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

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.

Interventions to Reduce Severe Brain Injury Risk in Preterm Neonates: A Systematic Review and Meta-analysis

Importance

Interventions to reduce severe brain injury risk are the prime focus in neonatal clinical trials.

Objective

To evaluate multiple perinatal interventions across clinical settings for reducing the risk of severe intraventricular hemorrhage (sIVH) and cystic periventricular leukomalacia (cPVL) in preterm neonates.

Data Sources

MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched from inception until September 8, 2022, using prespecified search terms and no language restrictions.

Study Selection

Randomized clinical trials (RCTs) that evaluated perinatal interventions, chosen a priori, and reported 1 or more outcomes (sIVH, cPVL, and severe brain injury) were included.

Data Extraction and Synthesis

Two co-authors independently extracted the data, assessed the quality of the trials, and evaluated the certainty of the evidence using the Cochrane GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Fixed-effects pairwise meta-analysis was used for data synthesis.

Main Outcomes and Measures

The 3 prespecified outcomes were sIVH, cPVL, and severe brain injury.

Results

A total of 221 RCTs that assessed 44 perinatal interventions (6 antenatal, 6 delivery room, and 32 neonatal) were included. Meta-analysis showed with moderate certainty that antenatal corticosteroids were associated with small reduction in sIVH risk (risk ratio [RR], 0.54 [95% CI, 0.35-0.82]; absolute risk difference [ARD], -1% [95% CI, -2% to 0%]; number needed to treat [NNT], 80 [95% CI, 48-232]), whereas indomethacin prophylaxis was associated with moderate reduction in sIVH risk (RR, 0.64 [95% CI, 0.52-0.79]; ARD, -5% [95% CI, -8% to -3%]; NNT, 20 [95% CI, 13-39]). Similarly, the meta-analysis showed with low certainty that volume-targeted ventilation was associated with large reduction in risk of sIVH (RR, 0.51 [95% CI, 0.36-0.72]; ARD, -9% [95% CI, -13% to -5%]; NNT, 11 [95% CI, 7-23]). Additionally, early erythropoiesis-stimulating agents (RR, 0.68 [95% CI, 0.57-0.83]; ARD, -3% [95% CI, -4% to -1%]; NNT, 34 [95% CI, 22-67]) and prophylactic ethamsylate (RR, 0.68 [95% CI, 0.48-0.97]; ARD, -4% [95% CI, -7% to 0%]; NNT, 26 [95% CI, 13-372]) were associated with moderate reduction in sIVH risk (low certainty). The meta-analysis also showed with low certainty that compared with delayed cord clamping, umbilical cord milking was associated with a moderate increase in sIVH risk (RR, 1.82 [95% CI, 1.03-3.21]; ARD, 3% [95% CI, 0%-6%]; NNT, -30 [95% CI, -368 to -16]).

Conclusions and Relevance

Results of this study suggest that a few interventions, including antenatal corticosteroids and indomethacin prophylaxis, were associated with reduction in sIVH risk (moderate certainty), and volume-targeted ventilation, early erythropoiesis-stimulating agents, and prophylactic ethamsylate were associated with reduction in sIVH risk (low certainty) in preterm neonates. However, clinicians should carefully consider all of the critical factors that may affect applicability in these interventions, including certainty of the evidence, before applying them to clinical practice.

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.

Singapore Neonatal Resuscitation Guidelines 2021

Neonatal resuscitation is a coordinated, team-based series of timed sequential steps that focuses on a transitional physiology to improve perinatal and neonatal outcomes. The practice of neonatal resuscitation has evolved over time and continues to be shaped by emerging evidence as well as key opinions. We present the revised Neonatal Resuscitation Guidelines for Singapore 2021. The recommendations from the International Liaison Committee on Resuscitation Neonatal Task Force Consensus on Science and Treatment Recommendations (2020) and guidelines from the American Heart Association and European Resuscitation Council were compared with existing guidelines. The recommendations of the Neonatal Subgroup of the Singapore Resuscitation and First Aid Council were derived after the work group discussed and appraised the current available evidence and their applicability to local clinical practice.

