Apnoeic oxygenation during paediatric tracheal intubation: a systematic review and meta-analysis.

BACKGROUND: Supplemental oxygen administration by apnoeic oxygenation during laryngoscopy for tracheal intubation is intended to prolong safe apnoea time, reduce the risk of hypoxaemia, and increase the success rate of first-attempt tracheal intubation under general anaesthesia. This systematic review examined the efficacy and effectiveness of apnoeic oxygenation during tracheal intubation in children. METHODS: This systematic review and meta-analysis included randomised controlled trials and non-randomised studies in paediatric patients requiring tracheal intubation, evaluating apnoeic oxygenation by any method compared with patients without apnoeic oxygenation. Searched databases were MEDLINE, Embase, Cochrane Library, CINAHL, ClinicalTrials.gov, International Clinical Trials Registry Platform (ICTRP), Scopus, and Web of Science from inception to March 22, 2023. Data extraction and risk of bias assessment followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) recommendation. RESULTS: After initial selection of 40 708 articles, 15 studies summarising 9802 children were included (10 randomised controlled trials, four pre-post studies, one prospective observational study) published between 1988 and 2023. Eight randomised controlled trials were included for meta-analysis (n=1070 children; 803 from operating theatres, 267 from neonatal intensive care units). Apnoeic oxygenation increased intubation first-pass success with no physiological instability (risk ratio [RR] 1.27, 95% confidence interval [CI] 1.03-1.57, P=0.04, I2=0), higher oxygen saturation during intubation (mean difference 3.6%, 95% CI 0.8-6.5%, P=0.02, I2=63%), and decreased incidence of hypoxaemia (RR 0.24, 95% CI 0.17-0.33, P<0.01, I2=51%) compared with no supplementary oxygen administration. CONCLUSION: This systematic review with meta-analysis confirms that apnoeic oxygenation during tracheal intubation of children significantly increases first-pass intubation success rate. Furthermore, apnoeic oxygenation enables stable physiological conditions by maintaining oxygen saturation within the normal range. CLINICAL TRIAL REGISTRATION: Protocol registered prospectively on PROSPERO (registration number: CRD42022369000) on December 2, 2022.

Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines.

Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1C). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1C). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B).

Emergency front-of-neck access in infants: A pragmatic crossover randomized control trial comparing two approaches on a simulated rabbit model.

BACKGROUND: Rapid-sequence tracheotomy and scalpel-bougie tracheotomy are two published approaches for establishing emergency front-of-neck access in infants. It is unknown whether there is a difference in performance times and success rates between the two approaches. AIMS: The aim of this cross-over randomized control trial study was to investigate whether the two approaches were equivalent for establishing tracheal access in rabbit cadavers. The underlying hypothesis was that the time to achieve the tracheal access is the same with both techniques. METHODS: Between May and September 2022, thirty physicians (pediatric anesthesiologists and intensivists) were randomized to perform front-of-neck access using one and then the other technique: rapid-sequence tracheotomy and scalpel-bougie tracheotomy. After watching training videos, each technique was practiced four times followed by a final tracheotomy during which study measurements were obtained. Based on existing data, an equivalence margin was set at ∆ = ±10 s for the duration of the procedure. The primary outcome was defined as the duration until tracheal tube placement was achieved successfully. Secondary outcomes included success rate, structural injuries, and subjective participant self-evaluation. RESULTS: The median duration of the scalpel-bougie tracheotomy was 48 s (95% CI: 37-57), while the duration of the rapid-sequence tracheotomy was 59 s (95% CI: 49-66, p = .07). The difference in the median duration between the two approaches was 11 s (95% CI: -4.9 to 29). The overall success rate was 93.3% (95% CI: 83.8%-98.2%). The scalpel-bougie tracheotomy resulted in significantly fewer damaged tracheal rings and was preferred among participants. CONCLUSIONS: The scalpel-bougie tracheotomy was slightly faster than the rapid-sequence tracheotomy and favored by participants, with fewer tracheal injuries. Therefore, we propose the scalpel-bougie tracheostomy as a rescue approach favoring the similarity to the adult approach for small children. The use of a comparable equipment kit for both children and adults facilitates standardization, performance, and logistics. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05499273.

Emergency front-of-neck access in pediatric anesthesia: A narrative review.

