Cimatti Anna Giulia, Martini Silvia, Galletti Silvia, Vitali Francesca, Aceti Arianna, Frabboni Giulia, Faldella Giacomo, Corvaglia Luigi
Neonatal Intensive Care Unit, S. Orsola-Malpighi University Hospital, Bologna, Italy.
Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy.
Front Pediatr. 2020 Jul 15;8:381. doi: 10.3389/fped.2020.00381. eCollection 2020.
The transitional period, defined as the first 72 h after preterm birth, is often characterized by a significant hemodynamic instability, which represents an important risk factor for such neurological complications of prematurity as intraventricular hemorrhage (IVH). The impairment of cerebral autoregulation plays a key role in the pathogenesis of IVH, whose incidence is highest during the transitional period. This pilot study aimed to evaluate whether patterns of cerebral autoregulation and oxygenation differ in relation to IVH development in very preterm infants during the transitional period. Infants <32 weeks' gestation were enrolled within 12 h from birth. A simultaneous monitoring of cerebral oxygenation (CrSO) by near-infrared spectroscopy and of heart rate and peripheral oxygen saturation by pulse oximetry was performed over the first 72 h. Cerebral fractional oxygen extraction (cFTOE) and tissue oxygenation-heart rate reactivity index (TOHRx), which represents a marker of cerebrovascular reactivity, were calculated. Daily cranial and cardiac ultrasound scans were performed, in order to assess the hemodynamic status and to detect a possible IVH onset. CrSO and cFTOE, clustered on 6-hour epochs, were compared between infants who developed IVH during the study period and those who did not. A between-group comparison of TOHRx before and after IVH detection was also performed. Twenty preterm infants with a median gestational age of 27 weeks (interquartile range, IQR: 25-30 weeks) and median birth weight of 895 g (IQR: 822-1208 g) were enrolled. Of these, 8 developed IVH. The median age at IVH detection was 40 h (IQR: 30-48 h). Pre-IVH TOHRx was significantly higher compared to matched control periods ( <0.001). CrSO was significantly lower from 12 to 30 h and from 42 h onwards in cases compared to controls; however, a temporary CrSO rise preceded IVH detection. Similarly, cFTOE was significantly higher in IVH infants from 12 to 30 h and from 48 to 72 h, with a transient decrease between the two periods. In preterm infants during the transitional period, the development of IVH is preceded by transient changes in cerebral oxygenation and oxygen extraction which, in turn, may underlie an early impairment of cerebral autoregulation. Larger studies are needed to confirm these preliminary findings.
过渡期定义为早产出生后的头72小时，其特征通常是显著的血流动力学不稳定，这是早产的神经并发症如脑室内出血（IVH）的一个重要危险因素。脑自动调节功能受损在IVH的发病机制中起关键作用，其发病率在过渡期最高。这项初步研究旨在评估极早早产儿在过渡期内，脑自动调节和氧合模式与IVH发生之间是否存在差异。孕周<32周的婴儿在出生后12小时内入组。在头72小时内，通过近红外光谱法同时监测脑氧合（CrSO），并通过脉搏血氧饱和度仪监测心率和外周血氧饱和度。计算脑分数氧摄取（cFTOE）和组织氧合-心率反应指数（TOHRx），后者是脑血管反应性的一个指标。每天进行头颅和心脏超声扫描，以评估血流动力学状态并检测可能的IVH发作。将研究期间发生IVH的婴儿与未发生IVH的婴儿在6小时时段内聚类的CrSO和cFTOE进行比较。还对IVH检测前后的TOHRx进行了组间比较。20名孕周中位数为27周（四分位间距，IQR：25 - 30周）、出生体重中位数为895克（IQR：822 - 1208克）的早产儿入组。其中，8名发生了IVH。IVH检测时的中位年龄为40小时（IQR：30 - 48小时）。与匹配的对照期相比，IVH前的TOHRx显著更高（<0.001）。与对照组相比，病例组在12至30小时以及42小时及以后CrSO显著更低；然而，在IVH检测前CrSO有短暂升高。同样，IVH婴儿在12至30小时以及48至72小时的cFTOE显著更高，在这两个时段之间有短暂下降。在过渡期的早产儿中，IVH的发生之前脑氧合和氧摄取会出现短暂变化，这反过来可能是脑自动调节早期受损的基础。需要更大规模的研究来证实这些初步发现。
