The Effect of Postnatal Lying Position on Cerebral Oxygenation in Newborns
Conditions: Vital Signs
Sponsor: Dr. Behcet Uz Children's Hospital

12.02.2022 
The Effect of Postnatal Lying Position  
on  
Cerebral Oxygenation in Newborns  
 
 
 
Ethical Approval: 
    The study was approved by the Clinical Research Ethics Committee of Dr Behçet Uz 
Pediatrics and Surgery Training and Research Hospital (2018/193) and all procedures 
performed in studies involving human participants were in accordance with the ethical standarts 
of the institutional and/ or national research committee and with the 1964 Helsinki declaration 
and its later amendments or comparable ethical standarts.  
    Parents were informed of the study prior to birth and written consent was obtained from those 
who were willing to participate. 
 
 
 
 
 
 
 
 

MATERIALS AND METHODS 
This was a prospective, randomized, observational study performed in 2 months in the 
Delivery Room of the Department of Obstetrics and Gynecology by the Newborn Department 
where approximately 3,500 infants are delivered annually. Stabilization followed the NRP 
guidelines and is implemented by a neonatology fellow and three pediatric assistants with NRP 
certificates. Single, term, appropriate for gestational age (AGA) babies who did not need 
resuscitation and babies in whom skin-to-skin contact cannot be applied were included in the 
study. Vaginal births were not included, only babies born with cesarean sectio (CS) and 
couldnot not exposed to early skin-to-skin contact were included.   
 Spinal anesthesia was used for the mothers for CS, mother was not given oxygen therapy 
until the baby came out. Parents were informed of the study prior to birth and written consent 
was obtained from those who were willing to participate. The babies were randomized by 
opening of envelopes containing positional codes and were placed supine, on the right or left 
side, or prone (15/group). 
1.Infant positioning: 
When the baby was born, first care was done under the radiant heater. Infants with a need 
for positive pressure ventilation were excluded; all were placed supine. 
2.Medical records and vital parameters: 
All evaluations commenced 30 s after delivery and terminated at 10 min. For each infant, 
the 1st and 5th min Apgar scores were calculated by the same person, and the heart rate (HR), 
pulse oximetry, and perfusion index (PI) were recorded at 2nd, 5th, and 10th min using a Masimo 
Radical-7 pulse co-oximetry with an adhesive sensor. The probe was placed preductally (on the 
right wrist) and then connected to the oximetry. The fraction of inspired oxygen (FiO2) was 
only 0.21 ("room-air") during all the stabilization period. In line with the NRP 2015 guideline, 

aspiration was not routinely performed in the delivery room; the number of times that touch 
stimulation was required and the tactile stimulus time were recorded. Although 
electrocardiography (ECG) recommended in the latest guidelines and reads heart rate much 
faster, pulse oximetry had to be used in our study because the relationship between position and 
saturation and cerebral oximetry was evaluated. 
3.Cerebral oxygenation: 
Near-infrared spectroscopy (NIRS), which measures tissue oxygenation noninvasively, was 
used to evaluate cerebral oxygenation; the mean values at 5th and 10th min were recorded using 
a Covidien INVOS 5100C instrument. The cerebral regional cerebral oxygen saturation (rScO2) 
is the ratio of cerebral oxygenated hemoglobin (CHbO2) to the total oxygen bound to cerebral 
hemoglobin (CHb) and CHbO2 (rScO2 = CHbO2/CHb + CHbO2) (1). The rScO2 is the mean 
oxygen saturation of cerebral arterial, venule, and capillary blood; the venule data is 
predominate (2). Infrared light reveals the extent of saturation of the so-called watershed zone 
(a mixture of 33% arterial and 67% venous blood at a depth of 1-1,5 cm) (3). The NIRS probe 
was placed on both sides of the frontal lobe; the probe was cleaned before placement. The first 
measured value served as the basal value; rScO2 changes were then recorded at 2-s intervals to 
60 s and the mean calculated. The cerebral rScO2 is normally 50-80, but may vary by 10-20% 
at any time (4). A decrease >20% for patients with a basal cerebral rScO2 value >50 and a 
decrease >15% for those with a basal cerebral rScO2 <50 indicate cerebral ischemia (5). Data 
were captured at 0.1 Hz and collected for 10 min, after application in each position 
consequently. Cerebral fractional oxygen extraction (cFOE) was calculated for 5th and 10th min 
average as ( (SpO2-rScO2)/SpO2 ) (SpO2: pulse oximetry oxygen saturation) for each position, 
which reflects the balance between oxygen delivery and consumption in the tissue (6).  

