Education of schoolchildren in cardiopulmonary resuscitation - overview of the current literature.

PURPOSE OF REVIEW: Recognition of cardiac arrest and initiation of cardiopulmonary resuscitation (CPR) can be learned and adequately replicated by schoolchildren. Regular instruction of schoolchildren in CPR is therefore a core element to increase low bystander CPR rates. Thereby, schoolchildren CPR training evolved as own scientific field within the last decade. Aim was to describe current evidence in terms of epidemiology, teaching approaches and political aspects. RECENT FINDINGS: Schoolchildren demonstrate a high motivation to be trained in CPR. Teaching approaches that combine theoretical and practical learning sessions guarantee a sustainable learning effect. Schoolchildren can adequately perform chest compressions and mouth-to-mouth ventilation from the age of 12 years. Use of digital media is a highly promising teaching approach. CPR training conducted by teachers from the own school is effective and guarantees continuous development of CPR skills. Integration of schoolchildren CPR training into school curricula is the foundation for a sustainable increase of lay resuscitation rates in the population. Scientific and political promotion of schoolchildren CPR training is needed to sensitize the population and move bystander CPR in the social focus. SUMMARY: While bystander CPR rates are low in Europe comprehensive establishment of schoolchildren CPR training may sustainably increase survival after cardiac arrest.

The efficacy of apneic oxygenation during intubation using a prototype of an oxygenation laryngoscope - a technical simulation.

BACKGROUND: Recently, a non-commercial oxygenation laryngoscope was able to maintain apneic oxygenation during simulated intubation efforts. Since that prototype was 3 mm wider than a standard Macintosh laryngoscope blade, the intubation performance of this device may differ from standard blades. A new prototype of an oxygenation laryngoscope was developed, consisting of a standard-size Macintosh blade and a fixed oxygen supply line to the side. Actually, it is unclear at which point of this blade the oxygen supply line should end to facilitate the best possible oxygen supply for apneic oxygenation. METHODS: In this simulation study using a standardized human airway manikin, the efficacy of apneic oxygenation by oxygen insufflation using standard and modified Macintosh blades was compared: a standard Macintosh blade without oxygen supply line as control, one with an additional oxygen supply line ending proximal near the handle, one with the line ending at the middle of the blade, and one with the line ending near the tip. A preoxygenated test lung was connected to an oximeter with a flow rate of 200ml/min, simulating oxygen consumption of a male adult, and to the trachea of an anatomically correctly shaped airway manikin. Apneic oxygenation was performed and oxygen content was measured over a 20-minutes observation period. Experiments were repeated five times for each laryngoscope blade. RESULTS: Oxygen percentage in the test lung dropped from 100 ± 0% at the start of the experiment to 53 ± 1.5% in the room air control group (p < 0.001 compared to all other groups), and to 74 ± 2.5% in the proximal oxygen line group, whereas oxygen percentage remained at 100% in both the medium and distal oxygen line groups (p = 1 between these groups; p < 0.001 between all other groups). CONCLUSIONS: In this simulation study with a preoxygenated airway manikin, the use of a modified Macintosh laryngoscope blade with oxygen line attached at the tip or at the middle were able to maintain apneic oxygenation without measurable drop of oxygen content over 20 min. Proximal placement of the oxygen supply line still showed an advantage against room air, however it did not completely prevent room air from entering the airway. TRIAL REGISTRATION: Not applicable.

KIDS SAVE LIVES: Basic Life Support Education for Schoolchildren: A Narrative Review and Scientific Statement From the International Liaison Committee on Resuscitation.

