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Background: Although there have been no reported cardiac arrests in space to date, the risk of severe medical events occurring during long-duration spaceflights is a major concern. These critical events can endanger both the crew as well as the mission and include cardiac arrest, which would require cardiopulmonary resuscitation (CPR). Thus far, five methods to perform CPR in microgravity have been proposed. However, each method seems insufficient to some extent and not applicable at all locations in a spacecraft. The aim of the present study is to describe and gather data for two new CPR methods in microgravity. Materials and Methods: A randomized, controlled trial (RCT) compared two new methods for CPR in a free-floating underwater setting. Paramedics performed chest compressions on a manikin (Ambu Man, Ambu, Germany) using two new methods for a free-floating position in a parallel-group design. The first method (Schmitz–Hinkelbein method) is similar to conventional CPR on earth, with the patient in a supine position lying on the operator’s knees for stabilization. The second method (Cologne method) is similar to the first, but chest compressions are conducted with one elbow while the other hand stabilizes the head. The main outcome parameters included the total number of chest compressions (n) during 1 min of CPR (compression rate), the rate of correct chest compressions (%), and no-flow time (s). The study was registered on clinicaltrials.gov (NCT04354883). Results: Fifteen volunteers (age 31.0 ± 8.8 years, height 180.3 ± 7.5 cm, and weight 84.1 ± 13.2 kg) participated in this study. Compared to the Cologne method, the Schmitz–Hinkelbein method showed superiority in compression rates (100.5 ± 14.4 compressions/min), correct compression depth (65 ± 23%), and overall high rates of correct thoracic release after compression (66% high, 20% moderate, and 13% low). The Cologne method showed correct depth rates (28 ± 27%) but was associated with a lower mean compression rate (73.9 ± 25.5/min) and with lower rates of correct thoracic release (20% high, 7% moderate, and 73% low). Conclusions: Both methods are feasible without any equipment and could enable immediate CPR during cardiac arrest in microgravity, even in a single-helper scenario. The Schmitz–Hinkelbein method appears superior and could allow the delivery of high-quality CPR immediately after cardiac arrest with sufficient quality.

Background: Although there have been no reported cardiac arrests in space to date, the risk of severe medical events occurring during long-duration spaceflights is a major concern. These critical events can endanger both the crew as well as the mission and include cardiac arrest, which would require cardiopulmonary resuscitation (CPR). Thus far, five methods to perform CPR in microgravity have been proposed. However, each method seems insufficient to some extent and not applicable at all locations in a spacecraft. The aim of the present study is to describe and gather data for two new CPR methods in microgravity. Materials and Methods: A randomized, controlled trial (RCT) compared two new methods for CPR in a free-floating underwater setting. Paramedics performed chest compressions on a manikin (Ambu Man, Ambu, Germany) using two new methods for a free-floating position in a parallel-group design. The first method (Schmitz–Hinkelbein method) is similar to conventional CPR on earth, with the patient in a supine position lying on the operator’s knees for stabilization. The second method (Cologne method) is similar to the first, but chest compressions are conducted with one elbow while the other hand stabilizes the head. The main outcome parameters included the total number of chest compressions (n) during 1 min of CPR (compression rate), the rate of correct chest compressions (%), and no-flow time (s). The study was registered on clinicaltrials.gov (NCT04354883). Results: Fifteen volunteers (age 31.0 ± 8.8 years, height 180.3 ± 7.5 cm, and weight 84.1 ± 13.2 kg) participated in this study. Compared to the Cologne method, the Schmitz–Hinkelbein method showed superiority in compression rates (100.5 ± 14.4 compressions/min), correct compression depth (65 ± 23%), and overall high rates of correct thoracic release after compression (66% high, 20% moderate, and 13% low). The Cologne method showed correct depth rates (28 ± 27%) but was associated with a lower mean compression rate (73.9 ± 25.5/min) and with lower rates of correct thoracic release (20% high, 7% moderate, and 73% low). Conclusions: Both methods are feasible without any equipment and could enable immediate CPR during cardiac arrest in microgravity, even in a single-helper scenario. The Schmitz–Hinkelbein method appears superior and could allow the delivery of high-quality CPR immediately after cardiac arrest with sufficient quality.

Isolated caregivers in remote environments frequently request medical advice or decision support from distant experts. Among the multiple difficulties arising from this configuration, exchanging timely and pertinent information under pressure between the two parties poses a considerable challenge. Cognitive Work Analysis and notably the Turing Machine Task Analysis (TMTA) method that enables task processing simulation represent a methodological framework that can guide the specification of remote assistance systems. Within this perspective, TMTA was used to specify assistance functions within a case study of acute abdominal pain occurring on a remote location. Using previous studies and medical knowledge, a work domain analysis of acute abdominal pain was conducted. Based on this analysis, a Turing machine state space was formalized. Applying this method provides two main outcomes helping specify medical assistance functions: a global architecture of medical assistance for isolated caregivers and guidance to define the kind of assistance functions that could be implemented, notably owing to the simulation of Turing machine scenarios. Associated with the abstraction hierarchy technique, the Turing machine simulation process provides a model of the dynamics of interaction between agents and work domain within the framework of adaptive assistance.

