科研之友
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摘要
Objective To define levels of mean arterial blood pressure (MABP) where cerebrovascular reactivity is strongest in preterm infants (ie, optimal MABP, or MABP(OPT)) and correlate deviations from MABP(OPT) with mortality and intraventricular hemorrhage (IVH). Study design A total of 60 preterm infants born at median gestational age 26 +/- 2 weeks (23 +/- 2 to 32 +/- 1) with indwelling arterial catheter were studied at a median 34 hours (range 5-228) of age. Tissue oxygenation heart rate (HR) reactivity index, which estimates cerebrovascular reactivity, was calculated as the moving correlation coefficient between slow waves of tissue oxygenation index, measured with near-infrared spectroscopy, and HR. MABP(OPT) was defined by dividing MABP into 2-mm Hg bins and averaging the tissue oxygenation HR reactivity index within those bins. A measurement of divergence from MABP(OPT) was calculated as the absolute difference between mean MABP and mean MABP(OPT). Results Individual MABP(OPT) was defined in 81% of the patients. A measurement of divergence from MABP(OPT) was greater in those patients who died (mean 4.2 mm Hg; 95% CI 3.33-4.96) compared with those who survived (mean 2.1 mm Hg; 95% CI 1.64-2.56), P = .013. Patients who had MABP lower than MABP(OPT) by 4 mm Hg or more had a greater rate of mortality (40%) than those with MABP close to or above MABPOPT (13%), P = .049. Patients with MABP greater than MABPOPT by 4 mm Hg had greater IVH scores, P = .042. Conclusions Continuous monitoring of cerebrovascular reactivity allows the determination of MABP(OPT) in preterm neonates. Significant deviation below MABP(OPT) was observed in infants who died. Deviation of MABP above optimal level was observed in infants who developed more severe IVH.
- 出版日期2015-7