BACKGROUND: Basic life support education for schoolchildren has become a key initiative to increase bystander cardiopulmonary resuscitation rates. Our objective was to review the existing literature on teaching schoolchildren basic life support to identify the best practices to provide basic life support training in schoolchildren. METHODS: After topics and subgroups were defined, a comprehensive literature search was conducted. Systematic reviews and controlled and uncontrolled prospective and retrospective studies containing data on students <20 years of age were included. RESULTS: Schoolchildren are highly motivated to learn basic life support. The CHECK-CALL-COMPRESS algorithm is recommended for all schoolchildren. Regular training in basic life support regardless of age consolidates long-term skills. Young children from 4 years of age are able to assess the first links in the chain of survival. By 10 to 12 years of age, effective chest compression depths and ventilation volumes can be achieved on training manikins. A combination of theoretical and practical training is recommended. Schoolteachers serve as effective basic life support instructors. Schoolchildren also serve as multipliers by passing on basic life support skills to others. The use of age-appropriate social media tools for teaching is a promising approach for schoolchildren of all ages. CONCLUSIONS: Schoolchildren basic life support training has the potential to educate whole generations to respond to cardiac arrest and to increase survival after out-of-hospital cardiac arrest. Comprehensive legislation, curricula, and scientific assessment are crucial to further develop the education of schoolchildren in basic life support.

KIDS SAVE LIVES: Basic Life Support Education for Schoolchildren: A Narrative Review and Scientific Statement From the International Liaison Committee on Resuscitation.

BACKGROUND: Basic life support education for schoolchildren has become a key initiative to increase bystander cardiopulmonary resuscitation rates. Our objective was to review the existing literature on teaching schoolchildren basic life support to identify the best practices to provide basic life support training in schoolchildren. METHODS: After topics and subgroups were defined, a comprehensive literature search was conducted. Systematic reviews and controlled and uncontrolled prospective and retrospective studies containing data on students <20 years of age were included. RESULTS: Schoolchildren are highly motivated to learn basic life support. The CHECK-CALL-COMPRESS algorithm is recommended for all schoolchildren. Regular training in basic life support regardless of age consolidates long-term skills. Young children from 4 years of age are able to assess the first links in the chain of survival. By 10 to 12 years of age, effective chest compression depths and ventilation volumes can be achieved on training manikins. A combination of theoretical and practical training is recommended. Schoolteachers serve as effective basic life support instructors. Schoolchildren also serve as multipliers by passing on basic life support skills to others. The use of age-appropriate social media tools for teaching is a promising approach for schoolchildren of all ages. CONCLUSIONS: Schoolchildren basic life support training has the potential to educate whole generations to respond to cardiac arrest and to increase survival after out-of-hospital cardiac arrest. Comprehensive legislation, curricula, and scientific assessment are crucial to further develop the education of schoolchildren in basic life support.

[Medical emergencies during running events]. / Notfallmedizinische Aspekte bei Laufveranstaltungen.

Background: The number of short- and long-distance running events in Germany is increasing. Running as a popular sport is practiced by a large number of people of different ages, risk groups, and degrees of professionalism, which results in a wide range of medical emergencies. Objective: The present article elucidates incidence, pathophysiology and therapy of relevant emergencies during running events. Aim was the optimization of work processes of emergency personnel. Materials and methods: A literature search was conducted in PubMed. Results: Exercise-associated muscle cramps, gastrointestinal symptoms, collapse, compartment syndrome, and tendinopathy are common clinical manifestations. Cardiac arrest and sudden cardiac death are rare events. Consciousness and seizures are major complications. Disseminated intravascular coagulation, exercise-associated hyponatremia, heat stroke, rhabdomyolysis, and thromboembolism are associated with high morbidity and mortality. Substances increasing pain resilience as well as performance-enhancing substances are popular among amateur and professional runners and are associated with a high incidence of side effects. Conclusion: General symptoms including vomiting, fever, collapse, muscle-pain, nausea and weakness are the leading symptoms during running events. A careful anamnesis is important for targeted clinical therapy. Symptom control is the main task. Fluid management the most challenging task for healthcare providers in the prehospital setting.

Identification of the Optimal Position of a Nasal Oxygen Cannula for Apneic Oxygenation: A Technical Simulation.

