New Australian Neonatal Resuscitation Guidelines

Aspects on Oxygenation in Preterm Infants before, Immediately after Birth, and Beyond

BACKGROUND

Oxygen is crucial for life but too little (hypoxia) or too much (hyperoxia) may be fatal or cause lifelong morbidity.

SUMMARY

In this review, we discuss the challenges of balancing oxygen control in preterm infants during fetal development, the first few minutes after birth, in the neonatal intensive care unit and after hospital discharge, where intensive care monitoring and response to dangerous oxygen levels is more often than not, out of reach with current technologies and services.

KEY MESSAGES

Appropriate oxygenation is critically important even from before birth, but at no time is the need to strike a balance more important than during the first few minutes after birth, when body physiology is changing at its most rapid pace. Preterm infants, in particular, have a poor control of oxygen balance. Underdeveloped organs, especially of the lungs, require supplemental oxygen to prevent hypoxia. However, they are also at risk of hyperoxia due to immature antioxidant defenses. Existing evidence demonstrate considerable challenges that need to be overcome before we can ensure safe treatment of preterm infants with one of the most commonly used drugs in newborn care, oxygen.

Stimulating and maintaining spontaneous breathing during transition of preterm infants

Most preterm infants breathe at birth, but need additional respiratory support due to immaturity of the lung and respiratory control mechanisms. To avoid lung injury, the focus of respiratory support has shifted from invasive towards non-invasive ventilation. However, applying effective non-invasive ventilation is difficult due to mask leak and airway obstruction. The larynx has been overlooked as one of the causes for obstruction, preventing face mask ventilation from inflating the lung. The larynx remains mostly closed at birth, only opening briefly during a spontaneous breath. Stimulating and supporting spontaneous breathing could enhance the success of non-invasive ventilation by ensuring that the larynx remains open. Maintaining adequate spontaneous breathing and thereby reducing the need for invasive ventilation is not only important directly after birth, but also in the first hours after admission to the NICU. Respiratory distress syndrome is an important cause of respiratory failure. Traditionally, treatment of RDS required intubation and mechanical ventilation to administer exogenous surfactant. However, new ways have been implemented to administer surfactant and preserve spontaneous breathing while maintaining non-invasive support. In this narrative review we aim to describe interventions focused on stimulation and maintenance of spontaneous breathing of preterm infants in the first hours after birth.

Oxygen saturation (SpO2) targeting for newborn infants at delivery: Are we reaching for an impossible unknown?

For more than 200 years, pure oxygen was given ad libitum to newborn infants requiring resuscitation. Due to oxidative stress and injury concerns, a paradigm shift towards using "less" oxygen, including air (21% oxygen) instead of pure (100%) oxygen, occurred about twenty years ago. A decade later, clinicians were advised to adjust fractional inspired oxygen (FiO₂) to target oxygen saturations (SpO₂) that were derived from spontaneously breathing, healthy, mature infants. Whether these recommendations are achievable, beneficial, harmful or redundant is uncertain. The underlying pathology leading to resuscitation varies between infants and may considerably alter an infant's response to supplemental oxygen. In this review, we summarize available evidence for the use of SpO₂ monitoring at delivery for newborn infants, elucidate existing knowledge and service gaps, and suggest future research recommendations that will lead to the safest clinical strategies for this standard and important practice.

Trends in neonatal resuscitation patterns in Queensland, Australia - A 10-year retrospective cohort study

OBJECTIVES

To describe the frequency of neonatal resuscitation interventions implemented for newborn babies in the state of Queensland over a 10-year period and determine if these changes suggest adherence to changes in Australian guidelines.

STUDY DESIGN

A population-based retrospective cohort study utilising the Queensland Perinatal Data Collection dataset. All liveborn babies ≥23 + 0 weeks + days gestation born between 1 July 2007 and 30 June 2017 were included except those for whom resuscitation was not attempted and those babies <25 + 0 weeks for whom it was unsuccessful. Trends in resuscitation were demonstrated using Loess regression.

RESULTS

Of 618,589 eligible newborns,182,260 received any resuscitation manoeuvre (29.5%). The proportion receiving oxygen without assisted ventilation declined from 19.3% in 2007-08 to 5.6% in 2016-17. Upper airway suctioning also decreased. Assisted ventilation increased from 7.9% to 10.0% of all babies with the largest contribution from late preterm and term babies. The rate of endotracheal suctioning for meconium and the rate of narcotic antagonist use also declined. A greater proportion of babies received chest compressions (1.9-3.2 per 1000 babies) and adrenaline (epinephrine). Mortality decreased from 1.9 to 1.5 per 1000 babies in the cohort.

