CEREBRAL OXYGENATION AND PERIPHERAL OXIMETRY IN EXTREMELY PRETERM INFANTS WITH PULMONARY AND/OR CEREBRAL INTRAVENTRICULAR HEMORRHAGE IN THE FIRST 72 HOURS OF LIFE

Abstract

BACKGROUND: Extremely premature infants born <28 weeks of gestation are at higher risk of pulmonary (PH) and cerebral intraventricular (IVH) hemorrhage due to immature cardiovascular and transitioning physiology. Non-invasive monitoring has the potential to detect early abnormal circulation. OBJECTIVE(S): To explore time-frequency relationships between cerebral oxygenation and peripheral oximetry. DESIGN/METHODS: Near infrared spectroscopy cerebral regional haemoglobin oxygen saturation (CrSO2), preductal peripheral perfusion index (PI), heart rate (HR), capillary oxygen saturation (SpO2), and blood pressure (BP) were monitored in the first 72h of life. Patients were grouped in infants with PH and/or IVH (n=8) and controls (n=10). Signals were decomposed in wavelets allowing the analysis of localized variations of power. This approach allowed to quantify the common power and determine the duration of significant cross-correlation, phase and coherence between each pair of signals. Groups were compared with Wilcoxon tests. RESULT(S): Figure 1 shows an example of CrSO2 and PI, and their cross-correlation, phase (semblance) and coherence in a control (left column) and a PH-IVH patient (right column). Durations of significant cross-correlation between CrSO2 and HR (p<0.01), and CrSO2 and SpO2 (p=0.02) were significantly lower in PH-IVH infants compared to controls. The duration of significant anti-phase between CrSO2 and SpO2 (p=0.01) and the duration of significant coherence between PI and BP (p=0.03) were also significantly lower in PH-IVH infants compared to controls. These differences may indicate a disruption in auto-regulation, which is currently incompletely understood in this population. CONCLUSION(S): This study is the first to apply time-frequency analysis to simultaneous NIRS and preductal peripheral oximetry in extremely preterm infants early in life. Significantly lower durations of cross-correlation (CrSO2 with HR and SpO2), anti-phase (CrSO2, SpO2) and coherence (PI, BP) in PH-IVH patients may reflect early abnormal circulation. Our results show the potential of non-invasive monitoring to identify premature infants at-risk of early PH-IVH.