Pulse oximetry for monitoring infants in the delivery room: a review

Coupling between Regional Oxygen Saturation of the Brain and Vital Signs during Immediate Transition after Birth

INTRODUCTION

The primary aim was to analyze any coupling of heart rate (HR)/arterial oxygen saturation (SpO2) and regional cerebral oxygen saturation (rScO2) and regional cerebral fractional tissue oxygen extraction (cFTOE) during immediate transition after birth in term and preterm neonates to gain more insight into interactions.

METHODS

The present study is a post hoc analysis of data from 106 neonates, obtained from a prospective, observational study. Measurements of HR, SpO2, rScO2, and cFTOE were performed during the first 15 min after birth. The linear and nonlinear correlation were computed between these parameters in a sliding window. The resulting coupling curves were clustered. After clustering, demographic data of the clusters were de-blinded and compared.

RESULTS

Due to missing data, 58 out of 106 eligible patients were excluded. Two clusters were obtained: cluster 1 (N = 39) and cluster 2 (N = 9). SpO2 had linear and nonlinear correlations with rScO2 and cFTOE, whereby the correlations with rScO2 were more pronounced in cluster 2. HR-rScO2 and HR-cFTOE demonstrated a nonlinear correlation in both clusters, again being more pronounced in cluster 2, whereby linear correlations were mainly absent. After de-blinding, the demographic data revealed that the neonates in cluster 2 had significantly lower gestational age (mainly preterm) compared to cluster 1 (mainly term).

DISCUSSION

Besides SpO2, also HR demonstrated a nonlinear correlation with rScO2 and cFTOE in term and preterm neonates during immediate transition after birth. In addition, the coupling of SpO2 and HR with cerebral oxygenation was more pronounced in neonates with a lower gestational age.

A Randomized Controlled Trial of a 30- versus a 120-Second Delay in Cord Clamping after Term Birth

OBJECTIVE

Delayed cord clamping (DCC) has been recently adopted in neonatal resuscitation. The immediate cardiac hemodynamic effects related to DCC more than 30 seconds was not studied. We aimed to study the effect of DCC at 120 seconds compared with 30 seconds on multiple hemodynamic variables in full-term infants using an electrical cardiometry (EC) device.

STUDY DESIGN

Present study is a randomized clinical trial. The study was conducted with full-term infants who were delivered at the Obstetrics and Gynecology Department in Cairo University Hospital. Sixty-eight full term infants were successfully enrolled in this trial. Cardiac output (CO) and other hemodynamic parameters were evaluated in this study by EC device. Hemoglobin, glucose, and bilirubin concentrations were measured at 24 hours. Newborn infants were assigned randomly into group 1: DCC at 30 seconds, and group 2: DCC at 120 seconds, based on the time of cord clamping.

RESULTS

Stroke volume (SV) (mL) and CO (L/min) were significantly higher in group 2 compared with group 1 at 5 minutes (6.71 vs. 5.35 and 1.09 vs. 0.75), 10 minutes (6.43 vs. 5.59 and 0.88 vs. 0.77), 15 minutes (6.45 vs. 5.60 and 0.89 vs. 0.76), and 24 hours (6.67 vs. 5.75 and 0.91vs. 0.81), respectively. Index of contractility (ICON; units) was significantly increased in group 2 at 5 minutes compared with group1 (114.2 vs. 83.8). Hematocrit (%) and total bilirubin concentrations (mg/dL) at 24 hours were significantly increased in group 2 compared with group 1 (51.5 vs. 40.5 and 3.8 vs. 2.9, respectively).

CONCLUSION

Stroke volume and cardiac output are significantly higher in neonates with DCC at 120 seconds compared with 30 seconds that continues for the first 24 hours.

KEY POINTS

· CO is significantly increased with DCC at 120 seconds.. · SV is significantly increased with DCC at 120 seconds.. · Such effects continued during the entire 24 hours of life in full-term infants..

Monitoring SpO2: The Basics of Retinopathy of Prematurity (Back to Basics) and Targeting Oxygen Saturation

Oxygen (O2) is a drug frequently used in newborn care. Adverse effects of hypoxia are well known but the damaging effects of excess oxygen administration and oxidative stress have only been studied in the last 2 decades. Many negative effects have been described, including retinopathy of prematurity . Noninvasive pulse oximetry (SpO2) is useful to detect hypoxemia but requires careful evaluation and understanding of the frequently changing relationship between O2 and hemoglobin to prevent hyperoxemia. Intention to treat SpO2 ranges should be individualized for every newborn receiving supplemental O2, according to gestational age, post-natal age, and clinical condition.

Use of Pulse Oximetry during Resuscitation of 230 Newborns-A Video Analysis

BACKGROUND

European guidelines recommend the use of pulse oximetry (PO) during newborn resuscitation, especially when there is a need for positive pressure ventilation or supplemental oxygen. The objective was to evaluate (i) to what extent PO was used, (ii) the time and resources spent on the application of PO, and (iii) the proportion of time with a useful PO signal during newborn resuscitation.

METHODS

A prospective observational study was conducted at Stavanger University Hospital, Norway, between 6 June 2019 and 16 November 2021. Newborn resuscitations were video recorded, and the use of PO during the first ten minutes of resuscitation was recorded and analysed.

RESULTS

Of 7466 enrolled newborns, 289 (3.9%) received ventilation at birth. The resuscitation was captured on video in 230 cases, and these newborns were included in the analysis. PO was applied in 222 of 230 (97%) newborns, median (quartiles) 60 (24, 58) seconds after placement on the resuscitation table. The proportion of time used on application and adjustments of PO during ongoing ventilation and during the first ten minutes on the resuscitation table was 30% and 17%, respectively. Median two healthcare providers were involved in the PO application. Video of the PO monitor signal was available in 118 (53%) of the 222 newborns. The proportion of time with a useful PO signal during ventilation and during the first ten minutes on the resuscitation table was 5% and 35%, respectively.

CONCLUSION

In total, 97% of resuscitated newborns had PO applied, in line with resuscitation guidelines. However, the application of PO was time-consuming, and a PO signal was only obtained 5% of the time during positive pressure ventilation.

Noninvasive Monitoring to Demonstrate Postoperative Differences in Regional Hemodynamics in Newborn Infants With d-Transposition of the Great Arteries and Hypoplastic Left Heart Syndrome

BACKGROUND

The adequacy of tissue O₂ delivery in infants receiving intensive care is difficult to measure directly. Regional O₂ (rSO₂) and fractional tissue O₂ extraction (FTOE), the ratio of O₂ consumption to O₂ delivery, obtained from newer noninvasive tools, such as near-infrared spectroscopy (INVOS) and microvascular tissue oximetry (T-Stat) can provide important information on the adequacy of tissue oxygenation and aid in managing critically ill infants.

METHODS

We prospectively evaluated differences in rSO₂ and FTOE in 26 infants with hypoplastic left heart syndrome (HLHS) (n = 12) or d-transposition of the great arteries (d-TGA) (n = 14). Continuous noninvasive monitoring of SpO₂, heart rate, and perfusion index with pulse oximetry, cerebral-rSO₂ and renal-rSO₂ with INVOS, and buccal tissue oxygenation using T-Stat were performed during immediate postoperative period for 24 hours.

RESULTS

The SpO₂ and rSO₂ in infants with d-TGA were higher compared with the infants with HLHS at all measured sites (buccal mucosa, cerebral, and renal). Significant regional differences were also observed in FTOE across all infants with the highest at the buccal mucosa tissue level, followed by cerebral and renal measurement sites. As compared with infants with d-TGA, infants with HLHS had higher regional FTOE and heart rate, with a lower arterial O₂ content and perfusion index.