CONCLUSION

Ten-year trends showed reduced use of oxygen or upper airway suctioning without assisted ventilation, reduced intubation to suction meconium, reduced use of narcotic antagonists and greater use of assisted ventilation suggesting appropriate practice change in response to Australian neonatal resuscitation guidelines. The increase in the use of chest compressions and adrenaline was unexpected and the reasons for it are unclear.

Have the 2015 Neonatal Resuscitation Program Guidelines changed the management and outcome of infants born through meconium-stained amniotic fluid?

BACKGROUND

In 2015, the Neonatal Resuscitation Program (NRP) guidelines were updated to recommend that nonvigorous infants delivered through meconium-stained amniotic fluid (MSAF) do not require routine intubation and tracheal suction.

OBJECTIVE

Explore the implications of 2015 NRP guidelines on delivery room management and outcome of infants born through MSAF.

DESIGN

Retrospective cohort study.

SETTINGS

King Abdul-Aziz University Hospital (KAUH).

PATIENTS AND METHODS

All term ( greater than or equal 37 weeks) infants born in KAUH through MSAF between January 1, 2016, and December 31, 2017, were included. Patients were divided into two groups according to the date of birth: period 1 (January 1, 2016, to December 31, 2016), before the implementation of the new NRP guidelines; period 2 (January 1, 2017, to December 31, 2017), after the implementation.

MAIN OUTCOME MEASURES

Outcomes of infants born through MSAF.

SAMPLE SIZE

420 infants.

RESULTS

A majority of infants (n=261) were born in period 1 and 159 after in period 2. No differences were found in the booking status of mothers, cesarean section rate, and number of deliveries attended by physicians between the 2 cohorts. Infants in both cohorts were of similar gestational age, birth weight, and gender. A nonsignificant lower rate of intubation at birth (2.3% vs 0.6%), admission to neonatal intensive care unit (3.8% vs 3.1%), and meconium aspiration syndrome (1.5% vs 0.6%) were found in period 2 compared with period 1. Only 1 infant died in period 1.

CONCLUSION

After the implementation of 2015 NRP guidelines, fewer infants were intubated at birth for MSAF. No difference was observed in the rate of associated morbidities and mortality.

LIMITATIONS

A single-center retrospective study of misclassification bias because some of the medical staff started practicing the new guidelines before the official implementation.

CONFLICT OF INTEREST

None.

Improving pregnancy outcomes in humans through studies in sheep

Experimental studies that are relevant to human pregnancy rely on the selection of appropriate animal models as an important element in experimental design. Consideration of the strengths and weaknesses of any animal model of human disease is fundamental to effective and meaningful translation of preclinical research. Studies in sheep have made significant contributions to our understanding of the normal and abnormal development of the fetus. As a model of human pregnancy, studies in sheep have enabled scientists and clinicians to answer questions about the etiology and treatment of poor maternal, placental, and fetal health and to provide an evidence base for translation of interventions to the clinic. The aim of this review is to highlight the advances in perinatal human medicine that have been achieved following translation of research using the pregnant sheep and fetus.

Outcomes of oxygen saturation targeting during delivery room stabilisation of preterm infants

OBJECTIVE

To determine the association between SpO₂ at 5 min and preterm infant outcomes.

DESIGN

Data from 768 infants <32 weeks gestation from 8 randomised controlled trials (RCTs) of lower (≤0.3) versus higher (≥0.6) initial inspiratory fractions of oxygen (FiO₂) for resuscitation, were examined.

SETTING

Individual patient analysis of 8 RCTs INTERVENTIONS: Lower (≤0.3) versus higher (≥0.6) oxygen resuscitation strategies targeted to specific predefined SpO₂ before 10 min of age.

PATIENTS

Infants <32 weeks gestation.

MAIN OUTCOME MEASURES

Relationship between SpO₂ at 5 min, death and intraventricular haemorrhage (IVH) >grade 3.

RESULTS

5 min SpO₂ data were obtained from 706 (92%) infants. Only 159 (23%) infants met SpO₂ study targets and 323 (46%) did not reach SpO₂80%. Pooled data showed decreased likelihood of reaching SpO₂80% if resuscitation was initiated with FiO₂ <0.3 (OR 2.63, 95% CI 1.21 to 5.74, p<0.05). SpO₂ <80% was associated with lower heart rates (mean difference -8.37, 95% CI -15.73 to -1.01, *p<0.05) and after accounting for confounders, with IVH (OR 2.04, 95% CI 1.01 to 4.11, p<0.05). Bradycardia (heart rate <100 bpm) at 5 min increased risk of death (OR 4.57, 95% CI 1.62 to 13.98, p<0.05). Taking into account confounders including gestation, birth weight and 5 min bradycardia, risk of death was significantly increased with time taken to reach SpO₂80%.

