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Hypoxic-ischaemic encephalopathy is associated with regional changes in cerebral blood flow velocity and alterations
R G Bennhagen1, R G Weintraub, N R Lundström
1Division of Paediatric Cardiology, University Hospital, Lund, Sweden. rolf.bennhagen@mbox318.swipnet.se
Insights
Infants with hypoxic-ischaemic encephalopathy (HIE) show altered cerebral blood flow velocity (CBFV) patterns and impaired left ventricular function. These changes, particularly in resistance indices, evolve in the hours following birth.
Area of Science:
- Neonatal Neurology
- Pediatric Cardiology
- Cerebrovascular Physiology
Background:
- Hypoxic-ischaemic encephalopathy (HIE) is a major cause of neonatal brain injury.
- Assessing cerebral blood flow velocity (CBFV) and cardiac function is crucial for understanding HIE pathophysiology.
- Early detection of hemodynamic changes can guide therapeutic interventions.
Purpose of the Study:
- To investigate Doppler-derived cerebral blood flow velocity (CBFV) indices in infants with HIE.
- To evaluate left ventricular function in neonates diagnosed with HIE.
- To correlate hemodynamic parameters with the severity of HIE.
Main Methods:
- Measured CBFV using Doppler ultrasound in 18 HIE infants and 28 controls.
- Assessed left ventricular function via echocardiography.
- Analyzed pulsatility and resistance indices over the first 85 hours postnatally.
Main Results:
- HIE infants exhibited subnormal CBFV with a postnatal increase.
- Cerebral blood flow velocity was consistently higher in the internal carotid artery than the anterior cerebral artery.
- Initially elevated resistance indices in HIE patients decreased from 30-85 hours postnatally, especially in severe cases.
- 50% of HIE infants showed depressed left ventricular function and/or hypotension.
Conclusions:
- HIE is associated with distinct alterations in CBFV patterns and cerebrovascular resistance.
- Impaired left ventricular function and hypotension are common in HIE.
- Dynamic changes in cerebral hemodynamics occur in the early postnatal period in HIE.
Abstract:
Doppler-derived indices of cerebral blood flow velocity (CBFV) and echocardiographic parameters of left ventricular function were measured in 18 patients with hypoxic-ischaemic encephalopathy HIE (group I) and in 28 normal controls (group II). Group-I infants had a subnormal distribution of CBFV values increasing over the first 85 h postnatally. CBFV values were constantly higher in the internal carotid than in the anterior cerebral artery. During the first 24 h postnatally, pulsatility and resistance indices of cerebral blood flow were significantly higher in group-I patients. From 30 to 85 h after birth, resistance indices were lower in group-I infants with severe HIE. Depressed left ventricular function and/or hypotension was documented in 50% of group-I patients.