Role of cerebral blood volume, tissue oxygenation index, troponin I and neuro-physiological variables in birth asphyxia, related to outcome.

AIM: To evaluate cerebral blood volume (DCBV), tissue oxygenation index (TOI), troponin I and neuro-physiological variables in term neonates affected at birth by cardiorespiratory depression or asphyxia and their correlation with outcome. DESIGN/METHODS: Case-control study. Inclusion criteria: arterial pH less or equal to 7.25, excessive base deficit (BE) and Apgar at 5 min less or equal to 6. We evaluated grade of encephalopathy (HIE) at birth as well as neurodevelopmental performance at 12 months. The 15 control neonates were with Apgar score more or equal to 9 at 5 min, with near infrared spectroscopy (NIRS) and troponin I at the same age. Optodes were placed on the frontotemporal area in the first 14±7.6h after birth. DCBV was calculated from D[Hb sum]x0.89/Hb (g/dL). We assessed troponin I and blood gases (before 1 hour of life) on admission. Brain ultrasound (US) were performed at 24 hours and somatosensory evoked potentials (EP), at 2 weeks of life. Data are presented as mean±SD. RESULTS: Troponin I increased in the asphyxiated or depressed group in comparison with controls (0.39±0.54 vs 0.09±0.08, p=0.04) (Mann-Whitney test). ANOVA analysis showed a correlation between HIE grade at birth with EEG (p=0.03), EP (p=0.00009), US (p=0.009). A multiple regression model, including EEG, US and EP as independent variables and one year-outcome as dependent one, presents for EP a p=0.02 and Beta 0.57. Another multiple regression model including pH, BE, troponin I as well as DCBV and TOI as independent variables and one year-outcome shows for BE a p =0.008. CONCLUSION: In asphyxiated or depressed term newborn infants EEG, EP and US scan correlated with grade of HIE at birth. EP and BE correlated with one year outcome. DCBV and TOI seem not to indicate early and one-year outcome.