Virtual Reality-Induced Dissociative Symptoms: A Retrospective Study.

Objective: The use of virtual reality (VR) has been increasing worldwide, as devices are becoming more sophisticated and provide an escape from reality during the COVID-19 lockdown. This recent rise in the use of VR leads to new side effects being reported, such as dissociative symptoms that may or may not constitute a mental health concern. This retrospective study investigated the prevalence and intensity of dissociative symptoms in VR users, as well as some potential predisposing conditions that may trigger them, and their impact on the subjects' wellbeing. Materials and Methods: We conducted a survey (n = 358) that was posted on VR Facebook groups. This survey was approved by the University of Lisbon Medical Faculty's IRB, and comprised a modified version of the Clinician-Administered Dissociative State Scale (CADSS) and questions regarding potential risk factors known to induce dissociative disorders or experiences. Results: Data analysis revealed that 83.9% participants reported dissociative symptoms, with varying intensity according to CADSS (X̄=7.62;s=7.89). Significant correlations were found between CADSS score and the time spent playing, the use of software applications (apps) that involve virtual hands or hand tracking, history of previous dissociative experiences, traumatic childhood events, avoidant coping strategies, and psychiatric disorders. Nonetheless, most participants categorized the symptoms as nonanxiogenic (85.8%) and minute lasting (77.4%). Conclusion: In conclusion, this study revealed that although VR can induce dissociative experiences, they seem to be short lasting and nonthreatening to the individual's wellbeing and might be predicted or attenuated by managing other known risk factors for dissociative phenomena.

Space motion sickness: A common neurovestibular dysfunction in microgravity.

This article presents a review of the current findings related to neurovestibular physiology, aetiology, and proposed theories on space motion sickness (SMS) during acute and sustained exposure to microgravity. The review discusses the available treatment options including medication and nonpharmacological countermeasure methods that help to prevent the development of SMS in weightlessness. Ground-based simulations using virtual reality, flight simulations, and Barany's chairs can be applied to study SMS and demonstrate its signs and symptoms to space crew members. Space motion sickness has been observed in approximately 70% of astronauts within the first 72 h in microgravity, having in general an instantaneous onset of signs and symptoms. Stomach discomfort, nausea, vomiting, pallor, cold sweating, salivation, tachypnoea, belching, fatigue, drowsiness, and stress hormone release have been documented. This can have detrimental effects on the well-being of astronauts in the initial phase of a space mission. Mental and physical performance may be affected, jeopardizing operational procedures and mission safety.

Mars walking simulation: An electromyographic analysis.

CONTEXT: With a long duration return mission to Mars on the horizon, we must learn as much about the environment and its influence on the musculoskeletal system as possible to develop countermeasures and mitigate deleterious health effects and maladaptation. AIMS: To determine the influence of simulated Mars gravity on the activity of four locomotor muscles while walking, in comparison to 1 G, using lower body positive pressure (LBPP). MATERIAL AND METHODS: A total of 14 male subjects (mean age: 20.6 ± 2.4 years) performed bouts of walking in both simulated Mars gravity (0.38 G) and Earth gravity (1 G) using an LBPP device. The dependent variables were the muscle activity evoked in the tibialis anterior, vastus lateralis, gluteus maximus and lateral portion of the gastrocnemius, measured using electromyography and expressed as percentages of maximum voluntary isometric contractions, and heart rate (HR). For statistical analysis, a paired t-test was performed. Statistical significance was defined as P < 0.05. RESULTS: No significant differences in muscle activity were found across conditions for any of the investigated muscles. A significant mean difference in the HR was identified between Earth (105.15 ± 8.1 bpm) and Mars (98.15 ± 10.44 bpm) conditions (P = 0.027), wherein the HR was lower during the Mars trial. CONCLUSIONS: The Mars environment may not result in any deteriorative implications for the musculoskeletal system. However, if future research should report that stride frequency and thus activation frequency is decreased in the simulated Mars gravity, negative implications may be posed for muscle retention and reconditioning efforts on the Red Planet.

