Quantitative end-tidal carbon dioxide monitoring in the delivery room: a randomized controlled trial

Colorimetric CO2 Detector to Improve Effective Mask Ventilations in Very Preterm Infants: A Pilot Randomized Controlled Study

INTRODUCTION

End-tidal CO2 (ETCO2) detector is currently recommended for confirmation of endotracheal tube placement during neonatal resuscitation. Whether it is feasible to use ETCO2 detectors during mask ventilation to reduce risk of bradycardia and desaturations, which are associated with increased risk of death in preterm babies, is unknown.

METHODS

This is a pilot randomized controlled trial (NCT04287907) involving newborns 24 + 0/7 to 32 + 0/7 weeks gestation who required mask ventilation at birth. Infants were randomized into groups with or without colorimetric ETCO2 detectors. Combined duration of any bradycardia (<100 bpm) and time below prespecified target oxygen saturation (SpO2) as measured by pulse oximetry were compared.

RESULTS

Fifty participants were randomized, 47 with outcomes analysed (2 incomplete data, 1 postnatal diagnosis of trachea-oesophageal fistula). Mean gestational age and birthweight were 28.5 ± 1.9 versus 29.4 ± 1.6 weeks (p = 0.1) and 1,252.7 ± 409.7 g versus 1,334.6 ± 369.1 g (p = 0.5) in the intervention and control arm, respectively. Mean combined duration of bradycardia and desaturation was 276.7 ± 197.7 s (intervention) and 322.7 ± 277.7 s (control) (p = 0.6). Proportion of participants with any bradycardia or desaturation at 5 min were 38.1% (intervention) and 56.5% (control) (p = 0.2). No chest compressions, epinephrine administration, or death occurred in the delivery room.

CONCLUSION

This pilot study demonstrates the feasibility of a trial to evaluate colorimetric ETCO2 detectors during mask ventilation of very preterm infants to reduce bradycardia and low SpO2. Further assessment with a larger population will be required to determine if ETCO2 detector usage at resuscitation reduces risk of adverse outcomes, including death and disability, in very preterm infants.

2023 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation engages in a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation and first aid science. Draft Consensus on Science With Treatment Recommendations are posted online throughout the year, and this annual summary provides more concise versions of the final Consensus on Science With Treatment Recommendations from all task forces for the year. Topics addressed by systematic reviews this year include resuscitation of cardiac arrest from drowning, extracorporeal cardiopulmonary resuscitation for adults and children, calcium during cardiac arrest, double sequential defibrillation, neuroprognostication after cardiac arrest for adults and children, maintaining normal temperature after preterm birth, heart rate monitoring methods for diagnostics in neonates, detection of exhaled carbon dioxide in neonates, family presence during resuscitation of adults, and a stepwise approach to resuscitation skills training. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, using Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces list priority knowledge gaps for further research. Additional topics are addressed with scoping reviews and evidence updates.

Exhaled CO2 monitoring to guide non-invasive ventilation at birth: a systematic review

OBJECTIVE

Measuring exhaled carbon dioxide (ECO2) during non-invasive ventilation at birth may provide information about lung aeration. However, the International Liaison Committee on Resuscitation (ILCOR) only recommends ECO2 detection for confirming endotracheal tube placement. ILCOR has therefore prioritised a research question that needs to be urgently evaluated: 'In newborn infants receiving intermittent positive pressure ventilation by any non-invasive interface at birth, does the use of an ECO2 monitor in addition to clinical assessment, pulse oximetry and/or ECG, compared with clinical assessment, pulse oximetry and/or ECG only, decrease endotracheal intubation in the delivery room, improve response to resuscitation, improve survival or reduce morbidity?'.

DESIGN

Systematic review of randomised and non-randomised studies identified by Ovid MEDLINE, Embase and Cochrane CENTRAL search until 1 August 2022.

SETTING

Delivery room.

PATIENTS

Newborn infants receiving non-invasive ventilation at birth.

INTERVENTION

ECO2 measurement plus routine assessment compared with routine assessment alone.

MAIN OUTCOME MEASURES

Endotracheal intubation in the delivery room, response to resuscitation, survival and morbidity.

RESULTS

Among 2370 articles, 23 were included; however, none had a relevant control group. Although studies indicated that the absence of ECO2 may signify airway obstruction and ECO2 detection may precede a heart rate increase in adequately ventilated infants, they did not directly address the research question.

CONCLUSIONS

Evidence to support the use of an ECO2 monitor to guide non-invasive positive pressure ventilation at birth is lacking. More research on the effectiveness of ECO2 measurement in addition to routine assessment during non-invasive ventilation of newborn infants at birth is needed.

PROSPERO REGISTRATION NUMBER

CRD42022344849.

