[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.

Overinflation of the cuff and pressure on the neck reduce the preventive effect of supraglottic airways on pulmonary aspiration: an experimental study in human cadavers.

BACKGROUND: The oesophageal leak pressure is defined as the pressure which breaks the seal between the cuff of a supraglottic airway and the peri-cuff mucosa, allowing penetration of fluid into the pharynx and the oral cavity. As a consequence, a decrease in this variable increases the risk of reflux and can lead to pulmonary aspiration. The aim of this study was to analyse the effects of cuff overinflation and pressure on the neck on the oesophageal leak pressure of seven supraglottic airways. METHODS: Three laryngeal masks, two laryngeal tubes, and two oesophageal-tracheal tubes were tested in an experimental setting. In five human cadavers, we simulated a sudden increase in oesophageal pressure. To measure baseline values (control), we used an intracuff pressure as recommended by the manufacturer. The first intervention included overinflation of the cuff by applying twice the amount of pressure recommended. A second intervention was defined as external pressure on the neck. RESULTS: The oesophageal leak pressure was decreased for laryngeal masks (control, 28 cm H2O; overinflation, 9 cm H2O; pressure on the neck, 8 cm H2O; P<0.01) and for laryngeal tubes (control, 68 cm H2O; overinflation, 37 cm H2O; pressure on the neck, 39 cm H2O; P<0.01) and was unaffected for oesophageal-tracheal tubes (control, 126 cm H2O; overinflation/pressure on the neck, 130 cm H2O; n.s.). CONCLUSION: Cuff overinflation and pressure on the neck can enhance the risk of gastro-oesophageal reflux when using supraglottic airways. Therefore, both manoeuvres should be avoided in clinical practice.

Cadaver study of oesophageal insufflation with supraglottic airway devices during positive pressure ventilation in an obstructed airway.

BACKGROUND: Supraglottic airway devices (SADs) play an increasing role in airway management in clinical anaesthesia and emergency medicine. Until now, no data exist concerning the extent of oesophageal insufflation when oropharyngeal leak pressures are exceeded. METHODS: Laryngeal masks LMA-Supreme™ and LMA-ProSeal™, laryngeal tubes LTS-D and LTS II, Combitube™, and I-Gel were inserted into unfixed human cadavers. The oesophagus was connected to a volumeter, while the trachea was closed surgically to simulate complete airway obstruction. Volumes of oesophageal insufflation resulting from pressure-controlled ventilation at inspiratory pressures of 20, 40, and 60 mbar were measured. RESULTS: No oesophageal insufflation could be detected at a ventilation pressure of 20 mbar in any device. Using inspiratory pressures of 40 and 60 mbar, oesophageal insufflation occurred in all devices, with significantly higher volumes of intraoesophageal air for both laryngeal tubes. CONCLUSIONS: The use of SADs with inspiratory pressures of 20 mbar appears to be safe regarding the risk of intragastric insufflation. Higher inspiratory pressures should be strictly avoided.

Point-of-care testing in out-of-hospital cardiac arrest: a retrospective analysis of relevance and consequences.

BACKGROUND: Metabolic and electrolyte imbalances are some of the reversible causes of cardiac arrest and can be diagnosed even in the pre-hospital setting with a mobile analyser for point-of-care testing (POCT). METHODS: We conducted a retrospective observational study, which included analysing all pre-hospital resuscitations in the study region between October 2015 and December 2016. A mobile POCT analyser (Alere epoc®) was available at the scene of each resuscitation. We analysed the frequency of use of POCT, the incidence of pathological findings, the specific interventions based on POCT as well as every patient's eventual outcome. RESULTS: N = 263 pre-hospital resuscitations were included and in n = 98 of them, the POCT analyser was used. Of these measurements, 64% were performed using venous blood and 36% using arterial blood. The results of POCT showed that 63% of tested patients had severe metabolic acidosis (pH < 7.2 + BE < - 5 mmol/l). Of these patients, 82% received buffering treatment with sodium bicarbonate. Potassium levels were markedly divergent normal (> 6.0 mmol/l/ < 2.5 mmol/l) in 17% of tested patients and 14% of them received a potassium infusion. On average, the pre-hospital treatment time between arrival of the first emergency medical responders and the beginning of transport was 54 (± 20) min without POCT and 60 (± 17) min with POCT (p = 0.07). Overall, 21% of patients survived to hospital discharge (POCT 30% vs no POCT 16%, p = 0.01, Φ = 0.16). CONCLUSIONS: Using a POCT analyser in pre-hospital resuscitation allows rapid detection of pathological acid-base imbalances and potassium concentrations and often leads to specific interventions on scene and could improve the probability of survival.

[Effect of different training methods on the use of the i-gel laryngeal mask by lay persons on a manikin]. / Auswirkung verschiedener Ausbildungsmethoden auf die Anwendung der i-gel®-Larynxmaske durch Laien am Phantom.

BACKGROUND: Several studies have described the successful application of extraglottic airways by lay people to a phantom. OBJECTIVES: This study examined the influence of the training method on the success of the application. METHODS: A total of 150 visitors of a shopping mall were asked to place an i­gel laryngeal mask (Intersurgical GmbH, Sankt Augustin, Germany) on a manikin. The short instruction was randomized and performed either as a practical demonstration or through the self-study of an illustrated manual. RESULTS: Application success in the first attempt was 95.8 % for the practical demonstration group and 78.5 % for the written instruction group (p = 0.001). Placement times were also significantly different (median 11.5 s vs. 22.5 s, p < 0.001). CONCLUSIONS: Learning success can be achieved with both training methods. Initially, a hands-on training should be carried out with a practical demonstration.