Background: In a cannot-ventilate-cannot-intubate situation, careful preoxygenation with high FiO2 allowing subsequent apneic oxygenation can be life-saving. The best position for an oxygen supply line within the human airway at which oxygen insufflation is more effective than standard preoxygenation with a face mask is unknown. Methods: In this experimental study, we compared the effectiveness of preoxygenation by placing an oxygen cannula at the nose entrance, through the nose at the soft palatine, or at the base of the tongue; as a control we used ambient air. We connected a fully preoxygenated test lung on one side to an oximeter with a flow rate of 200 mL/min simulating the oxygen consumption of a normal adult on the other side of the trachea of an anatomically correctly shaped airway manikin over a 20 min observation period five times for each cannula placement in a random order. Results: The oxygen percentage in the test lung dropped from 100% in all groups to 53 ± 1% in the ambient air control group, to 87 ± 2% in the nasal cannula group, and to 96 ± 2% in the soft palatine group; it remained at 99 ± 1% in the base of the tongue group (p = 0.003 for the soft palatine vs. base of the tongue and p < 0.001 for all other groups). Conclusions: When simulating apneic oxygenation in a preoxygenated manikin, oxygen insufflation at the base of the tongue kept the oxygen percentage at baseline values of 99%, demonstrating a complete block of ambient air flowing into the airway of the manikin. Oxygen insufflation at the soft palatine or insufflation via a nasal cannula were less effective regarding this effect.

Shedding of the Endothelial Glycocalyx Independent of Systemic Tryptase Release during Oncologic Oral Surgery: An Observational Study.

The endothelial glycocalyx and endothelial surface layer are crucial for several functions of the vasculature. Damage to the glycocalyx ("shedding") occurs during diverse clinical conditions, including major surgery. Mast cell tryptase has been proposed as one possible "sheddase". During oncologic oral surgery, glycocalyx shedding could be detrimental due to loss of vascular barrier function and consequent oedema in the musculocutaneous flap graft. Concentrations of the glycocalyx components heparan sulphate and syndecan-1, as well as of tryptase in blood serum before and after surgery, were measured in 16 patients undergoing oncologic oral surgery. Secondary measures were the concentrations of these substances on postoperative days 1 and 2. Heparan sulphate rose from 692 (median, interquartile range: 535-845) to 810 (638-963) ng/mL during surgery. Syndecan-1 increased from 35 (22-77) ng/mL to 138 (71-192) ng/mL. Tryptase remained virtually unchanged with 4.2 (3-5.6) before and 4.2 (2.5-5.5) ng/mL after surgery. Concentrations of heparan sulphate and syndecan-1 in serum increased during surgery, indicating glycocalyx shedding. Tryptase concentration remained equal, suggesting other sheddases than systemic tryptase release to be responsible for damage to the glycocalyx. Investigating strategies to protect the glycocalyx during oncologic oral surgery might hold potential to improve flap viability and patient outcome.

Comparing suction rates of novel DuCanto catheter against Yankauer and standard suction catheter using liquids of different viscosity-a technical simulation.

PURPOSE: Aspiration is a feared complication that may occur during airway management, and can significantly contribute to morbidity and mortality. Availability of a suctioning device with a suction catheter capable of clearing the airway is mandatory for airway management. However, suction performance may be significantly different amongst different suction catheters. The aim of this study was to compare suction rates of a standard 14 Ch suction catheter (SC), a Yankauer catheter (Y) and a DuCanto catheter (DC) using 4 fluids with different viscosity. METHODS: In this simulation trial, 4 preparations with standardized viscosity were prepared using a Xanthane-based medical fluid thickener. Lowest viscosity was achieved using tap water without thickener, syrup-like viscosity was achieved by adding 10 g per liter tap water, honey-like viscosity was achieved by adding 20 g per liter, and a pudding-like viscosity was achieved by adding 30 g of thickening powder per liter tap water. Each preparation was suctioned for 15 s with the three different suctioning devices. Measurements were repeated four times. The amount of removed preparation by suctioning was measured using a tared scale. RESULTS: Suction rates for water were 580 ± 34 mg for SC, 888 ± 5 mg for Y and 1087 ± 15 for DC; for syrup-like viscosity it was 383 ± 34(SC) vs. 661 ± 64(Y) vs. 935 ± 42(DC); for honey-like viscosity it was 191 ± 21(SC) vs. 426 ± 34(Y) vs. 590 ± 68(DC); and for pudding-like viscosity 74 ± 13(SC) vs. 164 ± 6(Y) vs. 211 ± 8(DC). CONCLUSION: Suctioning liquids of different viscosity, the new DuCanto catheter was more effective than the Yankauer catheter that was more effective than a standard suctioning catheter. The relative superiority of the DuCanto was highest in fluids with high viscosity.