Sustained Lung Inflations During Neonatal Resuscitation at Birth: A Meta-analysis

CONTEXT

The International Liaison Committee on Resuscitation prioritized review of sustained inflation (SI) of the lung at birth.

OBJECTIVE

To complete a systematic review and meta-analysis comparing strategies using 1 or more SI ≥1 second with intermittent inflations <1 second for newborns at birth.

DATA SOURCES

Medline, Embase, and Evidence-Based Medicine Reviews were searched from January 1, 1946, to July 20, 2020.

STUDY SELECTION

Studies were selected by pairs of independent reviewers in 2 stages.

DATA EXTRACTION

Reviewers extracted data, appraised risk of bias, and assessed certainty of evidence for each outcome.

RESULTS

Ten trials enrolling 1502 preterm newborns were included. Five studies included newborns who did not receive assisted ventilation at the outset. There were no differences between SI and control groups for death before discharge or key morbidities. For death within the first 2 days, comparing SI with the controls, risk ratio was 2.42 (95% confidence interval = 1.15-5.09). In subgroup analysis of preterm infants ≤28 + 0 weeks' gestation, for death before discharge, risk ratio was 1.38 (95% confidence interval = 1.00-1.91). Together, these findings suggest the potential for harm of SI.

LIMITATIONS

The certainty of evidence was very low for death in the delivery room and low for all other outcomes.

CONCLUSIONS

In this systematic review, we did not find benefit in using 1 or more SI >5 seconds for preterm infants at birth. SI(s) may increase death before discharge among the subgroup born ≤28 + 0 weeks' gestation. There is insufficient evidence to determine the likely effect of SI(s) on other key morbidities.

2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for neonatal life support includes evidence from 7 systematic reviews, 3 scoping reviews, and 12 evidence updates. The Neonatal Life Support Task Force generally determined by consensus the type of evidence evaluation to perform; the topics for the evidence updates followed consultation with International Liaison Committee on Resuscitation member resuscitation councils. The 2020 CoSTRs for neonatal life support are published either as new statements or, if appropriate, reiterations of existing statements when the task force found they remained valid.Evidence review topics of particular interest include the use of suction in the presence of both clear and meconium-stained amniotic fluid, sustained inflations for initiation of positive-pressure ventilation, initial oxygen concentrations for initiation of resuscitation in both preterm and term infants, use of epinephrine (adrenaline) when ventilation and compressions fail to stabilize the newborn infant, appropriate routes of drug delivery during resuscitation, and consideration of when it is appropriate to redirect resuscitation efforts after significant efforts have failed.All sections of the Neonatal Resuscitation Algorithm are addressed, from preparation through to postresuscitation care. This document now forms the basis for ongoing evidence evaluation and reevaluation, which will be triggered as further evidence is published.Over 140 million babies are born annually worldwide (https://ourworldindata.org/grapher/births-and-deaths-projected-to-2100). If up to 5% receive positive-pressure ventilation, this evidence evaluation is relevant to more than 7 million newborn infants every year. However, in terms of early care of the newborn infant, some of the topics addressed are relevant to every single baby born.

Sustained inflation: The lung recruitment maneuvers for neonates

Establishing effective respiration is vital in the transition from fetal to neonatal life. Respiratory support mainly facilitates and creates functional residual capacity and maintains adequate gas exchange. Sustained inflation (SI) delivers prolonged inflation and rapidly creates and establishes the functional residual capacity. The use of SI in preterm infants in the delivery room is still controversial. The optimum settings of SI remain unknown. Animal studies and clinical reports have demonstrated the advantages and disadvantages of SI. In this article, the current literature was reviewed to examine the efficacy of SI in infants.

