PhD Scientific Days 2024

Poster Session P - Conservative Medicine

Severe cerebral oxygenation changes in neonates undergoing anaesthesia

Text of the abstract

Synchronized, multimodal, non-invasive monitoring system allows the description of events associated with cerebral tissue oxygenation (rSO2) decrease. Near-infrared spectroscopy (NIRS) for cerebral monitoring is not routinely used in clinical practice during neonatal anesthesia. Identifying physiological parameters that correlate with rSO2 changes could help predict adverse events.

We aimed to describe events related to rSO2 decrease and their relation to other physiological parameters during neonatal anesthesia.

Our prospective observational study was conducted in the Pediatric Centre of Semmelweis University. 95 newborns under 6 kg, who required surgical intervention due to their condition were enrolled between March 2021 and July 2023. During general anesthesia, we used a patient monitor and an anaesthesia machine (Drager Infinity DeltaXL, Perseus A500) along with a NIRS monitor (INVOS 5100C, Medtronic). Time-synchronized data were collected on a laptop. NIRS events were categorized as mild, moderate, and severe rSO2 decreases according to Olbrecht et al. Events with severe rSO2 decrease were analyzed. Changes in arterial oxygen saturation (SpO2), heart rate (HR), mean arterial pressure (MAP), and end-tidal carbon dioxide (EtCO2) were assesed during the 5 minutes preceding events with severe rSO2 decrease (“baseline”) and at the time of rSO2 nadir.

The median [IQR] gestational age of the newborns was 36 [28;38] weeks. At the time of surgery, they were 32 [6;68] days old and weighed 2800 [2100;3500] g. The median duration of surgeries was 126 [87;196] minutes. Event with mild, moderate, and severe rSO2 decrease occurred in 59, 30 and 40 cases respectively, with median durations of 2.5 [1.5;5.7], 18 [7;43] and 39 [15;85] minutes. During events with severe rSO2 decrease, MAP showed a decrease of 4% at the rSO2 nadir (p=0.150) and the nadir of MAP occurred a median of 2.5 minutes after the rSO2 nadir (p=0.021; significant difference in time). Similarly, EtCO2 decreased by a median of 22% compared to baseline (p=0.034) and the time of EtCO2 nadir matched the rSO2 nadir (p=0.660; no significant difference in time). There was no correlation between SpO2 and HR with rSO2 nadir.

Our findings suggest that ventilation significantly influences cerebral tissue oxygenation during anesthesia in newborns.

Funding
TKP2021-EGA25, OTKA135222, RRF-2.3.1-21-2022-00011