Addressing the Helper's and Victim's Gender Is Crucial in Schoolchildren Resuscitation Training-A Prospective, Educative Interventional Trial.

Background: A victim's gender is a known factor that influences the willingness of adult bystanders to perform cardiopulmonary resuscitation (CPR) if an out-of-hospital cardiac arrest (OHCA) occurs. This study aims to identify whether gender characteristics of OHCA victims are also relevant to schoolchildren, who are the key target group of CPR trainings worldwide. Methods: A prospective, educative intervention study was performed in schoolchildren (5th−7th grade). Schoolchildren's willingness to perform CPR was assessed by means of questionnaires before (t0) and after (t1) standardized CPR training. Participants were asked how determined they were to perform CPR in male and female OHCA victims on a 5-point Likert scale (not being determined to being very determined). A data analysis was performed according to the gender characteristics of schoolchildren. Results: Overall, 342 schoolchildren aged 10−15 years were included, and 166 male (MG) and 176 female (FG) schoolchildren served as a comparison group. Before (t0) and after (t1) the intervention, females showed a significantly higher general willingness to perform CPR than males (t0: 97.1% vs. 89.0%; p < 0.003 and t1: 95.7% vs. 98.9%; p = 0.038). The general willingness to perform CPR after training had a stronger increase in males (8.0% vs. 2.3%; p = 0.017). In the case that the OHCA victim was female, male schoolchildren were less willing to perform CPR than females at baseline (MG: n = 101;60.8% vs. FG: n = 147;84.5%; p < 0.001) and after training (MG: n = 97;58.4% vs. FG: n = 138;79.3%; p < 0.001). At t1, CPR willingness for female victims was improved in males (MG: n = 36;21.7% vs. FG: n = 19;10.9%; p = 0.006). Conclusions: The gender characteristics of OHCA victims, as well as schoolchildren themselves, have a relevant impact on the willingness to perform CPR. Training concepts should effectively motivate male schoolchildren to reduce preexisting inhibitions, especially towards female OHCA patients. Trial registration: This study was registered at the German Clinical Trials Register (Registration number: DRKS00017707) on 2 August 2019.

Facilitators and barriers for the implementation of resuscitation training programmes for schoolchildren: A systematic review.

BACKGROUND: Training schoolchildren in resuscitation seems to improve rates of resuscitation by bystanders. Leading medical societies recommend comprehensive resuscitation education in schools. To date, no widespread implementation within the European Union has happened. OBJECTIVE: The study aim was to identify facilitators and barriers for the implementation of cardiopulmonary resuscitation training for schoolchildren within the European Union. DESIGN: Systematic review. DATA SOURCES: A literature search in PubMed was conducted between 1 January 1999 and 30 June 2020 in accordance with the PRISMA statement. The search terms 'resuscitation', 'children' and 'Europe' were combined with the Boolean Operator 'AND' and 'OR'. Medical subject heading terms were used in order to include relevant articles. ELIGIBILITY CRITERIA: Articles were included if cardiopulmonary resuscitation training specifically tailored for schoolchildren aged 12 to 18 years was considered in countries of the European Union. Articles that fulfilled the following criteria were excluded: duplicates, training methods only for specific patient groups, articles not accessible in the English language, and articles that did not include original data.Findings were structured by an evidence-based six-level approach to examine barriers and facilitators in healthcare. RESULTS: Thirty out of 2005 articles were identified. Large variations in cardiopulmonary resuscitation training approaches ranging from conventional to innovative training methods can be observed. Schoolteachers as resuscitation instructors act either as barrier or facilitator depending on their personal attitude and their exposure to training in resuscitation. Cardiopulmonary resuscitation training in schoolchildren is effective. The uncoordinated interplay between the generally motivated schools and the political orientation towards resuscitation training for schoolchildren serve as barrier. The lack of financial support, absent systematic organisation, and standardisation of training create major barriers. CONCLUSION: Training schoolchildren in cardiopulmonary resuscitation is effective. More financial support and political guidance is needed. Until then, local initiatives, motivated teachers, and dedicated principles combined with innovative and low-cost training methods facilitate cardiopulmonary resuscitation training in schools.

