Changes in Cerebral Partial XXXX Pressure and Cerebrovascular Reactivity During Intracranial Pressure Plateau Waves.

@entity1 @entity131 @entity428 @entity26 @entity10166
BACKGROUND: Plateau waves in @entity428 ( @entity428 ) are frequently recorded in neuro intensive care and are not yet fully understood. To further investigate this phenomenon, we analyzed partial pressure of cerebral @entity26 (pbtO2) and a moving correlation coefficient between @entity428 and mean arterial blood pressure (ABP), called @entity10166 , along with the cerebral @entity26 reactivity index (ORx), which is a moving correlation coefficient between cerebral perfusion pressure (CPP) and pbtO2 in an observational study. METHODS: We analyzed 55 plateau waves in 20 @entity1 after severe @entity131 . We calculated ABP, ABP pulse amplitude (ampABP), @entity428 , CPP, pbtO2, heart rate (HR), @entity428 pulse amplitude (ampICP), @entity10166 , and ORx, before, during, and after each plateau wave. The analysis of variance with Bonferroni post hoc test was used to compare the differences in the variables before, during, and after the plateau wave. We considered all plateau waves, even in the same @entity1 , independent because they are separated by long intervals. RESULTS: We found increases for @entity428 and ampICP according to our operational definitions for plateau waves. @entity10166 increased significantly (p  =  0.00026), CPP (p  <  0.00001) and pbtO2 (p  =  0.00007) decreased significantly during the plateau waves. ABP, ampABP, and HR remained unchanged. @entity10166 during the plateau was higher than before the onset of wave in 40 cases (73  %) with no differences in baseline parameters for those with negative and positive   @entity10166 (difference during and after). ORx showed an increase during and a decrease after the plateau waves, however, not statistically significant. PbtO2 overshoot after the wave occurred in 35 times (64  %), the mean difference was 4.9      4.6  Hg (mean      SD), and we found no difference in baseline parameters between those who overshoot and those who did not overshoot. CONCLUSIONS: Arterial blood pressure remains stable in @entity428 plateau waves, while cerebral autoregulatory indices show distinct changes, which indicate cerebrovascular reactivity impairment at the top of the wave. PbtO2 decreases during the waves and may show a slight overshoot after normalization. We assume that this might be due to different latencies of the cerebral blood flow and @entity26 level control mechanisms. Other factors may include baseline conditions, such as pre-plateau wave cerebrovascular reactivity or pbtO2 levels, which differ between studies.