CONCLUSIONS

Our study demonstrates the utility of noninvasive hemodynamic monitoring to assess regional oxygenation and perfusion, as evidenced by significant differences in infants with HLHS and d-TGA, conditions with different circulation physiologies. Such comprehensive monitoring can potentially aid in evaluating treatment strategies aimed at preventing organ damage from O₂ insufficiency.

A Comparison of Finger Pulse Oximeter and SET-Based Neonatal Pulse Oximeter in Neonates in Terms of SpO2 Values and Response Time

Pulse oximetry is an imperative noninvasive tool to detect hypoxia. Signal extraction technology (SET)-based pulse oximeters recommended in neonates are expensive, while finger pulse oximeters are cheaper and widely available. Oxygen saturation (SpO₂) values and reliable saturation reading time of 30 neonates were obtained using MEDITIVE MPO-03 fingertip pulse oximeter and Masimo SET-Rad-97 pulse oximeter on the right hand and right foot. Bland-Altman technique, paired t-test and Pearson correlational analysis were used. There was a good agreement of paired SpO₂ measurements between the two oximeters on right foot. The agreement limits and bias were -1.2% to 0.8%, -0.1% for right hand, and -0.7% to 0.7%, -0.01% for right foot, respectively with a confidence interval of 95%. The mean response time obtained for finger pulse oximeter on right hand and right foot was 66.4 ± 4.6 and 58.9 ± 5.0 and for SET-based pulse oximeter was 47.8 ± 2.9 and 48.3 ± 3.0 s, respectively. Finger pulse oximeters can be considered in low-resource settings on the foot of the neonate, with a response time of 59 s.

Racial discrepancy in pulse oximeter accuracy in preterm infants

OBJECTIVE

Pulse oximetry is commonly used in Neonatology, however recent adult data suggest racial disparity in accuracy, with overestimation of oxygen saturation for Black patients.

STUDY DESIGN

Black and White infants <32 weeks gestation underwent simultaneous arterial blood gas and pulse oximetry measurement. Error by race was examined using mean bias, Arms, Bland-Altman, and linear/non-linear analysis.

RESULTS

A total of 294 infants (124 Black, 170 White) were identified with mean GA of 25.8 ± 2.1 weeks and mean BW of 845 ± 265 grams, yielding 4387 SaO2-SpO2 datapoints. SpO2 overestimation, measured by mean bias, was 2.4-fold greater for Black infants and resulted in greater occult hypoxemia (SpO2 > 90% when SaO2 < 85%; 9.2% vs. 7.7% of samples). Sensitivity and specificity for detection of true hypoxemia were similar between groups (39 vs. 38%; 81 vs. 78%).

CONCLUSION

There is a modest but consistent difference in SpO2 error between Black and White infants, with increased incidence of occult hypoxemia in Black infants.

Monitoring oxygen saturation and heart rate during neonatal transition. comparison between two different pulse oximeters and electrocardiography

OBJECTIVE

To compare the efficacy and reliability of two pulse-oximeters (POx) (Masimo Radical-7 and Nellcor^™ Oxymax Bedside) and evaluate the feasibility of routine ECG monitoring during delivery room transition.

STUDY DESIGN

Prospective observational comparative study. Sixty newborns were connected simultaneously to both POxs and ECG monitor (as a gold standard for HR). Times to achieve a stable signal were compared. Heart rates were compared to simultaneous ECG.

RESULTS

A significant difference in times to stable signal was found: Mean, Median (Interquartile range) for Nellcor and Masimo, were 15, 8.5 (6-18) and 27, 12 (9-34) seconds, respectively. Compared to ECG, false bradycardia was displayed in 18 of 55 (35%) newborns by the Masimo POx and in no newborns by the Nellcor POx. Attaching the ECG monitor was feasible but consumed additional resources.

CONCLUSIONS

The time for achievement of a stable saturation reading in an uncomplicated resuscitation setting differed significantly between POxs.

Characterisation of Textile Embedded Electrodes for Use in a Neonatal Smart Mattress Electrocardiography System

Heart rate monitoring is the predominant quantitative health indicator of a newborn in the delivery room. A rapid and accurate heart rate measurement is vital during the first minutes after birth. Clinical recommendations suggest that electrocardiogram (ECG) monitoring should be widely adopted in the neonatal intensive care unit to reduce infant mortality and improve long term health outcomes in births that require intervention. Novel non-contact electrocardiogram sensors can reduce the time from birth to heart rate reading as well as providing unobtrusive and continuous monitoring during intervention. In this work we report the design and development of a solution to provide high resolution, real time electrocardiogram data to the clinicians within the delivery room using non-contact electric potential sensors embedded in a neonatal intensive care unit mattress. A real-time high-resolution electrocardiogram acquisition solution based on a low power embedded system was developed and textile embedded electrodes were fabricated and characterised. Proof of concept tests were carried out on simulated and human cardiac signals, producing electrocardiograms suitable for the calculation of heart rate having an accuracy within ±1 beat per minute using a test ECG signal, ECG recordings from a human volunteer with a correlation coefficient of ~ 87% proved accurate beat to beat morphology reproduction of the waveform without morphological alterations and a time from application to heart rate display below 6 s. This provides evidence that flexible non-contact textile-based electrodes can be embedded in wearable devices for assisting births through heart rate monitoring and serves as a proof of concept for a complete neonate electrocardiogram monitoring system.

Delivery room desaturations and bradycardia in the early postnatal period of healthy term neonates - a prospective observational study

OBJECTIVE

It has been suggested that desaturations and bradycardia precede acute life-threatening events (ALTE) and that ALTE is more common in the delivery room than later in life. However, frequency, duration and severity of desaturations in the first hours of life and additional risk factors have not readily been studied.

METHODS

Term neonates (n = 100) were monitored for the first two hours after birth by pulse oximetry. The impact of maternal and perinatal factors on the frequency and severity of desaturations (<85%) and bradycardia (<80/min) was evaluated.

RESULTS

Desaturations were detected in 30%, prolonged desaturations in 25% of infants. Desaturations were observed significantly more often in infants born by planned Cesarean section (pCs) compared to other modes of delivery (pCs 20/49; others 10/51; p = .029). Desaturations were also more frequent in infants diagnosed with neonatal infection (NI) or infants born to a mother with gestational diabetes (GDM), although not significantly. No bradycardia <80/min was detected.

CONCLUSIONS

In our collective 4% of healthy term neonates had prolonged, clinically relevant desaturations in the first hours after birth. The mode of delivery and maternal risk factors may increase the risk for these events. However, our cohort was too small to detect any ALTE or SIDS and determine potential risk factors for these events. Our data lay ground for a large-scale prospective trial to investigate whether the mode of delivery could be an indication for general pulse oximetry monitoring of newborn in the delivery room.

Oxygen in the neonatal period: Oxidative stress, oxygen load and epigenetic changes

Preterm infants frequently require positive pressure ventilation and oxygen supplementation in the first minutes after birth. It has been shown that the amount of oxygen provided during stabilization, the oxygen load, if excessive may cause hyperoxia, and oxidative damage to DNA. Epidemiologic studies have associated supplementation with pure oxygen in the first minutes after birth with childhood cancer. Recent studies have shown that the amount of oxygen supplemented to preterm infants after birth modifies the epigenome. Of note, the degree of DNA hyper-or hypomethylation correlates with the oxygen load provided upon stabilization. If these epigenetic modifications would persist, oxygen supplied in the first minutes after birth could have long term consequences. Further studies with a robust power calculation and long-term follow up are needed to bear out the long-term consequences of oxygen supplementation during postnatal stabilization of preterm infants.