CONCLUSION

Not reaching SpO₂80% at 5 min is associated with adverse outcomes, including IVH. Whether this is because of infant illness or the amount of oxygen that is administered during stabilisation is uncertain and needs to be examined in randomised trials.

Oxygen and preterm infant resuscitation: what else do we need to know?

PURPOSE OF REVIEW

To evaluate current evidence for the use of lower or higher oxygen strategies for preterm infant resuscitation RECENT FINDINGS: The equipoise for using higher fraction of inspired oxygen (FiO2) (>0.4) to initiate preterm infant respiratory stabilization has been lost. Recent meta-analyses of randomized controlled trials assessing outcomes after using higher (FiO2 ≥ 0.6) vs. lower (FiO2 ≤ 0.3) oxygen strategies to initiate preterm resuscitation shows no difference in the rates of death or major morbidities. However, not achieving pulse oximetry saturations of at least 80% by 5 min of age, whether it was due to iatrogenic oxygen insufficiency or poor infant pulmonary function, was associated with lower heart rates (mean difference -8.37, 95% confidence interval: -15.73, -1.01) and major intraventricular hemorrhage. There remains scarce neurodevelopmental data in this area and information about the impact of oxygen targeting strategies in low resourced areas. These knowledge gaps are research priorities that must be addressed in large, well designed randomized controlled trials.

SUMMARY

Most clinicians now use lower oxygen strategies to initiate respiratory support for all infants, including preterm infants with significant lung disease. However, the impact of such strategies, particularly for neurodevelopmental outcomes and for lower resourced areas, remains uncertain and must be urgently addressed.

Repetitive versus standard tactile stimulation of preterm infants at birth - A randomized controlled trial

AIM

To evaluate the direct effect of repetitive tactile stimulation on breathing effort of preterm infants at birth.

METHODS

This randomized controlled trial compared the effect of repetitive stimulation on respiratory effort during the first 4 min after birth with standard stimulation based on clinical indication in preterm infants with a gestational age of 27-32 weeks. All details of the stimulation performed were noted. The main study parameter measured was respiratory minute volume, other study parameters assessed measures of respiratory effort; tidal volumes, rate of rise to maximum tidal volumes, percentage of recruitment breaths, and oxygenation of the infant.

RESULTS

There was no significant difference in respiratory minute volume in the repetitive stimulation group when compared to the standard group. Oxygen saturation was significantly higher (87.6 ± 3.3% vs 81.7 ± 8.7%, p = .01) while the amount of FiO₂ given during transport to the NICU was lower (28.2 (22.8-35.0)% vs 33.6 (29.4-44.1)%, p = .04). There was no significant difference in administration of positive pressure ventilation (52% vs 78%, p = .13), or the duration of ventilation (median (IQR) time 8 (0-118)s vs 35 (13-131)s, p = .23). Caregivers decided less often to administer caffeine in the delivery room to stimulate breathing in the repetitive stimulation group (10% vs 39%, p = .036).

CONCLUSION

Although the increase in respiratory effort during repetitive stimulation did not reach significance, oxygenation significantly improved with a lower level of FiO₂ at transport to the NICU. Repetitive tactile stimulation could be of added value to improve breathing effort at birth.

A review of international clinical practice guidelines for the use of oxygen in the delivery room resuscitation of preterm infants

AIM

To collate and assess international clinical practice guidelines (CPG) to determine current recommendations guiding oxygen management for respiratory stabilisation of preterm infants at delivery.

METHODS

A search of public databases using the terms 'clinical practice guidelines', 'preterm', 'oxygen' and 'resuscitation' was made and complemented by direct query to consensus groups, resuscitation expert committees and clinicians. Data were extracted to include the three criteria for assessment: country of origin, gestation and initial FiO₂ and target SpO₂ for the first 10 minutes of life.

RESULTS

A total of 45 CPGs were identified: 36 provided gestation specific recommendations (<28 to <37 weeks) while eight distinguished only between 'preterm' and 'term'. The most frequently recommended initial FiO₂ were between 0.21 and 0.3 (n = 17). Most countries suggested altering FiO₂ to meet SpO₂ targets recommended by expert committees, However, specific five-minute SpO₂ targets differed by up to 20% (70-90%) between guidelines. Five countries did not specify SpO₂ targets.

CONCLUSION

CPG recommendations for delivery room oxygen management of preterm infants vary greatly, particularly in regard to gestational ages, initial FiO₂ and SpO₂ targets and most acknowledge the lack of evidence behind these recommendations. Sufficiently large and well-designed randomised studies are needed to inform on this important practice.