A special oropharyngeal oxygenation device to facilitate apneic oxygenation in comparison to high flow oxygenation devices.

Oxygen application and apneic oxygenation may reduce the risk of hypoxemia due to apnea during awake fiberoptic intubation or failed endotracheal intubation. High flow devices are recommended, but their effect compared to moderate deep oropharyngeal oxygen application is unknown. Designed as an experimental manikin trial, we made a comparison between oxygen application via nasal prongs at 10 L/min (control group), applying oxygen via oropharyngeal oxygenation device (at 10 L/min), oxygen application via high flow nasal oxygen with 20 L/min and 90% oxygen (20 L/90% group), oxygen application via high flow nasal oxygen with 60 L/min and 45% oxygen (60 L/45% group), and oxygen application via sealed face mask with a special adapter to allow for fiberoptic entering of the airway. We preoxygenated the lung of a manikin and measured the decrease in oxygen level during the following 20 minutes for each way of oxygen application. Oxygen levels fell from 97 ± 1% at baseline to 75 ± 1% in control group, and to 86 ± 1% in oropharyngeal oxygenation device group. In the high flow nasal oxygen group, oxygen level dropped to 72 ± 1% in the 20 L/90% group and to 44 ± 1% in the 60 L/45% group. Oxygen level remained at 98 ± 0% in the face mask group. In conclusion, in this manikin simulation study of apneic oxygenation, oxygen insufflation using a sealed face mask kept oxygen levels in the test lung at 98% over 20 minutes, oral oxygenation device led to oxygen levels at 86%, whereas all other methods resulted in the decrease of oxygen levels below 75%.

KIDS SAVE LIVES in schools: cross-sectional survey of schoolteachers.

Training schoolchildren in basic life support (BLS) is strongly recommended to effectively increase bystander cardiopulmonary resuscitation (CPR) rates. Paediatricians and other health staff members used to be involved in BLS training, but the wide dissemination of BLS skills would need additional support; as a solution, schoolteachers might have enough knowledge necessary to help to achieve this goal. The aim of this cross-sectional survey study, which involved 3423 schoolteachers, was to evaluate the knowledge related to first aid (FA) and BLS of schoolteachers in Spain. In addition, the study aimed to evaluate the content taught to the schoolchildren regarding FA and teachers' attitudes towards teaching FA. Three-quarters of the surveyed schoolteachers reported knowing FA, and 17% reported teaching it. The emergency medical telephone number and CPR were the subjects taught most often by schoolteachers. However, the schoolteachers demonstrated a lack of knowledge in the identification of cardiac arrest and in CPR. Ninety-eight percent of the respondents agreed with including FA training in schools and as part of university degree programmes and supported the KIDS SAVE LIVES statement. Teaching FA was a positive predictor to be willing to perform CPR (OR: 1.7; 95% CI 1.32-2.31) and to use a defibrillator (OR: 1.4; 95% CI 1.10-1.67).Conclusions: Schoolteachers are willing to teach FA in schools. However, more training and specific curricula are needed to increase the quality of schoolchildren's CPR training. The training of schoolteachers in CPR might be the foundation for the sustainable transfer of CPR-related knowledge to schoolchildren. Therefore, the inclusion of FA and BLS in university degree programmes seems to be essential. What is Known: • Bystander cardiopulmonary resuscitation rates are associated with improved survival rates. • Resuscitation training in schools increases the bystander cardiopulmonary resuscitation rate. What is New: • Schoolteachers are willing to teach basic life support, but they need more and better training. • Schoolteachers agreed with the inclusion of first aid training in schools and university degree programmes aimed at training teachers/undergraduate teaching degrees.

