Table 1.
Admission characteristics and outcomes of the patient cohort.
Fig 1.
Boxplots of individual patients’ mean lactate-pyruvate ratio (LPR) over the first 72h following injury, by (A) Glasgow Outcome Score (GOS) and (B) dichotomised GOS.
Table 2.
Proportional odds regression against Glasgow Outcome Score (GOS) of baseline characteristics, microdialysis analytes, and monitoring parameters averaged over different intervals following injury.
Fig 2.
Fitted population mean time courses for microdialysis analytes using Generalised Additive Mixed Models (GAMM), by dichotomised glasgow outcome score group.
Lactate (A), Pyruvate (B), Lactate-Pyruvate Ratio (LPR, C), Glucose (D), Glutamate (E), and Glycerol (F). Shaded areas indicated 95% confidence intervals.
Fig 3.
Fitted population mean time courses for intracranial pressure derived parameters and brain tissue oxygenation.
Temporal course fitted with generalised additive mixed models (GAMM), by dichotomised Glasgow Outcome Score group. ICP (A), CPP (B), PRx (C), and PbtO2 (D), Shaded areas indicated 95% confidence intervals.
Fig 4.
Relationship between lactate-pyruvate ratio (LPR) and other physiological parameters.
In each panel a GAMM fit of glucose (A), CPP (B), PRx (C), and PbtO2 (D) against LPR is plotted. On the left axis LPR is scaled to zero mean without the intercept term; on the right axis the scale includes the overall intercept. Shaded region indicates 95%CI for the fit. The regions of each curve highlighted in yellow indicate non-zero first derivative i.e. where the is significant change. Alongside each plot is the distribution of random effects for intercept and slope/coefficient. Rug plot within in each panel indicates density of data.
Fig 5.
LPR elevation and associated physiological derangements.
Survival based curves (A) indicating likelihood of LPR >25 and the cumulative incidence of at least one epoch of LPR>25. Euler plot (B) showing prevalence of abnormalities in brain glucose, CPP, PRx, and PbtO2 (defined by the thresholds described in the text) during episodes of elevated LPR. Alternative representation as ‘Upset’ plot (C) showing differing frequency of permutations of physiological abnormalities (as indicated in the panel beneath the x-axis) associated with elevated LPR.