This focused review summarizes the medical, logistical and environmental challenges that would be associated with dealing with a traumatic surgical case during an interplanetary space mission in the near future.

In the next few years, the number of long-term space missions will significantly increase. Providing safe concepts for emergencies including airway management will be a highly challenging task. The aim of the present trial is to compare different airway management devices in simulated microgravity using a free-floating underwater scenario. Five different devices for airway management [laryngeal mask (LM), laryngeal tube (LT), I-GEL, direct laryngoscopy (DL), and video laryngoscopy (VL)] were compared by n = 20 paramedics holding a diving certificate in a randomized cross-over setting both under free-floating conditions in a submerged setting (pool, microgravity) and on ground (normogravity). The primary endpoint was the successful placement of the airway device. The secondary endpoints were the number of attempts and the time to ventilation. A total of 20 paramedics (3 female, 17 male) participated in this study. Success rate was highest for LM and LT and was 100% both during simulated microgravity and normogravity followed by the I-GEL (90% during microgravity and 95% during normogravity). However, the success rate was less for both DL (60% vs. 95%) and VL (20% vs. 60%). Fastest ventilation was performed with the LT both in normogravity (13.7 ± 5.3 s; n = 20) and microgravity (19.5 ± 6.1 s; n = 20). For the comparison of normogravity and microgravity, time to ventilation was shorter for all devices on the ground (normogravity) as compared underwater (microgravity). In the present study, airway management with supraglottic airways and laryngoscopy was shown to be feasible. Concerning the success rate and time to ventilation, the optimum were supraglottic airways (LT, LM, I-GEL) as their placement was faster and associated with a higher success rate. For future space missions, the use of supraglottic airways for airway management seems to be more promising as compared to tracheal intubation by DL or VL.

BACKGROUND Medical support for space exploration missions must prepare for severe medical events in conditions of microgravity. A key component to managing these events is techniques of airway management. The aim of the present trial is to compare airway management devices in simulated microgravity. METHODS In this randomized cross-over trial (RCT), four different devices were compared under simulated microgravity conditions utilizing a neutrally buoyant free-floating underwater manikin and poolside in normal gravity (control group). The primary endpoint was the successful placement of the airway device. The secondary endpoints were the number of attempts and the duration of each attempt. RESULTS A total of 20 participants performed placement of each device in both gravity conditions in an Airway mannequin. The fastest time to initial ventilation in simulated microgravity was possible with the laryngeal tube (18.9 ± 8 seconds) followed by laryngeal mask (20.1 ± 9 seconds). The I-gel® supraglottic airway device required substantially more time for successful insertion in simulated microgravity (35.4 ± 25 seconds) as did endotracheal tube intubation by direct laryngoscopy (70.4 ± 35 seconds). Simulated microgravity conditions prolonged time to initial ventilation by 3.3 seconds (LM), 3.9 seconds (LT), 19.9 seconds (I-gel) and 43.1 seconds (endotracheal intubation, ETI) when compared to poolside attempts in normogravity. CONCLUSION In simulated microgravity conditions, use of the laryngeal tube or laryngeal mask provided the quickest time to initial ventilation, without deliberate tethering of the mannequin and rescuer to a fixed surface. Endotracheal intubation required significantly longer procedure times and, thus, was considered insufficient for clinical use in microgravity.

BackgroundWith the “Artemis”-mission mankind will return to the Moon by 2024. Prolonged periods in space will not only present physical and psychological challenges to the astronauts, but also pose risks concerning the medical treatment capabilities of the crew. So far, no guideline exists for the treatment of severe medical emergencies in microgravity. We, as a international group of researchers related to the field of aerospace medicine and critical care, took on the challenge and developed a an evidence-based guideline for the arguably most severe medical emergency – cardiac arrest.MethodsAfter the creation of said international group, PICO questions regarding the topic cardiopulmonary resuscitation in microgravity were developed to guide the systematic literature research. Afterwards a precise search strategy was compiled which was then applied to “MEDLINE”. Four thousand one hundred sixty-five findings were retrieved and consecutively screened by at least 2 reviewers. This led to 88 original publications that were acquired in full-text version and then critically appraised using the GRADE methodology. Those studies formed to basis for the guideline recommendations that were designed by at least 2 experts on the given field. Afterwards those recommendations were subject to a consensus finding process according to the DELPHI-methodology.ResultsWe recommend a differentiated approach to CPR in microgravity with a division into basic life support (BLS) and advanced life support (ALS) similar to the Earth-based guidelines. In immediate BLS, the chest compression method of choice is the Evetts-Russomano method (ER), whereas in an ALS scenario, with the patient being restrained on the Crew Medical Restraint System, the handstand method (HS) should be applied. Airway management should only be performed if at least two rescuers are present and the patient has been restrained. A supraglottic airway device should be used for airway management where crew members untrained in tracheal intubation (TI) are involved.DiscussionCPR in microgravity is feasible and should be applied according to the Earth-based guidelines of the AHA/ERC in relation to fundamental statements, like urgent recognition and action, focus on high-quality chest compressions, compression depth and compression-ventilation ratio. However, the special circumstances presented by microgravity and spaceflight must be considered concerning central points such as rescuer position and methods for the performance of chest compressions, airway management and defibrillation.

