Oxygenation Instability Assessed by Oxygen Saturation Histograms during Supine vs Prone Position in Very Low Birthweight Infants Receiving Noninvasive Respiratory Support

Supine versus Prone Position during Delayed Cord Clamping in Infants ≥36 Weeks: A Randomized Trial

OBJECTIVE

 There is no recommendation in the literature on optimal positioning of the newborn immediately at birth during delayed cord clamping. To evaluate if prone positioning on the mother's chest at birth during delayed cord clamping leads to a higher hematocrit at 30 hours of life compared to supine positioning.

STUDY DESIGN

 A randomized unblinded trial comparing prone and supine position of the newborn before umbilical cord clamping. Healthy newborns ≥36 weeks gestational age and born vaginally with cephalic presentation were included. The newborn was randomized to prone or supine position. Umbilical cord clamping was delayed in both groups to 1 minute after birth. The primary outcome was hematocrit at 30 hours of life. As a secondary outcome, cerebral tissue oxygenation (CrSO2) values were compared between both groups by near infrared spectroscopy.

RESULTS

 There was no difference in hematocrit at 30 hours of life between supine and prone positions with a mean at 52 and 53.1, respectively, mean difference -1.1 (95% confidence interval:-2.7, 0.5), p = 0.17. Newborns in supine and prone positions had comparable level of CrSO2 at 30 hours of life with a mean at 84.1 and 82.2, respectively, mean difference 1.9 (-0.2, 4.0), p = 0.07. There was no correlation between hematocrit and CrSO2 at 30 hours of life (r = 0.14).

CONCLUSION

 There was no difference between prone and supine positioning immediately after birth during delayed cord clamping on hematocrit at 30 hours of life. In the absence of clear findings, further studies with assessment of the effect of position on breastfeeding success in the case room, on maternal satisfaction and outcome beyond 30 hours are needed to make adequate recommendations on positioning.

KEY POINTS

· Delayed cord clamping at 60 seconds is recommended at birth, but optimal positioning is unknown.. · A randomized trial was conducted to compare hematocrit at 36 hours of life of prone versus supine position.. · No difference in hematocrit was found in prone versus supine position during delayed cord clamping..

Oxygenation Instability during Bolus versus Continuous Feeding among Very Low Birth Weight Premature Infants, Supported by Noninvasive Ventilation: A Randomized Prospective Study

OBJECTIVE

 This study aimed to compare oxygenation instability, as documented by the oxygen saturation (SpO₂) histograms, during bolus (over 30 minutes) versus continuous (over 2 hours) feeding among very low birth weight (VLBW) premature infants, supported with noninvasive ventilation (NIV).

STUDY DESIGN

 This was a randomized prospective study. VLBW infants supported with NIV received three consecutive feeds in a random order of bolus-continuous-bolus or continuous-bolus-continuous. During each feed, 30 minutes and 2 hours histograms were documented.

RESULTS

 Twenty-four infants (birth weight [mean ± standard deviation, SD] 820 ± 168 g, gestational age [mean ± SD] 27.0 ± 1.6 weeks) were included in our study (12 infants started with bolus feeding and 12 with continuous feeding) and 72 histograms were obtained (36 during bolus feeding and 36 during continuous feeding). No differences in mean fraction of inspired oxygen (FiO₂), and number of apnea events were observed between the two feeding modes. Oxygenation instability as assessed by time spent in different SpO₂ ranges and histogram types (stable or unstable) was comparable during bolus and continuous feedings. Changing feeding mode from bolus to continuous or vice versa did not significantly change the oxygenation instability of the group, though individual infants did show a consistence response to feeding length changes.

CONCLUSION

 Among VLBW infants supported with NIV, oxygenation instability, as documented by SpO₂ histograms, was comparable between bolus and continuous feedings. Individual infants may benefit from specific feeding length, and this can be easily demonstrated by the SpO₂ histograms.

KEY POINTS

· Feeding length did not affect oxygenation instability of preterm infants on noninvasive respiratory Support.. · Oxygen saturation histograms allow objective quantification of oxygenation instability at the bedside.. · Individual infants benefit from specific feeding length, as demonstrated by SpO2 histograms..

Oxygen saturation histogram classification system to evaluate response to doxapram treatment in preterm infants

BACKGROUND

An oxygen saturation (SpO₂) histogram classification system has been shown to enable quantification of SpO₂ instability into five types, based on histogram distribution and time spent at SpO₂ ≤ 80%. We aimed to investigate this classification system as a tool to describe response to doxapram treatment in infants with severe apnea of prematurity.

METHODS

This retrospective study included 61 very-low-birth-weight infants who received doxapram. SpO₂ histograms were generated over the 24-h before and after doxapram start. Therapy response was defined as a decrease of ≥1 histogram types after therapy start.

RESULTS

The median (IQR) histogram type decreased from 4 (3-4) before to 3 (2-3) after therapy start (p < 0.001). The median (IQR) FiO₂ remained constant before (27% [24-35%]) and after (26% [22-35%]) therapy. Thirty-six infants (59%) responded to therapy within 24 h. In 34/36 (94%) of the responders, invasive mechanical ventilation (IMV) was not required during the first 72 h of therapy, compared to 15/25 (60%) of non-responders (p = 0.002). Positive and negative predictive values of the 24-h response for no IMV requirement within 72 h were 0.46 and 0.94, respectively.

CONCLUSIONS

Classification of SpO₂ histograms provides an objective bedside measure to assess response to doxapram therapy and can serve as a tool to detect changes in oxygenation status around respiratory interventions.