Australian and New Zealand Committee on Resuscitation Neonatal Resuscitation guidelines 2016

New Australian and New Zealand Neonatal Resuscitation guidelines reflect recent advances in neonatal resuscitation science, as critically appraised by the International Liaison Committee on Resuscitation. Substantial changes since the 2010 guidelines include: (i) updates to the Newborn Resuscitation Flowchart to include a greater emphasis on maintaining normal body temperature, and to emphasise the importance of beginning assisted ventilation by 1 min in infants who have absent or ineffective spontaneous breathing; (ii) updates to the physiology of the normal perinatal transition that resuscitation is trying to restore; (iii) recommendations for more frequent reinforcement of training, and for structured feedback for resuscitation training instructors; (iv) new guidance in relation to the timing of cord clamping for preterm newborn infants; (v) recommendation to monitor body temperature on admission to newborn units as a resuscitation quality indicator; (vi) suggestion to consider electrocardiographic (ECG) monitoring (as an adjunct to oximetry) to obtain more rapid and accurate estimation of heart rate during resuscitation; (vii) removal of previous suggestions to intubate meconium-exposed, non-vigorous term infants to suction the trachea; and (viii) suggestion to establish vascular access to enable administration of intravenous adrenaline (epinephrine) as soon as chest compressions are deemed to be needed.

Tactile Stimulation to Stimulate Spontaneous Breathing during Stabilization of Preterm Infants at Birth: A Retrospective Analysis

BACKGROUND AND AIMS

Tactile maneuvers to stimulate breathing in preterm infants are recommended during the initial assessment at birth, but it is not known how often and how this is applied. We evaluated the occurrence and patterns of tactile stimulation during stabilization of preterm infants at birth.

METHODS

Recordings of physiological parameters and videos of infants <32 weeks gestational age were retrospectively analyzed. Details of tactile stimulation during the first 7 min after birth (timing, duration, type, and indication) were noted.

RESULTS

Stimulation was performed in 164/245 (67%) infants. The median (IQR) GA was 28 6/7 (27 2/7-30 1/7) weeks, birth weight 1,153 (880-1,385) g, Apgar score at 5 min was 8 (7-9), 140/245 (57%) infants were born after cesarean section, and 134/245 (55%) were male. There were no significant differences between the stimulated and the non-stimulated infants with regard to basic characteristics. In the stimulated infants, the first episode of stimulation was given at a median (IQR) of 114 (73-182) s after birth. Stimulation was repeated 3 (1-5) times, with a median (IQR) duration of 8 (4-16) s and a total duration of 32 (15-64) s. Modes of stimulation were: rubbing (68%) or flicking (2%) the soles of the feet, rubbing the back (12%), a combination (9%), or other (8%). In 67% of the stimulation episodes, a clear indication was noted (25% bradycardia, 57% apnea, 48% hypoxemia, 43% combination) and an effect was observed in 18% of these indicated stimulation episodes. A total effect of all stimulation episodes per infant remains unclear, but infants who did not receive stimulation were more often intubated in the delivery room (14/79 (18%) vs 12/164 (7%), p < 0.05).

CONCLUSION

There was a large variation in the use of tactile stimulation in preterm infants during stabilization at birth. In most cases, there was an indication for stimulation, but only in a small proportion an effect could be observed.

Targeted Oxygen in the Resuscitation of Preterm Infants, a Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

Lower concentrations of oxygen (O₂) (≤30%) are recommended for preterm resuscitation to avoid oxidative injury and cerebral ischemia. Effects on long-term outcomes are uncertain. We aimed to determine the effects of using room air (RA) or 100% O₂ on the combined risk of death and disability at 2 years in infants <32 weeks' gestation.

METHODS

A randomized, unmasked study designed to determine major disability and death at 2 years in infants <32 weeks' gestation after delivery room resuscitation was initiated with either RA or 100% O₂ and which were adjusted to target pulse oximetry of 65% to 95% at 5 minutes and 85% to 95% until NICU admission.

RESULTS

Of 6291 eligible patients, 292 were recruited and 287 (mean gestation: 28.9 weeks) were included in the analysis (RA: n = 144; 100% O₂: n = 143). Recruitment ceased in June 2014, per the recommendations of the Data and Safety Monitoring Committee owing to loss of equipoise for the use of 100% O₂. In non-prespecified analyses, infants <28 weeks who received RA resuscitation had higher hospital mortality (RA: 10 of 46 [22%]; than those given 100% O₂: 3 of 54 [6%]; risk ratio: 3.9 [95% confidence interval: 1.1-13.4]; P = .01). Respiratory failure was the most common cause of death (n = 13).

