Collaborative virtual reality environment in disaster medicine: moving from single player to multiple learners.

BACKGROUND: The use of virtual reality (VR) in healthcare education is on the increase. In disaster medicine, it could be a solution to the cost and logistic constraints for a "full-scale" scenarios. However, VR is mainly designed for single players, which is not appropriate for the objectives pursued in disaster medicine. We decided to evaluate the educational value of using individual VR simulation in disaster medicine on a group of learners. METHODS: The VR scenario used was a reproduction of a major train crash, with 21 victims and whose objectives were START triage and first aid techniques. The sessions were carried out in multi-participant groups with different roles (active and immersed with headset, paper triage without headset, and active for communications not immersed in the headset). Their perceived self-efficacy was assessed before (T0), after (T1) and 2 months (T2) after the training. Satisfaction and confidence in learning were also measured. RESULTS: The median levels of satisfaction and confidence in learning were of 21/25 and 32/40 respectively. Their perceived self-efficacy increased significantly between T0 and T1 (p < 0.001), and remained stable until T2. The different roles of participant showed no difference in terms of satisfaction, confidence in learning or changes in perceived self-efficacy. One third of the participants agreed that the number of participants had interfered with their learning. A significant negative correlation (rS = -0.51, p = 0.002) was found between satisfaction and the fact of having been hindered by the number of participants. Around 90% of participants found the activity entertaining and found the new technologies appropriate for learning technical skills. CONCLUSIONS: This first experience of VR in a group setting is satisfactory and shows its positive effects. The limitations highlighted here will enable areas of improvement to be identified for the use of VR in disaster medicine, pending the development of multi-player tools. It would now be appropriate to analyse the impact of this type of simulation on learning and its retention over time.

Ejection Fraction May Not Reflect Contractility: Example in Veno-Arterial Extracorporeal Membrane Oxygenation for Heart Failure.

Precise assessment of left ventricular (LV) contractility during veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is crucial. However, changes in loading conditions may mask changes in LV function when assessed with load-dependent parameters. We compared end-systolic elastance (Ees, mm Hg/ml), the reference load-independent parameter of LV contractility, with LV ejection fraction (LVEF) in two patients. The first patient was a 54-year-old patient supported with femoro-femoral VA-ECMO for a cardiogenic shock. Afterload was calculated by using arterial elastance (Ea, mm Hg/ml). Although Ees near doubled from day 0 to day 3, no significant change was observed in LVEF. The second patient was a 61-year-old patient supported with femoro-femoral VA-ECMO for severe heart failure complicated with sepsis. We retrospectively showed that discrepancy between LVEF and Ees resulted from changes in LV-arterial coupling. We concluded that LVEF may be misleading in the assessment of LV function during VA-ECMO for heart failure.