2023 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation engages in a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation and first aid science. Draft Consensus on Science With Treatment Recommendations are posted online throughout the year, and this annual summary provides more concise versions of the final Consensus on Science With Treatment Recommendations from all task forces for the year. Topics addressed by systematic reviews this year include resuscitation of cardiac arrest from drowning, extracorporeal cardiopulmonary resuscitation for adults and children, calcium during cardiac arrest, double sequential defibrillation, neuroprognostication after cardiac arrest for adults and children, maintaining normal temperature after preterm birth, heart rate monitoring methods for diagnostics in neonates, detection of exhaled carbon dioxide in neonates, family presence during resuscitation of adults, and a stepwise approach to resuscitation skills training. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, using Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces list priority knowledge gaps for further research. Additional topics are addressed with scoping reviews and evidence updates.

Quantitative end-tidal carbon dioxide at initiation of resuscitation may help guide the ventilation of infants born at less than 30 weeks gestation

AIM

Estimation of end-tidal carbon dioxide (EtCO2 ) with capnography can guide mask ventilation in infants born at less than 30 weeks of gestation. Chemical-sensitive colorimetric devices to detect CO2 are widely used at resuscitation. We aimed to quantify EtCO2 in the first breaths following initiation of mask ventilation at birth and correlated need for endotracheal intubation.

METHODS

Infants <30 weeks gestation receiving mask ventilation were randomised into two groups of mask-hold technique (one-person vs. two-person). Data on EtCO2 in the first 30 breaths, time to achieve 5 mmHg, 10 mmHg and 15 mmHg CO2 using a respiratory function monitor was determined.

RESULTS

Twenty-five infants with a mean gestation of 27.3 (±3 weeks) and mean birth weight 920.4 (±188.3 g) were analysed. The median EtCO2 was 5.6 mmHg in the first 10 breaths, whereas it was 12.6 mmHg for 11-20 breaths and 18 mmHg for 21-30 breaths. There was no significant difference in maximum median EtCO2 for the first 20 breaths, although EtCO2 was significantly lower in infants who were intubated (32.0 vs. 15.0, p = 0.018).

CONCLUSION

EtCO2 monitoring in infants <30 weeks gestation at birth is feasible and reflective of alveolar ventilation. EtCO2 may help guide ventilation of preterm infants at birth.

Positive pressure ventilation at birth

OBJECTIVE

To review the current state of the art of positive pressure ventilation (PPV) during resuscitation FINDINGS: The frequency of PPV during delivery room resuscitation varies across settings and gestational age subgroups. Goal targets and parameters for delivery room PPV remain undefined. The T-piece resuscitator provides the most consistent pressures during PPV and may improve clinical outcomes. The laryngeal mask may be an important alternative interface for PPV, but more data are needed to identify the optimal role of the supraglottic airway during PPV. No objective monitors of PPV have conclusively demonstrated improved outcomes to date.

CONCLUSION

More information, including real-world data from population-based studies, is needed to provide data-driven guidelines for positive pressure ventilation during neonatal transition after birth.

Feasibility of portable capnometer for mechanically ventilated preterm infants in the delivery room

This study aimed to determine whether a specific portable capnometer (EMMA™) can facilitate the maintenance of an appropriate partial pressure of arterial carbon dioxide (PaCO₂) in intubated preterm infants in the delivery room. This study included preterm infants with a gestational age of 26 + 0 to 31 + 6 weeks who required intubation in the delivery room. We prospectively identified 40 infants who underwent the EMMA™ monitoring intervention group and 43 infants who did not undergo monitoring (historical control group). PaCO₂ was evaluated either at admission in the neonatal intensive care unit or at 2 h after birth. The proportion of infants with an appropriate PaCO₂ (35-60 mmHg) was greater in the intervention group than in the control group (80% vs. 42%; p = 0.001). There were no significant differences in the rate of accidental extubation (5.0% vs. 7.0%, p = 1.00) or in the proportion of infants with an appropriate PaCO₂ among infants whose birth weight was < 1000 g (54% vs. 40%, p = 0.49). However, among infants whose birth weight was ≥ 1000 g, the PaCO₂ tended to be more appropriate in the intervention group than in the control group (93% vs. 44%; p < 0.001).Conclusion: The EMMA™ facilitated the maintenance of an appropriate PaCO₂ for mechanically ventilated preterm infants, especially infants with birth weight ≥1000 g, in the delivery room. What is Known: • An inappropriate partial pressure of arterial carbon dioxide has been associated with intraventricular hemorrhage in preterm infants. • There is a need to appropriately control the partial pressure of arterial carbon dioxide in preterm infants. What is New: • This is the first report regarding the feasibility of a portable capnometer, the EMMA™, in the delivery room. • The EMMA™ may be considered a feasible monitoring device in the delivery room for intubated preterm infants, especially infants with birth weight ≥1000 g.

