Effects of tilt on cerebral hemodynamics measured by NeoDoppler in healthy neonates

Abstract

Background Today, there are conflicting descriptions of how neonates respond to tilt. Examining physiologic responses of cerebral blood flow velocities (BFVs) in challenging situations like a tilt requires equipment that can cope with positional changes. We aimed to characterize how healthy term neonates respond to mild cerebral hemodynamic stress induced by a 90° tilt test using the recently developed NeoDoppler ultrasound system. Methods A small ultrasound probe was fixated to the neonatal fontanel by a cap, and measured cerebral BFV in healthy neonates during and after a 90° head-up tilt test, five min in total, at their first and second day of life. Unsupervised k-means cluster analysis was used to characterize common responses. Results Fifty-six ultrasound recordings from 36 healthy term neonates were analyzed. We identified five distinct, immediate responses that were related to specific outcomes in BFV, heart rate, and pulsatility index the next two min. Among 20 neonates with two recordings, 13 presented with different responses in the two tests. Conclusions Instant changes in cerebral BFV were detected during the head-up tilt tests, and the cluster analysis identified five different hemodynamic responses. Continuous recordings revealed that the differences between groups persisted two min after tilt. Impact NeoDoppler is a pulsed-wave Doppler ultrasound system with a probe fixated to the neonatal fontanel by a cap that can measure continuous cerebral blood flow velocity. Healthy neonates present with a range of normal immediate cerebral hemodynamic responses to a 90° head-up tilt, categorized in five groups by cluster analysis. This paper adds new knowledge about connection between immediate responses and prolonged responses to tilt. We demonstrate that the NeoDoppler ultrasound system can detect minute changes in cerebral blood flow velocity during a 90° head-up tilt.

Low frequency cerebral arterial and venous flow oscillations in healthy neonates measured by NeoDoppler

“…The neonates could be together with their parents and/or breastfeed during examinations, and the NeoDoppler probe did not seem to cause discomfort. While recording with the NeoDoppler probe, it is possible to lift the neonates to comfort them, as demonstrated in a previous tilt test ( 39 ). The possibility for continuous monitoring of arterial and venous CBF velocities in several depths simultaneously is unique for NeoDoppler.…”

The Effect of 12-Week Treatment with Intermittent Negative Pressure on Blood Flow Velocity and Flowmotion, Measured with a Novel Doppler Device (Earlybird). Secondary Outcomes from a Randomized Sham-Controlled Trial in Patients with Peripheral Arterial Disease

“…21 The underlying technology has been used to monitor cerebral blood flow velocities in neonates. 22,23 The aim of this study was to evaluate the applicability of a novel Doppler ultrasound device (earlybird), to assess blood flow characteristics in patients with PAD during a treatment session with INP and whether certain flow-properties could determine who could benefit INP-treatment.…”

Hjernens hemodynamiske respons ved stillingsendring hos friske nyfødte målt med NeoDoppler

“…Vi har nylig benyttet NeoDoppler til å studere hva som skjer med nyfødtes hjernesirkulasjon når de løftes opp fra liggende stilling [3]. Førtifire nyfødte ble løftet fra ryggleie og vippet 90 grader inn mot brystet, mens barnet hadde NeoDoppler-proben festet over fontanellen (▶ Fig.…”