Abstract 177

Aims: To study cerebral circulatory changes during the first 48 hs in preterm infants in stable oxygenation, ventilation and hemodynamic condition, by NIRS and CDFI and to assess their relation with brain injury diagnosed by cerebral ultrasound (CUS). Patients: 48 infants (BW 1140±650 g and GA 29.3±2.5 wk were studied the 1est and 2nd day. Measurements: Blood flow velocity (BFV)(cm/sec) [peak systolic (PSFV), diastolic flow (EDFV), mean flow (TMFV)] and resistance index (RI) were determined in internal carotid (ICA), anterior cerebral (ACA), ophthalmic (OA) and striate arteries (head of the caudate nucleus level) (SA). Cerebral blood flow (CBF) (ml/min/hg) and cerebral blood volume (CBV) (ml/hg) were stimated by NIRS (Critikon®). Serial CUS were performed to detect changes in parenchymal echogenicity or periventricular-intraventricular hemorrhage (PIVH). Results: NIRS and Doppler values (TMFV) are exposed in the Table. Data given as mean±SD. Except for OA (0.82±0.07 1est day vs 0.76±0.1 2nd day, p<0.05), the RI did not change. During the 1est day CBF was significantly greater in babies with PIVH (31.4±13.3) as compared with those without PIVH(21.6±10)(p<0.05). SatO2, TcPO2, TCPCO2, and ABP did not change. Conclusions: In stable patients, the adaptation of CBF to metabolic demands is independent of ABP. Improved venous return instead of vasodilation could play an important role. These first prospective NIRS data are in accordance with Doppler findings. Higher CBF appear related to the development PIVH.

Table 1
Full size table

(Supported by FIS 94/0198)