Non-invasive carbon dioxide monitoring in neonates: methods, benefits, and pitfalls

Wide fluctuations in partial pressure of carbon dioxide (PaCO2) can potentially be associated with neurological and lung injury in neonates. Blood gas measurement is the gold standard for assessing gas exchange but is intermittent, invasive, and contributes to iatrogenic blood loss. Non-invasive carbon dioxide (CO2) monitoring has become ubiquitous in anesthesia and critical care and is being increasingly used in neonates. Two common methods of non-invasive CO2 monitoring are end-tidal and transcutaneous. A colorimetric CO2 detector (a modified end-tidal CO2 detector) is recommended by the International Liaison Committee on Resuscitation (ILCOR) and the American Academy of Pediatrics to confirm endotracheal tube placement. Continuous CO2 monitoring is helpful in trending PaCO2 in critically ill neonates on respiratory support and can potentially lead to early detection and minimization of fluctuations in PaCO2. This review includes a description of the various types of CO2 monitoring and their applications, benefits, and limitations in neonates.

European Resuscitation Council Guidelines 2021: Newborn resuscitation and support of transition of infants at birth

The European Resuscitation Council has produced these newborn life support guidelines, which are based on the International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support. The guidelines cover the management of the term and preterm infant. The topics covered include an algorithm to aid a logical approach to resuscitation of the newborn, factors before delivery, training and education, thermal control, management of the umbilical cord after birth, initial assessment and categorisation of the newborn infant, airway and breathing and circulation support, communication with parents, considerations when withholding and discontinuing support.

[Newborn resuscitation and support of transition of infants at birth]

The European Resuscitation Council has produced these newborn life support guidelines, which are based on the International Liaison Committee on Resuscitation (ILCOR) 2020 Consensus on Science and Treatment Recommendations (CoSTR) for Neonatal Life Support. The guidelines cover the management of the term and preterm infant. The topics covered include an algorithm to aid a logical approach to resuscitation of the newborn, factors before delivery, training and education, thermal control, management of the umbilical cord after birth, initial assessment and categorisation of the newborn infant, airway and breathing and circulation support, communication with parents, considerations when withholding and discontinuing support.

Noninvasive Ventilation in the Delivery Room for the Preterm Infant

A decade ago, preterm infants were prophylactically intubated and mechanically ventilated starting in the delivery room; however, now the shift is toward maintaining even the smallest of neonates on noninvasive respiratory support. The resuscitation of very low gestational age neonates continues to push the boundaries of neonatal care, as the events that transpire during the golden minutes right after birth prove ever more important for determining long-term neurodevelopmental outcomes. Continuous positive airway pressure (CPAP) remains the most important mode of noninvasive respiratory support for the preterm infant to establish and maintain functional residual capacity and decrease ventilation/perfusion mismatch. However, the majority of extremely low gestational age infants require face mask positive pressure ventilation during initial stabilization before receiving CPAP. Effectiveness of face mask positive pressure ventilation depends on the ability to detect and overcome mask leak and airway obstruction. In this review, the current evidence on devices and techniques of noninvasive ventilation in the delivery room are discussed.

Tools to assess lung aeration in neonates with respiratory distress syndrome

AIM

Respiratory distress syndrome is a common condition among preterm neonates, and assessing lung aeration assists in diagnosing the disease and helping to guide and monitor treatment. We aimed to identify and analyse the tools available to assess lung aeration in neonates with respiratory distress syndrome.

METHODS

A systematic review and narrative synthesis of studies published between January 1, 2004, and August 26, 2019, were performed using the OVID Medline, PubMed, Embase and Scopus databases.

RESULTS

A total of 53 relevant papers were retrieved for the narrative synthesis. The main tools used to assess lung aeration were respiratory function monitoring, capnography, chest X-rays, lung ultrasound, electrical impedance tomography and respiratory inductive plethysmography. This paper discusses the evidence to support the use of these tools, including their advantages and disadvantages, and explores the future of lung aeration assessments within neonatal intensive care units.

CONCLUSION

There are currently several promising tools available to assess lung aeration in neonates with respiratory distress syndrome, but they all have their limitations. These tools need to be refined to facilitate convenient and accurate assessments of lung aeration in neonates with respiratory distress syndrome.

Predictors for expired CO2 in neonatal bag-mask ventilation at birth: observational study

BACKGROUND

Expired carbon dioxide (ECO2) indicates degree of lung aeration immediately after birth. Favourable ventilation techniques may be associated with higher ECO2 and a faster increase. Clinical condition will however also affect measured values. The aim of this study was to explore the relative impact of ventilation factors and clinical factors on ECO2 during bag-mask ventilation of near-term newborns.

METHODS

Observational study performed in a Tanzanian rural hospital. Side-stream measures of ECO2, ventilation data, heart rate and clinical information were recorded in 434 bag-mask ventilated newborns with initial heart rate <120 beats per minute. We studied ECO2 by clinical factors (birth weight, Apgar scores and initial heart rate) and ventilation factors (expired tidal volume, ventilation frequency, mask leak and inflation pressure) in random intercept models and Cox regression for time to ECO2 >2%.

