Resumen: Background: Growing evidence suggests that critical illness often results in significant long-term neurocognitive impairments in one-third of survivors. Although these neurocognitive impairments are long-lasting and devastating for survivors, rehabilitation rarely occurs during or after critical illness. Our aim is to describe an early neurocognitive stimulation intervention based on virtual reality for patients who are critically ill and to present the results of a proof-of-concept study testing the feasibility, safety, and suitability of this intervention. Methods: Twenty critically ill adult patients undergoing or having undergone mechanical ventilation for =24 h received daily 20-min neurocognitive stimulation sessions when awake and alert during their ICU stay. The difficulty of the exercises included in the sessions progressively increased over successive sessions. Physiological data were recorded before, during, and after each session. Safety was assessed through heart rate, peripheral oxygen saturation, and respiratory rate. Heart rate variability analysis, an indirect measure of autonomic activity sensitive to cognitive demands, was used to assess the efficacy of the exercises in stimulating attention and working memory. Results: Patients successfully completed the sessions on most days. No sessions were stopped early for safety concerns, and no adverse events occurred. Heart rate variability analysis showed that the exercises stimulated attention and working memory. Critically ill patients considered the sessions enjoyable and relaxing without being overly fatiguing. Conclusions: The results in this proof-of-concept study suggest that a virtual-reality-based neurocognitive intervention is feasible, safe, and tolerable, stimulating cognitive functions and satisfying critically ill patients. Future studies will evaluate the impact of interventions on neurocognitive outcomes. Trial registration Clinical trials.gov identifier: NCT02078206. Idioma: Inglés DOI: 10.1186/s13613-017-0303-4 Año: 2017 Publicado en: Annals of intensive care 7, 81 (2017), [11 pp] ISSN: 2110-5820 Factor impacto JCR: 3.771 (2017) Categ. JCR: CRITICAL CARE MEDICINE rank: 9 / 33 = 0.273 (2017) - Q2 - T1 Factor impacto SCIMAGO: 1.819 - Critical Care and Intensive Care Medicine (Q1)