Cerebral regional tissue Oxygen Saturation to Guide Oxygen Delivery in preterm neonates during immediate transition after birth (COSGOD III): an investigator-initiated, randomized, multi-center, multi-national, clinical trial on additional cerebral tissue oxygen saturation monitoring combined with defined treatment guidelines versus standard monitoring and treatment as usual in premature infants during immediate transition: study protocol for a randomized controlled trial

BACKGROUND

Transition immediately after birth is a complex physiological process. The neonate has to establish sufficient ventilation to ensure significant changes from intra-uterine to extra-uterine circulation. If hypoxia or bradycardia or both occur, as commonly happens during immediate transition in preterm neonates, cerebral hypoxia-ischemia may cause perinatal brain injury. The primary objective of the COSGOD phase III trial is to investigate whether it is possible to increase survival without cerebral injury in preterm neonates of less than 32 weeks of gestation by targeting cerebral tissue oxygen saturation (crSO2) using specified clinical treatment guidelines during the immediate transition period after birth (the first 15 min) in addition to the routine monitoring of arterial oxygen saturation (SpO2) and heart rate (HR).

METHODS/DESIGN

COSGOD III is an investigator-initiated, randomized, multi-center, multi-national, phase III clinical trial. Inclusion criteria are neonates of less than 32 weeks of gestation, decision to provide full life support, and parental informed consent. Exclusion criteria are severe congenital malformations of brain, heart, lung, or prenatal cerebral injury or a combination of these. The premature infants will be randomly assigned to study or control groups. Both groups will have a near-infrared spectroscopy (NIRS) device (left frontal), pulse oximeter (right palm/wrist), and electrocardiogram placed immediately after birth. In the study group, the crSO2, SpO2, and HR readings are visible, and the infant will receive treatment in accordance with defined treatment guidelines. In the control group, only SpO2 and HR will be visible, and the infant will receive routine treatment. The intervention period will last for the first 15 min after birth during the immediate transition period and resuscitation. Thereafter, each neonate will be followed up for primary outcome to term date or discharge. The primary outcome is mortality or cerebral injury (or both) defined as any intra-ventricular bleeding or cystic periventricular leukomalacia (or both). Secondary outcomes are neonatal morbidities.

DISCUSSION

crSO2 monitoring during immediate transition has been proven to be feasible and improve cerebral oxygenation during immediate transition. The additional monitoring of crSO2 with dedicated interventions may improve outcome of preterm neonates as evidenced by increased survival without cerebral injury.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03166722 . Registered March 5, 2017.

Cerebral Oxygenation in Neonates Immediately after Cesarean Section and Mode of Maternal Anesthesia

BACKGROUND

Cerebral regional oxygen saturation (crSO2) during immediate transition and resuscitation immediately after birth is of increasing interest.

OBJECTIVES

The aim of the present study was to assess whether the type of maternal anesthesia during cesarean section (CS; general anesthesia vs. spinal anesthesia) has an influence on cerebral oxygenation during immediate neonatal transition after birth.

METHODS

Secondary outcome parameters of prospective observational studies were analyzed. Neonates born by CS from November 2009 to September 2016 at the Medical University of Graz (Austria) were eligible. Term and preterm neonates were included, provided that: (1) crSO2 was measured by near-infrared spectroscopy, and (2) peripheral arterial oxygen saturation (SpO2) and heart rate (HR) were measured by pulse oximetry during the first 15 min after birth. Administration of supplemental oxygen was recorded and cerebral fractional tissue oxygen extraction (cFTOE) was calculated out of crSO2 and SpO2. For comparison, term and preterm neonates with maternal general anesthesia were matched to neonates with maternal spinal anesthesia during CS.

RESULTS

Out of 760 eligible neonates, 64 term (38.8 ± 0.9 weeks of gestation; 32 neonates in each group) and 54 preterm neonates (32.0 ± 2.9 weeks of gestation; 27 neonates in each group) were included. In term neonates, maternal general anesthesia was associated with lower initial SpO2, HR values, and Apgar scores. The fraction of inspired oxygen (FiO2) was statistically significantly higher in the general anesthesia group. Nevertheless, crSO2 and cFTOE did not differ statistically significantly between the groups. In preterm neonates there were no statistically significant differences in SpO2, HR, crSO2, and cFTOE between the general and spinal anesthesia groups. Apgar scores at 1 min were statistically significantly lower and FiO2 was statistically significantly higher in the general anesthesia group.

CONCLUSION

Cerebral tissue oxygenation in neonates during immediate transition after birth was similar after maternal general and spinal anesthesia during CS, despite differences in SpO2, HR, and supplemental oxygen in term neonates and differences in supplemental oxygen in preterm neonates.

Promoting Newborn Safety Using the RAPPT Assessment and Considering Apgar Criteria: A Quality Improvement Project

PURPOSE

The aim of this project was to evaluate the implementation of the Respiratory, Activity, Perfusion, Position, and Tone (RAPPT) instrument in assessing the infant's transition to extrauterine life while in skin-to-skin contact (SSC). Sample/Design: Nurses (n = 17) completed a pretest and posttest of RAPPT and Apgar scoring knowledge, attended an in-service about accurate scoring, and were observed during 17 deliveries when newborns were in SSC.

OUTCOME VARIABLES

Primary variables were knowledge scores, use of RAPPT, and accurate RAPPT scoring. Apgar scoring was also measured.

RESULTS

Knowledge scores increased significantly after education, RAPPT scores were correctly assessed, and 1 of 17 newborns had a sudden unexpected postnatal collapse. Apgar scoring accuracy did not change and nurses reported that their Apgar scores were based on their overall impressions of the infant instead of Apgar criteria.

Challenges and opportunities in clinical translation of biomedical optical spectroscopy and imaging

Medical devices face many hurdles before they enter routine clinical practice to address unmet clinical needs. This is also the case for biomedical optical spectroscopy and imaging systems that are used here to illustrate the opportunities and challenges involved. Following initial concept, stages in clinical translation include instrument development, preclinical testing, clinical prototyping, clinical trials, prototype-to-product conversion, regulatory approval, commercialization, and finally clinical adoption and dissemination, all in the face of potentially competing technologies. Optical technologies face additional challenges from their being extremely diverse, often targeting entirely different diseases and having orders-of-magnitude differences in resolution and tissue penetration. However, these technologies can potentially address a wide variety of unmet clinical needs since they provide rich intrinsic biochemical and structural information, have high sensitivity and specificity for disease detection and localization, and are practical, safe (minimally invasive, nonionizing), and relatively affordable.

Early skin-to-skin contact after cesarean section: A randomized clinical pilot study

Objective

Early bonding by skin-to-skin contact (SSC) has been demonstrated to be beneficial for mothers and newborns following vaginal delivery. The aim of this study was to investigate the impact of intraoperative bonding (early SSC) after cesarean section on neonatal adaptation, maternal pain and stress response.

Study design

This prospective, randomized-controlled pilot study was performed at a single academic tertiary hospital (Department of Obstetrics and Gynecology, Medical University of Graz, Austria) between September 2013 and January 2014. Women were randomly assigned to intraoperative (“early”) SCC (n = 17) versus postoperative (“late”) SCC (n = 18). Main variables investigated were neonatal transition (Apgar score, arterial oxygen saturation, heart rate and temperature), maternal pain perception and both maternal and neonatal stress response by measuring the stress biomarkers salivary free cortisol and salivary alpha amylase.

Results

There was no evidence for differences in parameters reflecting neonatal transition or stress response between the ‘Early SSC Group’ and the ‘Late SSC Group’. Maternal salivary cortisol and alpha-amylase levels as well as maternal wellbeing and pain did not differ between the groups. However, the rise of maternal salivary alpha-amylase directly after delivery was higher in the ‘Early SSC Group’ compared to the ‘Late SSC Group’ (p = 0.004).

Conclusions

This study did not reveal significant risks for the newborn in terms of neonatal transition when early SSC is applied in the operating room. Maternal condition and stress marker levels did not differ either, although the rise of maternal salivary alpha-amylase directly after delivery was higher in the ‘Early SSC Group’ compared to the ‘Late SSC Group’, which may indicate a stressor sign due to intensive activation of the sympathetic-adreno-medullary-system. This needs to be further evaluated in a larger prospective randomized trial.

