yields was negligible. In a soil core from a PFAS-polluted agricultural site, precursors were concentrated in the upper 40 cm with long-chain precursors being prevalent. After oxidative digestion, the total molar PFAA-concentrations increased by factors of 1.6 to 5.0. More than 40 cm below ground precursors of TFAA, PFPrA and PFBA accounted for ∼50% of the reaction products, underlining the importance of their inclusion in mass balances based on the TOP assay.

Trace-level determination of phosphonates in liquid and solid phase of wastewater and environmental samples by IC-ESI-MS/MS

Phosphonates are increasingly used as water-softening agents in detergents, care products, and industrial processes. Despite poor biodegradability, high removal rates during wastewater treatment (WWT) have been observed, owing to strong adsorption affinity to activated sludge and mineral surfaces. Due to phosphonates representing challenging analytes, no method for the compound-specific quantification of phosphonates from solid samples has hitherto been published. In order to improve the data foundation on the environmental fate of phosphonates, an analytical method based on anion exchange chromatography and detection by electrospray ionization coupled to tandem mass spectrometry (IC-ESI-MS/MS) was developed, allowing the trace quantification of phosphonates from surface water (LOQs between 0.04 and 0.16 μg/L), wastewater (LOQs between 0.6 and 2.3 μg/L), sediment and suspended matter of rivers (LOQ < 0.1 mg/kg), and suspended matter of wastewater (LOQ < 1 mg/kg). Specificity and selectivity were enhanced by the implementation of isotope-labeled internal phosphonate standards derived through synthesis. This study describes the development of a comprehensive tool set for the determination of aminotris(methylenephosphonic acid) (ATMP), diethylenetriaminepenta(methylenephosphonic acid) (DTPMP), ethylenediaminetetra(methylenephosphonic acid) (EDTMP), 1-hydroxyethanediphosphonic acid (HEDP), and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) during WWT and in the aqueous environment. In the investigated matrices, HEDP and PBTC were generally present in highest and EDTMP in lowest abundance. The phosphonate contents detected in river water were in the sub to low μg/L range, depending on the wastewater burden, whereas contents in the low to medium μg/L range were found in untreated wastewater. The loads of the solid phases exceeded the contents of the corresponding liquid phases by roughly three orders of magnitude. Current data imply that phosphonates undergo significant partitioning to the solid phase during WWT and in natural water bodies. Graphical abstract.

Approach for analytical characterization and toxicological assessment of ozonation products in drinking water on the example of acesulfame

The monitoring and control of drinking water quality is generally important as it significantly contributes to the health of the population. In this context, particular attention has to be paid to the use of treatment techniques during drinking water treatment. It is known that the formation of reaction products (transformation products) has to be taken into account when oxidizing agents such as ozone are used. Different transformation products are classified as critical to health and require analytical examination. The risk assessment for previously unknown transformation products can be difficult as far as not all transformation products are present as single substances or the individual substances are not present in a sufficient high concentration or cannot be isolated from the original solution. The aim of this work is to show exemplarily the identification and quantification of ozonation products (OPs) after ozonation and their toxicological characterization, using the artificial sweetener acesulfame. It was shown that OPs can be fully characterized using ion chromatography in combination with different detection systems. A major OP could be recovered as a pure substance by crystallization and direct genotoxicological testing was possible without previous enrichment processes. Acesulfame samples of different concentrations in ultrapure and in drinking water after ozonation were tested in several genotoxicity tests. These tests revealed genotoxic effects of acesulfame after ozonation in ultrapure water in several genotoxicological test systems (micronucleus test, umu test, Ames-fluctuation-test and comet assay). In contrast, the crystallized ozonation product OP168 did not show any positive effects. Therefore, it seems likely that the observed effect was caused by the second major product OP170. However, a sufficiently large amount of analytically pure substance OP170 could not be obtained. It was also shown that the rate of the OP170 formation in drinking water is significantly lower than in ultrapure water and that ozonation in drinking water did not induce genotoxic effects.

An exploratory clinical evaluation of a head-worn display based multiple-patient monitoring application: impact on supervising anesthesiologists' situation awareness

PURPOSE

Supervising anesthesiologists overseeing several operating rooms must be aware of the status of multiple patients, so they can consult with the anesthetist in single operating rooms or respond quickly to critical events. However, maintaining good situation awareness can be challenging when away from patient bedsides or a central monitoring station. In this proof-of-concept study, we evaluated the potential of a head-worn display that showed multiple patients' vital signs and alarms to improve supervising anesthesiologists' situation awareness.

