Evaluation and application of ultra-low-frequency pressure reactivity index in pediatric traumatic brain injury patients. - Gritti P; Bonfanti M; Zangari R; Bonanomi E; Pellicioli I; Mandelli P; Longhi L; Rasulo FA; Bertuetti R; Farina A; Biroli F; Lorini FL (Acta neurochirurgica, 2023)