Anaesthesia protocol evaluation of the videolaryngoscopy with the McGrath MAC and direct laryngoscopy for tracheal intubation in 1000 patients undergoing rapid sequence induction: the randomised multicentre LARA trial study protocol.

INTRODUCTION: Rapid sequence induction of anaesthesia is indicated in patients with an increased risk of pulmonary aspiration. The main objective of the technique is to reduce the critical time period between loss of airway protective reflexes and rapid inflation of the cuff of the endotracheal tube to minimise the chance of aspiration of gastric contents. The COVID-19 pandemic has reinforced the importance of first-pass intubation success to ensure patient and healthcare worker safety. The aim of this study is to compare the first-pass intubation success rate (FPS) using the videolaryngoscopy compared with conventional direct laryngoscopy in surgical patients with a high risk of pulmonary aspiration. METHODS AND ANALYSIS: The LARA trial is a multicentre, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath MAC videolaryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of FPS is 92% in the McGrath group and 82% in the Macintosh group. Each group must include a total of 500 patients to achieve 90% power for detecting a difference at the 5% significance level. Successful intubation with the FPS is the primary endpoint. The secondary endpoints are the time to intubation, the number of intubation attempts, the necessity of airway management alternatives, the visualisation of the glottis using the Cormack and Lehane Score and the Percentage Of Glottic Opening Score and definite adverse events. ETHICS AND DISSEMINATION: The project is approved by the local ethics committee of the Medical Association of the Rhineland Palatine state (registration number: 2020-15502) and medical ethics committee of the University of Freiburg (registration number: 21-1303). The results of this study will be made available in form of manuscripts for publication and presentations at national and international meetings. TRIAL REGISTRATION: NCT04794764.

Oesophageal seal of the novel supralaryngeal airway device I-Gel in comparison with the laryngeal mask airways Classic and ProSeal using a cadaver model.

BACKGROUND: Supraglottic airway devices are increasingly used in anaesthesia and emergency medicine. This study was designed to investigate the oesophageal seal of the novel supralaryngeal airway device, I-Gel (I-Gel), in comparison with two of the laryngeal mask airways, Classic (cLMA) and ProSeal (pLMA), in a model of elevated oesophageal pressure. METHODS: The three supralaryngeal airway devices were inserted into eight unfixed cadaver models with exposed oesophagi that had been connected to a water column producing both a slow and a fast oesophageal pressure increase. The pressure applied until the loss of oesophageal seal during a slow and fast pressure increase was measured. RESULTS: During the slow increase of pressure, the pLMA withstood an oesophageal pressure up to a median of 58 cm H(2)O, while the cLMA was able to block the oesophagus up to a median of 37 cm H(2)O, and I-Gel already lost its seal at 13 cm H(2)O. One minute after maximum pressure had been applied, the pLMA withstood an oesophageal pressure of 59 cm H(2)O, the cLMA of 46 cm H(2)O, and I-Gel airway of 21 cm H(2)O. A fast release of oesophageal fluid was accomplished through the oesophageal lumen of both the pLMA and I-Gel. CONCLUSIONS: Both the pLMA and cLMA provided a better seal of the oesophagus than the novel I-Gel airway. The pLMA and I-Gel drain off gastrointestinal fluid fast through the oesophageal lumen. Thus, tracheal aspiration may be prevented with their use. Further study is necessary.

Adherence to guideline-based standard operating procedures in pre-hospital emergency patients with chronic obstructive pulmonary disease.

This study investigated improvements in pre-hospital care for patients with acute exacerbated chronic obstructive pulmonary disease (aeCOPD) achieved by using a standard operating procedure (SOP). An SOP for pre-hospital treatment of patients with aeCOPD was designed based on valid national guidelines. A total of 1000 Emergency Medical Service patient care reports were analysed prospectively: 500 before and 500 after introduction of the SOP. Overall guideline adherence was 34.6% before and 53.8% after introduction of the SOP; this increase was not statistically significant. After SOP introduction, the administration of ß(2) mimetics by inhalative, intravenous and subcutaneous routes increased significantly. The level of knowledge of the national guidelines was rated at 67% by emergency physicians during self-assessment, but was only 33% when physicians were asked specific questions during interview. Introducing the SOP for patients with aeCOPD did not significantly improve adherence to valid national guidelines, but did help to improve specific elements of therapy.

Influence of an impedance threshold valve on ventilation with supraglottic airway devices during cardiopulmonary resuscitation in a manikin.

AIM: This study investigates if a n impedance threshold valve (ITV) might improve survival after cardiac arrest by increasing vital organ blood flow. The combination of ITV and supraglottic airway devices (SADs) has not been previously studied. This simulation study in a manikin aimed at analysing differences in ventilation with different SADs without and with an ITV. METHODS: In a resuscitation manikin, cardiopulmonary resuscitation (CPR) was performed with interrupted (30:2) and continuous chest compressions using facemask, tracheal tube and 10 SADs (six different laryngeal masks, LT-D, LTS-D, Combitube((R)) and Easy Tube((R))). Ventilation was performed with and without an ITV. A total of 550 CPR cycles of 3-min duration were performed with chest compressions and ventilation standardised by use of a mechanical thumper device and an emergency ventilator. RESULTS: Sufficient ventilation was possible with all devices tested. For ventilation during continuous chest compressions, there were significantly reduced tidal volumes for all airway devices with ITV use. By contrast, during interrupted chest compressions, no differences in tidal volumes with the ITV occurred in the majority of devices. The maximum reduction of tidal volume for any device was 7.8% of the volume reached without the ITV. CONCLUSION: Based on the findings of this manikin trial, the use of an ITV for ventilation during CPR is possible in combination with supraglottic airway devices. Merging these two strategies warrants further clinical evaluation to judge the relevance of tidal volume reduction found in this trial.