BACKGROUND AND OBJECTIVES: Children undergoing airway management during general anesthesia may experience airway complications resulting in a rare but life-threatening situation known as "Can't Intubate, Can't Oxygenate". This situation requires immediate recognition, advanced airway management, and ultimately emergency front-of-neck access. The absence of standardized procedures, lack of readily available equipment, inadequate knowledge, and training often lead to failed emergency front-of-neck access, resulting in catastrophic outcomes. In this narrative review, we examined the latest evidence on emergency front-of-neck access in children. METHODS: A comprehensive literature was performed the use of emergency front-of-neck access (eFONA) in infants and children. RESULTS: Eighty-six papers were deemed relevant by abstract. Finally, eight studies regarding the eFONA technique and simulations in animal models were included. For all articles, their primary and secondary outcomes, their specific animal model, the experimental design, the target participants, and the equipment were reported. CONCLUSION: Based on the available evidence, we propose a general approach to the eFONA technique and a guide for implementing local protocols and training. Additionally, we introduce the application of innovative tools such as 3D models, ultrasound, and artificial intelligence, which can improve the precision, safety, and training of this rare but critical procedure.

Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines.

Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1С). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1С). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO 2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B).

Noninvasive ventilation in children: A review for the pediatric anesthesiologist.

Preserving adequate respiratory function is essential in the perioperative period. Mechanical ventilation with endotracheal intubation is widely used for this purpose. In select patients, noninvasive ventilation (NIV) may be an alternative to invasive ventilation or may complement respiratory management. NIV is used to provide ventilatory support and increase gas exchange at the alveolar level without the use of an invasive artificial airway such as an endotracheal tube or tracheostomy. NIV includes both continuous positive airway pressure (CPAP) and noninvasive positive pressure ventilation. Indications for NIV range from acute hypoxic respiratory failure in the intensive care unit or the emergency department, to chronic respiratory failure in patients with neuromuscular disease with nocturnal hypoventilation. In the perioperative setting, NIV is commonly applied as CPAP, and bilevel positive airway pressure (BPAP). There are limited data on the role of NIV in children in the perioperative setting, and there are no clear guidelines regarding optimal timing of use and pressure settings of perioperative NIV. Contraindications to the use of NIV include reduced level of consciousness, apnea, severe respiratory distress, and inability to maintain upper airway patency or airway protective reflexes. Common problems encountered during NIV involve airway leaks and asynchrony with auto-triggering. High-flow nasal oxygen (HFNO) has emerged as an alternative to NIV when trying to decrease the work of breathing and improve oxygenation in children. HFNO delivers humidified and heated oxygen at rates between 2 and 70 L/min using specific nasal cannulas, and flows are determined by the patient's weight and clinical needs. HFNO can be useful as a method for preoxygenation in infants and children by prolonging apnea time before desaturation, yet in children with decreased minute ventilation or apnea HFNO does not improve alveolar gas exchange. Clinicians experienced with these devices, such as pediatric intensivists and pulmonary medicine specialists, can be useful resources for the pediatric anesthesiologist caring for complex patients on NIV.

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study.

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348.

Effects of a single aerobic exercise on perfused boundary region and microvascular perfusion: a field study.

The endothelium and the glycocalyx play a pivotal role in regulating microvascular function and perfusion in health and critical illness. It is unknown today, whether aerobic exercise immediately affects dimensions of the endothelial surface layer (ESL) in relation to microvascular perfusion as a physiologic adaption to increased nutritional demands. This monocentric observational study was designed to determine real-time ESL and perfusion measurements of the sublingual microcirculation using sidestream dark field imaging performed in 14 healthy subjects before and after completing a 10 km trial running distance. A novel image acquisition and analysis software automatically analysed the perfused boundary region (PBR), an inverse parameter for red blood cell (RBC) penetration of the ESL, in vessels between 5 and 25 µm diameter. Microvascular perfusion was assessed by calculating RBC filling percentage. There was no significant immediate effect of exercise on PBR and RBC filling percentage. Linear regression analysis revealed a distinct association between change of PBR and change of RBC filling percentage (regression coefficient ß: - 0.026; 95% confidence interval - 0.043 to - 0.009; p = 0.006). A single aerobic exercise did not induce a change of PBR or RBC filling percentage. The endothelium of the microvasculature facilitates efficient perfusion in vessels reacting with an increased endothelial surface layer.