RESULTS

ECO2 rose non-linearly with increasing expired tidal volume up to >10 mL/kg, and sufficient tidal volume was critical for the time to reach ECO2 >2%. Ventilation frequency around 30/min was associated with the highest ECO2. Higher birth weight, Apgar scores and initial heart rate were weak, but significant predictors for higher ECO2. Ventilation factors explained 31% of the variation in ECO2 compared with 11% for clinical factors.

CONCLUSIONS

Our findings indicate that higher tidal volumes than currently recommended and a low ventilation frequency around 30/min are associated with improved lung aeration during newborn resuscitation. Low ECO2 may be used to identify unfavourable ventilation technique. Clinical factors are also associated with persistently low ECO2 and must be accounted for in the interpretation.

Continuous Noninvasive Carbon Dioxide Monitoring in Neonates: From Theory to Standard of Care

Ventilatory support may affect the short- and long-term neurologic and respiratory morbidities of preterm infants. Ongoing monitoring of oxygenation and ventilation and control of adequate levels of oxygen, pressures, and volumes can decrease the incidence of such adverse outcomes. Use of pulse oximetry became a standard of care for titrating oxygen delivery, but continuous noninvasive monitoring of carbon dioxide (CO₂) is not routinely used in NICUs. Continuous monitoring of CO₂ level may be crucial because hypocarbia and hypercarbia in extremely preterm infants are associated with lung and brain morbidities, specifically bronchopulmonary dysplasia, intraventricular hemorrhage, and cystic periventricular leukomalacia. It is shown that continuous monitoring of CO₂ levels helps in maintaining stable CO₂ values within an accepted target range. Continuous monitoring of CO₂ levels can be used in the delivery room, during transport, and in infants receiving invasive or noninvasive respiratory support in the NICU. It is logical to hypothesize that this will result in better outcome for extremely preterm infants. In this article, we review the different noninvasive CO₂ monitoring alternatives and devices, their advantages and disadvantages, and the available clinical data supporting or negating their use as a standard of care in NICUs.

Systematic Review of Capnography with Mask Ventilation during Cardiopulmonary Resuscitation Maneuvers

The latest guidelines identify capnography as an instrument used to assess bag-valve-mask ventilation during cardiopulmonary resuscitation (CPR). In this review, we analyzed the feasibility and reliability of capnography use with face mask ventilation during CPR maneuvers in adults and children. This systematic review was completed in December 2018; data for the study were obtained from the following databases: EBSCOhost, SCOPUS, PubMed, Índice Bibliográfico Español en Ciencias de la Salud (IBECS), TESEO, and Cochrane Library Plus. Two reviewers independently assessed the eligibility of the articles; we analyzed publications from different sources and identified studies that focused on the use of capnography with a face mask during CPR maneuvers in order to describe the capnometry value and its correlation with resuscitation outcomes and the assistance of professionals. A total of 888 papers were collected, and 17 papers were included that provided objective values for the use of capnography with a mask for ventilation. Four were randomized clinical trials (RCT) and the rest were observational studies. Four studies were completed in adults and 13 were completed in newborns. After the analysis of the papers, we recommended a capnographic level of C in adults and B in newborns. Despite the little evidence obtained, capnography has been demonstrated to facilitate the advanced clinical practice of mask ventilation in cardiopulmonary resuscitation, to be reliable in the early detection of heart rate increase in newborns, and to asses in-airway patency and lung aeration during newborn resuscitation.

Systematic Review of Capnography with Mask Ventilation during Cardiopulmonary Resuscitation Maneuvers

The latest guidelines identify capnography as an instrument used to assess bag-valve-mask ventilation during cardiopulmonary resuscitation (CPR). In this review, we analyzed the feasibility and reliability of capnography use with face mask ventilation during CPR maneuvers in adults and children. This systematic review was completed in December 2018; data for the study were obtained from the following databases: EBSCOhost, SCOPUS, PubMed, Índice Bibliográfico Español en Ciencias de la Salud (IBECS), TESEO, and Cochrane Library Plus. Two reviewers independently assessed the eligibility of the articles; we analyzed publications from different sources and identified studies that focused on the use of capnography with a face mask during CPR maneuvers in order to describe the capnometry value and its correlation with resuscitation outcomes and the assistance of professionals. A total of 888 papers were collected, and 17 papers were included that provided objective values for the use of capnography with a mask for ventilation. Four were randomized clinical trials (RCT) and the rest were observational studies. Four studies were completed in adults and 13 were completed in newborns. After the analysis of the papers, we recommended a capnographic level of C in adults and B in newborns. Despite the little evidence obtained, capnography has been demonstrated to facilitate the advanced clinical practice of mask ventilation in cardiopulmonary resuscitation, to be reliable in the early detection of heart rate increase in newborns, and to asses in-airway patency and lung aeration during newborn resuscitation.