An infant/pediatric sensor (Covidien INVOS 5100C) costs between $110 and $140 each. 
No outside funding was used for the budget in this study. Within the budget and time period, 
the maximum number of patients enrolled in the study. 
4.Sample Size: 
In the investigators’ center, monthly birth rate is 300 and since our hospital is the largest 
perinatology center in our region; the number of births with maternal and neonatal problems is 
high. When the investigators evaluated our records for the number of infants who were born > 
37 GA with CS under spinal anesthesia and did not require any resuscitation efforts; the number 
was approximately 15 per month. (P=0.05) with a 2-sided a error of 5% and power of 80%, a 
total sample size of 37 total was required. 
 
references: 
1. Mutoh T., Guest R., Lamm W. et al. Prone position alters the effect of 
volume overload on regional pleural pressures and improves 
hypoxemia in pigs in vivo. Am. Rev. Respir. Dis. 1992; 146: 300-306 
2. Hou X, Ding H, Teng Y et al. Research on the relationship between 
brain anoxia at different regional oxygen saturations and brain 
damage using near-infrared spectroscopy. Physiol Meas 2007; 28: 
1251-1265 
3. Brodsky J. What intraoperative monitoring makes sense? Chest 
1999; 115: 101S-105S 
4. Baikoussis N, Karanikolas M, Siminelakis S et al. Baseline cerebral 
oximetry values in cardiac and vascular surgery patients: a 
prospective observational study. Journal of Cardiothoracic Surgery. 
2010; 5: 41 
5. Samra SA, Dy EA, Welch K et al. Evaluation of a cerebral oximeter as 
a monitor of cerebral ischemia during carotid endarterectomy. 
Anesthesiology 2000; 93: 964-970 
6. Naulaers G, Meyns B, Miserez M et al. Use of tissue oxygenation 
index and fractional tissue oxygen extraction as non-invasive 
parameters for cerebral oxygenation. Avalidation study in piglets. 
Neonatology 2007; 92 (2):120-6 
 

Statistical Analyses: 
SPSS 25.0 (IBM Corporation, Armonk, New York, United States) and PAST 3 (Hammer, 
Ø., Harper, D.A.T., Ryan, P.D. 2001. Paleontological statistics) programs were used in the 
analysis of the variables. The conformity of univariate data to normal distribution was evaluated 
with the Shapiro-Wilk francia test, while homogeneity of variance was evaluated with the 
Levene test. Mardia for the conformity of multivariate data to normal distribution; while the 
(Dornik and Hansen omnibus) test was used, the Box-M test was used for variance 
homogeneity. In the comparison of more than two groups according to quantitative data, 
Fisher's Least Significant Difference (LSD) tests were used for One-Way Anova post hoc 
analysis, one of the parametric methods, Kruskal-Wallis H Test, which is one of the 
nonparametric tests, was used with the results of Monte Carlo simulation technique, and Dunn's 
Test was used for Post Hoc analyses. The Paired-Samples T test was tested using Bootstrap 
results, while the Wilcoxon Signed Ranks Test was tested using the monte carlo simulation 
method to compare two replicate measurements of dependent quantitative variables with each 
other. While Friedman's Two-Way test was tested using the monte carlo simulation method to 
test the variables with more than two repeated measurements and to examine the interaction 
according to the groups, the General Linear Model-Repeated Anova test from parametric 
methods was used, and the LSD test was used for Post Hoc analyses. In the comparison of 
categorical variables with each other, Fisher-Freeman-Holton test was tested with Monte Carlo 
Simulation technique. While quantitative variables were expressed as mean (standard 
deviation) and Median (Percentile 25 / Percentile 75) in the tables, categorical variables were 
shown as n (%). The variables were analyzed at 95% confidence level, and a p value less than 
0.05 was considered significant.