Word count of the text: 3089Word count of the abstract: 258
Conflict of interest: noneThere was no financial support for this study.
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ABSTRACT PURPOSEThe purpose of this study was to evaluate the significance of cerebrovascular CO 2 reactivity (CO 2 R) in the course and outcome of inflammatory CNS diseases.
METHODSSixty eight patients with inflammatory CNS diseases and thirty healthy volunteers were included in this prospective observational cohort study. The observational period was between January 2005 and May 2009. CO 2 reactivity was measured by Transcranial Doppler ultrasound (TCD) using the breath-holding method. We compared patients with normal CO 2 R (BHI m ≥ 1.18 = BHI N group) with patients who showed impaired CO 2 R (BHI m < 1.18 = BHI R group). We also analyzed the association of impaired CO 2 R with the etiology, severity and outcome of disease.
RESULTSWhen compared to BHI N group, the patients from BHI R group were older, had a heavier consciousness disturbance, experienced more frequent respiratory failure, and subsequently had worse outcomes. There were no fatalities among the 28 patients in the BHI N group. The comparison of subjects with bacterial and non-bacterial meningitis revealed no significant differences. The unfavorable outcome of disease (GOS 1-3) was significantly more common in subjects with impaired CO 2 reactivity (62.5% vs. 10.7%).Logistic regression analysis was performed in order to establish the prognostic value of BHI m . The outcome variable was unfavorable outcome (GOS 1-3), while the independent variables were age, GCS and BHI m . The age and BHI m showed the strongest influence on disease outcome. A decrease of BHI m for each 0,1 unit increased the risk of unfavorable outcome for 17%.
CONCLUSIONSOur study emphasizes the importance of CO 2 reactivity assessment in patients with inflammatory CNS diseases.