Intracranial pressure variability: relation to clinical outcome, intracranial pressure –volume index, cerebrovascular reactivity and blood pressure variability

In this study, we aimed to further investigate the explanatory variables for ICPV and its relation to outcome. Data from 362 TBI patients were retrospectively analyzed day 2 to 5 post-injury. ICPV was evaluated in three ways. First, variability in the sub-minute time interval (similar to B waves) was calculated as the amplitude of the ICP slow waves using a bandpass filter, limiting the analysis to oscillations of 55 to 15  s (ICP AMP 55–15). The second and third ICPV measures were calculated as the deviation from the mean ICP averaged over 30 min (ICPV-30m) and 4 h (ICPV-4h), respectively. All ICPV measures were associated with a reduced intracranial pressure/volume state (high ICP and RAP) and high blood pressu re variability in multiple linear regression analyses. Higher ICPV was associated with better pressure reactivity in the univariate, but not the multiple analyses. All ICPV measures were associated with favorable outcome in univariate analysis, but only ICP AMP 55–15 and ICPV-30m did so in the mul tiple logistic regression analysis. Higher ICPV can be explained by a reduced intracranial compliance and variations in cerebral blood volume due to the vessel response to unstable blood pressure. As ICP AMP 55–15 and ICPV-30m independently predicted favorable outcome, it may represent general cer ebral vessel activity, associated with better cerebral blood flow regulation and less secondary insults.
Source: Journal of Clinical Monitoring and Computing - Category: Information Technology Source Type: research