Neonatal Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for neonatal life support includes evidence from 7 systematic reviews, 3 scoping reviews, and 12 evidence updates. The Neonatal Life Support Task Force generally determined by consensus the type of evidence evaluation to perform; the topics for the evidence updates followed consultation with International Liaison Committee on Resuscitation member resuscitation councils. The 2020 CoSTRs for neonatal life support are published either as new statements or, if appropriate, reiterations of existing statements when the task force found they remained valid. Evidence review topics of particular interest include the use of suction in the presence of both clear and meconium-stained amniotic fluid, sustained inflations for initiation of positive-pressure ventilation, initial oxygen concentrations for initiation of resuscitation in both preterm and term infants, use of epinephrine (adrenaline) when ventilation and compressions fail to stabilize the newborn infant, appropriate routes of drug delivery during resuscitation, and consideration of when it is appropriate to redirect resuscitation efforts after significant efforts have failed. All sections of the Neonatal Resuscitation Algorithm are addressed, from preparation through to postresuscitation care. This document now forms the basis for ongoing evidence evaluation and reevaluation, which will be triggered as further evidence is published. Over 140 million babies are born annually worldwide (https://ourworldindata.org/grapher/births-and-deaths-projected-to-2100). If up to 5% receive positive-pressure ventilation, this evidence evaluation is relevant to more than 7 million newborn infants every year. However, in terms of early care of the newborn infant, some of the topics addressed are relevant to every single baby born.

Sustained Inflation vs Standard Resuscitation for Preterm Infants: A Systematic Review and Meta-analysis

IMPORTANCE

Most preterm infants require respiratory support to establish lung aeration after birth. Intermittent positive pressure ventilation and continuous positive airway pressure are standard therapies. An initial sustained inflation (inflation time >5 seconds) is a widely practiced alternative strategy.

OBJECTIVE

To conduct a systematic review and meta-analysis of sustained inflation vs intermittent positive pressure ventilation and continuous positive airway pressure for the prevention of hospital mortality and morbidity for preterm infants.

DATA SOURCES

MEDLINE (through PubMed), Embase, the Cumulative Index of Nursing and Allied Health Literature, and the Cochrane Central Register of Controlled Trials were searched through June 24, 2019.

STUDY SELECTION

Randomized clinical trials of preterm infants born at less than 37 weeks' gestation that compared sustained inflation (inflation time >5 seconds) vs standard resuscitation with either intermittent positive pressure ventilation or continuous positive airway pressure were included. Studies including other cointerventions were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers assessed the risk of bias of included studies. Meta-analysis of pooled outcome data used a fixed-effects model specific to rarer events. Subgroups were based on gestational age and study design (rescue vs prophylactic sustained inflation).

MAIN OUTCOMES AND MEASURES

Death before hospital discharge.

RESULTS

Nine studies recruiting 1406 infants met inclusion criteria. Death before hospital discharge occurred in 85 of 736 infants (11.5%) treated with sustained inflation and 62 of 670 infants (9.3%) who received standard therapy for a risk difference of 3.6% (95% CI, -0.7% to 7.9%). Although analysis of the primary outcome identified important heterogeneity based on gestational age subgroups, the 95% CI for the risk difference included 0 for each individual gestational age subgroup. There was no difference in the primary outcome between subgroups based on study design. Sustained inflation was associated with increased risk of death in the first 2 days after birth (risk difference, 3.1%; 95% CI, 0.9%-5.3%). No differences in the risk of other secondary outcomes were identified. The quality-of-evidence assessment was low owing to risk of bias and imprecision.

CONCLUSIONS AND RELEVANCE

There was no difference in the risk of the primary outcome of death before hospital discharge, and there was no evidence of efficacy for sustained inflation to prevent secondary outcomes. These findings do not support the routine use of sustained inflation for preterm infants after birth.

Sustained versus standard inflations during neonatal resuscitation to prevent mortality and improve respiratory outcomes

BACKGROUND

At birth, infants' lungs are fluid-filled. For newborns to have a successful transition, this fluid must be replaced by air to enable gas exchange. Some infants are judged to have inadequate breathing at birth and are resuscitated with positive pressure ventilation (PPV). Giving prolonged (sustained) inflations at the start of PPV may help clear lung fluid and establish gas volume within the lungs.