Relationship of resuscitation, respiratory function monitoring data and outcomes in preterm infants

Intraventricular haemorrhage (IVH) and bronchopulmonary dysplasia (BPD) are major complications of premature birth. We tested the hypotheses that prematurely born infants who developed an IVH or BPD would have high expiratory tidal volumes (V_TE) (V_TE > 6 ml/kg) and/or low-end tidal carbon dioxide (ETCO₂) levels (ETCO₂ levels < 4.5 kPa) as recorded by respiratory function monitoring or hyperoxia (oxygen saturation (SaO₂) > 95%) during resuscitation in the delivery suite. Seventy infants, median gestational age 27 weeks (range 23-33), were assessed; 31 developed an IVH and 43 developed BPD. Analysis was undertaken of 31,548 inflations. The duration of resuscitation did not differ significantly between the groups. Those who developed an IVH compared to those who did not had a greater number of inflations with a high V_TE and a low ETCO₂, which remained significant after correcting for differences in gestational age and birth weight between groups (p = 0.019). Differences between infants who did and did not develop BPD were not significant after correcting for differences in gestational age and birth weight. There were no significant differences in the duration of hyperoxia between the groups.Conclusions: Avoidance of high tidal volumes and hypocarbia in the delivery suite might reduce IVH development. What is known • Hypocarbia on the neonatal unit is associated with the development of intraventricular haemorrhage (IVH) and bronchopulmonary dysplasia (BPD). What is new • Infants who developed an IVH compared to those who did not had significantly more inflations with high expiratory tidal volumes and low ETCO₂s.

Effective ventilation: The most critical intervention for successful delivery room resuscitation

Lung aeration is the critical first step that triggers the transition from fetal to postnatal cardiopulmonary physiology after birth. When an infant is apneic or does not breathe sufficiently, intervention is needed to support this transition. Effective ventilation is therefore the cornerstone of neonatal resuscitation. In this article, we review the physiology of cardiopulmonary transition at birth, with particular attention to factors the caregiver should consider when providing ventilation. We then summarize the available clinical evidence for strategies to monitor and perform positive pressure ventilation in the delivery room setting.

Respiratory changes in term infants immediately after birth

INTRODUCTION

Over 5% of infants worldwide receive breathing support immediately after birth. Our goal was to define references ranges for exhaled carbon dioxide (ECO₂), exhaled tidal volume (VTe), and respiratory rate (RR) immediately after birth in spontaneously breathing, healthy infants born at 36 weeks' gestational age or older.

METHODS

This was a single-centre, observational study at the Royal Women's Hospital in Melbourne, Australia, a busy perinatal referral centre. Immediately after the infant's head was delivered, we used a face mask to measure ECO₂, VTe, and RR through the first ten minutes after birth. Respiratory measurements were repeated at one hour.

RESULTS

We analysed 14,731 breaths in 101 spontaneously breathing infants, 51 born via planned caesarean section and 50 born vaginally with a median (IQR) gestational age of 39^1/7 weeks (38^3/7-39^5/7). It took a median of 7 (4-10) breaths until ECO₂ was detected. ECO₂ quickly increased to peak value of 48 mmHg (43-53) at 143 s (76-258) after birth, and decreased to post-transitional values, 31 mmHg (28-24), by 7 min. VTe increased after birth, reaching a plateau of 5.3 ml/kg (2.5-8.4) by 130 s for the remainder of the study period. Maximum VTe was 19 ml/kg (16-22) at 257 s (82-360). RR values increased slightly over time, being higher from minute five to ten as compared to the first two minutes after birth.

CONCLUSIONS

This study provides reference ranges of exhaled carbon dioxide, exhaled tidal volumes, and respiratory rate for the first ten minutes after birth in term infants who transition without resuscitation.

Using exhaled CO2 to guide initial respiratory support at birth: a randomised controlled trial

IMPORTANCE

A sustained inflation (SI) provided at birth might reduce bronchopulmonary dysplasia (BPD).

OBJECTIVE

This study aims to examine whether an SI-guided exhaled carbon dioxide (ECO₂) compared with positive pressure ventilation (PPV) alone at birth decreases BPD.

DESIGN

Randomised controlled trial. Infants were randomly allocated to either SI (SI group) or PPV (PPV group).

PARTICIPANTS

Participants of this study include infants between 23⁺⁰ and 32⁺⁶ weeks gestation with a need for PPV at birth.

INTERVENTION

Infants randomised into the SI group received an initial SI with a peak inflation pressure (PIP) of 24 cmH₂O over 20 s. The second SI was guided by the amount of ECO₂. If ECO₂ was ≤20 mm Hg, a further SI of 20 s was delivered. If ECO₂ was >20 mm Hg the second SI was 10 s. Infants randomised into the PPV group received mask PPV with an initial PIP of 24 cmH₂O.

PRIMARY OUTCOMES

Reduction in BPD defined as the need for respiratory support or supplemental oxygen at corrected gestational age of 36 weeks.

RESULTS

SI (n=76) and PPV (n=86) group had similar rates of BPD (23% vs 33%, p=0.090, not statistically significant). The duration of mechanical ventilation was significantly reduced with SI versus PPV (63 (10-246) hours versus 204 (17-562) hours, respectively (p=0.045)). No short-term harmful effects were identified from two SI lasting up to 40 s (eg, pneumothorax, intraventricular haemorrhage or patent ductus arteriosus).