CONCLUSIONS

Using RA to initiate resuscitation was associated with an increased risk of death in infants <28 weeks' gestation. This study was not a prespecified analysis, and it was underpowered to address this post hoc hypothesis reliably. Additional data are needed.

Endotracheal suction in term non vigorous meconium stained neonates-A pilot study

AIM

To evaluate the effect of 'No endotracheal suction' on occurrence of meconium aspiration syndrome (MAS) and/or all-cause mortality in non-vigorous neonates born through meconium stained amniotic fluid (MSAF).

METHODS

This pilot randomized controlled trial enrolled term non-vigorous neonates (≥37 weeks) born through MSAF. Neonates randomized to 'No Endotracheal suction group' ('No ET' Group; n=88) did not undergo endotracheal suction before the definitive steps of resuscitation. Neonates randomized to 'Endotracheal suction group' ('ET' Group; n=87) underwent tracheal suction as part of the initial steps as per the current NRP recommendations. The primary outcome was occurrence of MAS and/or death. Secondary outcome variables were duration and severity of respiratory distress, need for respiratory support, development of hypoxic ischemic encephalopathy (HIE) and duration of oxygen therapy and hospitalization.

RESULTS

Baseline characters including birth weight and gestational age were similar between the two groups. MAS was present in 23 (26.1%) vs. 28 (32.2%) neonates in 'No ET' and 'ET' groups respectively (OR 0.4 (0.12-1.4); p=0.14) with 4 (4.6%) and 9 (10.34%) deaths amongst these neonates with MAS in respective groups (OR 0.75 (0.62-1.2); p=0.38). Other parameters like severity and duration of respiratory distress, need for respiratory support, incidence of HIE, duration of oxygen therapy and duration of hospitalization were comparable.

CONCLUSION

This study demonstrates that it is feasible to randomize non-vigorous infants born through meconium stained liquor to receive on not receive endotracheal suction. There is a need for a multi-center trial to address whether the current practices and guidelines can be justified.

A randomized trial of stylets for intubating newborn infants

OBJECTIVE

Endotracheal intubation of newborn infants is a common and potentially lifesaving procedure but a skill that trainees find difficult. Despite widespread use, no data are available on whether the use of a stylet (introducer) improves success rates. We aimed to determine whether pediatric trainees were more successful at neonatal orotracheal intubation when a stylet was used.

METHODS

An unblinded randomized controlled trial conducted between July 2006 and January 2009 at a tertiary perinatal center, the Royal Women's Hospital, Melbourne, Australia. Eligible participants were newborn infants in the delivery room or NICU requiring endotracheal intubation for respiratory support. Infants were intubated by pediatric residents or fellows. Infants were randomized to have the procedure performed by using either an endotracheal tube alone or with a stylet. Successful intubation at the first attempt assessed by colorimetric detection of expired carbon dioxide was the primary outcome.

RESULTS

Three hundred two intubations were performed in 232 infants (residents performed 75%, fellows 25%). Intubation was successful in 57% of the stylet group and 53% of the no stylet group (P = .47); odds ratio 1.18 (95% confidence interval 0.75-1.86). There were no differences in the duration of attempts or in the rate of upper airway trauma between the 2 groups. These results were consistent across subgroups of infants based on birth weight, gestational age, and site of intubation (delivery room or NICU).

CONCLUSIONS

Using an endotracheal stylet did not significantly improve the success rate of pediatric trainees at neonatal orotracheal intubation.

Use of oxygen for delivery room neonatal resuscitation in non-tertiary Australian and New Zealand hospitals: a survey of current practices, opinions and equipment

BACKGROUND

Delivery room resuscitation of hypoxic newborn infants with pure or 100% oxygen causes oxidative toxicity and increases mortality. Current international resuscitation guidelines therefore recommend that oxygen be used judiciously. However, this requires staff education and special equipment that may not be available in non-tertiary maternity hospitals where the majority of births occur.

AIM

To determine current attitudes, practices and available equipment for the use of air and blended oxygen for newborn delivery room resuscitation in non-tertiary maternity hospitals of Australia and New Zealand (ANZ).

METHODS

Structured questionnaires sent by mail and e-mail after personal phone contact. A total of 203 eligible hospitals in ANZ were identified. A second mailing was conducted a month later for non-responders. RESPONDERS: Final response rate was 64% (n= 130: 70% physicians, 30% midwives). The majority (121, 93%) of respondents were aware of Australian Resuscitation Council recommendations, but only one in five hospitals had the capacity to deliver blended oxygen and 38% used pulse oximeters at delivery. Only 24 (18.5%) hospitals had guidelines. Air would be used by 68 (57%) hospitals to resuscitate term infants compared to 35 (31%) for preterm infants. Most (111, 91%) advocated the use of blended oxygen despite the lack of facilities.