Attitudes towards Interprofessional education in the medical curriculum: a systematic review of the literature.

BACKGROUND: There is agreement among educators and professional bodies that interprofessional education needs to be implemented at the pre-registration level. We performed a systematic review assessing interprofessional learning interventions, measuring attitudes towards interprofessional education and involving pre-registration medical students across all years of medical education. METHODS: A systematic literature review was performed using PubMed, PsycINFO, EThOS, EMBASE, PEDro and SCOPUS. Search terms were composed of interprofession*, interprofessional education, inter professional, inter professionally, IPE, and medical student. Inclusion criteria were 1) the use of a validated scale for assessment of attitudes towards IPE, and results for more than 35 medical students; 2) peer-reviewed articles in English and German, including medical students; and 3) results for IPE interventions published after the 2011 Interprofessional Education Collaborative (IPEC) report. We identified and screened 3995 articles. After elimination of duplicates or non-relevant topics, 278 articles remained as potentially relevant for full text assessment. We used a data extraction form including study designs, training methods, participant data, assessment measures, results, and medical year of participants for each study. A planned comprehensive meta-analysis was not possible. RESULTS: This systematic review included 23 articles with a pre-test-post-test design. Interventions varied in their type and topic. Duration of interventions varied from 25 min to 6 months, and interprofessional groups ranged from 2 to 25 students. Nine studies (39%) reported data from first-year medical students, five (22%) from second-year students, six (26%) from third-year students, two (9%) from fourth-year students and one (4%) from sixth-year students. There were no studies including fifth-year students. The most frequently used assessment method was the Readiness for Interprofessional Learning Scale (RIPLS) (n = 6, 26%). About half of study outcomes showed a significant increase in positive attitudes towards interprofessional education after interventions across all medical years. CONCLUSIONS: This systematic review showed some evidence of a post-intervention change of attitudes towards IPE across different medical years studied. IPE was successfully introduced both in pre-clinical and clinical years of the medical curriculum. With respect to changes in attitudes to IPE, we could not demonstrate a difference between interventions delivered in early and later years of the curriculum. TRIAL REGISTRATION: PROSPERO registration number:  CRD42020160964 .

In vivo estimation of transverse relaxation time constant (T2 ) of 17 human brain metabolites at 3T.

PURPOSE: The transverse relaxation times T2 of 17 metabolites in vivo at 3T is reported and region specific differences are addressed. METHODS: An echo-time series protocol was applied to one, two, or three volumes of interest with different fraction of white and gray matter including a total number of 106 healthy volunteers and acquiring a total number of 128 spectra. The data were fitted with the 2D fitting tool ProFit2, which included individual line shape modeling for all metabolites and allowed the T2 calculation of 28 moieties of 17 metabolites. RESULTS: The T2 of 10 metabolites and their moieties have been reported for the first time. Region specific T2 differences in white and gray matter enriched tissue occur in 16 of 17 metabolites examined including single resonance lines and coupled spin systems. CONCLUSION: The relaxation time T2 is regions specific and has to be considered when applying tissue composition correction for internal water referencing. Magn Reson Med 80:452-461, 2018. © 2018 International Society for Magnetic Resonance in Medicine.

[Effectivity of Inpatient Psychosomatic Treatment - Results of a Naturalistic Two-Year Survey in a Psychosomatic Service at a General Hospital]. / Effektivität stationärer psychosomatischer Behandlung ­ Ergebnisse einer naturalistischen Zweijahresuntersuchung.