OBJECTIVES

To assess the benefits and harms of an initial sustained lung inflation (SLI) (> 1 second duration) versus standard inflations (≤ 1 second) in newborn infants receiving resuscitation with intermittent PPV.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 3), MEDLINE via PubMed (1966 to 1 April 2019), Embase (1980 to 1 April 2019), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 1 April 2019). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles to identify randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing initial sustained lung inflation (SLI) versus standard inflations given to infants receiving resuscitation with PPV at birth.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of included trials using Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria (assessing randomisation, blinding, loss to follow-up, and handling of outcome data). We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data; and mean standard deviation (SD), and weighted mean difference (WMD) for continuous data. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

Ten trials enrolling 1467 infants met our inclusion criteria. Investigators in nine trials (1458 infants) administered sustained inflation with no chest compressions. Use of sustained inflation had no impact on the primary outcomes of this review: mortality in the delivery room (typical RR 2.66, 95% confidence interval (CI) 0.11 to 63.40 (I² not applicable); typical RD 0.00, 95% CI -0.02 to 0.02; I² = 0%; 5 studies, 479 participants); and mortality during hospitalisation (typical RR 1.09, 95% CI 0.83 to 1.43; I² = 42%; typical RD 0.01, 95% CI -0.02 to 0.04; I² = 24%; 9 studies, 1458 participants). The quality of the evidence was low for death in the delivery room because of limitations in study design and imprecision of estimates (only one death was recorded across studies). For death before discharge the quality was moderate: with longer follow-up there were more deaths (n = 143) but limitations in study design remained. Among secondary outcomes, duration of mechanical ventilation was shorter in the SLI group (mean difference (MD) -5.37 days, 95% CI -6.31 to -4.43; I² = 95%; 5 studies, 524 participants; low-quality evidence). Heterogeneity, statistical significance, and magnitude of effects of this outcome are largely influenced by a single study at high risk of bias: when this study was removed from the analysis, the size of the effect was reduced (MD -1.71 days, 95% CI -3.04 to -0.39; I² = 0%). Results revealed no differences in any of the other secondary outcomes (e.g. risk of endotracheal intubation outside the delivery room by 72 hours of age (typical RR 0.91, 95% CI 0.79 to 1.04; I² = 65%; 5 studies, 811 participants); risk of surfactant administration during hospital admission (typical RR 0.99, 95% CI 0.91 to 1.08; I² = 0%; 9 studies, 1458 participants); risk of chronic lung disease (typical RR 0.99, 95% CI 0.83 to 1.18; I² = 0%; 4 studies, 735 participants); pneumothorax (typical RR 0.89, 95% CI 0.57 to 1.40; I² = 34%; 8 studies, 1377 infants); or risk of patent ductus arteriosus requiring pharmacological treatment (typical RR 0.99, 95% CI 0.87 to 1.12; I² = 48%; 7 studies, 1127 infants). The quality of evidence for these secondary outcomes was moderate (limitations in study design ‒ GRADE) except for pneumothorax (low quality: limitations in study design and imprecision of estimates ‒ GRADE). We could not perform any meta-analysis in the comparison of the use of initial sustained inflation versus standard inflations in newborns receiving resuscitation with chest compressions because we identified only one trial for inclusion (a pilot study of nine preterm infants).

AUTHORS' CONCLUSIONS

Our meta-analysis of nine studies shows that sustained lung inflation without chest compression was not better than intermittent ventilation for reducing mortality in the delivery room (low-quality evidence ‒ GRADE) or during hospitalisation (moderate-quality evidence ‒ GRADE), which were the primary outcomes of this review. However, the single largest study, which was well conducted and had the greatest number of enrolled infants, was stopped early for higher mortality rate in the sustained inflation group. When considering secondary outcomes, such as rate of intubation, rate or duration of respiratory support, or bronchopulmonary dysplasia, we found no benefit of sustained inflation over intermittent ventilation (moderate-quality evidence ‒ GRADE). Duration of mechanical ventilation was shortened in the SLI group (low-quality evidence ‒ GRADE); this result should be interpreted cautiously, however, as it might have been influenced by study characteristics other than the intervention. There is no evidence to support the use of sustained inflation based on evidence from our review.

[Application of sustained lung inflation in preterm infants with a gestational age of <34 weeks: a Meta analysis]

OBJECTIVE

To systematically review the effect of sustained lung inflation (SLI) in preterm infants with a gestational age of <34 weeks.