CONCLUSION

Preterm infants <33 weeks gestation receiving SI at birth had lower duration of mechanical ventilation and similar incidence of BPD compared with PPV. Using ECO₂ to guide length of SI is feasible.

TRIAL REGISTRATION NUMBER

NCT01739114; Results.

Application of end-tidal carbon dioxide monitoring via distal gas samples in ventilated neonates

BACKGROUND

Previous research has suggested correlations between the end-tidal partial pressure of carbon dioxide (P_ETCO₂) and the partial pressure of arterial carbon dioxide (PaCO₂) in mechanically ventilated patients, but both the relationship between P_ETCO₂ and PaCO₂ and whether P_ETCO₂ accurately reflects PaCO₂ in neonates and infants are still controversial. This study evaluated remote sampling of P_ETCO₂ via an epidural catheter within an endotracheal tube to determine the procedure's clinical safety and efficacy in the perioperative management of neonates.

METHODS

Abdominal surgery was performed under general anesthesia in 86 full-term newborns (age 1-30 days, weight 2.55-4.0 kg, American Society of Anesthesiologists class I or II). The infants were divided into 2 groups (n = 43 each), and carbon dioxide (CO₂) gas samples were collected either from the conventional position (the proximal end) or a modified position (the distal end) of the epidural catheter.

RESULTS

The P_ETCO₂ measured with the new method was significantly higher than that measured with the traditional method, and the difference between P_ETCO₂ and PaCO₂ was also reduced. The accuracy of P_ETCO₂ measured increased from 78.7% to 91.5% when the modified sampling method was used. The moderate correlation between P_ETCO₂ and PaCO₂ by traditional measurement was 0.596, which significantly increased to 0.960 in the modified sampling group. Thus, the P_ETCO₂ value was closer to that of PaCO₂.

CONCLUSION

P_ETCO₂ detected via modified carbon dioxide monitoring had a better accuracy and correlation with PaCO₂ in neonates.

Management of Extremely Low Birth Weight Infants in Delivery Room

Extremely low birth weight (ELBW) infants are particularly vulnerable at birth, and stabilization in the delivery room (DR) remains challenging. After birth, ELBW infants are at high risk for the development of thermal dysregulation, respiratory insufficiency, and hemodynamic instability due to their immature physiology and anatomy. Although successful stabilization facilitates the transition and reduces acute morbidity, suboptimal care in the DR could cause long-term sequelae. This review addresses the challenges in stabilization in the DR and current neonatal resuscitation guidelines and recommendations.

A Randomized Controlled Trial of End-Tidal Carbon Dioxide Detection of Preterm Infants in the Delivery Room

OBJECTIVE

To compare the ability of qualitative versus quantitative methods of end-tidal carbon dioxide (EtCO₂) detection to maintain normocarbia during face mask ventilation (FMV) of preterm infants (<32 weeks) in the delivery room.

STUDY DESIGN

Preterm infants <32 weeks were randomly assigned to the use of a disposable PediCap EtCO₂ detector (Covidien, Dublin, Ireland) (qualitative) or a Microstream side stream capnography device (Covidien) (quantitative) for FMV in the delivery room, via a NeoPuff T-piece resuscitator (Fisher and Paykel, Auckland, New Zealand). The primary outcome was the presence of normocarbia, based on partial pressure of CO₂ (PaCO₂) readings obtained in the neonatal intensive care unit within an hour of birth. Normocarbia was defined as a PaCO₂ measure between 37.5 and 60 mm Hg (5-8 kPa).

RESULTS

Of the 59 infants included, 59% (35/59) were within the PaCO₂ target range within an hour of birth. There was no difference in the primary outcome; 64% (21/33) of infants in the quantitative group were within the PaCO₂ range compared with 54% (14/26) in the qualitative group (P = .594); and 93% of participants <28 weeks' gestation were within the PaCO₂ normocarbic range (90% [9/10] in quantitative group and 100% [5/5] in the qualitative group [P = 1]). There was no difference in the intubation rate, days of ventilation, or bronchopulmonary dysplasia rates between the 2 groups.

CONCLUSIONS

Quantitative or qualitative EtCO₂ detection methods are both feasible for FMV in the delivery room. Although there was no difference in the incidence of normocarbia, the use of either form of EtCO₂ monitoring should be considered during newborn stabilization, especially in infants less than 28 weeks' gestation.

TRIAL REGISTRATION

ISRCTN: ISRCTN10934870.

Impact of Changing Clinical Practices on Early Blood Gas Analyses in Very Preterm Infants and Their Associated Inpatient Outcomes

BACKGROUND

Early studies suggest an association of abnormal carbon dioxide (PCO₂) or oxygen (PO₂) levels with adverse inpatient outcomes in very preterm babies. Recent resuscitation practice changes, such as targeted oxygen therapy, end-expiratory pressure, and rescue surfactant may influence these associations.