CONCLUSION

Only one in five ANZ non-tertiary maternity hospitals had the capacity to resuscitate newborn infants with air or blended oxygen. Most are aware of current recommendations and agreed that the use of less oxygen would be beneficial for this purpose. Further study into the necessary infrastructure required to implement these guidelines are recommended.

Targeted oxygen therapy in special care nurseries: is uniformity a good thing?

AIM

There is wide variation in the commencement of inspired oxygen (FiO2) and the oxygen saturation (SpO(2) ) targets set in special care nurseries (SCNs). Evidence supports minimising unnecessary oxygen exposure. Does the introduction of a protocol advocating the uniform approach of commencing FiO2 at 30% and targeting SpO2 of 94-96% for infants ≥ 33 weeks gestation with respiratory distress reduce oxygen exposure?

METHODS

A 'Before After' study was undertaken in three SCNs. Data were recorded for all infants admitted to the SCNs who required oxygen over a 3-year period. Infants were analysed in gestational age groups: 33-36 weeks (late preterm) and +37 weeks (term/post-term).

RESULTS

Of the 19,830 infants born, 868 (4%) were treated with oxygen. The introduction of an oxygen-targeting protocol resulted in a statistically and clinically significant reduction in the proportion of infants who were treated with any oxygen for 1 h or more, 4 h or more and in the proportion who received >30% FiO2 for 1 h or more (all P ≤ 0.01). This reduction was significant for infants of both gestational age groups. The median duration of oxygen for term/post-term infants was reduced from 12 h pre-protocol to 10 h post-protocol (P= 0.01); however, no significant difference was found for the preterm group (reduced from 11 to 8 h, P= 0.07).

CONCLUSION

Introduction of a uniform oxygen protocol in SCNs for infants ≥ 33 weeks gestation with respiratory distress reduces the number of infants receiving oxygen and, in term infants, the duration of oxygen exposure.

Low versus high gas flow rate for respiratory support of infants at birth: a manikin study

BACKGROUND

Neonatal resuscitation guidelines do not specify the gas flow rate during mask ventilation.

AIM

Investigating the effect of gas flow rates on pressures, volumes delivered and mask leak.

METHODS

Flow 5 and 10 liters/min were tested. In study part 1, pressure ranges were measured when ventilating an intubated manikin with a Neopuff®. In study part 2, pediatric staff mask-ventilated a manikin (peak inflation pressure (PIP) 30 cm H(2)O, positive end expiratory pressure (PEEP) 5 cm H(2)O). We measured pressures, expired tidal volume (V(Te)) and mask leak.

RESULTS

Study part 1:an intubated manikin was ventilated with flow 5 versus 10 liters/min: range in PEEP was 0.4-3.6 and 2-14 cm H(2)O, respectively, maximum PIP was 73 cm H(2)O with both flow rates. Study part 2: when mask ventilation was given with flow 5 versus 10 liters/min: leak decreased (24% (8-85) vs. 80% (34- 94); p < 0.0001), V(Te) increased (6.7 (5.1-7.8) vs. 4.7 (2.4-7.0) ml; p < 0.001), PEEP decreased (3.1 (0.8) vs. 3.7 (0.7) cm H(2)O; p < 0.001), PIP was similar (28.1 (2.7) vs. 28.0 (2.3) cm H(2)O; NS). Large leaks decreased V(Te) and PEEP during both flow rates, PIP only with flow 5 liters/min.

CONCLUSION

A low flow rate during neonatal mask ventilation may be a good alternative approach in reducing mask leak, provided that inflation time and flow rate warrants set pressures. Only large leaks seem to influence delivered pressures and volumes. Before resuscitation guidelines are advised, more studies on gas flow rates are needed.

Variability in the assessment of 'adequate' chest excursion during simulated neonatal resuscitation

BACKGROUND

International neonatal resuscitation guidelines recommend assessing chest excursion when the heart rate is not improving. However, the accuracy in assessing 'adequate' chest excursion lacks objectivity.

AIM

It was the aim of this study to test the accuracy in the assessment of 'adequate' chest excursion by measuring intra- and inter-observer variability of participants during simulated neonatal resuscitation.

METHODS

Thirty-seven staff members (8 neonatologists, 8 registrars, 21 nurses) of the Neonatal Intensive Care Unit, Leiden University Medical Center, Leiden, The Netherlands, ventilated 2 different intubated, leak-free manikins at 2 attempts, each with a different compliance. Blinded to the manometer, participants could change the peak inflation pressure until chest movement was adequate according to their perception. Inflating pressures were recorded.