IMPACT

The SpO₂ histogram classification system provides a tool for quantifying response to doxapram therapy. The classification system allowed estimation of the probability of invasive mechanical ventilation requirement, already within a few hours of treatment. The SpO₂ histogram classification system allows an objective bedside assessment of the oxygenation status of the preterm infant, making it possible to assess the changes in oxygenation status in response to respiratory interventions.

Unstable SpO2 in preterm infants: The key role of reduced ventilation to perfusion ratio

Introduction: Instability of peripheral oxyhemoglobin saturation (SpO₂) in preterm infants is correlated with late disability and is poorly understood. We hypothesised that a reduced ventilation to perfusion ratio (V_A/Q) is the key predisposing factor for SpO₂ instability. Methods: We first used a mathematical model to compare the effects of reduced V_A/Q or shunt on SaO₂ stability (SaO₂ and SpO₂ are used for model and clinical studies respectively). Stability was inferred from the slope of the SaO₂ vs. inspired oxygen pressure (P _IO₂) curve as it intersects the 21 kPa P _IO₂ line (breathing air). Then, in a tertiary neonatal intensive care unit, paired hourly readings of SpO₂ and P _IO₂ were recorded over a 24 h period in week old extremely preterm infants. We noted SpO₂ variability and used an algorithm to derive V_A/Q and shunt from the paired SpO₂ and P _IO₂ measurements. Results: Our model predicted that when V_A/Q < 0.4, a 1% change in P _IO₂ results in >8% fluctuation in SaO₂ at 21 kPa P _IO₂. In contrast, when a 20% intrapulmonary shunt was included in the model, a 1% change in P _IO₂ results in <1% fluctuation in the SaO₂. Moreover, further reducing the V_A/Q from 0.4 to 0.3 at 21 kPa P _IO₂ resulted in a 24% fall in SaO₂. All 31 preterm infants [mean gestation (±standard deviation) 26.2 (±1) week] had V_A/Q < 0.74 (normal >0.85) but only two infants had increased shunt at 1.1 (±0.5) weeks' postnatal age. Median (IQR) SpO₂ fluctuation was 8 (7)%. The greatest SpO₂ fluctuations were seen in infants with V_A/Q < 0.52 (n = 10): SpO₂ fluctuations ranged from 11%-17% at a constant P _IO₂ when V_A/Q < 0.52. Two infants had reduced V_A/Q and increased shunt (21% and 27%) which resolved into low V_A/Q after 3-6 h. Discussion: Routine monitoring of P _IO₂ and SpO₂ can be used to derive a hitherto elusive measure of V_A/Q. Predisposition to SpO₂ instability results from reduced V_A/Q rather than increased intrapulmonary shunt in preterm infants with cardiorespiratory disease. SpO₂ instability can be prevented by a small increase in P _IO₂.

Oxygenation in the NICU: there is more to it than meets the eye

Dormishian and colleagues in their study address an issue that care teams in the NICU encounter on a daily basis, regarding motion artifacts during oxygenation monitoring. In our commentary, we discuss the available tools that allow continuous noninvasive monitoring of oxygenation in the NICU, and modalities that increase the time premature infants spend in the desired SpO₂ range and impact their clinical outcomes.

Position management on pulmonary function and bronchopulmonary dysplasia in premature infants: study protocol for a randomised controlled trial

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is a common disease caused by various factors and mechanisms in premature infants. Owing to lung hypoplasia and the lack of alveolar surfactants in premature infants, oxygen therapy is often needed to maintain adequate breathing. Nevertheless, prolonged oxygen therapy can easily induce BPD, and there is currently no effective treatment. Therefore, the prevention of BPD in premature infants during hospitalisation is essential. Studies have revealed that the prone position can effectively improve the oxygenation of premature infants. However, a few studies have reported whether prone positioning can improve lung function and reduce BPD incidence. This trial will determine whether the prone position, compared with the supine position, can reduce BPD incidence and improve lung function in preterm infants.

METHODS AND ANALYSIS

This study protocol is for a single-centre, single-blind, randomised controlled trial of the prone position in premature infants. Following daily feeding, premature infants will be placed in the lateral position for 30 min; then they will be turned to the supine position (control group) or prone position (intervention group) for 2 hours each in the morning and afternoon. Moreover, infants in both groups will be placed in the supine or lateral position alternately according to their medical needs for the remaining time. The study begins when the premature infants are stable within 5 days after admission and ends when they are discharged from the hospital or at 36 weeks postmenstrual age. The primary outcome is the survival rate without BPD. The secondary outcomes include lung function parameters and lung oxygen saturation.

ETHICS AND DISSEMINATION

This trial is approved by the ethics committee of the Affiliated Hospital of Southwest Medical University, (ref approval no.KY2021186). The results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR2100049847.

Regional oxygenation, perfusion and body and/or head position: Are preterm infants adversely impacted? A systematic review

This review addresses regional oxygenation and perfusion changes for preterm infants and changes with body position, with or without head rotation. Future directions for improving neurodevelopmental and clinical outcomes are suggested. The MEDLINE, Embase and Scopus databases were searched up to July 2021. Fifteen out of 470 studies met the inclusion criteria. All were prospective, observational studies with a moderate risk of bias. Significant variation was found for the baseline characteristics of the cohort, postnatal ages, and respiratory support status at the time of monitoring. When placed in a non-supine position, preterm infants showed a transient reduction in cardiac output and stroke volume without changes to heart rate or blood pressure. No studies reported on long-term neurodevelopmental outcomes. Overall, side lying or prone position does not appear to adversely affect regional, and specifically cerebral, oxygenation or cerebral perfusion. The effect of head rotation on regional oxygenation and perfusion remains unclear.