Neurological changes in outer space.

Space travel, once considered esoteric and part of science fiction, is becoming a reality in our lifetime. Closely monitoring health parameters in real-time and providing health care to Vyomanauts 200 km above the Earth's surface will be a reality in India, in just another 40 months. This will be the ultimate feat in Telemedicine! This review article gives an overview of what a "Space Doctor" needs to know with specific reference to the nervous system.

A new method for the performance of external chest compressions during hypogravity simulation.

INTRODUCTION: 2015 UK resuscitation guidelines aim for 50-60 mm depth when giving external chest compressions (ECCs). This is achievable in hypogravity if the rescuer flexes and extends their arms during CPR, or using a new method trialed; the 'Mackaill-Russomano' (MR CPR) method. METHODS: 10 participants performed 3 sets of 30 ECCs in accordance with 2015 guidelines. A control was used at 1Gz, with eight further conditions using Mars and Moon simulations, with and without braces in the terrestrial position and using the MR CPR method. The MR CPR method involved straddling the mannequin, using its legs for stabilization. A body suspension device, with counterweights, simulated hypogravity environments. ECC depth, rate, angle of arm flexion and heart rate (HR) were measured. RESULTS: Participants completed all conditions, and ECC rate was achieved throughout. Mean (±â€¯SD) ECC depth using the MR CPR method at 0.38Gz was 54.1 ±â€¯0.55 mm with braces; 50.5 ±â€¯1.7 mm without. ECCs were below 50 mm at 0.17Gz using the MR CPR method (47.5 ±â€¯1.47 mm with braces; 47.4 ±â€¯0.87 mm without). In the terrestrial position, ECCs were more effective without braces (49.4 ±â€¯0.26 mm at 0.38Gz; 43.9 ±â€¯0.87 mm at 0.17Gz) than with braces (48.5 ±â€¯0.28 mm at 0.38Gz; 42.4 ±â€¯0.3 mm at 0.17Gz). Flexion increased from approximately 2° - 8° with and without braces respectively. HR did not change significantly from control. DISCUSSION: 2015 guidelines were achieved using the MR CPR method at 0.38Gz, with no significant difference with and without braces. Participants were closer to achieving the required ECC depth in the terrestrial position without braces. ECC depth was not achieved at 0.17Gz, due to a greater reduction in effective body weight.

Monophasic and biphasic shock for transthoracic conversion of atrial fibrillation: Systematic review and network meta-analysis.

OBJECTIVES: Conduct a systematic review of the literature to compare the efficacy of different biphasic and monophasic shock waveforms technologies for transthoracic cardioversion of Atrial Fibrillation (AF). METHODS: We searched PubMed, EMBASE, The Cochrane Library, LILACS and ClinicalTrials.gov databases for randomized clinical trials comparing two or more defibrillation waveforms when performing elective transthoracic cardioversion of AF. The outcomes assessed were 1st shock success, overall success, cumulative energy and number of shocks to restore Normal Sinus Rhythm. RESULTS: Were included 23 trials involving 3046 patients, 5 biphasic and the monophasic waveform. Direct meta-analysis revealed that Biphasic waveforms have higher chance to achieve cardioversion in the 1st shock (OR: 3.2; 95% CI 2.2-4.7) and after a sequence of attempts (OR:2.4; 95% CI 1.5-3.9), requiring 296 less Joules (95% CI 356-237) and 0.74 less shocks (95%CI 1.03-0.44) when compared to Monophasic. Network meta-analysis showed no significant differences between the Biphasic technologies of PhysioControl ADAPTIV, Philips SMART and ZOLL Rectilinear, in any of the four outcomes. CONCLUSION: The evidences points to a Biphasic waveform superiority over Monophasic to perform AF cardioversion, supporting current guidelines to use less energy when using a Biphasic defibrillator. It is suggested that the Biphasic defibrillators from PhysioControl ADAPTIV, Philips SMART and ZOLL Rectilinear have similar efficacy and the use of any of them may result in similar chances, energy and number of shocks to achieve successful AF cardioversion.