METHODS

Eight supervising anesthesiologists each monitored the vital signs of patients in six operating rooms for 3 h with the head-worn display, and for another 3 h without the head-worn display. In interviews with each anesthesiologist, we assessed in which situations the head-worn display was used and whether the continuous availability of the vital signs improved situation awareness. We also measured situation awareness quantitatively from six of the eight anesthesiologists, by instructing them to press a button whenever they noticed a patient alarm.

RESULTS

The median number of patient alarms occurring was similar when the anesthesiologists monitored with the head-worn display (42.0) and without the head-worn display (40.5). However, the anesthesiologists noticed significantly more patient alarms with the head-worn display (66.7%) than without (7.1%), P = 0.028, and they reported improved situation awareness with the head-worn display. The head-worn display helped the anesthesiologists to perceive and comprehend patients' current status and to anticipate future developments. A negative effect of the head-worn display was its tendency to distract during demanding procedures.

CONCLUSIONS

Head-worn displays can improve supervising anesthesiologists' situation awareness in multiple-patient monitoring situations. The anesthesiologists who participated in the study expressed enthusiasm about monitoring patients with a head-worn display and wished to use and evaluate it further.

Small, mobile, persistent: Trifluoroacetate in the water cycle - Overlooked sources, pathways, and consequences for drinking water supply

Elevated concentrations of trifluoroacetate (TFA) of more than 100 μg/L in a major German river led to the occurrence of more than 20 μg/L TFA in bank filtration based tap waters. Several spatially resolved monitoring programs were conducted and discharges from an industrial company were identified as the point source of TFA contamination. Treatment options for TFA removal were investigated at full-scale waterworks and in laboratory batch tests. Commonly applied techniques like ozonation or granulated activated carbon filtration are inappropriate for TFA removal, whereas TFA was partly removed by ion exchange and completely retained by reverse osmosis. Further investigations identified wastewater treatment plants (WWTPs) as additional TFA dischargers into the aquatic environment. TFA was neither removed by biological wastewater treatment, nor by a retention soil filter used for the treatment of combined sewer overflows. WWTP influents can even bear a TFA formation potential, when appropriate CF₃-containing precursors are present. Biological degradation and ozonation batch experiments with chemicals of different classes (flurtamone, fluopyram, tembotrione, flufenacet, fluoxetine, sitagliptine and 4:2 fluorotelomer sulfonate) proved that there are yet overlooked sources and pathways of TFA, which need to be addressed in the future.

A Tablet-Based Documentation Tool for In-Hospital Resuscitations

The exact documentation of cardiopulmonary resuscitations—in particular the exact time of intervention delivery—is important for checking and improving quality. However, due to time-critical, stressful treatment and mostly retrospective documentation, data quality is often poor. This paper describes the development of a tablet-based application for documentation of in-hospital cardiopulmonary resuscitations that enables real-time documentation by a member of the resuscitation team. The application was developed following a comprehensive user-centered design process. Due to an efficient context-related information architecture, the application has the potential to enable real-time documentation of certain interventions and to accelerate time-consuming documentation after the resuscitation ended. Furthermore, the use of the application may contribute to the optimization of resuscitation processes and resuscitation training by providing more accurate and reliable data.

Eye Tracking in Anesthesiology

Eye tracking has become a valuable method to study performance and cognition in diverse settings. For the present paper, we reviewed the literature on eye tracking in anesthesiology and identified nine publications. We have summarized the method and results of these publications. Further, we identified and discussed several methodological issues that occur when conducting eye tracking in anesthesiology, such as sample size, large data loss, and differences in study settings. Finally, we suggest future research topics in anesthesiology, which may particularly benefit from eye tracking.

Real-time tablet-based resuscitation documentation by the team leader: evaluating documentation quality and clinical performance

Background

Precise and complete documentation of in-hospital cardiopulmonary resuscitations is important but data quality can be poor. In the present study, we investigated the effect of a tablet-based application for real-time resuscitation documentation used by the emergency team leader on documentation quality and clinical performance of the emergency team.

Methods

Senior anaesthesiologists either used the tablet-based application during the simulated resuscitation for documentation and also used the application for the final documentation or conducted the full documentation at the end of the scenario using the local hospital information system. The latter procedure represents the current local documentation method. All scenarios were video recorded. To assess the documentation, we compared the precision of intervention delivery times, documentation completeness, and final documentation time. To assess clinical performance, we compared adherence to guidelines for defibrillation and adrenaline administration, the no-flow fraction, and the time to first defibrillation.