Background The risk of severe medical and surgical events during long-duration spaceflight is significant. In space, many environmental and psychological factors may make tracheal intubation more difficult than on Earth. We hypothesised that, in microgravity, tracheal intubation may be facilitated by the use of a videolaryngoscope compared with direct laryngoscopy. Methods In a non-randomised, controlled, cross-over simulation study, we compared intubation performance of novice operators and experts, using either a direct laryngoscope or a videolaryngoscope, in weightlessness and in normogravity. The primary outcome was the success rate of tracheal intubation. Time to intubation and the confidence score into the success of tube placement were also recorded. Results When novices attempted to intubate the trachea in microgravity, the success rate of tracheal intubation using a videolaryngoscope was significantly higher (20/25 [80%]; 95% confidence interval [CI], 64.3–95.7 vs eight/20 [40%]; 95% CI, 18.5–61.5; P=0.006), and intubation time was shorter, compared with using a direct laryngoscope. In normogravity, the success rate of tracheal intubation by experts was significantly higher than that by novices (16/20 [80%]; 95% CI, 62.5–97.5 vs seven/25 [28%]; 95% CI, 10.4–45.6; P=0.001), but in microgravity, there was no significant difference between the experts and novices (19/20 [95%]; 95% CI, 85.4–100 vs 20/25 [80%]; 95% CI, 64.3–95.7; P=0.113). Higher confidence scores were achieved with videolaryngoscopy compared with direct laryngoscopy by both experts and novices in both microgravity and normogravity. Conclusions Videolaryngoscopy was associated with higher intubation success rate and speed, and higher confidence for correct tube placement by novice operators in microgravity, and as such may represent the best technique for advanced airway management during long-duration spaceflight.

Through the Dynamic Safety Model, Rasmussen (1990) pointed out that operators in complex work systems must cope with many degrees of freedom that involve uncertainty and risk. How to deal with these degrees of freedom without risk constitutes a central issue to devise proactive methods in risk analysis. The Abstraction Hierarchy technique is viewed as a tool that can assist operators in resolving the degrees of freedom problem. The method consists in creating a functional model of the work domain to help operators understand and control it. Such a method is well-adapted to organizations tightly coupled with their work domain (e.g. aviation, nuclear plants). However, in more loosely coupled work systems, many degrees of freedom also come significantly from the organization itself (self-organizing processes, equipment, and team management) in addition to those coming from the work domain. Through a heuristic version of Cognitive Work Analysis, this article presents the State Space Sketch as a technique to describe the constraints required to control a loosely coupled work system. The resulting model of constraints may be used to analyse potential failures and failure propagation. A first application to a medical emergency situation controlled by a medical team is presented. The State Space Sketch conforms to the formative and proactive requirements involved in the Cognitive Work Analysis framework and can contribute to devising assistance strategies.

De nouveaux projets de conquêtes spatiales sont prévues dans les années à venir vers la lune et Mars. Le temps estimé d’une mission martienne est de 950 jours. L’intubation orotrachéale est un geste d’urgence que les équipages devront maîtriser pour prendre en charge de nombreuses pathologies médico-chirurgicales. C’est une procédure technique et difficile en particulier chez des novices en intubation. Nous avons émis l’hypothèse que le vidéo-laryngoscope permettrait un meilleur succès de l’intubation en particulier chez des novices.Matériel et Méthode : six sujets (trois novices et trois experts) ont réalisé 180 intubations orotrachéales sur mannequins (90 en micropesanteur et 90 en normopesanteur). La moitié des tentatives a été réalisée avec un vidéo-laryngoscope et l’autre moitié avec un laryngoscope classique. Le critère de jugement principal était le taux de succès d’intubation. Le temps d’intubation et le score de certitude de succès ou d’échec du geste ont également été évalués.Résultats : le taux de succès de l’intubation chez les opérateurs novices en micropesanteur était plus important avec le vidéo-laryngoscope par rapport au laryngoscope direct (80% (20/25) vs 40% (8/20), p