Ensaio pré-clínico com desfibrilador externo / Pre-clinical trial with external defibrillator

OBJETIVOS: Avaliar a eficácia da desfibrilação em resposta à fibrilação ventricular induzida e descrever as mudanças macroscópicas ocorridas nos corações de suínos após choque de descarga capacitiva exponencial truncada aplicado por protótipo de desfibrilador produzido no Brasil e por um desfibrilador de referência, líder de mercado internacional.MÉTODOS: Dezesseis suínos foram agrupados em quatro grupos de quatro animais, para verificar a eficácia da desfibrilação em resposta à fibrilação ventricular induzida, aplicando cargas de 50 J e 100 J, assim como avaliar a segurança dos desfibriladores usados, através de análises macroscópicas da pele e do coração. Foram avaliados eritema, edema, bolhas, líquido na cavidade pericárdica, queimaduras e tecido carbonizado pós-choque.RESULTADOS: Todos os suínos, após um minuto da indução à fibrilação ventricular, desenvolveram taquicardia que progrediu à fibrilação ventricular. Quando utilizada baixa energia, o equipamento protótipo obteve 25% de sucesso com um suíno revertido, enquanto o equipamento referência obteve 50% de sucesso, com duas reversões. Entretanto, com energia a 100 J, o equipamento protótipo reestabeleceu o ritmo sinusal em três suínos (75%) e o equipamento referência realizou somente uma desfibrilação eficaz (25%). A aplicação de energia 100 J associou-se com queimadura cutânea de Grau II em apenas um suíno com o desfibrilador protótipo e em quatro suínos com o equipamento referência. As lesões do tecido cardíaco ocorreram em igual número com ambos os desfibriladores.CONCLUSÕES: O desfibrilador protótipo, quando aplicado com energia 100 J, demonstrou maior eficácia na reversão da fibrilação ventricular e apresentou menor injúria que o desfibrilador de referência com a mesma energia. Este estudo ajudará a elevar o padrão tecnológico e a ampliar a oferta qualificada de equipamentos para a saúde produzidos no Brasil, substituindo e/ou diminuindo importações e oferecendo um dispositivo seguro de última geração.

AIMS: To evaluate the efficacy of defibrillation in response to induced ventricular fibrillation and to describe the macroscopic changes in porcine hearts after truncated exponential capacitive discharge shock applied by a prototype defibrillator produced in Brazil and a reference, international market leader defibrillator.METHODS: Sixteen pigs were divided into four groups of four animals each, to verify the effectiveness of the defibrillator in response to induced ventricular fibrillation by applying loads of 50 J to 100 J, and assess the safety of the defibrillator by macroscopic analysis of the skin and heart. Erythema, edema, blistering, fluid in the pericardial cavity, burns, and post-shock charred tissue were evaluated.RESULTS: All pigs, after one minute of inducing ventricular fibrillation, developed tachycardia and progressed to ventricular fibrillation. When used low energy, the prototype equipment obtained 25% of success, with one reversed pig, while the reference equipment has obtained a success rate of 50%, with two reversals. However, with energy 100 J, the prototype equipment reestablished sinus rhythm in three pigs (75%) and the reference product only made effective defibrillation in one (25%). The application of 100 J energy was associated with skin burns Grade II in only one pig with the prototype defibrillator and four pigs with the reference equipment. The heart tissue injuries occurred in equal numbers with both defibrillators.CONCLUSIONS: The prototype defibrillator, when applied with 100 J energy, was more effective in reversing ventricular fibrillation and showed less injury than the reference defibrillator with the same energy. This study may help to raise the technological standard and to increase the supply of qualified health equipment produced in Brazil, replacing and/or decreasing imports and providing a secure next-generation device.