Results

The results showed significant benefits for the tablet-based application compared to the hospital information system for precision of the intervention delivery times, the final documentation time, and the no-flow fraction. We observed no differences between the groups for documentation completeness, adherence to guidelines for defibrillation and adrenaline administration, and the time to first defibrillation.

Discussion

In the presented study, we observed that a tablet-based application can improve documentation data quality. Furthermore, we demonstrated that a well-designed application can be used in real-time by a member of the emergency team with possible beneficial effects on clinical performance.

Conclusion

The present evaluation confirms the advantage of tablet-based documentation tools and also shows that the application can be used by an active member of an emergency team without compromising clinical performance.

Monitoring of in-hospital cardiac arrest events with the focus on Automated External Defibrillators--a retrospective observational study

Background

Patients with cardiac arrest have lower survival rates, when resuscitation performance is low. In In-hospital settings the first responders on scene are usually nursing staff without rhythm analysing skills. In such cases Automated External Defibrillators (AED) might help guiding resuscitation performance. At the Wuerzburg University Hospital (Germany) an AED-program was initiated in 2007.

Aim of the presented study was to monitor the impact of Automated External Defibrillators on the management of in-hospital cardiac arrest events.

Methods

The data acquisition was part of a continuous quality improvement process of the Wuerzburg University Hospital. For analysing the CPR performance, the chest compression rate (CCR), compression depth (CCD), the no flow fraction (NFF), time interval from AED-activation to the first compression (TtC), the time interval from AED-activation to the first shock (TtS) and the post schock pause (TtCS) were determined by AED captured data. A questionnaire was completed by the first responders.

Results

From 2010 to 2012 there were 359 emergency calls. From these 53 were cardiac arrests with an AED-application. Complete data were available in 46 cases. The TtC was 34 (32–52) seconds (median and IQR).The TtS was 30 (28–32) seconds (median and IQR) . The TtCS was 4 (3–6) seconds (median and IQR) . The CCD was 5.5 ± 1 cm while the CCR was 107 ± 11/min. The NFF was calculated as 41 %.

ROSC was achieved in 21 patients (45 %), 8 patients (17 %) died on scene and 17 patients (37 %) were transferred under ongoing CPR to an Intensive Care Unit (ICU).

Conclusion

The TtS and TtC indicate that there is an AED-user dependent time loss. These time intervals can be markedly reduced, when the user is trained to interrupt the AED’s “chain of advices” by placing the electrode-paddles immediately on the patient’s thorax. At this time the AED switches directly to the analysing mode. Intensive training and adaption of the training contents is needed to optimize the handling of the AED in order to maximize its advantages and to minimize its disadvantages.

Body posture during simulated tracheal intubation: GlideScope(®) videolaryngoscopy vs Macintosh direct laryngoscopy for novices and experts

Tracheal intubation requires the anaesthetist to adopt an awkward body posture. To investigate how posture may be improved, we compared the effects of laryngoscopy technique (GlideScope(®) vs Macintosh blade) and experience (novices vs experts) on body posture angles and the Rapid Entire Body Assessment postural analysis score. Novices (25 medical students) and experts (26 anaesthetists) were video-recorded performing intubation in a manikin using both devices. The GlideScope resulted in smaller deflections for all analysed posture angles (all p values < 0.001) except the wrist compared with the Macintosh blade. Novices showed more trunk (p < 0.001) and neck (p = 0.002) flexion than experts. Using the GlideScope resulted in a lower Rapid Entire Body Assessment score compared with using the Macintosh blade (p < 0.001), indicating that the GlideScope resulted in body posture less likely to induce musculoskeletal injuries. From an ergonomic point of view, the GlideScope should be the preferred technique for laryngoscopy.

Emerging nitrogenous disinfection byproducts: Transformation of the antidiabetic drug metformin during chlorine disinfection of water

As an environmental contaminant of anthropogenic origin metformin is present in the high ng/L- up to the low μg/L-range in most surface waters. Residues of metformin may lead to the formation of disinfection by-products during chlorine disinfection, when these waters are used for drinking water production. Investigations on the underlying chemical processes occurring during treatment of metformin with sodium hypochlorite in aqueous medium led to the discovery of two hitherto unknown transformation products. Both substances were isolated and characterized by HPLC-DAD, GC-MS, HPLC-ESI-TOF, (1)H-NMR and single-crystal X-ray structure determination. The immediate major chlorination product is a cyclic dehydro-1,2,4-triazole-derivate of intense yellow color (Y; C4H6ClN5). It is a solid chlorimine of limited stability. Rapid formation was observed between 10 °C and 30 °C, as well as between pH 3 and pH 11, in both ultrapure and tap water, even at trace quantities of reactants (ng/L-range for metformin, mg/L-range for free chlorine). While Y is degraded within a few hours to days in the presence of light, elevated temperature, organic solvents and matrix constituents within tap water, a secondary degradation product was discovered, which is stable and colorless (C; C4H6ClN3). This chloroorganic nitrile has a low photolysis rate in ambient day light, while being resistant to heat and not readily degraded in the presence of organic solvents or in the tap water matrix. In addition, the formation of ammonia, dimethylamine and N,N-dimethylguanidine was verified by cation exchange chromatography.