Positron Emission Tomography Imaging of Long-Term Expression of the 18 kDa Translocator Protein After Sudden Cardiac Arrest in Rats.

BACKGROUND: Knowledge about the neuroinflammatory state during months after sudden cardiac arrest is scarce. Neuroinflammation is mediated by cells that express the 18 kDa translocator protein (TSPO). We determined the time course of TSPO-expressing cells in a rat model of sudden cardiac arrest using longitudinal in vivo positron emission tomography (PET) imaging with the TSPO-specific tracer [18F]DAA1106 over a period of 6 months. METHODS: Five male Sprague Dawley rats were resuscitated from 6 min sudden cardiac arrest due to ventricular fibrillation, three animals served as shams. PET measurements were performed on day 5, 8, 14, 90, and 180 after intervention. Magnetic resonance imaging was performed on day 140. Imaging was preceded by Barnes Maze spatial memory testing on day 3, 13, 90, and 180. Specificity of [18F]DAA1106 binding was confirmed by Iba-1 immunohistochemistry. RESULTS: [18F]DAA1106 accumulated bilaterally in the dorsal hippocampus of all sudden cardiac arrest animals on all measured time points. Immunohistochemistry confirmed Iba-1 expressing cells in the hippocampal CA1 region. The number of Iba-1-immunoreactive objects per mm2 was significantly correlated with [18F]DAA1106 uptake. Additionally, two of the five sudden cardiac arrest rats showed bilateral TSPO-expression in the striatum that persisted until day 180. In Barnes Maze, the relative time spent in the target quadrant negatively correlates with dorsal hippocampal [18F]DAA1106 uptake on day 14 and 180. CONCLUSIONS: After sudden cardiac arrest, TSPO remains expressed over the long-term. Sustainable treatment options for neuroinflammation may be considered to improve cognitive functions after sudden cardiac arrest.

Apneic laryngeal oxygenation during elective fiberoptic intubation - a technical simulation.

BACKGROUND: Sedation during elective fiberoptic intubation for difficult airway can cause respiratory depression, apnea and periods of desaturation. During apneic episodes, hypoxemia can be prevented by insufflation of oxygen in the deep laryngeal space. The aim of this study was to evaluate an oropharyngeal oxygenation device (OOD) designed for deep laryngeal insufflation during fiberoptic intubation. METHODS: The OOD is split in the front to form a path for the bronchoscope. An external lumen delivers oxygen in the deep laryngeal space. In this experimental study, air application (as control group), oxygen application via nasal prongs, oxygen application via the OOD, and oxygen application via the working channel of a bronchoscope were compared in a technical simulation. In a preoxygenated test lung of a manikin, decrease of the oxygen saturation was measured over 20 min for each method. RESULTS: Oxygen saturation in the test lung dropped from 97 ± 1% (baseline in all groups) to 58 ± 3% in the control-group (p < 0.001 compared to all other groups) and to 78 ± 1% in the nasal prong group (p < 0.001 compared to all other groups). Oxygen saturation remained at 95 ± 2% in both the OOD group and the bronchoscopy group (p = 0.451 between those two groups). CONCLUSION: Simulating apneic laryngeal oxygenation in a preoxygenated manikin, both oxygen insufflation via the OOD and the bronchoscope kept oxygen saturation in the test lung at 95% over 20 min. Both methods significantly were more effective than oxygen insufflation via nasal prongs.

Temperature loss by ventilation in a calorimetric bench model.

