Cerebral extracellular chemistry and outcome following XXXX : a microdialysis study of 223 @entity1 .

@entity1 @entity131 @entity2227 @entity653 @entity880 @entity413 @entity2388
Secondary insults can adversely influence outcome following severe @entity131 . Monitoring of cerebral extracellular chemistry with microdialysis has the potential for early detection of metabolic derangements associated with such events. The objective of this study was to determine the relationship between the fundamental biochemical markers and neurological outcome in a large cohort of @entity1 with @entity131 . Prospectively collected observational neuromonitoring data from 223 @entity1 were analysed. Monitoring modalities included digitally recorded intracranial pressure, cerebral perfusion pressure, cerebrovascular pressure reactivity index and microdialysis markers @entity413 , @entity880 , @entity2388 , @entity2227 , @entity653 and the @entity880 / @entity2388 ratio. Outcome was assessed using the Glasgow Outcome Scale at 6 months post-injury. @entity1 -averaged values of parameters were used in statistical analysis, which included univariate non-parametric methods and multivariate logistic regression. Monitoring with microdialysis commenced on median (interquartile range) Day 1 (1-2) from injury and median (interquartile range) duration of monitoring was 4 (2-7) days. Averaged over the total monitoring period levels of @entity2227 (P = 0.048), @entity880 / @entity2388 ratio (P = 0.044), intracranial pressure (P = 0.006) and cerebrovascular pressure reactivity index (P = 0.01) were significantly higher in @entity1 who died. During the initial 72 h of monitoring, median @entity653 levels were also higher in the mortality group (P = 0.014) and median @entity880 / @entity2388 ratio (P = 0.026) and @entity880 (P = 0.033) levels were significantly lower in @entity1 with favourable outcome. In a multivariate logistic regression model (P < 0.0001), which employed data averaged over the whole monitoring period, significant independent positive predictors of mortality were @entity413 (P = 0.024), @entity880 / @entity2388 ratio (P = 0.016), intracranial pressure (P = 0.029), cerebrovascular pressure reactivity index (P = 0.036) and age (P = 0.003), while @entity2388 was a significant independent negative predictor of mortality (P = 0.004). The results of this study suggest that extracellular metabolic markers are independently associated with outcome following @entity131 . Whether treatment-related improvement in biochemistry translates into better outcome remains to be established.