OBJECTIVE

The aim of this study is to assess the range of the initial partial pressures of PCO₂ and PO₂ in preterm neonates <33 weeks gestational age after birth and their correlation to inpatient neonatal outcomes.

STUDY DESIGN

This is a prospective observational cohort study of infants <33 weeks gestational age with arterial or venous blood gas analysis performed within the first hour after birth.

RESULTS

One hundred seventy infants (arterial n = 75, venous n = 95) with mean (SD) gestational age of 28 (3) weeks and birth weight of 1,111 (403) g were included. None of the infants with arterial blood gases had hypocarbia (<30 mmHg), 32 (43%) had normocarbia (30-55 mmHg), and 43 (57%) had hypercarbia (>55 mmHg). Seventeen of the infants with arterial blood gases (22%) had hypoxia (<50 mmHg), 50 (67%) normoxia, and 8 (11%) hyperoxia (>80 mmHg). In infants with venous blood samples, none had venous PCO₂ < 40 mmHg, 41 (43%) had venous PCO₂ 40-60 mmHg, and 54 (57%) had venous PCO₂ > 60 mmHg. Multivariable logistic regression analysis showed no association of low or high PCO₂ or PO₂ with death or major inpatient morbidities.

CONCLUSION

With current resuscitation and stabilization practices, hyperoxia and hypocarbia was uncommon, and hypercarbia occurred frequently. None of these findings correlate with adverse inpatient outcomes or death. Our findings are in direct contrast to published observations using historical practices.

Enhanced Monitoring of the Preterm Infant during Stabilization in the Delivery Room

Monitoring of preterm infants in the delivery room (DR) remains limited. Current guidelines suggest that pulse oximetry should be available for all preterm infant deliveries, and that if intubated a colorimetric carbon dioxide detector should provide verification of correct endotracheal tube placement. These two methods of assessment represent the extent of objective monitoring of the newborn commonly performed in the DR. Monitoring non-invasive ventilation effectiveness (either by capnography or respiratory function monitoring) and cerebral oxygenation (near-infrared spectroscopy) is becoming more common within research settings. In this article, we will review the different modalities available for cardiorespiratory and neuromonitoring in the DR and assess the current evidence base on their feasibility, strengths, and limitations during preterm stabilization.

Spontaneously Breathing Preterm Infants Change in Tidal Volume to Improve Lung Aeration Immediately after Birth

OBJECTIVE

To examine the temporal course of lung aeration at birth in preterm infants <33 weeks gestation.

STUDY DESIGN

The research team attended deliveries of preterm infants <33 weeks gestation at the Royal Alexandra Hospital. Infants who received only continuous positive airway pressure were eligible for inclusion. A combined carbon dioxide (CO2) and flow-sensor was placed between the mask and the ventilation device. To analyze lung aeration patterns during spontaneous breathing, tidal volume (VT), and exhaled CO2 (ECO2) were recorded for the first 100 breaths.

RESULTS

Thirty preterm infants were included with a total of 1512 breaths with mask leak <30%. Mean (SD) gestational age and birth weight was 30 (1) weeks and 1478 (430) g. Initial VT and ECO2 for the first 30 breaths was 5-6 mL/kg and 15-22 mm Hg, respectively. VT and ECO2 increased over the next 20 breaths to 7-8 mL/kg and 25-32 mm Hg, respectively. For the remaining observation period VT decreased to 4-6 mL/kg and ECO2 continued to increase to 35-37 mm Hg.

CONCLUSIONS

Preterm infants begin taking deeper breaths approximately 30 breaths after initiating spontaneous breathing to inflate their lungs. Concurrent CO2 removal rises as alveoli are recruited. Lung aeration occurs in 2 phases: initially, large volume breaths with poor alveolar aeration followed by smaller breaths with elimination of CO2 as a consequence of adequate aeration.

Quantitative or qualitative carbon dioxide monitoring for manual ventilation: a mannequin study

AIM

To compare the effectiveness of an in-line EtCO2 detector (DET) and a quantitative EtCO2 detector (CAP), both attached to a t-piece resuscitator, during PPV via a face mask.

METHODS

Paediatric trainees were randomly assigned to determine the method of PPV they commenced with (No device (ND), DET or CAP). Participants used each method for 2 min. Participants were video-recorded to determine the amount of effective ventilations delivered with each method.

RESULTS

Twenty-three paediatric trainees provided a total of 6035 ventilations, and 91.2% were deemed effective. The percentages of median effective ventilations with the ND, the DET and the CAP were 91.0%, 93.0% and 94.0%, respectively. Fourteen (61%) of the trainees indicated a preference for the DET method, 8 (35%) for the CAP method, and 1 (4%) of the trainees indicated a preference for the ND method. Capnography was the most effective method per patient.

CONCLUSION

There was no adverse effect with the addition of EtCO2 detectors. Trainees favoured methods of EtCO2 monitoring during ventilation. The NeoStat device was the preferred device by the majority. The greatest efficacy was achieved with the capnography device. Capnography may enhance face mask ventilation.