Transformation of the artificial sweetener acesulfame by UV light

The transformation of the artificial sweetener acesulfame by direct photolysis was investigated at various pH values, in different water types and at various concentration levels. Main photodegradation products of acesulfame were elucidated and analyzed both in laboratory experiments and in a full-scale waterworks using UV treatment for disinfection purposes. The degradation of acesulfame was found to be independent of the pH (range 5-11) and followed pseudo first order kinetics in a concentration range between 1 μg∙L(-1) and 10 mg∙L(-1). Calculated rate constants were in the range between 5.4·10(-3)s(-1) and 7.4·10(-3)s(-1). The main photodegradation products of acesulfame were separated by ion exchange chromatography and high performance liquid chromatography and were identified as hydroxylated acesulfame and iso-acesulfame by high resolution mass spectrometry and fragmentation experiments. In the case of iso-acesulfame an intramolecular rearrangement is assumed as the transformation product has a higher polarity and different product ions after MS fragmentation compared to acesulfame. Minor transformation products were identified as amidosulfonic acid and sulfate by comparison with analytical standards. The transformation pathway was found to be transferable to drinking water production as the identified transformation products were also detected to a similar extent in fortified tap water. In a Swiss full-scale waterworks acesulfame concentrations were reduced by approximately 30% and one of the main UV transformation products could be qualitatively detected.

[Helsinki Declaration on Patient Safety in Anaesthesiology--Part 8: SOP for checking equipment and drugs]

In 2010 the Helsinki Declaration on Patient Safety in Anaesthesiology was launched. In this joined statement under the auspice of the European Society of Anaesthesiology the need for protocols for different aspects of perioperative procedures that could affect patient safety was stated. All participating institutions should have--among others--protocols for checking equipment and drugs required for the delivery of safe anaesthesia. The background for this being the fact that the lack of carefully checking equipment and drugs--or not adhering to existing checklists--is a latent threat to patient safety and thus may increase morbidity and mortality.In this part of a series the authors present protocols existing in their clinic for checking anaesthesia equipment and drugs.

Approach for detecting mutagenicity of biodegraded and ozonated pharmaceuticals, metabolites and transformation products from a drinking water perspective

Many pharmaceuticals and related metabolites are not efficiently removed in sewage treatment plants and enter into surface water. There, they might be subject of drinking water abstraction and treatment by ozonation. In this study, a systematic approach for producing and effect-based testing of transformation products (TPs) during the drinking water ozonation process is proposed. For this, two pharmaceutical parent substances, three metabolites and one environmental degradation product were investigated with respect to their biodegradability and fate during drinking water ozonation. The Ames test (TA98, TA100) was used for the identification of mutagenic activity present in the solutions after testing inherent biodegradability and/or after ozonation of the samples. Suspicious results were complemented with the umu test. Due to the low substrate concentration required for ozonation, all ozonated samples were concentrated via solid phase extraction (SPE) before performing the Ames test. With the exception of piracetam, all substances were only incompletely biodegradable, suggesting the formation of stable TPs. Metformin, piracetam and guanylurea could not be removed completely by the ozonation process. We received some evidence that technical TPs are formed by ozonation of metformin and piracetam, whereas all tested metabolites were not detectable by analytical means after ozonation. In the case of guanylurea, one ozonation TP was identified by LC/MS. None of the experiments showed an increase of mutagenic effects in the Ames test. However, the SPE concentration procedure might lead to false-positive results due to the generation of mutagenic artefacts or might lead to false-negative results by missing adequate recovery efficiency. Thus, these investigations should always be accompanied by process blank controls that are carried out along the whole ozonation and SPE procedure. The study presented here is a first attempt to investigate the significance of transformation products by a systematic approach. However, the adequacy and sensitivity of the methodology need to be further investigated. The approach of combining biodegradation and ozonation with effect-based assays is a promising tool for the early detection of potential hazards from TPs as drinking water contaminants. It can support the strategy for the evaluation of substances and metabolites in drinking water. A multitude of possible factors which influence the results have to be carefully considered, among them the selectivity and sensibility of the mutagenicity test applied, the extraction method for concentrating the relevant compounds and the biocompatibility of the solvent. Therefore, the results have to be carefully interpreted, and possible false-negative and false-positive results should be considered.