Trial registration

ClinicalTrials.gov NCT01894880

Pulse Oximetry During the First 24 Hours as a Screening Tool for Congenital Heart Defects

Introduction

Although screening for congenital heart defects (CHD) relies mainly on antenatal ultrasonography and clinical examination after birth, life-threatening cardiac malformations are often not diagnosed before the patient is discharged.

Aim

To assess the use of routine pulse oximetry in the delivery room and at 24 hours postpartum, and to study its feasibility as a screening test for CHD.

Material and Methods

In this prospective study, all infants born in “Cuza Voda” Maternity Hospital, Iasi, Romania, were enrolled over a thirteen-month period. Preductal oximetry was assessed during the first hour, and postductal oximetry was evaluated at twenty-four hours postpartum. Data were then analyzed to establish the sensitivity and specificity of pulse oximetry, as a screening test for CHD.

Results

5406 infants were included in the study, with a mean gestational age of 38.2 weeks and a mean birth weight of 3175 grams. During the first minute, blood oxygen saturation varied between 40% and 90% and at 24 hours of life, it ranged between 90% and 100%. Following oximetry assessment, 14 infants with critical CHD were identified. Blood oxygen saturation values in infants with CHD were lower throughout the entire period of evaluation. Pulse oximetry had good sensitivity and specificity at 1 hour (Se=87.5%, Sp=95.5%) and 24 hours (Se=92.5%, Sp=97.4%) for the diagnosis of CHD. Blood oxygen saturation values at one minute, 1 hour and 24 hours are strong discriminative parameters for the early diagnosis of CHD.

Conclusion

Routine pulse oximetry during the first 24 hours postpartum represents an early indicator of CHD to facilitate timely intervention. Pulse oximetry provides excellent sensitivity and specificity and has tremendous potential as a standard screening test for CHD during the first 24 hours of life.

Measurement of brain tissue oxygen saturation in term infants using a new portable near-infrared spectroscopy device

BACKGROUND

A small oximeter with the probe attached to the examiner's finger has been developed. The aim of this study was to determine the feasibility of measuring regional oxygenation of the brain tissue using this device in healthy term infants immediately after birth.

METHODS

We conducted a prospective observational study. Using a new near-infrared spectroscopy (NIRS) device, we measured changes in regional cerebral tissue oxygen saturation (crSO₂ ) during the first 10 min of life in 32 healthy term infants after delivery. Arterial oxygen saturation (SpO₂ ) was also simultaneously measured.

RESULTS

Median crSO₂ increased from 43% (1 min after birth) to 49% (4 min after birth); thereafter, no significant changes were observed. Median SpO₂ increased constantly from min 3 to min 7, from 77% to 92% and did not change significantly after 8 min. A stable oxygen saturation signal was measured in 59% of infants (crSO₂ ) and in 0% of infants (SpO₂ ) at 1 min, and in 97% (crSO₂ ) and in 78% (SpO₂ ) at 3 min.

CONCLUSIONS

During the transition after birth, crSO₂ can be more easily and quickly measured in healthy newborn infants using the novel NIRS device than SpO₂ .

Haemodynamic Transition after Birth: A New Tool for Non-Invasive Cardiac Output Monitoring

BACKGROUND

Substantial haemodynamic changes occur during the first minutes after birth. Currently, only heart rate (HR) and arterial oxygen saturation are routinely used to monitor haemodynamic transition after birth.

OBJECTIVES

The aim of the present study was to continuously assess haemodynamic changes during transition in term infants for the first time by using electrical velocimetry (EV), a new method of non-invasive cardiac output monitoring (NICOM), based on impedance cardiography technology.

METHODS

In this prospective observational study, term neonates delivered by elective caesarean section underwent NICOM measurements within the first 15 min after birth. The beat-to-beat measurement over a 10-second period was used to calculate cardiac output (CO) for each minute after birth. The data of CO were only accepted when the signal quality index (SQI) remained >80% during the measurement period of 10 s.

RESULTS

100 term neonates underwent 1,500 NICOM measurements. 1,143 (76.2%) measurements were excluded because of a SQI <80%. HR and CO showed a trend to increase within the first minutes, and decreased significantly from minute 3 (HR) and 4 (CO), until minute 12 and 10, respectively. Stroke volume remained stable during the observation period.

CONCLUSION

The present study was the first using EV for NICOM during the transition period in a larger cohort of newborn infants. Results of NICOM were similar to available echocardiography data. The possibility of NICOM offers continuous CO measurement. The present study supports the idea that CO is closely related to HR in newborn infants.

Arterial oxygen saturation and heart rate after birth in newborns with and without maternal bonding

BACKGROUND

The aim of this study was to determine and compare changes in arterial oxygen saturation (SpO₂ ) and heart rate (HR) in healthy term infants with and without maternal bonding.

METHOD

This was a prospective observational study in healthy term infants. SpO₂ and HR were recorded from 1 to 10 min after birth. After this, SpO₂ and HR were registered at 15, 30 and 60 min and then at 12 and 24 h after birth. SpO₂ and HR were measured with a pulse oximeter.

RESULTS

A total of 216 healthy term infants were divided into three different groups: 136 (63%) born by vaginal delivery, 56 (26%) born by cesarean section with bonding, and 24 (11%) born by cesarean section without bonding. No difference in SpO₂ was found in babies born by cesarean section with or without maternal bonding. In neonates delivered vaginally, SpO₂ was significantly higher during the first 10 min after birth than in neonates born by cesarean section with bonding (P < 0.05). Compared with infants born by cesarean section without bonding, this tendency was not significant. In general, HR was similar across groups, although, for infants born by cesarean section, neonates who received bonding had lower HR from 6 to 8 min (P < 0.05).

CONCLUSIONS

In healthy term newborns, maternal bonding in infants born by cesarean section did not have effects on SpO₂ . Some differences were observed in HR between infants born by cesarean section with and without bonding.

Analyzing video recorded support of postnatal transition in preterm infants following a c-section

Background

Over the past years, research on neonatal resuscitation has focused on single interventions. The present study was performed to analyze the process quality of delivery room management of preterm infants born by c-section in our institution.

Methods

We performed a cross-sectional study of videos of preterm infants born by c-section. Videos were analyzed according to time point, duration and number of performed medical interventions. The study period occurred between January 2012 and December 2013. Infants were caterogized in 3 groups according to their gestational age.

Results

One hundred eleven videos were analyzed. 100 (90 %) of the infants were transferred to NICU and 91 (83 %) received respiratory support after a median of 0.5 min. All infants were auscultated after 8 (5–16) seconds median (IQR) and an oxygen saturation sensor was placed after 37 (28–52) seconds. 23 infants were intubated after 9 (6–17) minutes and 17 received exogenous surfactant; 29 % according to INSURE (intubation-surfactant-extubation) technique. The duration of intubation attempts was 47 (25–60) seconds. 51 % of the newborns received a sustained inflation for 8 (6–9) seconds. A successful IV-line placement occurred after 15 (12–20) minutes. 4 % of the infants were transported to the NICU without an IV-line after 3 (difference range: 2–5) unsuccessful attempts.

Conclusions

Using video analysis as a tool to study process quality, we conclude that interventions differ not only between but also within similar age groups. This data can be used for benchmarking with current guidelines and practice in other centers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1045-2) contains supplementary material, which is available to authorized users.

Critical congenital heart disease screening

Critical congenital heart disease (CCHD) is a heart lesion for which neonates require early surgical intervention to survive. Without intervention, the rates of mortality and survival with significant disability are extremely high. Early diagnosis can potentially improve health outcomes in newborns with CCHD. Until recent years, no routine screening protocol existed. In the last few years, pulse oximetry screening for CCHD in newborns has been added to the list of recommended uniform screening panels and advocated by several health-care authorities. A positive screening test result warrants an echocardiogram to evaluate for CCHD. Newborn screens do not usually require parental consent. However, most of the states mandates in the United States include a statement allowing exemption from the screen on the basis of parental religious or personal beliefs.

