Cardiopulmonary resuscitation (CPR) during spaceflight - a guideline for CPR in microgravity from the German Society of Aerospace Medicine (DGLRM) and the European Society of Aerospace Medicine Space Medicine Group (ESAM-SMG).

BACKGROUND: With 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. METHODS: After 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. RESULTS: We 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. DISCUSSION: CPR 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.

In-flight cardiac arrest and in-flight cardiopulmonary resuscitation during commercial air travel: consensus statement and supplementary treatment guideline from the German Society of Aerospace Medicine (DGLRM).

By the end of the year 2016, approximately 3 billion people worldwide travelled by commercial air transport. Between 1 out of 14,000 and 1 out of 50,000 passengers will experience acute medical problems/emergencies during a flight (i.e., in-flight medical emergency). Cardiac arrest accounts for 0.3% of all in-flight medical emergencies. So far, no specific guideline exists for the management and treatment of in-flight cardiac arrest (IFCA). A task force with clinical and investigational expertise in aviation, aviation medicine, and emergency medicine was created to develop a consensus based on scientific evidence and compiled a guideline for the management and treatment of in-flight cardiac arrests. Using the GRADE, RAND, and DELPHI methods, a systematic literature search was performed in PubMed. Specific recommendations have been developed for the treatment of IFCA. A total of 29 specific recommendations for the treatment and management of in-flight cardiac arrests were generated. The main recommendations included emergency equipments as well as communication of the emergency. Training of the crew is of utmost importance, and should ideally have a focus on CPR in aircraft. The decision for a diversion should be considered very carefully.

Evaluation of two oxygen face masks with special regard to inspiratory oxygen fraction (FiO2) for emergency use in rescue helicopters.

INTRODUCTION: Effective oxygenation during acute respiratory insufficiency depends on the inspiratory oxygen fraction (FiO(2)) and the oxygen face mask used. Recent studies demonstrated significant advantages of the Hi-Ox80 mask as compared with a basic mask. The aim of this study was to measure FiO(2) in the laryngopharynx of patients and to apply these data to the setting in rescue helicopters. METHODS: In spontaneously breathing patients, FiO(2) was measured with an O(2)-sensor (Draeger Medical, Luebeck, Germany) in the laryngopharynx, depending on the adjusted oxygen flow. Flow increments of 1 up to 12 L/min were analyzed using a basic oxygen mask (Intersurgical Ltd., Berkshire, UK) and a Hi-Ox80 mask (Viasys Healthcare GmbH, Hoechberg, Germany) in a randomized order on the same patient. Data were applied to the special helicopter environment and analyzed with respect to oxygen delivery per minute and resulting equipment benefits. Statistika (StatSoft GmbH, Hamburg, Germany) and t-test were used for statistical analysis. P

Lung MRI using an MR-compatible active breathing control (MR-ABC).

This work introduces an MR-compatible active breathing control device (MR-ABC) that can be applied to lung imaging. An MR-ABC consists of a pneumotachograph for respiratory monitoring and an airway-sealing unit. Using an MR-ABC, the subjects were forced to suspend breathing for short time intervals, which were used in turn for data acquisition. While the breathing flow was stopped, data acquisition was triggered by ECG to achieve simultaneous cardiac and respiratory synchronization and thus avoid artifacts from blood flow or heart movement. The flow stoppage allowed a prolonged acquisition window of up to 1.5 sec. To evaluate the potential of an MR-ABC for segmented k-space acquisition, diaphragm displacement was investigated in five volunteers and compared with images acquired using breath-holding, a respiratory belt, and free breathing. Respiratory movement was comparatively low using the breath-hold approach, a respiratory belt or an MR-ABC. During free-breathing diaphragm displacement was comparatively large. To demonstrate the potential of an MR-ABC, lung MRI was performed using whole-chest 3D gradient-echo imaging, multislice turbo spin-echo (TSE) imaging, and short tau inversion recovery TSE (STIR-TSE). Cardiorespiratory synchronization was used for each sequence. None of the volunteers reported any discomfort or inconvenience when using an MR-ABC. Flow stoppage of up to 2.5 sec per breathing cycle was well tolerated, therefore allowing for a reduction of the total imaging time as compared to usage of a respiratory belt or MR navigator.

Oxygen delivery comparison of two constant-flow masks during flight to 6863 m.

OBJECTIVE: Differences in mask design may alter the oxygen flow required to gain similar oxygenation at a particular altitude. The selection of the most efficient mask would be advantageous for general aviation and other applications where oxygen supply is limited. METHODS: We compared a basic mask (BAS) without valves or oxygen reservoir bag to a test mask (TST) with three valves and a reservoir designed to deliver up to 80% oxygen for critically ill patients. Randomly assigned parachutists (n = 31) used the masks during a flight with a gradual climb to 6863 m (22,500 ft). The oxygen flow was individually controlled to produce oxygen saturation (SpO2) of 95-97% as determined by pulse oximetry. Oxygen flow and SpO2 were obtained every 305 m (1000 ft). RESULTS: Baseline age, lung function indices, and SpO2 were comparable for the two groups. Mean in-flight Spo2 values were 95.3 +/- 0.5% for the BAS and 96.2 +/- 1.1 % for the TST, respectively. Above 3965 m (13,000 ft) the TST required significantly less oxygen flow than the BAS to maintain the target SpO2. At 6863 m (22,500 ft), mean oxygen flow was 5.5 +/- 3.5 L x min(-1) for the BAS vs. 3.4 +/- 2.3 L x min(-1) for the TST (p = 0.029). No adverse reactions were reported from either group. CONCLUSION: The TST required significantly less oxygen flow compared with the BAS at high altitudes and may, therefore, reduce total oxygen use, resulting in reduced costs and longer oxygen availability during a flight.