METHODS

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, China Biology Medicine disc, Chinese Journal Full-text Database, and Weipu Database were searched for randomized controlled trials (RCTs) on the application of SLI versus noninvasive positive pressure ventilation alone in preterm infants. Revman 5.3 was used to perform a Meta analysis for the RCTs which met the inclusion criteria.

RESULTS

A total of 9 RCTs were included, with 1 432 preterm infants in total (with a gestational age of 23-33.7 weeks). The Meta analysis showed that compared with the control group, the SLI group had a significantly lower proportion of the infants who needed mechanical ventilation within 72 hours (51.9% vs 56.9%, RR=0.91, P=0.04, 95%CI: 0.83-0.99). There were no significant differences between the two groups in the mortality rate, rate of use of pulmonary surfactant, and incidence rates of related complications (bronchopulmonary dysplasia, pneumothorax, and grade III-IV intracranial hemorrhage) (P>0.05).

CONCLUSIONS

SLI can reduce the use of mechanical ventilation in preterm infants with a gestational age of <34 weeks and does not increase the risk of other complications.

Improving Newborn Respiratory Outcomes With a Sustained Inflation: A Systematic Narrative Review of Factors Regulating Outcome in Animal and Clinical Studies

Respiratory support is critically important for survival of newborns who fail to breathe spontaneously at birth. Although there is no internationally accepted definition of a sustained inflation (SI), it has commonly been defined as a positive pressure inflation designed to establish functional residual capacity and applied over a longer time period than normally used in standard respiratory support (SRS). Outcomes vary distinctly between studies and to date there has been no comprehensive investigation of differences in SI approach and study outcome in both pre-clinical and clinical studies. A systematic literature search was performed and, after screening, identified 17 animal studies and 17 clinical studies evaluating use of a SI in newborns compared to SRS during neonatal resuscitation. Study demographics including gestational age, SI parameters (length, repetitions, pressure, method of delivery) and study outcomes were compared. Animal studies provide mechanistic understanding of a SI on the physiology underpinning the cardiorespiratory transition at birth. In clinical studies, there is considerable difference in study quality, delivery of SIs (number, pressure, length) and timing of primary outcome evaluation which limits direct comparison between studies. The largest difference is method of delivery, where the role of a SI has been observed in intubated animals, as the inflation pressure is directly applied to the lung, bypassing the obstructed upper airway in an apnoeic state. This highlights a potential limitation in clinical use of a SI applied non-invasively. Further research is required to identify if a SI may have greater benefits in subpopulations of newborns.

Incidence and Risk Factors for Hypoglycemia During Fetal-to-Neonatal Transition in Premature Infants

Objective: To determine the incidence and risk factors associated with neonatal hypoglycemia in the premature population <33 weeks' gestation. Methods: This was a secondary retrospective analysis from previous infants enrolled in randomized controlled trials. A total of 255 infants <33 weeks' gestation were born during the study period. Eight infants were excluded due to missing glucose or maternal data and 175 infants were analyzed. Main outcome measures: Primary outcome was hypoglycemia (blood glucose <2.6mmol/L) determined via glucose oxidase method on arterial or venous blood gas. Birth weight subgroups: small for gestational age (SGA, birth weight <10%ile for gestational age) and large for gestational age (LGA, birth weight >90%ile for gestational age). Maternal hypertension was systolic blood pressure >140mmHg. Results: 175 infants <33 weeks' gestational age (89 male, 84 female) were analyzed. Hypoglycemia occurred in 59 infants (33.7%). Maternal hypertension (OR 3.07, 95% CI 1.51-6.30, p = 0.002) was the sole risk factor for neonatal hypoglycemia. Protective factors for hypoglycemia included labor at time of delivery (OR 4.51, 95% CI 2.29-9.18, p <0.0001) and antenatal magnesium sulfate (OR 2.53, 95% CI 1.23-5.50, p = 0.01). There were no significant differences between hypoglycemic and euglycemic infants in sex, gestational age, LGA infants, antenatal steroids, vaginal birth, or maternal diabetes. SGA infants were excluded from analysis due to sample size. Conclusions: Premature infants <33 weeks' gestation have increased risk of hypoglycemia. Maternal hypertension increases hypoglycemia risk. Antenatal magnesium sulfate administration or labor at time of delivery decrease hypoglycemia risk.