Elective caesarean delivery adversely affects preductal oxygen saturation during birth transition

OBJECTIVE

To compare preductal oxygen saturation (SpO2), heart rate (HR) and cord blood pH after birth in healthy term neonates delivered by elective caesarean delivery (CD) and vaginal delivery (VD), managed according to 2010 Neonatal Resuscitation Guidelines.

DESIGN

In a prospective cohort study, sensors were placed on the right hand of the neonate.

SETTING

III level Maternity ward of the Department of Obstetrics and Gynaecology of Padua University, Padua, Italy.

MAIN OUTCOME MEASURES

SpO2 and HR were recorded during the first 10 min after birth. Umbilical artery blood gas analysis was obtained immediately after delivery.

PATIENTS

We studied 60 newborn infants by elective CD and 60 by VD.

RESULTS

The SpO2 gradually significantly improved during the first 10 min of life (p<0.0001), with a trend towards a slower increase in caesarean-delivered neonates (p=0.09) (Friedman's two-way non-parametric analysis of variance (ANOVA)). Instead, HR varied during the first 10 min of life (p=0.001) without significant difference between the two delivery groups (p=0.41). Umbilical artery pH values were lower in VD (p=0.005). At 10th minute, elective CD had a significantly negative effect on SpO2 (ß=-2.44; 95% CI -4.52 to -0.36; p=0.02) with respect to VD. Conversely, at 10th minute, delivery mode had no statistically significant effect on HR (ß=0.33; 95% CI -9.39 to 10.01; p=0.95).

CONCLUSIONS

In healthy term neonates, the SpO2 gradually improved during the first 10 min of life. At 10th minute, elective CD had a significantly negative effect on SpO2, but these changes did not result in an impaired HR pattern.

The perfusion index of healthy term infants during transition at birth

Perfusion index is a continuous parameter provided by pulse oximetry and might be useful for evaluating hemodynamic changes at birth and identifying transitional problems. The objective was to describe perfusion index values in term infants immediately after birth. Perfusion index of 71 healthy term born infants were recorded during the first 10 min after birth, using a pulse oximetry sensor placed preductally. A Wilcoxon signed-rank test was used to compare between time points. No significant trend in perfusion index could be observed in term-delivered infants. There was a significant difference between 2 and 3 min (2.4 (1.6-5.0) vs. 2.3 (1.6-3.7), p = 0.05) and between 3 and 4 min after birth (2.3 (1.6-3.7) vs. 2.1 (1.4-3.2), p < 0.001). There was no significant change in median PI values in the following 8 min.

CONCLUSION

Perfusion index does not change significantly during transition at birth in healthy term infants born by normal vaginal delivery or cesarean section. Large variation in perfusion index causes monitoring this parameter to have limited value.

WHAT IS KNOWN

• Perfusion index is a non-invasive indicator for peripheral perfusion. • Perfusion index values <1.24 are seen as an accurate predictor for severity of illness for infants admitted to the neonatal intensive care unit. What is new: • Although significant physiological changes occur during birth, perfusion index remains stable. • Large variation in perfusion index causes monitoring of this value to have limited value as an additional parameter for evaluating transition at birth.

Pulse Oximetry: Could Wrist and Ankle Be Alternative Placement Sites?

OBJECTIVE

To compare the accuracy of pulse oximetry oxygen saturation (SpO2) measured on the right wrist and right ankle in relation to the ipsilateral palm and sole, respectively.

STUDY DESIGN

A prospective observational study carried out on neonates and infants admitted to intensive care units. SpO2 was measured at the right palm and wrist and the right sole and ankle. Sensitivity and specificity tests were performed.

RESULTS

Ninety-four patients, mean postnatal age of 29.9 days, were included in our study. Sensitivity and specificity tests for right wrist SpO2 in comparison to right palm SpO2 revealed sensitivity of 100% and specificity of 80.4%. Sensitivity and specificity tests for right ankle SpO2 in comparison to right sole SpO2 revealed sensitivity of 100% and specificity of 77.4%.

CONCLUSION

The results of the current study revealed that the wrist and ankle can be alternative placement sites for the measurement of SpO2 in newborn and infants instead of the routinely used palm or sole.

Cesarean under general or epidural anesthesia: does it differ in terms of regional cerebral oxygenation?

OBJECTIVE

It is aimed to evaluate whether there is a difference in regional cerebral saturation of newborns measured by near infrared spectroscopy born either by general anesthesia or combined spinal epidural anesthesia during elective cesarean deliveries.

METHODS

After approval from the ethics committee of our hospital, and informed consents of the parturients were taken, 68 patients were included in the study. The regional cerebral oxygen saturations (RcSO2) of newborns were measured by near infrared spectroscopy (NIRS) measurements at 1st, 5th min after birth. In group I (n=32), general anesthesia was performed for the cesarean operation and in group II (n=36), combined spinal epidural anesthesia (CSEA) was the anesthetic management. The age of the mother, gestation, the problems related to the pregnancy, heart rate, blood pressure, oxygen saturation (SpO2) of the mother had been recorded. The measurements of the newborn were; SpO2 of right hand, RcSO2 measured by NIRS, the delivery time (from incision to the cessation of circulation in the placental cord), Apgar score. Data were analyzed using GraphPad Prism 5.0 (GraphPad Software, La Jolla, California) and presented as mean +/- SD. Results obtained in different groups were compared using upaired t-test. Differences were statistically significant at p < 0.05.

RESULTS

There were no significant differences between the groups related to the mother's age, gestation week and baseline blood pressure. Both the systolic and diastolic blood pressures measured at 1st and 5th min after induction or start of the spinal block were significantly lower in the mothers who had undergone combined spinal epidural anesthesia. The heart rates of the mothers who had been under CSEA were significantly higher than the general anesthesia group. The Apgar at the 1st min were observed significantly higher in Group II. Oxygen saturation of the newborns were significantly higher in Group II. Regional cerebral oxygenation measured by NIRS were significantly higher in CSEA group.

CONCLUSION

Combined spinal epidural anesthesia, besides other known advantages, had been shown to be superior to general anesthesia as a means of regional cerebral oxygenation of the newborns.

Oxygen saturation profile in late-preterm and term infants: a prospective cohort study

OBJECTIVE

To determine oxygen saturation profile over 6 h monitoring period in healthy late-preterm and term neonates during the first 48 h of age, and to assess the impact of gestational age, birth weight and method of delivery on this profile.

STUDY DESIGN

Prospective cohort study of measurement of SpO2 over 6 h in 20 late-preterm (35 to 36 weeks gestation) and 40 term infants within 12 to 48 h of birth was conducted. Infants with cardiorespiratory symptoms or need for cardiorespiratory support at birth were excluded. Percentage time spent at SpO2 >90% and ⩽90% was calculated by gestational age and birth weight.

RESULT

Late-preterm infants and infants born weighing <2.5 kg spent approximately 7% of the time at SpO2 ⩽90%; this time decreased as gestational age and birth weight increased. Time at SpO2 >90% was significantly different between late-preterm and term infants (93% (5%) vs 96% (3%); P =0.002). Time at SpO2 >90% was not significantly different between males and females (95% (5%) vs 95% (4%), both n=30; P =0.72) or between vaginal births and cesarean births (95% (4%), n=32, vs 95% (4%), n=28; P =0.39). Cumulative time with SpO2 <90 was mean (s.d.) of 25 (18) in preterm vs 13 (10) min in term infants.