RESULTS

According to the participants, a median (interquartile range) pressure of 18 cm H2O (16-22) at the first and 18 cm H2O (16-25) at the second attempt were needed to reach adequate chest excursion in the Laerdal manikin. The HAL manikin needed 26 cm H2O (19-31) and 24 cm H2O (22-33), respectively. The inter-observer coefficient of variance was 30% with the Laerdal manikin at both attempts, and 35 and 40% with the HAL manikin, respectively. The intra-observer coefficient of variance was 15% (8-23) with the Laerdal and 13% (9-20) with the HAL manikin. In both manikins and attempts, no significant differences in pressures and variances of pressures between the 3 groups were found.

CONCLUSION

'Adequate' chest excursion is a subjective parameter for guidance of appropriate ventilation during neonatal resuscitation.

Clinical assessment of extremely premature infants in the delivery room is a poor predictor of survival

BACKGROUND

Some neonatologists state that at the delivery of extremely premature infants they rely on "how the baby looks" when deciding whether to initiate resuscitation. Previous studies have reported poor correlation between early clinical signs and prognosis.

OBJECTIVE

To determine if neonatologists can accurately predict survival to discharge of extremely premature infants on the basis of observations in the first minutes after birth.

METHODS

We showed videos of the resuscitation of 10 extremely premature infants (<26 weeks' gestation) to attending neonatologists and fellows from the 3 major perinatal centers in Melbourne, Australia. Antenatal information was available to the observers. A monitor visible in each video displayed the heart rate and oxygen saturation of the infant. Observers were asked to estimate the likelihood of survival to discharge for each infant at 3 time points: 20 seconds, 2 minutes, and 5 minutes after birth. The predictive ability of observers was expressed as the area (95% confidence interval [CI]) under the receiver-operating-characteristic curve.

RESULTS

Seventeen attending neonatologists and 17 neonatal fellows completed the study. Receiver-operating-characteristic curves were generated for the combined and individual groups. Observers' ability to predict survival was poor (combined results): 0.61 (95% CI: 0.54-0.67) at 20 seconds, 0.59 (95% CI: 0.52-0.64) at 2 minutes, and 0.61 (95% CI: 0.55-0.67) at 5 minutes. Level of experience did not affect the observers' accuracy of predicting survival.

CONCLUSION

Neonatologists' reliance on initial appearance and early response to resuscitation in predicting survival for extremely premature infants is misplaced.

Establishing functional residual capacity at birth: the effect of sustained inflation and positive end-expiratory pressure in a preterm rabbit model

The effect of a 20 s sustained inflation (SI) and positive end-expiratory pressure (PEEP) on functional residual capacity (FRC) formation at birth were investigated. Preterm rabbit pups (28 d) were randomized at birth into four groups (n = 6 for each): 1) SI, PEEP 5 cm H2O, 2) no SI, PEEP 5 cm H2O, 3) no SI + no PEEP, 4) SI + no PEEP. FRC and tidal volume (Vt) were measured by plethysmography and uniformity of lung aeration by phase contrast x-ray imaging. Ventilation with a SI and PEEP uniformly aerated the lung and Vt and FRC were recruited by the first tidal inflation. Ventilation without a SI, with PEEP, gradually recruited Vt and FRC with each inflation but aeration was not uniform. Ventilation without a SI or PEEP, gradually recruited Vt, but no FRC. Ventilation with a SI, without PEEP, uniformly aerated the lung and recruited Vt but no FRC. FRC was greater with SI (p = 0.006) during the first minute, but was larger with PEEP than without PEEP throughout the first 7 min (p < 0.0005). Effects of PEEP and SI were additive. In ventilated preterm rabbits at birth, combining a SI and PEEP improved FRC formation and uniformity of lung aeration, but PEEP had the greatest influence.

Breathing patterns in preterm and term infants immediately after birth

There is limited data describing how preterm and term infants breathe spontaneously immediately after birth. We studied spontaneously breathing infants >or=29 wk immediately after birth. Airway flow and tidal volume were measured for 90 s using a hot wire anemometer attached to a facemask. Twelve preterm and 13 term infants had recordings suitable for analysis. The median (interquartile range) proportion of expiratory braking was very high in both groups (preterm 90 [74-99] vs. term 87 [74-94]%; NS). Crying pattern was the predominant breathing pattern for both groups (62 [36-77]% vs. 64 [46-79]%; NS). Preterm infants showed a higher incidence of expiratory hold pattern (9 [4-17]% vs. 2 [0-6]%; p = 0.02). Both groups had large tidal volumes (6.7 [3.9] vs. 6.5 [4.1] mL/kg), high peak inspiratory flows (5.7 [3.8] vs. 8.0 [5] L/min), lower peak expiratory flow (3.6 [2.4] vs. 4.8 [3.2] L/min), short inspiration time (0.31 [0.13] vs. 0.32 [0.16] s) and long expiration time (0.93 [0.64] vs. 1.14 [0.86] s). Directly after birth, both preterm and term infants frequently brake their expiration, mostly by crying. Preterm infants use significantly more expiratory breath holds to defend their lung volume.