BACKGROUND: Hospital psychosomatic treatment matches care expectations of a modern society. Evidence of its effectiveness through investigation in different settings is of importance because of prominent role of psychotherapy in German Healthcare System. OBJECTIVE: First, to explore whether clinical as well as personal resources could improve significantly due to a hospital psychosomatic treatment. Second, to assess possible associations between outcome variables and other variables from the multidimensional profile of the sample. METHOD: The sample consists of all 2014 - 2015 admitted patients who agree with investigation (N=283). Pre-post comparisons of results from validated questionnaires were performed by means of t-tests, including effect sizes. Associations between outcome variables (pre-post differences of clinical and resources related variables) and variables from the multidimensional profile were performed by means of bivariate and multivariate regression tests. Outcome differences were assessed by means of logistic regression models. RESULTS: Drop-out-rate due to refusal of participation amounts 11.8%; from remaining participants uncompleted datasets additional 6.9%; due to declining further participation during hospitalisation additional 4.1% (total drop-out rate amounted 22.8%). Functionality, self-efficacy, disease severity, psychological as well as physical symptom burden, depressiveness, interpersonal concerns, and embitterment improved significantly (p<0.001) displaying effect sizes between 0.39 and 1.42 (average level for clinical variables 0.98). Considerable associations between clinical and resources related variables in both directions were found. 10% of patients reported worsening. DISCUSSION: Psychosomatic hospital treatment is effective according to clinical improvement as well as to perceived quality of treatment. Clinical and resources related variables are positively bidirectional associated notwithstanding the kind of working causality. Robust prognostic factors are hard to identify. CONCLUSIONS: Inpatient psychosomatic treatment is effective when the admission is indicated and the unit accomplishes mandatory quality criteria. The outcome occurs individually and is hard to be predicted. Depressiveness and embitterment could be considered as epiphenomena of all psychosomatic illnesses.

Aortic Atherosclerosis Determines Increased Retrograde Blood Flow as a Potential Mechanism of Retrograde Embolic Stroke.

BACKGROUND: Retrograde brain embolization from complex plaques of the proximal descending aorta (DAo) has been identified as a new potential mechanism of stroke. Our purpose was to identify predictors of increased retrograde aortic blood flow indicating an elevated risk of brain embolization from the DAo. METHODS: A total of 485 patients with acute ischemic stroke were prospectively included and underwent transesophageal echocardiography. Blood flow velocities in the proximal DAo were studied using 2D pulse-wave Doppler ultrasound. Velocity-time integrals (VTI) were calculated for antegrade and retrograde velocity directions. The ratio (VTIretrograde/VTIantegrade) was used to estimate retrograde flow extent. Associations between patient demographics, cardiovascular risk factors, echocardiographic parameters, and VTIratio were analyzed using multivariate linear regression. RESULTS: Retrograde blood flow in the DAo occurred in all patients. Velocity profiles in the proximal DAo were as follows (mean ± SD): VTIantegrade = 21.1 ± 6.5, VTIretrograde = 11.0 ± 3.6, and VTIratio = 0.54 ± 0.16. Diameter (r = 0.25, p < 0.001), presence of complex plaques (r = 0.12, p = 0.007), and reduced strain of the DAo (r = -0.23, p < 0.001) had significant partial effects in a predictor model based on predefined variables, which predicted 26% (adjusted R2 = 0.26) of the variance in VTIratio. A unit increase in the DAo diameter was associated with a 2% increase in VTIratio (95% CI 1-2.8%, p < 0.001). Presence of complex plaques increased VTIratio by 7% (95% CI 2-13%, p = 0.007) and an increase in strain by 0.1 indicated a decrease in VTIratio by about 11% (95% CI 6.2-15.5%, p < 0.001). Complex atheroma was found in the proximal DAo of 79 subjects, of which 40 (50.6%) had a VTIratio above average (VTIratio ≥0.54) compared to 87 of 261 (33.3%) patients without any complex plaques (p < 0.001). Twenty-five of 79 (31.7%) patients with complex DAo plaques had a VTIratio ≥0.60, which indicates a high likelihood of retrograde pathline length of ≥3 cm and thus increased risk of retrograde cerebral embolization. Stroke etiology of those 25 patients was determined in 13 and cryptogenic in 12 cases. CONCLUSIONS: Retrograde blood flow in the DAo was found in all stroke patients. However, it increased further in patients with concomitant complex plaques, low strain, and/or large aortic diameter, that is, in those with atherosclerosis of the DAo. Accordingly, such patients may be predisposed to retrograde embolization in case of occurrence of a complex plaque in proximity to a brain-supplying artery.

ProFit revisited.