CONCLUSION

Over a 6-h period healthy late-preterm and term infants spent significant time at SpO2 ⩽90%. Lower gestation and lower birth weight were associated with higher time at SpO2 ⩽90%.

Pulse oximetry in newborns with delayed cord clamping and immediate skin-to-skin contact

OBJECTIVE

To assess whether defined reference ranges of oxygen saturation (SpO₂) and heart rate (HR) of term infants after birth also apply for infants born after midwifery supervised uncomplicated vaginal birth, where delayed cord clamping (DCC) and immediate skin to skin contact (ISSC) is routine management.

DESIGN

Prospective observational study.

SETTING AND PATIENTS

Infants born vaginally after uncomplicated birth, that is, no augmentation, maternal pain relief or instrumental delivery.

INTERVENTIONS

Midwives supervising uncomplicated birth at home or in hospital in the Leiden region (The Netherlands) used an oximeter and recorded SpO₂ and HR in the first 10 min after birth.

MAIN OUTCOME MEASURES

SpO₂ and HR values were compared to the international defined reference ranges.

RESULTS

In Leiden, values of 109 infants were obtained and are comparable with previously defined reference ranges, except for a higher SpO₂ (p<0.05) combined with a slower increase in the first 3 min. The Leiden cohort also had a lower HR (p<0.05) during the first 10 min with a slower increase in the first 3 min. In the first minutes after birth, tachycardia (HR>180 bpm) occurred less often, and a bradycardia (<80 bpm) more often (p<0.05).

CONCLUSIONS

Defined reference ranges can be used in infants born after uncomplicated vaginal birth with DCC and ISSC, but higher SpO₂ and lower HR were observed in the first minutes.

Oxygen saturation immediately after birth in infants delivered in tertiary care hospital in India

OBJECTIVE

To study the sequential changes in SpO2 values in newborns delivered in a teaching hospital in India.

METHODS

Full-term infants born by normal vaginal delivery to registered mothers at KLE University Hospital, Belgaum with birth weight more than 2,500 g, no congenital anomalies and who had received only routine care at birth were included in the study. After delivery, newborn infants were placed on a resuscitation trolley under a radiant warmer; the oxygen saturation sensor was attached (Nellcor DURA-Y multisite oxygen sensor) and then connected to the monitor (Planet 55 multiparameter recorder).

RESULTS

The mean (SD) gestational age of infants included in the study was 38.8 (1.1) wk and birth weight was 2,800 (300) g. The median (IQR) oxygen saturation level (SpO2) at 2 min of age was 69 % (68 %-79 %). The median level of SpO2 at 90 % and 95 % saturation was attained at 6.5 min and at 11 min of life, respectively.

CONCLUSIONS

Infants delivered in resource poor facilities of developing countries take 11 min to reach 95 % saturations after birth but they are within the reference range values of Neonatal Resuscitation Program 2010 guidelines.

Measuring physiological changes during the transition to life after birth

The transition to life after birth is characterized by major physiological changes in respiratory and hemodynamic function, which are predominantly initiated by breathing at birth and clamping of the umbilical cord. Lung aeration leads to the establishment of functional residual capacity, allowing pulmonary gas exchange to commence. This triggers a significant decrease in pulmonary vascular resistance, consequently increasing pulmonary blood flow and cardiac venous return. Clamping the umbilical cord also contributes to these hemodynamic changes by altering the cardiac preload and increasing peripheral systemic vascular resistance. The resulting changes in systemic and pulmonary circulation influence blood flow through both the oval foramen and ductus arteriosus. This eventually leads to closure of these structures and the separation of the pulmonary and systemic circulations. Most of our knowledge on human neonatal transition is based on human (fetal) data from the 1970s and extrapolation from animal studies. However, there is renewed interest in performing measurements directly at birth. By using less cumbersome techniques (and probably more accurate), our previous understanding of the physiological transition at birth is challenged, as well as the causes and consequences for when this transition fails to progress. This review will provide an overview of physiological measurements of the respiratory and hemodynamic transition at birth. Also, it will give a perspective on some of the upcoming technological advances in physiological measurements of neonatal transition in infants who are unable to make the transition without support.

Reference ranges for regional cerebral tissue oxygen saturation and fractional oxygen extraction in neonates during immediate transition after birth

OBJECTIVE

To define reference ranges for regional cerebral tissue oxygen saturation (crSO2) and regional cerebral fractional tissue oxygen extraction (cFTOE) during the first 15 minutes after birth in neonates requiring no medical support.

STUDY DESIGN

The crSO2 was measured using near infrared spectroscopy (Invos 5100 cerebral/somatic oximeter monitor; Somanetics Corp, Troy, Michigan) during the first 15 minutes after birth for term and preterm neonates. The near infrared spectroscopy sensor was placed on the left forehead. Peripheral oxygen saturation and heart rate were continuously measured by pulse oximetry, and cFTOE was calculated. Neonates were excluded if they required any medical support.

RESULTS

A total of 381 neonates were included: 82 term neonates after vaginal delivery, 272 term neonates after cesarean delivery, and 27 preterm neonates after cesarean delivery. In all neonates, median (10th-90th percentiles) crSO2 was 41% (23-64) at 2 minutes, 68% (45-85) at 5 minutes, 79% (65-90) at 10 minutes, and 77% (63-89) at 15 minutes of age. In all neonates, median (10th-90th percentiles) cFTOE was 33% (11-70) at 2 minutes, 21% (6-45) at 5 minutes, 15% (5-31) at 10 minutes, and 18% (7-34) at 15 minutes of age.

CONCLUSION

We report reference ranges of crSO2 and cFTOE in neonates requiring no medical support during transition immediately after birth. The use of cerebral oxygenation monitoring and use of these reference ranges in neonates during transition may help to guide oxygen delivery and avoid cerebral hypo-oxygenation and hyperoxygenation.

Comparison of heart rate and oxygen saturation measurements from Masimo and Nellcor pulse oximeters in newly born term infants

AIM

To compare heart rate (HR) measurements from Masimo and Nellcor pulse oximeters (POs) against HR measured via a three lead electrocardiograph (ECG) (HRECG ). We also compared peripheral oxygen saturation (SpO2 ) measurements between Nellcor and Masimo oximeters.

METHOD

Term infants born via elective caesarean section were studied. ECG leads were placed on the infant's chest and abdomen. Masimo and Nellcor PO sensors were randomly allocated to either foot. The monitors were placed on a trolley, and data from each monitor screen captured by a video camera. HR, SpO2 measurements and signal quality were extracted. Bland-Altman analysis was used to determine agreement between HR from the ECG and each oximeter, and between SpO2 from the oximeters.

RESULTS

We studied 44 infants of whom 4 were resuscitated. More than 8000 pairs of observations were used for each comparison of HR and SpO2. The mean difference (±2SD) between HRECG and HRN ellcor was -0.8 (±11) beats per minute (bpm); between HRECG and HRM asimo was 0.2 (±9) bpm. The mean (±2SD) difference between SpO2Masimo and SpO2Nellcor was -3 (±15)%. The Nellcor PO measured 20% higher than the Masimo PO at SpO2 <70%.

CONCLUSION

Both oximeters accurately measure HR. There was good agreement between SpO2 measurements when SpO2 ≥70%. At lower SpO2 , agreement was poorer.

Correlation of pulse oximetry and apgar scoring in the normal newborns

CONTEXT

Apgar score (AS) is routinely used for assessment of newborns immediately after birth. Within acceptable limits, low saturations at birth are normal in vigorous newborn babies. Various studies have questioned the reliability of AS.

AIMS

To detect whether AS is an accurate indicator of hypoxemia and to study the correlation of different components of AS with the arterial oxygenation saturation (SpO2) levels of normal newborns in the delivery room.

SETTINGS AND DESIGN

A prospective cross-sectional observational study on normal healthy neonates delivered vaginally in a tertiary level referral medical college.