Effect of Sustained Inflations vs Intermittent Positive Pressure Ventilation on Bronchopulmonary Dysplasia or Death Among Extremely Preterm Infants: The SAIL Randomized Clinical Trial

IMPORTANCE

Preterm infants must establish regular respirations at delivery. Sustained inflations may establish lung volume faster than short inflations.

OBJECTIVE

To determine whether a ventilation strategy including sustained inflations, compared with standard intermittent positive pressure ventilation, reduces bronchopulmonary dysplasia (BPD) or death at 36 weeks' postmenstrual age without harm in extremely preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

Unmasked, randomized clinical trial (August 2014 to September 2017, with follow-up to February 15, 2018) conducted in 18 neonatal intensive care units in 9 countries. Preterm infants 23 to 26 weeks' gestational age requiring resuscitation with inadequate respiratory effort or bradycardia were enrolled. Planned enrollment was 600 infants. The trial was stopped after enrolling 426 infants, following a prespecified review of adverse outcomes.

INTERVENTIONS

The experimental intervention was up to 2 sustained inflations at maximal peak pressure of 25 cm H2O for 15 seconds using a T-piece and mask (n = 215); standard resuscitation was intermittent positive pressure ventilation (n = 211).

MAIN OUTCOME AND MEASURES

The primary outcome was the rate of BPD or death at 36 weeks' postmenstrual age. There were 27 prespecified secondary efficacy outcomes and 7 safety outcomes, including death at less than 48 hours.

RESULTS

Among 460 infants randomized (mean [SD] gestational age, 25.30 [0.97] weeks; 50.2% female), 426 infants (92.6%) completed the trial. In the sustained inflation group, 137 infants (63.7%) died or survived with BPD vs 125 infants (59.2%) in the standard resuscitation group (adjusted risk difference [aRD], 4.7% [95% CI, -3.8% to 13.1%]; P = .29). Death at less than 48 hours of age occurred in 16 infants (7.4%) in the sustained inflation group vs 3 infants (1.4%) in the standard resuscitation group (aRD, 5.6% [95% CI, 2.1% to 9.1%]; P = .002). Blinded adjudication detected an imbalance of rates of early death possibly attributable to resuscitation (sustained inflation: 11/16; standard resuscitation: 1/3). Of 27 secondary efficacy outcomes assessed by 36 weeks' postmenstrual age, 26 showed no significant difference between groups.

CONCLUSIONS AND RELEVANCE

Among extremely preterm infants requiring resuscitation at birth, a ventilation strategy involving 2 sustained inflations, compared with standard intermittent positive pressure ventilation, did not reduce the risk of BPD or death at 36 weeks' postmenstrual age. These findings do not support the use of ventilation with sustained inflations among extremely preterm infants, although early termination of the trial limits definitive conclusions.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02139800.

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.

Impact of delivered tidal volume on the occurrence of intraventricular haemorrhage in preterm infants during positive pressure ventilation in the delivery room

BACKGROUND AND OBJECTIVES

Delivery of inadvertent high tidal volume (V_T) during positive pressure ventilation (PPV) in the delivery room is common. High V_T delivery during PPV has been associated with haemodynamic brain injury in animal models. We examined if V_T delivery during PPV at birth is associated with brain injury in preterm infants <29 weeks' gestation.

METHODS

A flow-sensor was placed between the mask and the ventilation device. V_T values were compared with recently described reference ranges for V_T in spontaneously breathing preterm infants at birth. Infants were divided into two groups: V_T<6  mL/kg or V_T>6 mL/kg (normal and high V_T, respectively). Brain injury (eg, intraventricular haemorrhage (IVH)) was assessed using routine ultrasound imaging within the first days after birth.

RESULTS

A total of 165 preterm infants were included, 124 (75%) had high V_T and 41 (25%) normal V_T. The mean (SD) gestational age and birth weight in high and normal V_T group was similar, 26 (2) and 26 (1) weeks, 858 (251) g and 915 (250) g, respectively. IVH in the high V_T group was diagnosed in 63 (51%) infants compared with 5 (13%) infants in the normal V_T group (P=0.008).Severe IVH (grade III or IV) developed in 33/124 (27%) infants in the high V_T group and 2/41 (6%) in the normal V_T group (P=0.01).

