Neonatal Cerebral Oxygenation and Electrical Activity at Different Altitude Levels

Study Overview
=================
Brief Summary
-----------------
In this study, the objective is to compare neonatal cerebral oxygenation and electrical activity within 3 days after birth across different altitude areas using non-invasive methods, specifically near infrared spectroscopy (NIRS) and amplitude-integrated electroencephalography (aEEG), and establish reference value for each altitude level.

Official Title
-----------------
Neonatal Cerebral Oxygenation and Electrical Activity at Different Altitude Levels: A Prospective Observational Cohort Study

Conditions
-----------------
Altitude Hypoxia, Neonatal Encephalopathy

Intervention / Treatment
-----------------
* Device: NIRS
* Device: aEEG


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Singleton term infants (gestational age between 37 0/7 and 41 6/7 weeks) born in the participating hospital. Infants appear well as defined by normal vital signs (heart rate ranging from 110 to 180 beats/min, respiratory rate ranging from 30 to 60 breaths/min, temperature ranging from 36.5°C to 37.5°C), absence of signs of illness such as cyanosis, respiratory distress and heart murmur. The mother is permanent residence of the current altitude level and live in the study area for the entire duration of pregnancy. Exclusion Criteria: Need for supplemental oxygen or assisted ventilation. Any evidence of intrauterine distress such as meconium-stained amniotic fluid, Apgar score <7 at 1 or 5 min. Referred to neonatal intensive care unit or neonatology department for any reason other than observation. With major congenital anomaly. Probes cannot be properly placed due to scalp lesions or hematomas. Reject or withdraw from the study.

Ages Eligible for Study
-----------------
Minimum Age: 0 Hours
Maximum Age: 72 Hours

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1<br>Nujiang (880m) | Device: NIRS<br>* cerebral oxygenation and electrical activity monitoring<br>Device: aEEG<br>* amplitude-integrated electroencephalography<br>|
| Group 2<br>Kunming(1800m) | Device: NIRS<br>* cerebral oxygenation and electrical activity monitoring<br>Device: aEEG<br>* amplitude-integrated electroencephalography<br>|
| Group 3<br>Lijiang(2500m) | Device: NIRS<br>* cerebral oxygenation and electrical activity monitoring<br>Device: aEEG<br>* amplitude-integrated electroencephalography<br>|
| Group 4<br>Shangri-La (3500 m) | Device: NIRS<br>* cerebral oxygenation and electrical activity monitoring<br>Device: aEEG<br>* amplitude-integrated electroencephalography<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in cerebral oxygenation in neonates within three days after birth at different altitudes | Cerebral regional oxygen saturation (crSO2 in percentage) is measured by NIRS device. | within three days after birth | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in tissue oxygen extraction in neonates within three days after birth at different altitudes | Tissue oxygen extraction (TOE in percentage) was calculated as TOE=SpO2- crSO2. | within three days after birth | 
| Differences in cerebral fractional tissue oxygen extraction in neonates within three days after birth at different altitudes | Cerebral fractional tissue oxygen extraction (cFTOE) is calculated as cFTOE = TOE/ SpO2. | within three days after birth | 
| Differences in aEEG indicators in neonates within three days after birth at different altitudes | aEEG data are acquired by aEEG device. This minimum and maximum value is used as the preliminary smoothing value for that specific time point. Next, a three-order low-pass filter is employed to further refine the preliminary values, and a phase compensation algorithm is applied to restore temporal information and obtain smoothed boundaries.The active sleep (AS) and quiet sleep (QS) cyclical pattern is recognized as periodic changes in the band-width of the aEEG tracing, with narrower and lower periods for AS and broader and higher periods for QS. For further analyzing the aEEG data, a total of 722 signal features were extracted to reflect the amplitude, rEEG, spectral density, and connectivity-related aspects by the Auto-Neo-EEG pipeline. | within three days after birth | 
| Establish reference values for each altitude level | If significant differences exist across altitude levels, the 3rd, 10th, 50th, 75th, 90th, and 97th percentile for crSO2, upper and lower threshold of aEEG will be established for each group separately. Otherwise a combined reference interval will be provided using the average value of lower limit value. | within three days after birth | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
altitude, neonate, Amplitude integrated electroencephalography, cerebral oxygenation