Fig. 3
Boxplots of cerebral perfusion and oxygenation at the different time points. Box and whisker plots showing median (line), interquartile range (shaded) and outliers (circles) for partial pressure of tissue oxygen (PbrO2, in mmHg) (a) and laser speckle perfusion units (b) in the normal blood pressure group (NBP) and low blood pressure group (LBP). Whiskers extend a maximum of 1.5× the interquartile range. The value for ischaemic threshold is shown (dashed line). Experimental time points: PCB pre-caval block, PR-1 initial baseline for propofol-remifentanil TIVA, PR-2 immediately before dexmedetomidine administration, PRD following propofol–remifentanil–dexmedetomidine TIVA. Significant differences from either the ischaemia limit (vertical bars) or between timepoints (horizontal bars) are shown