Structural elucidation of main ozonation products of the artificial sweeteners cyclamate and acesulfame

PURPOSE

The two artificial sweeteners cyclamate (CYC) and acesulfame (ACE) have been detected in wastewater and drinking water treatment plants. As in both facilities ozonation might be applied, it is important to find out if undesired oxidation products (OPs) are formed.

METHODS

For the separation and detection of the OPs, several analytical techniques, including nuclear magnetic resonance experiments, were applied. In order to distinguish between direct ozone reaction and a radical mechanism, experiments were carried out at different pH values with and without scavenging OH radicals. Kinetic experiments were used for confirmation that the OPs are formed during short ozone contact time applied in waterworks. Samples from a waterworks using bank filtrate as raw water were analyzed in order to prove that the identified OPs are formed in real and full-scale ozone applications.

RESULTS

In the case of CYC, oxidation mainly occurs at the carbon atom, where the sulfonamide moiety is bound to the cyclohexyl ring. Consequently, amidosulfonic acid and cyclohexanone are formed as main OPs of CYC. When ozone reacts at another carbon atom of the ring a keto moiety is introduced into the CYC molecule. Acetic acid and the product ACE OP170, an anionic compound with m/z=170 and an aldehyde hydrate moiety, were identified as the main OPs for ACE. The observed reaction products suggest an ozone reaction according to the Criegee mechanism due to the presence of a C=C double bond. ACE OP170 was also detected after the ozonation unit of a full-scale drinking water treatment plant which uses surface water-influenced bank filtrate as raw water.

CONCLUSIONS

Acesulfame can be expected to be found in anthropogenic-influenced raw water used for drinking water production. However, when ACE OP170 is formed during ozonation, it is not expected to cause any problem for drinking water suppliers, because the primary findings suggest its removal in subsequent treatment steps, such as activated carbon filters.

[Training for real: simulation, team-training and communication to improve trauma management]

The focus on the role of non-technical skills such as communication, dynamic decision making, situational awareness and teamwork in emergency medicine has gained importance over the past few years. Especially during time-critical and complex treatment of severely injured patients in a multidisciplinary and interprofessional trauma-team these factors play an important role for patient-safety and process optimization and are a key factor influencing the perceived quality of a given scenario by the team members. Thus, apart from medical expertise and technical excellence of single actors within a trauma team, non-technical skills need to be incorporated in trainings for trauma management. For the improvement of non-technical skills, particularly team communication and teamwork, a simulator-based training represents a valuable tool. The technical performance of portable manikin-based simulators has improved tremendously during the last decade, which facilitates realistic and true-to-life multidisciplinary team-training in trauma management.

Characterization of stable aluminium-citrate species as reference substances for aluminium speciation by ion chromatography

Well-defined anionic aluminium-citrate species are accessible from crystalline aluminium complexes. The solution chemistry of those species can be investigated using ion chromatography as a powerful tool for aluminium speciation in aqueous samples. The separation of three anionic aluminium-citrate complexes by anion exchange chromatography is possible within 5 min using isocratic conditions. The element specific detection was done by online coupled ICP-AES. The remaining charge of the complexes after dissolution can be determined by ion chromatography using a retention model. Time-dependent monitoring of the species distribution gave information about the species stabilities and the decomposition pathways. With citric acid as an aluminium chelator partially very stable anionic species are observed. These complexes are important components in biological systems. An example for the practical use of the separation method and the well-defined standards is given for plant sap, which showed two species with similar behavior compared to the investigated stable aluminium-citrate complexes.

Plasma aldosterone, cortisol and electrolyte concentrations in physical exercise after magnesium supplementation

Plasma aldosterone, cortisol, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) as well as urine and sweat Na, K, Ca and Mg concentrations were measured in nine male healthy persons during an one hour ergometer exercise before and after a fourteen day magnesium aspartate (Mg) supplementation. The usual aldosterone and cortisol increase during exercise was not observed and cortisol concentration was significantly lower after Mg supplementation. Na and K in plasma increased during the exercise; these changes were not affected by Mg. The Mg concentration was elevated in plasma and erythrocytes after Mg supplementation. During the ergometer course plasma Mg was unchanged but decreased significantly in the red blood cells. Mg and K concentration in sweat decreased during the exercise. No influence of Mg on urinary electrolyte excretion was observed.