In intensive care medicine heat moisture exchangers are standard tools to warm and humidify ventilation gases in order to prevent temperature loss of patients or airway epithelia damage. Despite being at risk of hypothermia especially after trauma, intubated emergency medicine patients are often ventilated with dry and in winter probably cold ventilation gases. We tried to assess the amount of temperature-loss due to ventilation with cold, dry medical oxygen in comparison to ventilation with warm and humidified oxygen. We ventilated a 50-kg water-dummy representing the calorimetric capacity of a 60-kg patient over a period of 2 hours (tidal volume 6.6 mL/kg = 400 mL; respiratory rate 13/min). Our formal null-hypothesis was that there would be no differences in temperature loss in a 50 kg water-dummy between ventilation with dry oxygen at 10°C vs. ventilation with humidified oxygen at 43°C. After 2 hours the temperature in the water-dummy using cold and dry oxygen was 29.7 ± 0.1°C compared to 30.4 ± 0.1°C using warm and humidified oxygen. This difference in cooling rates between both ventilation attempts of 0.7 ± 0.1°C after 2 hours represents an increased cooling rate of ~0.35°C per hour. Ventilation with cool, dry oxygen using an automated transport ventilator resulted in a 0.35°C faster cooling rate per hour than ventilation with warm humidified oxygen in a bench model simulating calorimetric features of a 60-kg human body.

First-time evaluation of ascending compared to rectangular transthoracic defibrillation waveforms in modelled out-of-hospital cardiac arrest.

AIM OF THE STUDY: Prognosis in out-of-hospital cardiac arrest (OHCA) depends on cardiopulmonary resuscitation (CPR) duration. Therefore, the optimal biphasic defibrillation waveform shows high conversion rates besides low energy. Matthew Fishler theoretically predicted it to be truncated ascending exponential. We realised a prototypic defibrillator and compared ascending with conventional rectangular waveforms in modelled OHCA and CPR. METHODS: Approved by the authorities, 57 healthy swine (Landrace â€‹× â€‹Piétrain) were randomised to ASCDefib (n 26) or CONVDefib (n 26). Five swine served as sham control. We induced ventricular fibrillation (VF) electrically in anaesthetised swine randomised to ASCDefib or CONVDefib and discontinued mechanical ventilation. After 5 â€‹min of untreated cardiac arrest, we started CPR with mechanical chest compressions and ventilation. We performed transthoracic biphasic defibrillations after 2, 4, 6 and 8 â€‹min CPR targeting 4 â€‹J/kg in either group. Depending on the randomised group, the defibrillation protocol was either three ascending followed by one rectangular waveform (ASCDefib) or three rectangular followed by one ascending waveform (CONVDefib). RESULTS: Under our model-specific conditions, VF was initially terminated by 13/80 ascending waveforms and 13/79 rectangular waveforms and persistent return of spontaneous circulation was achieved in 8/26 (ASCDefib) vs. 10/26 (CONVDefib) animals. Mean current rather than waveform design was predictive for defibrillation success in a generalised linear model. CONCLUSION: Contrary to theoretical assumptions, transthoracic biphasic defibrillation with ascending waveforms is not superior to rectangular waveforms in modelled OHCA. We advocate defibrillation dosage to be guided by current, that has proven its predictive value again. INSTITUTIONAL PROTOCOL NUMBER: 84-02.04.2017.A176.

Esophageal Heat Exchanger Versus Water-Circulating Cooling Blanket for Targeted Temperature Management.