PURPOSE: An enhanced version of the ProFit fitting tool was developed and validated to improve the quantification of two-dimensional JRPESS spectroscopic data. METHODS: The proposed enhancements were achieved by flexible organization of prior knowledge, configurations for different situations, the inclusion of measured macromolecular baseline contribution, additional baseline splines and a model-free lineshape based on self-deconvolution. The new software was tested and tuned on simulated data and subsequently applied to in vivo intrasubject and intersubject data. RESULTS: Fit results of simulated and acquired spectra show good overall quality suggesting the potential reliable detection of up to 18 metabolites on a 3T system yielding Cramer-Lower-Bounds below 20%. CONCLUSION: The proposed enhanced version of ProFit together with two-dimensional J-resolved spectroscopy offers the opportunity to reliably detect a wide selection of important brain metabolites on 3T.

Structural analogues of the natural products magnolol and honokiol as potent allosteric potentiators of GABA(A) receptors.

Biphenylic compounds related to the natural products magnolol and 4'-O-methylhonokiol were synthesized, evaluated and optimized as positive allosteric modulators (PAMs) of GABA(A) receptors. The most efficacious compounds were the magnolol analog 5-ethyl-5'-hexylbiphenyl-2,2'-diol (45) and the honokiol analogs 4'-methoxy-5-propylbiphenyl-2-ol (61), 5-butyl-4'-methoxybiphenyl-2-ol (62) and 5-hexyl-4'-methoxybiphenyl-2-ol (64), which showed a most powerful potentiation of GABA-induced currents (up to 20-fold at a GABA concentration of 3µM). They were found not to interfere with the allosteric sites occupied by known allosteric modulators, such as benzodiazepines and N-arachidonoylglycerol. These new PAMs will be useful as pharmacological tools and may have therapeutic potential for mono-therapy, or in combination, for example, with GABA(A) receptor agonists.

To gel or not to gel - Tuning the sulfation pattern of carrageenans to expand their field of application.

Carrageenans represent a major cell wall component of red macro algae and, as established gelling and thickening agents, they contribute significantly to a broad variety of commercial applications in the food and cosmetic industry. As a highly sulfated class of linear polysaccharides, their functional properties are strongly related to the sulfation pattern of their carrabiose repeating units. Therefore, the biocatalytic fine-tuning of these polymers by generating tailored sulfation architectures harnessing the hydrolytic activity of sulfatases could be a powerful tool to produce novel polymer structures with tuned properties to expand applications of carrageenans beyond their current use. To contribute to this vision, we sought to identify novel carrageenan sulfatases by studying several putative carrageenolytic clusters in marine heterotrophic bacteria. This approach revealed two novel formylglycine-dependent sulfatases from Cellulophaga algicola DSM 14237 and Cellulophaga baltica DSM 24729 with promiscuous hydrolytic activity towards the sulfated galactose in the industrially established ι- and κ-carrageenan, converting them into α- and ß-carrageenan, respectively, and enabling the production of a variety of novel pure and hybrid carrageenans. The rheological analysis of these enzymatically generated structures revealed significantly altered physicochemical properties that may open the gate to a variety of novel carrageenan-based applications.

Biocatalytic Conversion of Carrageenans for the Production of 3,6-Anhydro-D-galactose.

Marine biomass stands out as a sustainable resource for generating value-added chemicals. In particular, anhydrosugars derived from carrageenans exhibit a variety of biological functions, rendering them highly promising for utilization and cascading in food, cosmetic, and biotechnological applications. However, the limitation of available sulfatases to break down the complex sulfation patterns of carrageenans poses a significant limitation for the sustainable production of valuable bioproducts from red algae. In this study, we screened several carrageenolytic polysaccharide utilization loci for novel sulfatase activities to assist the efficient conversion of a variety of sulfated galactans into the target product 3,6-anhydro-D-galactose. Inspired by the carrageenolytic pathways in marine heterotrophic bacteria, we systematically combined these novel sulfatases with other carrageenolytic enzymes, facilitating the development of the first enzymatic one-pot biotransformation of ι- and κ-carrageenan to 3,6-anhdyro-D-galactose. We further showed the applicability of this enzymatic bioconversion to a broad series of hybrid carrageenans, rendering this process a promising and sustainable approach for the production of value-added biomolecules from red-algal feedstocks.

[Airway management in neonates and infants : Recommendations according to the ESAIC/BJA guidelines]. / Atemwegssicherung bei Neugeborenen und Säuglingen : Handlungsempfehlung gemäß der BJA/ESAIC-Leitlinie.

