[Normal values of cerebral blood flow velocities in neonates]

Comparison of Umbilical Cord Milking and Delayed Cord Clamping on Cerebral Blood Flow in Term Neonates

OBJECTIVE

To compare the effect of umbilical cord milking (UCM) and delayed cord clamping (DCC) on cerebral blood flow in term neonates.

METHODS

This randomized controlled trial was conducted at a teaching hospital in India during 2012 to 2013. Two hundred newborns (>36wk) were randomized to UCM and DCC groups. UCM was done on 25cm of cord length. In DCC group, clamping was delayed by 60 to 90s. Resistive Index (RI), Pulsatility Index (PI) and cerebral blood flow velocities of middle cerebral artery (MCA) were measured at 24 to 48h of life.

RESULTS

Baseline characteristics and hemodynamic parameters were comparable. Mean PI [1.18 (0.26)] and RI [0.65 (0.08)] in UCM group was comparable to mean PI [1.18 (0.25)] and RI [0.65 (0.08)] in DCC group. The peak systolic velocity and end diastolic velocity (cm/s) of blood flow in MCA for UCM group were 34.94 (11.82) and 11.71 (4.75) respectively, while in DCC group they were 37.24 (12.63) and 13.07 (4.78) (p 0.23 and 0.07) respectively. Indices among growth retarded babies were not different.

CONCLUSIONS

DCC and UCM had similar effect on cerebral blood flow velocities and Doppler indices in MCA, in term neonates.

Extracranial Segments of the Vertebral Artery: Insight in the Developmental Changes up to the 21st Year of Life

The vertebral artery (VA) bilaterally arises usually from the subclavian artery and courses within the bony canals of cervical vertebrae, and then it reverses directions on the first vertebra before piercing the dura to enter the cranium.The aim was to follow (ab)normal developmental changes of extracranial VA from prenatal status to age 21. This chapter included a brief description of the arterial embryology and morphofunctional specificity of the VA in prevertebral, cervical, and atlantic parts, during prenatal and postnatal period.The authors concluded that the subclavian origin of the VA was in most of fetal and adult cases. The incidences of variable VA origins and domination of one of the VAs were different from one series of human specimens to the second one. Although in most of cases, anomalous origin and/or variable course of the extracranial VA had little or did not result in clinical symptoms in infants and young adults, the true value of their discovery is in the diagnostic gain before vascular surgery of supra-aortic arteries.

Cerebral blood flow velocity in early-onset neonatal sepsis and its clinical significance

Chorioamnionitis is a known risk factor for neurological damage in newborns. The present study aimed at assessing the changes in cerebral blood flow velocity (CBFV) in early-onset neonatal sepsis (EONS) and determining its predictive value as well as prognostic significance. Inborn neonates with antenatal risk factors for chorioamnionitis were followed up for development of EONS, diagnosed by presence of clinical signs along with positive blood culture and/or elevated interleukin-6 (IL-6) concentrations (≥50 pg/mL) in umbilical cord blood. Comparison group was formed by asymptomatic neonates who had risk factors for chorioamnionitis but did not develop EONS and cord blood IL-6 concentrations were <50 pg/mL. CBFV (resistance and pulsatility indices, peak systolic flow velocity, and vascular diameter) of internal carotid, vertebral, and middle cerebral arteries was assessed by transcranial Doppler ultrasonography within 24 h of birth. The babies were kept under clinical and radiological follow-up for a minimum period of 6 months. Data were analyzed by SPSS 16.0. Final study group contained 55 neonates with sepsis and 35 asymptomatic control neonates. Blood culture was positive in 27 babies of the sepsis group with a preponderance of Gram-negative bacterial isolation. Significantly lower resistance, vasodilatation, and higher blood flow were noted in all the cerebral arteries of the sepsis group. Increase in CBFV was correlated with elevated IL-6 concentrations. CBFV parameters showed significant predictive accuracy as early diagnostic markers of EONS. Among the sepsis group, 14 patients showed signs of intracranial hemorrhage during the hospital stay of which four expired and six showed signs of ventricular dilatation during follow-up. These patients had significantly higher CBFV compared to those who survived. Assessment of CBFV at early hours of birth can be adopted as an additional bedside, non-invasive investigation with immediate diagnostic and late prognostic significance.