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

Lung-protective ventilation in the management of congenital diaphragmatic hernia

Prioritizing lung-protective ventilation has produced a clear mortality benefit in neonates with congenital diaphragmatic hernia (CDH). While there is a paucity of CDH-specific evidence to support any particular approach to lung-protective ventilation, a growing body of data in adults is beginning to clarify the mechanisms behind ventilator-induced lung injury and inform safer management of mechanical ventilation in general. This review summarizes the adult data and attempts to relate the findings, conceptually, to the CDH population. Critical lessons from the adult studies are that much of the damage done during conventional mechanical ventilation affects normal lung tissue and that most of this damage occurs at the low-volume and high-volume extremes of the respiratory cycle. Consequently, it is important to prevent atelectasis by using sufficient positive end-expiratory pressure while also avoiding overdistention by scaling tidal volume to the amount of functional lung tissue rather than body weight. Paralysis early in acute respiratory distress syndrome improves outcomes, possibly because consistent respiratory mechanics facilitate avoidance of both atelectasis and overdistention-a mechanism that may also apply to the CDH population. Volume-targeted conventional modes may be advantageous in CDH, but determining optimal tidal volume is challenging. Both high-frequency oscillatory ventilation and high-frequency jet ventilation have been used successfully as 'rescue modes' to avoid extracorporeal membrane oxygenation, and a prospective trial comparing the two high-frequency modalities as the primary ventilation strategy for CDH is underway.

Ventilation practices in the neonatal intensive care units in Saudi Arabia, survey of the utilization of volume-targeted ventilation among practicing neonatologists

OBJECTIVE

To assess the current practice in using volume-targeted ventilation among neonatologists working at the Neonatal Intensive Care Units (NICU) of Saudi Arabia.

METHODS

The questionnaire was provided electronically to 153 practicing Neonatologists working in 39 NICUs. The survey's results were received and statistically analyzed.

RESULTS

One hundred nineteen (119) responses were received with, a 78% response rate. Volume Targeted Ventilation (VTV) was used routinely by 67.2%, whereas 21.8% still use only pressure control (PC)/pressure limited (PL) mode. During the acute phase of ventilation support, Assist Control was the most popular synchronized mode, whereas Synchronized Intermittent Mandatory Ventilation (SIMV) with pressure support (PS) or PSV were the two most common modes during the weaning phase, 31.8%, and 31% respectively. The majority of the neonatologists used a tidal volume of 4 ml/kg as the lowest and 6 ml/kg as the highest. The major reasons for not implementing VTV were the limited availability of ventilator devices that have an option of VTV, followed by lack of experience.

CONCLUSION

VTV is the predominant ventilation practice approach among neonatologists working in the KSA. Limited availability and lack of experience in using are the main challenges. Efforts to equip NICUs with the most advanced ventilation technology, enhance practitioners' experience and sufficient training in its use are warranted.

Delivery Room Resuscitation of Infants with Congenital Diaphragmatic Hernia: Lessons Learned through Video Review

INTRODUCTION

Delivery room (DR) interventions for infants with congenital diaphragmatic hernia (CDH) are not well described. This study sought to describe timing and order of DR interventions and identify system factors impacting CDH DR resuscitations using a human factors framework.

METHODS

Single center observational study of video recorded CDH DR resuscitations documenting timing and order of interventions. The team used the Systems Engineering Initiative for Patient Safety (SEIPS) model to identify system factors impacting DR resuscitations and time to invasive ventilation.

RESULTS

We analyzed 31 video recorded CDH resuscitations. We observed variability in timing and order of resuscitation tasks. The 'Internal Environment' and 'Tasks' components of the SEIPS model were prominent factors affecting resuscitation efficiency; significant room and bed spatial constraints exist, and nurses have a significant task burden. Additionally, endotracheal tube preparation was a prominent barrier to timely invasive ventilation.