Ventilation and spontaneous breathing at birth of infants with congenital diaphragmatic hernia

OBJECTIVE

To describe the interaction of spontaneous breaths, manual ventilation, and tidal volumes (V(T)) during stabilization of infants with congenital diaphragmatic hernia (CDH) in the delivery room.

STUDY DESIGN

We studied infants with CDH receiving respiratory support at birth. Airway pressure, flow, and volume were measured, and each breath or inflation was analyzed. Each V(T) was classified as a manual inflation, a spontaneous breath, or a spontaneous breath coinciding with manual inflation on the basis of the timing of the pressure and flow waves.

RESULTS

Twelve infants had 2957 breaths suitable for analysis, with spontaneous breathing in 11 infants (92%). The mean (+/-SD) proportion of manual inflations was 41% (+/-24%), spontaneous breaths 43% (+/-25%), spontaneous but coinciding with manual inflation 16% (+/-12%). V(T) was significantly different for spontaneous breaths (3.8 +/- 1.9 mL/kg), spontaneous breaths coinciding with manual inflation (4.7 +/- 2.5 mL/kg), and manual inflations alone (2.6 +/- 1.6 mL/kg).

CONCLUSIONS

Most infants with CDH breathed spontaneously, and manual ventilation was mostly asynchronous. We observed large differences in tidal volumes between spontaneous breaths, manual inflations, or where these coincided, with manual inflations having the lowest V(T). Monitoring the respiratory pattern of these infants could improve respiratory support.

Use of oxygen in the resuscitation of preterm infants: current opinion and practice in Australia and New Zealand

AIM

The aim of this paper was to explore the opinions and practices of tertiary health-care professionals in Australia and New Zealand regarding air and oxygen blending (OB) for the resuscitation of preterm infants.

METHODS

Structured questionnaires were sent to the directors of 25 tertiary perinatal units, with instructions to distribute the questionnaires to 15 pertinent clinical staff.

RESULTS

Response rate was 72% (n = 271); medical-staff response was 25%. Sixteen (64%) perinatal units had OB resuscitation equipment. Among respondents, 114 (42%) had access to OB and 73 (27%) had OB for all resuscitations. Pulse oximetry was available to 160 (59%) of respondents. The majority (173, 64%) would initiate resuscitation with Fractional inspired oxygen (FiO(2)) ranging from 0.3 to 0.9 (mean 0.5), with 15% and 21% preferring air and 100% oxygen, respectively. There were large variations in managing FiO(2) changes thereafter. Half of the respondents were either unsure (39%) or not convinced (15%) that 100% oxygen during resuscitation would cause harm. Conversely, 42% suggested that OB might improve outcome with bronchopulmonary dysplasia and retinopathy of prematurity being the most important considerations. Most (92%) would advocate for OB in the delivery suite. Set-up cost (50%) and lack of guided experience (38%) ranked highest as barriers to change.

CONCLUSIONS

Two-thirds of the tertiary centres have at least some OB equipment in the delivery suite, but the ways and opinions in which OB is utilised differ widely. Most practitioners would advocate for a change. There is an urgent need for further research to achieve a consistent and meaningful clinical management for OB resuscitation of preterm infants.

Neonatal resuscitation--an analysis of the transatlantic divide

AIM

To highlight the main differences between the current editions of the Newborn Life Support (NLS; Resuscitation Council, UK) and the Neonatal Resuscitation Program (NRP; American Academy of Pediatrics and American Heart Association), and to analyse differences between the evidence underlying NLS and NRP.

MATERIAL AND METHODS

We undertook a detailed comparison of recommendations and references, based on the NLS and the NRP provider course manuals issued in 2006. Literature on neonatal resuscitation, published in 2005 and thereafter, was searched, focusing on controversies between NLS and NRP.

RESULTS

A multitude of important differences between NLS and NRP have been reaffirmed in their current editions, leading to conflicting messages regarding many aspects of resuscitation. An incongruent selection of evidence appears to be a major factor accounting for this divergence.

CONCLUSION

To avoid confusion among health care providers and to support the credibility of both NLS and NRP, an intensified dialogue and a more congruent evidence base between NRP and NLS is required. Mutual recognition of equivalency appears unrealistic until substantial progress in this direction has been achieved.