Abstract
The aim of this study was to analyse the behaviour of cerebral oxygenation and cerebral
blood volume (CBV) in preterm infants during apnoea by means of near-infrared spectroscopy
(NIRS). The sum of oxygenated and deoxygenated haemoglobin, the total cerebral haemoglobin
(Hbtot) corresponds to CBV, whereas the difference of oxygenated minus deoxygenated
haemoglobin (HbD) represents a value for cerebral oxygenation. During 2 hours of daytime
sleep, 72 polygraphic tracings (including NIRS) were done in 58 premature infants.
The main criteria for study entry were clinically evident episodes of apnoeas and
prematurity. According to their length, apnoeas were divided into two groups: apnoeas
of 5-14 seconds (Group 1) and apnoeas ≥ 15 seconds (Group 2). Periodic breathing was
excluded from analysis. A total number of 1345 apnoeas in Group 1 and 74 apnoeas in
Group 2 were recorded, 647 (46 %) fulfilled critera for further analysis. We observed
different patterns of CBV behaviour, but the majority, namely 94 % in Croup 1 and
87 % in Croup 2, showed a decrease of CBV during apnoea. There was always a cerebral
deoxygenation (decrease in HbD) in association with apnoeas, which was significantly
increased in apnoeas of longer duration.
Key words
Near-infrared spectroscopy - Cerebral blood volume - Cerebral oxygenation - Apnoea
- Premature infants