Exhaled carbon dioxide in healthy term infants immediately after birth

OBJECTIVE

To measure exhaled carbon dioxide (ECO2) in term infants immediately after birth.

STUDY DESIGN

Infants >37 weeks gestation born at The Royal Women's Hospital, Melbourne, Australia were eligible. A combined flow sensor and mainstream carbon dioxide (CO2) analyzer was placed in series proximal to a facemask to measure ECO2 and tidal volumes in the first 120 seconds after birth.

RESULTS

Term infants (n = 20) with a mean (SD) birth weight of 2976 (697) g and gestational age of 38 (2) weeks were included. Infants took a median (range) 3 (1-8) breaths before ECO2 was detected. The median (range) of maximum ECO2 was 51 (40-73) mm Hg at 70 (21-106) seconds after birth. Within the first 10 breaths, CO2 increased from 0-27 (22-34) mm Hg. The median (IQR) tidal volume during the breaths without CO2 was 1.2 (0.8-3.1) mL/kg compared with 7.3 (3.2-10.9) mL/kg during the first 10 breaths where CO2 was exhaled.

CONCLUSIONS

The first breaths for an infant after birth did not contain ECO2. With aeration of the distal gas exchange regions, tidal volume and ECO2 significantly increased. ECO2 can be used to monitor lung aeration immediately after birth.

Exhaled carbon dioxide can be used to guide respiratory support in the delivery room

Respiratory support in the delivery room remains challenging. Assessing chest rise is imprecise, and mask leak and airway obstruction are common problems. We describe recordings of respiratory signals during delivery room resuscitations and discuss guidance on positive-pressure ventilation using respiratory parameters and exhaled carbon dioxide (ECO2 ) during neonatal resuscitations.

CONCLUSION

Observing tidal volume and ECO2 waveforms adds objectivity to clinical assessments. ECO2 could help assess lung aeration and improve lung recruitment immediately after birth.

A review of carbon dioxide monitoring in preterm newborns in the delivery room

INTRODUCTION

The physiologic adaptation to extra uterine life during the immediate neonatal period is unique. Many newborns require assistance in this adaptive process. Recent evidence now supports titrating oxygen to guide resuscitation but no guidance is provided on utilizing exhaled CO2 measurements.

AIM

To review the current evidence relating to the use of CO2 monitoring in preterm newborns in the delivery room.

METHODS

Search was performed using the Cochrane Central Register of Controlled Trials, MEDLINE (1966-2014) and PREMEDLINE, EMBASE (1980-2014), CINAHL (1982-2014), Web of Science (1975-2014) and the Oxford Database of Perinatal Trials.

RESULTS

The search revealed 21 articles relating to CO2 detection, either quantitative or qualitative, in the newborn infant. The majority of these were observational studies, eight relating to CO2 detection as a means of confirming correct endotracheal tube placement in the newborn infant. The other indication is for mask ventilation, and there is one randomized control trial and four observational studies of CO2 detection during mask ventilation. The overall recommendation for CO2 detection for both clinical uses in the delivery suite is level B.

DISCUSSION

CO2 detection may be of particular benefit for preterm infants in the delivery suite. However there is a need for further research into CO2 detection, in particular capnography, as a means of confirming effective PPV in neonatal resuscitation.

Monitoring lung aeration during respiratory support in preterm infants at birth

Background

If infants fail to initiate spontaneous breathing, resuscitation guidelines recommend respiratory support with positive pressure ventilation (PPV). The purpose of PPV is to establish functional residual capacity and deliver an adequate tidal volume (V_T) to achieve gas exchange.

Objective

The aim of our pilot study was to measure changes in exhaled carbon dioxide (ECO₂), V_T, and rate of carbon dioxide elimination (VCO₂) to assess lung aeration in preterm infants requiring respiratory support immediately after birth.

Method

A prospective observational study was performed between March and July 2013. Infants born at <37 weeks gestational age who received continuous positive airway pressure (CPAP) or PPV immediately after birth had V_T delivery and ECO₂ continuously recorded using a sensor attached to the facemask.

Results

Fifty-one preterm infants (mean (SD) gestational age 29 (3) weeks and birth weight 1425 (592 g)) receiving respiratory support in the delivery room were included. Infants in the CPAP group (n = 31) had higher ECO₂ values during the first 10 min after birth compared to infants receiving PPV (n = 20) (ranging between 18–30 vs. 13–18 mmHg, p<0.05, respectively). At 10 min no significant difference in ECO₂ values was observed. V_T was lower in the CPAP group compared to the PPV group over the first 10 min ranging between 5.2–6.6 vs. and 7.2–11.3 mL/kg (p<0.05), respectively.

Conclusions

Immediately after birth, spontaneously breathing preterm infants supported via CPAP achieved better lung aeration compared to infants requiring PPV. PPV guided by V_T and ECO₂ potentially optimize lung aeration without excessive V_T administered.

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.