To date, the optimal cooling device for targeted temperature management (TTM) remains unclear. Water-circulating cooling blankets are broadly available and quickly applied but reveal inaccuracy during maintenance and rewarming period. Recently, esophageal heat exchangers (EHEs) have been shown to be easily inserted, revealed effective cooling rates (0.26-1.12°C/h), acceptable deviations from target core temperature (<0.5°C), and rewarming rates between 0.2 and 0.4°C/h. The aim of this study was to compare cooling rates, accuracy during maintenance, and rewarming period as well as side effects of EHEs with water-circulating cooling blankets in a porcine TTM model. Mean core temperature of domestic pigs (n = 16) weighing 83.2 ± 3.6 kg was decreased to a target core temperature of 33°C by either using EHEs or water-circulating cooling blankets. After 8 hours of maintenance, rewarming was started at a goal rate of 0.25°C/h. Mean cooling rates were 1.3 ± 0.1°C/h (EHE) and 3.2 ± 0.5°C/h (blanket, p < 0.0002). Mean difference to target core temperature during maintenance ranged between ±1°C. Mean rewarming rates were 0.21 ± 0.01°C/h (EHE) and 0.22 ± 0.02°C/h (blanket, n.s.). There were no differences with regard to side effects such as brady- or tachycardia, hypo- or hyperkalemia, hypo- or hyperglycemia, hypotension, shivering, or esophageal tissue damage. Target temperature can be achieved faster by water-circulating cooling blankets. EHEs and water-circulating cooling blankets were demonstrated to be reliable and safe cooling devices in a prolonged porcine TTM model with more variability in EHE group.

Intravascular Cooling Device Versus Esophageal Heat Exchanger for Mild Therapeutic Hypothermia in an Experimental Setting.

BACKGROUND: Targeted temperature management is a standard therapy for unconscious survivors of cardiac arrest. To date, multiple cooling methods are available including invasive intravascular cooling devices (IVDs), which are widely used in the clinical setting. Recently, esophageal heat exchangers (EHEs) have been developed providing cooling via the esophagus that is located close to the aorta and inferior vena cava. The objective was to compare mean cooling rates, as well as differences, to target temperature during maintenance and the rewarming period of IVD and EHE. METHODS: The study was conducted in 16 female domestic pigs. After randomization to either IVD or EHE (n = 8/group), core body temperature was reduced to 33°C. After 24 hours of maintenance (33°C), animals were rewarmed using a target rate of 0.25°C/h for 10 hours. All cooling phases were steered by a closed-loop feedback system between the internal jugular vein and the chiller. After euthanasia, laryngeal and esophageal tissue was harvested for histopathological examination. RESULTS: Mean cooling rates (4.0°C/h ± 0.4°C/h for IVD and 2.4°C/h ± 0.3°C/h for EHE; P < .0008) and time to target temperature (85.1 ± 9.2 minutes for IVD and 142.0 ± 21.2 minutes for EHE; P = .0008) were different. Mean difference to target temperature during maintenance (0.07°C ± 0.05°C for IVD and 0.08°C ± 0.10°C for EHE; P = .496) and mean rewarming rates (0.2°C/h ± 0.1°C/h for IVD and 0.3°C/h ± 0.2°C/h for EHE; P = .226) were similar. Relevant laryngeal or esophageal tissue damage could not be detected. There were no significant differences in undesired side effects (eg, bradycardia or tachycardia, hypokalemia or hyperkalemia, hypoglycemia or hyperglycemia, hypotension, overcooling, or shivering). CONCLUSIONS: After insertion, target temperatures could be reached faster by IVD compared to EHE. Cooling performance of IVD and EHE did not significantly differ in maintaining target temperature during a targeted temperature management process and in active rewarming protocols according to intensive care unit guidelines in this experimental setting.

Safer employment of nitrous oxide in anesthesia machines-a technical simulation.

Several incidents of anesthesia-attributed mortality in the past were caused by misconnection of gas pipelines resulting in ventilation with pure nitrous oxide. A simple safety feature may be to "mark" nitrous oxide with a lower pressure than oxygen and room air within the hospital's gas pipeline system. Then, any misconnection of gas pipelines could be detected by pressure differences with a manometer in the anesthesia machine. To check technical suitability, we tested maximum achievable nitrous oxide flows of an anesthesia machine at different pressures in the nitrous oxide supply line. Using decreased pressures for nitrous oxide compared to oxygen did not result in decreased nitrous oxide flows, as long as pressure in the nitrous oxide supply line was >1500 hPa. A concept of different pressures for nitrous oxide and oxygen could be used to technically differentiate between those two gases, and to avoid potentially fatal misconnections.