Association between temporal patterns of baroreflex sensitivity after traumatic brain injury and prognosis: a preliminary study

Fig. 1. Flow chart of study design. Abbreviations: TBI, traumatic brain injury; ABP, arterial blood pressure; ICP, intracranial pressure

Fig. 2. Illustrative examples of temporal patterns in baroreflex sensitivity (BRS; blue line, upper panels), intracranial pressure (ICP; red line, upper panels), and pressure reactivity index (PRx; red line, bottom panels) in A–B): 20-year-old man who survived with Glasgow Outcome Scale score of 4; C–D 69-year-old woman who died. Patients who survived presented a gradual increase in BRS after day 2. In contrast, patients who died demonstrated a gradual decrease in BRS after day 2.5

Fig. 3. Median values of baroreflex sensitivity (BRS), arterial blood pressure (ABP), and heart rate (HR) calculated in consecutive non-overlapping 12-h windows during the first 7 days following traumatic brain injury in the group with good outcome (blue dots; sub-panels: A, C, E) and poor outcome (orange-yellow dots; sub-panels: B, D, F). Group-averaged data are presented as medians (central thick black lines), interquartile ranges (gray boxes), and min-max values (whiskers). Individual patients are presented as dots

Fig. 4. The “breakpoint” analysis using Tukey’s bag plot: graphical representation of the day when baroreflex sensitivity (BRS) reached minimum value (BRS MIN), and pressure reactivity index (PRx) was the highest (PRx MAX) in the full group of traumatic brain injury (TBI) patients. BRS reached the minimum value on day 2 after TBI, while PRx was the highest on day 2.5 after TBI. The following notations are used in the Tukey plot: the red square is the Tukey median which is the point with maximum depth; the bag (dark blue) is the depth region (which is a convex polygon) that contains 50% of the points with the largest depth; the fence (light blue) was calculated as depth regions; points that are outside the outer fence are marked as outliers with asterisks