MATERIALS AND METHODS

SpO2 levels were monitored continuously in the newborns with a pulse oximeter and serial recording of SpO2 levels was done at 5 min intervals starting at 1 min of life until 30 min after birth. Simultaneously, AS was recorded in these newborns at 1 and 5 min of life.

STATISTICAL ANALYSIS

Data was analyzed using the Mann-Whitney-U test.

RESULTS

AS at 1 and 5 min of life didn't correlate with the changes in SpO2 of newborns. In AS; though respiratory efforts and muscle tone were significantly correlated with SpO2 of the newborns, body color did not have significant correlation with simultaneously recorded SpO2.

CONCLUSIONS

A revised AS in which evaluation of color is replaced by pulse oximetry monitoring would prove to be a better tool for neonatal evaluation in the immediate postnatal period.

Simple method of <100% oxygen resuscitation for preterm infants

BACKGROUND

The aim of this study was to determine the feasibility of 50-60% oxygen resuscitation by a simple method using a self-inflation bag without oxygen reservoir for positive pressure ventilation (PPV) or using a constant distance and flow rate for blow-by oxygen.

METHODS

Newborn infants ≤ 35 weeks gestational age were eligible. Infants requiring PPV were initiated with bag-mask PPV without oxygen reservoir. Nearly 100% oxygen was given by attaching oxygen reservoir if heart rate < 100 beats/min after PPV for 90 s or SpO(2) < 75% at 3 min. For those requiring blow-by oxygen, oxygen flow 5 L/min via facemask was given 5 cm from the nose. Almost 100% oxygen was given by close-fitting facemask to nose if SpO(2) < 80% at 5 min.

RESULTS

Ninety-one infants were eligible; 67 of them required resuscitation. Thirty-five infants required PPV; 27 (77.1%) responded to bag-mask PPV without oxygen reservoir. For 32 infants requiring blow-by oxygen, 28 (87.5%) reached the targeted SpO(2). No significant differences in clinical outcomes were observed between responders and non-responders.

CONCLUSIONS

The technique of <100% oxygen supplementation was effective for preterm newborn resuscitation with a high success rate. This technique may be useful for a limited-resource setting.

Regional cerebral oxygen saturation in newborn infants in the first 15 min of life after vaginal delivery

The objective of this study was to evaluate regional oxygen saturation of the brain during immediate transition after birth, and to correlate it with pre-ductal arterial oxygen saturation in newborn infants. The prospective observational study including newborn infants in the first 15 min after spontaneous vaginal delivery and uncomplicated transitional period was undertaken. Regional cerebral oxygen saturation (rSO(2)brain) was measured using near-infrared spectroscopy. Arterial oxygen saturation (SpO(2)) and heart rate (HR) were measured on the right wrist by pulse oximetry. rSO(2)brain, SpO(2) and HR measurements were started immediately after birth and were performed in the first 15 min of life. Cerebral fractional tissue oxygen extraction (FTOE) was calculated for each minute. Of 145 newborn infants, 16 were included and the gender allocation was 31 females (49.2%) and 32 males (50.8%). rSO(2)brain increased rapidly from 39% (2 min) to 69% (5 min), SpO(2) increased from 72% (2 min) to 96% (14 min) and FTOE showed a significant decrease from minute 2 (0.47) until minute 4 (0.30) and an increase between 8 to 13 min. rSO(2)brain increased rapidly after vaginal delivery. Although SpO(2) increased within the first 14 min after delivery, rSO(2)brain showed no further significant changes after 5 min. FTOE decreased in the first 4 min and reached standard values subsequently.

"New-generation" pulse oximeters in extremely low-birth-weight infants: how do they perform in clinical practice?

The aim of this study was to evaluate the performance of "new-generation" pulse oximeters in extremely low-birth-weight ([ELBW] ≤ 1000 g) infants. In a prospective crossover observational study, the performance of pulse oximeters of 3 brands (Masimo, Nellcor, and Philips) was evaluated by dual SpO2 measurement in ELBW infants. Disposable probes of either equal or different brands were placed around both feet of the patient simultaneously for approximately 4 hours. Probes were switched between feet every hour. Absolute differences in SpO2 values (ΔSpO2) and the bias between brands were studied. Nine ELWB infants were included (gestational age: mean ± SD = 26(3)/7 ± 1 4/7 weeks). The median (range) ΔSpO2 was 2% (0%-26%). In 9% of the time, ΔSpO2 was 5% or more. The variance of the difference of the 3 pulse oximeter brands was not significantly different. No consequent bias between brands was found. Simultaneously obtained pulse oximeter measurements from the feet of ELBW infants differ from each other. Our results suggest that it is not the brand but the handling of the pulse oximeter in clinical practice, such as the place and positioning of the probe, that influences the performance of the pulse oximeter the most. Improvement in the accuracy of oxygen-monitoring techniques for ELBW infants is required.

Accuracy of pulse oximeter readings from probe placement on newborn wrist and ankle

OBJECTIVE

To compare the accuracy of pulse oximetry oxygen saturation (SpO(2)) measured on the wrist compared with the ipsilateral palm, and SpO(2) measured on the ankle compared with the ipsilateral sole.

STUDY DESIGN

In this prospective observational study, neonates admitted to the neonatal intensive care unit were enrolled. We recorded SpO(2) (Masimo Radical-7 pulse oximeter) detected at the palm and ipsilateral wrist initially, then at 30 s, and at 1 min, and we repeated the same procedure over the sole and ipsilateral ankle. We recorded the time to obtain the SpO(2) readings from all these sites. Regression analysis was performed to determine the relationship between paired SpO(2) measurements. The mean difference (bias) and standard deviation of the paired SpO(2) differences (precision) were calculated (Bland-Altman plots).

RESULT

A total of 150 patients (birth weight 2381±1020 g, gestational age 34.3±4.3 weeks, median postnatal age 3.5 days (25th-75th percentile 1-16 days)) were enrolled. There was a good correlation between SpO(2) measured at the palm versus the wrist (r=0.95, P<0.001 (right); r=0.97, P< 0.001 (left)) and between SpO(2) measured at the sole versus the ankle (r=0.92, P<0.001 (right); r=0.91, P<0.001 (left)). There was also a good agreement between paired SpO(2) measurements from these sites. The bias and precision for SpO(2) at the right palm and right wrist was 0.08±0.94% and for the left palm and left wrist 0.22±0.87%. Similarly, the bias and precision for SpO(2) at the right sole and right ankle was -0.03±0.93% and for the left sole and left ankle was -0.01±0.93%.

CONCLUSION

Our results show that the wrist and ankle can be used as alternative sites to measure SpO(2) in newborn infants in place of the routinely used palm or sole.

Pulse oximetry in pediatric practice

The introduction of pulse oximetry in clinical practice has allowed for simple, noninvasive, and reasonably accurate estimation of arterial oxygen saturation. Pulse oximetry is routinely used in the emergency department, the pediatric ward, and in pediatric intensive and perioperative care. However, clinically relevant principles and inherent limitations of the method are not always well understood by health care professionals caring for children. The calculation of the percentage of arterial oxyhemoglobin is based on the distinct characteristics of light absorption in the red and infrared spectra by oxygenated versus deoxygenated hemoglobin and takes advantage of the variation in light absorption caused by the pulsatility of arterial blood. Computation of oxygen saturation is achieved with the use of calibration algorithms. Safe use of pulse oximetry requires knowledge of its limitations, which include motion artifacts, poor perfusion at the site of measurement, irregular rhythms, ambient light or electromagnetic interference, skin pigmentation, nail polish, calibration assumptions, probe positioning, time lag in detecting hypoxic events, venous pulsation, intravenous dyes, and presence of abnormal hemoglobin molecules. In this review we describe the physiologic principles and limitations of pulse oximetry, discuss normal values, and highlight its importance in common pediatric diseases, in which the principle mechanism of hypoxemia is ventilation/perfusion mismatch (eg, asthma exacerbation, acute bronchiolitis, pneumonia) versus hypoventilation (eg, laryngotracheitis, vocal cord dysfunction, foreign-body aspiration in the larynx or trachea). Additional technologic advancements in pulse oximetry and its incorporation into evidence-based clinical algorithms will improve the efficiency of the method in daily pediatric practice.