CONCLUSIONS

High V_T delivery during mask PPV at birth was associated with brain injury. Strategies to limit V_T delivery during mask PPV should be used to prevent high V_T delivery.

Sustained inflations and avoiding mechanical ventilation to prevent death or bronchopulmonary dysplasia: a meta-analysis

Sustained inflations and avoidance of endotracheal mechanical ventilation (eMV) are delivery room interventions aimed at preventing bronchopulmonary dysplasia (BPD). Their effectiveness is the subject of the present meta-analysis.The databases MEDLINE, EMBASE and CENTRAL were searched for randomised controlled trials (RCTs) of preterm infants that compared: 1) sustained inflations with intermittent positive-pressure ventilation; and 2) a non-intubated strategy of respiratory support with one that prescribed eMV at an earlier stage. Data extraction and analysis followed the standard methods of the Cochrane Collaboration. The primary outcome was death or BPD, defined as need for oxygen or positive pressure treatment at 36 weeks' postmenstrual age.Avoiding eMV (nine RCTs, 3486 infants) reduced the risk of death or BPD, with a risk ratio of 0.90 (95% CI 0.84-0.97) and a number needed to treat of 35. After sustained inflations (six RCTs, 854 infants), the risk ratio was 0.85 (95% CI 0.65-1.12). A current multicentre RCT of sustained inflations in very preterm infants was halted for increased early mortality in the sustained inflations arm.While strategies aimed at avoiding eMV had a small but significant impact on preventing BPD, sustained inflations had no effect and may even increase mortality in very preterm infants.

Chest compression during sustained inflation versus 3:1 chest compression:ventilation ratio during neonatal cardiopulmonary resuscitation: a randomised feasibility trial

BACKGROUND

Current neonatal resuscitation guidelines recommend 3:1 compression:ventilation (C:V) ratio. Recently, animal studies reported that continuous chest compressions (CC) during a sustained inflation (SI) significantly improved return of spontaneous circulation (ROSC). The approach of CC during SI (CC+SI) has not been examined in the delivery room during neonatal resuscitation.

HYPOTHESIS

It is a feasibility study to compare CC+SI versus 3:1 C:V ratio during neonatal resuscitation in the delivery room. We hypothesised that during neonatal resuscitation, CC+SI will reduce the time to ROSC. Our aim was to examine if CC+SI reduces ROSC compared with 3:1 C:V CPR in preterm infants <33 weeks of gestation.

STUDY DESIGN

Randomised feasibility trial.

METHOD

Once CC was indicated all eligible infants were immediately and randomly allocated to either CC+SI group or 3:1 C:V group. A sequentially numbered, brown, sealed envelope contained a folded card box with the treatment allocation was opened by the clinical team at the start of CC.

STUDY INTERVENTIONS

Infants in the CC+SI group received CC at a rate of 90/min during an SI with a duration of 20 s (CC+SI). After 20 s, the SI was interrupted for 1 s and the next SI was started for another 20 s until ROSC. Infants in the '3:1 group' received CC using 3:1 C:V ratio until ROSC.

PRIMARY OUTCOME

Overall the mean (SD) time to ROSC was significantly shorter in the CC+SI group with 31 (9) s compared with 138 (72) s in the 3:1 C:V group (p=0.011).

CONCLUSION

CC+SI is feasible in the delivery room.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT02083705, pre-results.

Clinical aspects of incorporating cord clamping into stabilisation of preterm infants

Fetal to neonatal transition is characterised by major pulmonary and haemodynamic changes occurring in a short period of time. In the international neonatal resuscitation guidelines, comprehensive recommendations are available on supporting pulmonary transition and delaying clamping of the cord in preterm infants. Recent experimental studies demonstrated that the pulmonary and haemodynamic transition are intimately linked, could influence each other and that the timing of umbilical cord clamping should be incorporated into the respiratory stabilisation. We reviewed the current knowledge on how to incorporate cord clamping into stabilisation of preterm infants and the physiological-based cord clamping (PBCC) approach, with the infant's transitional status as key determinant of timing of cord clamping. This approach could result in optimal timing of cord clamping and has the potential to reduce major morbidities and mortality in preterm infants.

