The Effect of Postnatal Lying Position on Cerebral Oxygenation in Newborns
Condition: Vital Signs
Study type: Observational

Summary: 
      In the international delivery room guidelines, it is not specified which position is optimal
      for the baby stabilization. Here, the investigators want to evaluate the effects of the
      positions on postnatal adaptation and cerebral oxygenation in the delivery room of infants
      who did not require resuscitation.

      Infants will be randomly stabilized in the supine, right-side, left-side and prone positions
      (60 babies in all, 15/position). The investigators will record the 1st and 5th min Apgar
      scores and the heart rate, pulse oximetry and perfusion index at 2nd,5th and 10thmin.
      Near-infrared spectroscopy will be used to assess cerebral regional oxygen saturation.
    

Detailed description: 
      This was a prospective, randomized, observational study performed in 2 months by the Newborn
      Department in the Delivery Room of the Department of Obstetrics and Gynecology where
      approximately 3,500 infants are delivered annually. Stabilization followed the NRP guideline
      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 could
      not 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:

           Infants were placed under radiant heat for 10 min in the various positions; first-step
           resuscitation was performed in a routine manner. 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.

        5. 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.
    

Intervention name(s): vital signs by postpartum position
Intervention type(s): Other
Intervention description(s): Evaluation of vital signs and NIRS values in 4 different positions after birth
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        newborn
      
Keywords: delivery room; neonatal resuscitation; postnatal adaptation; cerebral oxygenation