Regional oxygen saturation of the brain during birth transition of term infants: comparison between elective cesarean and vaginal deliveries

OBJECTIVE

To evaluate differences in regional oxygen saturation of the brains of term infants of vaginal or cesarean deliveries.

STUDY DESIGN

Vaginal delivery (n = 63) and elective cesarean delivery infants were prospectively evaluated for the first 10 minutes after delivery. Peripheral arterial oxygen saturation (SpO(2)) and heart rate were measured on the right hand using pulsoximetry with near infrared spectroscopy. Regional oxygen saturation of the brain (rSO(2)brain) was measured. Fractional tissue oxygen extraction was calculated for each minute.

RESULTS

From 4 to 8 minutes, SpO(2) values for cesarean delivery infants were significantly lower than for vaginally delivered infants. Heart rate of the cesarean delivery infants was significantly lower throughout the whole observation period. There was no difference between groups in rSO(2)brain. Fractional tissue oxygen extraction only differed at minute 10.

CONCLUSIONS

Although SpO(2) and heart rate were significantly lower in cesarean-delivered infants, there were no differences in rSO(2)brain with respect to mode of delivery.

Normal oxygen saturation trend in healthy term newborns within 30 minutes of birth

OBJECTIVE

To determine normal arterial oxygen saturation (SpO(2)) trend during first 30 min of life and to evaluate for difference in SpO(2) trends in healthy term newborns of normal vaginal delivery (NVD) and elective cesarean section (CS).

METHODS

This Prospective Cross-sectional Observational study was conducted in Department of Pediatrics and Obstetrics, Gandhi Medical College, Bhopal. Newborns born of NVD and elective CS in first 30 min of life, complying with the study criteria were included in the study. Soon after birth, newborns with Apgar score ≥ 7 were given routine care and pulse-oximeter probe was applied on wiped right hand continuously for 30 min. Readings were obtained at an interval of 5 min.

RESULTS

Among NVD, the mean SpO(2) at 1, 5, 10, 15, 20, 25 and 30 min were 64.26%, 76.23%, 86.05%, 90.78%, 91.41%, 91.73% and 93.48%, respectively. The mean SpO(2) for CS was 67.43%, 78.50%, 88.44%, 90.81%, 91.46%, 91.83% and 92.88%, respectively. There was no significant difference in the SpO(2) between NVD and CS [95% CI = 74.8612-94.8359 in NVD and 77.1231-94.6912 in CS] and the correlation between NVD and CS being significant [r = 0.997 at 0.01 level]. There exists a strong positive correlation between Apgar and SpO(2) [r = 0.995, significant at 0.01 level (1-tailed) in NVD and r = 0.980, significant at 0.01 level (2-tailed) in CS].

CONCLUSIONS

The study defines the normal SpO(2) in healthy term newborns of NVD and CS delivered newborns and also concludes that there is no significant difference in SpO(2) among NVD and CS.

Avoiding hyperoxemia during neonatal resuscitation: time to response of different SpO2 monitors

Aim

To assess the time to obtain reliable oxygen saturation readings by different pulse oximeters during neonatal resuscitation in the delivery room or NICU.

Methods

Prospective study comparing three different pulse oximeters: Masimo Radical-7 compared simultaneously with Ohmeda Biox 3700 or with Nellcor N395, in newborn infants who required resuscitation. Members of the research team placed the sensors for each of the pulse oximeters being compared simultaneously, one sensor on each foot of the same baby. Care provided routinely, without interference by the research team. The time elapsed until a reliable SpO2 was obtained was recorded using a digital chronometer. Statistical comparisons included chi-square and student's T-test.

Results

Thirty-two infants were enrolled; median gestational age 32 weeks. Seventeen paired measurements were made with the Radical-7 and Biox 3700; mean time to a stable reading was 20.2 ± 7 sec for the Radical-7 and 74.2 ± 12 sec for the Biox 3700 (p = 0.02). The Radical-7 and the N- 395 were paired on 15 infants; the times to obtain a stable reading were 20.9 ± 4 sec and 67.3 ± 12 sec, respectively (p = 0.03).

Conclusion

The time to a reliable reading obtained simultaneously in neonatal critical situations differs by the type of the pulse oximeter used, being significantly faster with Masimo Signal Extraction Technology. This may permit for better adjustments of inspired oxygen, aiding in the prevention of damage caused by unnecessary exposure to high or low oxygen.

Assessment of flow waves and colorimetric CO2 detector for endotracheal tube placement during neonatal resuscitation

AIM

Clinical assessment and end-tidal CO(2) (ETCO(2)) detectors are routinely used to verify endotracheal tube (ETT) placement. However, ETCO(2) detectors may mislead clinicians by failing to identify correct placement under a variety of conditions. A flow sensor measures gas flow in and out of an ETT. We reviewed video recordings of neonatal resuscitations to compare a colorimetric CO(2) detector (Pedi-Cap®) with flow sensor recordings for assessing ETT placement.

METHODS

We reviewed recordings of infants <32 weeks gestation born between February 2007 and January 2010. Airway pressures and gas flow were recorded with a respiratory function monitor. Video recording were used (i) to identify infants who were intubated in the delivery room and (ii) to observe colour change of the ETCO(2) detector. Flow sensor recordings were used to confirm whether the tube was in the trachea or not.

RESULTS

Of the 210 infants recorded, 44 infants were intubated in the delivery room. Data from 77 intubation attempts were analysed. In 35 intubations of 20 infants both a PediCap® and flow sensor were available for analysis. In 21 (60%) intubations, both methods correctly identified successful ETT placement and in 3 (9%) both indicated the ETT was not in the trachea. In the remaining 11 (31%) intubations the PediCap® failed to change colour despite the flow wave indicating correct ETT placement.

CONCLUSION

Colorimetric CO(2) detectors may mislead clinicians intubating very preterm infants in the delivery room. They may fail to change colour in spite of correct tube placement in up to one third of the cases.

Regional oxygen saturation of the brain and peripheral tissue during birth transition of term infants

OBJECTIVE

To evaluate regional tissue oxygenation of the brain and preductal and postductal peripheral (muscle) tissue during immediate transition after birth, and to correlate with peripheral preductal and postductal arterial oxygen saturation.

STUDY DESIGN

We conducted a prospective observational study. With near-infrared spectroscopy (NIRS), changes in regional oxygen saturation of the brain (rSO2brain), peripheral preductal tissue (rSO2pre), and peripheral postductal tissue (rSO2post) were measured during the first 10 minutes of life in 59 healthy term infants after elective caesarean delivery. Fractional tissue oxygen extraction was calculated for all 3 regions.

RESULTS

Mean rSO2brain increased rapidly from 44% (3 minutes) to 76% (7 minutes); thereafter no significant change occurred. Mean rSO2pre and rSO2post increased constantly from minute 3 to minute 10, from 36%(pre)/27%(post) to 66%(pre)/58%(post). Fractional tissue oxygen extraction decreased in all 3 regions during the first minutes of life. Fractional tissue oxygen extraction of the brain did not change significantly after 5 minutes, and preductal and postductal fractional tissue oxygen extraction did not change significantly after 8 minutes.

CONCLUSIONS

During transition, the brain had the highest saturation levels, indicating a preference of oxygen delivery to the brain. Fractional tissue oxygen extraction of the brain reached a plateau earlier compared with peripheral tissue.