Sustained versus standard inflations during neonatal resuscitation to prevent mortality and improve respiratory outcomes

BACKGROUND

At birth, infants' lungs are fluid-filled. For newborns to have a successful transition, this fluid must be replaced by air to enable effective breathing. Some infants are judged to have inadequate breathing at birth and are resuscitated with positive pressure ventilation (PPV). Giving prolonged (sustained) inflations at the start of PPV may help clear lung fluid and establish gas volume within the lungs.

OBJECTIVES

To assess the efficacy of an initial sustained (> 1 second duration) lung inflation versus standard inflations (≤ 1 second) in newly born infants receiving resuscitation with intermittent PPV.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1), MEDLINE via PubMed (1966 to 17 February 2017), Embase (1980 to 17 February 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 17 February 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles to identify randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing initial sustained lung inflation (SLI) versus standard inflations given to infants receiving resuscitation with PPV at birth.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of included trials using Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria (assessing randomisation, blinding, loss to follow-up, and handling of outcome data). We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data and mean, standard deviation (SD), and weighted mean difference (WMD) for continuous data. We assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

MAIN RESULTS

Eight trials enrolling 941 infants met our inclusion criteria. Investigators in seven trials (932 infants) administered sustained inflation with no chest compressions. Use of sustained inflation had no impact on the primary outcomes of this review - mortality in the delivery room (typical RR 2.66, 95% confidence interval (CI) 0.11 to 63.40; participants = 479; studies = 5; I² not applicable) and mortality during hospitalisation (typical RR 1.01, 95% CI 0.67 to 1.51; participants = 932; studies = 7; I² = 19%); the quality of the evidence was low for death in the delivery room (limitations in study design and imprecision of estimates) and was moderate for death before discharge (limitations in study design of most included trials). Amongst secondary outcomes, duration of mechanical ventilation was shorter in the SLI group (mean difference (MD) -5.37 days, 95% CI -6.31 to -4.43; participants = 524; studies = 5; I² = 95%; low-quality evidence). Heterogeneity, statistical significance, and magnitude of effects of this outcome are largely influenced by a single study: When this study was removed from the analysis, the effect was largely reduced (MD -1.71 days, 95% CI -3.04 to -0.39, I² = 0%). Results revealed no differences in any of the other secondary outcomes (e.g. rate of endotracheal intubation outside the delivery room by 72 hours of age (typical RR 0.93, 95% CI 0.79 to 1.09; participants = 811; studies = 5; I² = 0%); need for surfactant administration during hospital admission (typical RR 0.97, 95% CI 0.86 to 1.10; participants = 932; studies = 7; I² = 0%); rate of chronic lung disease (typical RR 0.95, 95% CI 0.74 to 1.22; participants = 683; studies = 5; I² = 47%); pneumothorax (typical RR 1.44, 95% CI 0.76 to 2.72; studies = 6, 851 infants; I² = 26%); or rate of patent ductus arteriosus requiring pharmacological treatment (typical RR 1.08, 95% CI 0.90 to 1.30; studies = 6, 745 infants; I² = 36%). The quality of evidence for these secondary outcomes was moderate (limitations in study design of most included trials - GRADE) except for pneumothorax (low quality: limitations in study design and imprecision of estimates - GRADE).

AUTHORS' CONCLUSIONS

Sustained inflation was not better than intermittent ventilation for reducing mortality in the delivery room and during hospitalisation. The number of events across trials was limited, so differences cannot be excluded. When considering secondary outcomes, such as need for intubation, need for or duration of respiratory support, or bronchopulmonary dysplasia, we found no evidence of relevant benefit for sustained inflation over intermittent ventilation. The duration of mechanical ventilation was shortened in the SLI group. This result should be interpreted cautiously, as it can be influenced by study characteristics other than the intervention. Future RCTs should aim to enrol infants who are at higher risk of morbidity and mortality, should stratify participants by gestational age, and should provide more detailed monitoring of the procedure, including measurements of lung volume and presence of apnoea before or during the SLI.