Securing an airway enables the oxygenation and ventilation of the lungs and is a potentially life-saving medical procedure. Adverse and critical events are common during airway management, particularly in neonates and infants. The multifactorial reasons for this include patient-dependent, user-dependent and also external factors. The recently published joint ESAIC/BJA international guidelines on airway management in neonates and infants are summarized with a focus on the clinical application. The original publication of the guidelines focussed on naming formal recommendations based on systematically documented evidence, whereas this summary focusses particularly on the practicability of their implementation.

SPECIAL semi-LASER with lipid artifact compensation for 1H MRS at 7 T.

The measurement of full metabolic profiles at ultrahigh fields including low concentrated or fast-relaxing metabolites is usually achieved by applying short echo time sequences. One sequence beside stimulated echo acquisition mode that was proposed in this regard is spin echo full intensity-acquired localized spectroscopy. Typical problems that are still persistent for spin echo full intensity-acquired localized spectroscopy are B(1) inhomogeneities especially for signal acquisition with surface coils and chemical shift displacement artifacts due to limited B(1) amplitudes when using volume coils. In addition, strong lipid contaminations in the final spectrum can occur when only a limited number of outer volume suppression pulses is used. Therefore, an adiabatic short echo time (= 19 ms) spin echo full intensity-acquired localized spectroscopy semilocalization by adiabatic selective refocusing sequence is presented that is less sensitive to strong B(1) variations and that offers increased excitation and refocusing pulse bandwidths than regular spin echo full intensity acquired localized spectroscopy. Furthermore, the existence of the systematic lipid artifact is identified and linked to unfavorable effects due to the preinversion localization pulse. A method to control this artifact is presented and validated in both phantom and in vivo measurements. The viability of the proposed sequence was further assessed for in vivo measurements by scanning 17 volunteers using a surface coil and moreover acquiring additional volume coil measurements. The results show well-suppressed lipid artifacts, good signal-to-noise ratio, and reproducible fitting results in accordance with other published studies.

Non-water-suppressed proton MR spectroscopy improves spectral quality in the human spinal cord.

Magnetic resonance spectroscopy enables insight into the chemical composition of spinal cord tissue. However, spinal cord magnetic resonance spectroscopy has rarely been applied in clinical work due to technical challenges, including strong susceptibility changes in the region and the small cord diameter, which distort the lineshape and limit the attainable signal to noise ratio. Hence, extensive signal averaging is required, which increases the likelihood of static magnetic field changes caused by subject motion (respiration, swallowing), cord motion, and scanner-induced frequency drift. To avoid incoherent signal averaging, it would be ideal to perform frequency alignment of individual free induction decays before averaging. Unfortunately, this is not possible due to the low signal to noise ratio of the metabolite peaks. In this article, frequency alignment of individual free induction decays is demonstrated to improve spectral quality by using the high signal to noise ratio water peak from non-water-suppressed proton magnetic resonance spectroscopy via the metabolite cycling technique. Electrocardiography (ECG)-triggered point resolved spectroscopy (PRESS) localization was used for data acquisition with metabolite cycling or water suppression for comparison. A significant improvement in the signal to noise ratio and decrease of the Cramér Rao lower bounds of all metabolites is attained by using metabolite cycling together with frequency alignment, as compared to water-suppressed spectra, in 13 healthy volunteers.

Electrocardiogram-triggered, higher order, projection-based B0 shimming allows for fast and reproducible shim convergence in spinal cord ¹H MRS.

¹H MRS allows insight into the chemical composition of the central nervous system. However, as a result of technical challenges, it has rarely been applied to the spinal cord. In particular, the strong susceptibility changes around the spinal cord and the pulsatile flow of the cerebrospinal fluid lead to distinct B0 field distortions which often considerably degrade the spectral quality. Hence, B0 shimming is one of the main challenges in ¹H MRS of the spinal cord. Electrocardiogram (ECG)-triggered, higher order, projection-based B0 shimming was introduced and compared with both conventional projection-based B0 shimming and B0 shimming based on ECG-triggered, three-dimensional B0 field mapping. The linewidth of the unsuppressed water peak was used to evaluate the reproducibility and the potential improvement to B0 homogeneity. The use of ECG-triggered projection-based B0 shimming in combination with ECG triggering during preparation phases and triggering during acquisition of the spectra is the most robust method and thus helps to improve the spectral quality for MRS of the spinal cord.