Study design and population
herniation, traumatic, TBI, Trauma, non-traumatic brain injury
BRAIN
This single center, cross-sectional study was conducted in six intensive care units (ICUs) of the Hospital das Clínicas, São Paulo University, Brazil between 2020 and 2022. Therefore, the present manuscript is a retrospective analysis of a prospective trial. The clinical trial study protocol was approved by the local Ethics Committee in April 2017 (Number NCT03144219, available at clinicaltrials.gov). Informed consent was obtained from legally authorized representatives/next of kin of patients before inclusion. This study was performed according to the Standards for Reporting of Diagnostic Accuracy Studies (STARD) (Supplemental Table 1).Patients were eligible for this study if they had: acute traumatic (TBI) or non-traumatic brain injury; (b) need for ventilatory support at enrollment; (c) required invasive ICP monitoring, according to the guidelines for high-risk of brain herniation of the Brain Trauma Foundation. Exclusion criterion was the presence of fixed mydriatic or middle-sized pupils for more than 2 h after ventilatory and hemodynamic stabilization. As part of a greater study for the assessment of ICP variations over cerebral blood flow and ICP waveforms, the present analysis comprised a single 10-min session (i.e., at least 700 heart beats) for each patient, including them within the first 5 days after admission. In this model, no comprehensive variations of the recorded parameters were induced. Simultaneous recording of invasive arterial blood pressure, ICP, NICPW (see below), electrocardiogram, temperature and oxygen saturation was obtained, as previously reported [