CONCLUSION

Video review revealed variation in event timing and order during CDH resuscitations. Standardization of room set-up, equipment, and event order and reallocation of tasks facilitate more efficient intubation and ventilation, representing targets for CDH DR improvement initiatives. This work emphasizes the utility of rigorous human factors review to identify areas for improvement during DR resuscitation.

Congenital diaphragmatic hernia: quality improvement using a maximal lung protection strategy and early surgery-improved survival

To evaluate the effectiveness of a novel protocol, adopted in our institution, as a quality improvement project for congenital diaphragmatic hernia (CDH). A maximal lung protection (MLP) protocol was implemented in 2019. This strategy included immediate use of high-frequency oscillatory ventilation (HFOV) after birth, during the stay at the Neonatal Intensive Care Unit (NICU), and during surgical repair. HFOV strategy included low distending pressures and higher frequencies (15 Hz) with subsequent lower tidal volumes. Surgical repair was performed early, within 24 h of birth, if possible. A retrospective study of all inborn neonates prenatally diagnosed with CDH and without major associated anomalies was performed at the NICU of Schneider Children's Medical Center of Israel between 2009 and 2022. Survival rates and pulmonary outcomes of neonates managed with MLP were compared to the historical standard care cohort. Thirty-three neonates were managed with the MLP protocol vs. 39 neonates that were not. Major adverse outcomes decreased including death rate from 46 to 18% (p = 0.012), extracorporeal membrane oxygenation from 39 to 0% (p < 0.001), and pneumothorax from 18 to 0% (p = 0.013).

CONCLUSION

 MLP with early surgery significantly improved survival and additional adverse outcomes of neonates with CDH. Prospective randomized studies are necessary to confirm the findings of the current study.

WHAT IS KNOWN

• Ventilator-induced lung injury was reported as the main cause of mortality in neonates with congenital diaphragmatic hernia (CDH). • Conventional ventilation is recommended by the European CDH consortium as the first-line ventilation modality; timing of surgery is controversial.

WHAT IS NEW

• A maximal lung protection strategy based on 15-Hz high-frequency oscillatory ventilation with low distending pressures as initial modality and early surgery significantly reduced mortality and other outcomes.

Respiratory function after birth in infants with congenital diaphragmatic hernia

OBJECTIVE

To characterise the transitional pulmonary physiology of infants with congenital diaphragmatic hernia (CDH) using measures of expiratory tidal volume (TV) and end-tidal carbon dioxide (ETCO2).

DESIGN

Prospective single-centre observational study.

SETTING

Quaternary neonatal intensive care unit.

PATIENTS

Infants with an antenatal diagnosis of CDH born at the Children's Hospital of Philadelphia.

INTERVENTIONS

TV and ETCO2 were simultaneously recorded using a respiratory function monitor (RFM) during invasive positive pressure ventilation immediately after birth.

MAIN OUTCOME MEASURES

TV per birth weight and ETCO2 values were summarised for each minute after birth. Subgroups of interest were defined by liver position (thoracic vs abdominal) and extracorporeal membrane oxygenation (ECMO) treatment.

RESULTS

RFM data were available for 50 infants from intubation until a median (IQR) of 9 (7-14) min after birth. TV and ETCO2 values increased for the first 10 min after birth, but intersubject values were heterogeneous. TVs were overall lower and ETCO2 values higher in infants with an intrathoracic liver and infants who were ultimately treated with ECMO. On hospital discharge, survival was 88% (n=43) and 34% (n=17) of infants were treated with ECMO.

CONCLUSION

Respiratory function immediately after birth is heterogeneous for infants with CDH. Lung aeration, as evidenced by expired TV and ETCO2, appears to be ongoing throughout the first 10 min after birth during invasive positive pressure ventilation. Close attention to expired TV and ETCO2 levels by 10 min after birth may provide an opportunity to optimise and individualise ventilatory support for this high-risk population.

The Association between the First Cry and Clinical Outcomes in CDH Neonates: A Retrospective Study

Congenital diaphragmatic hernia (CDH) is a life-threatening condition characterized by the herniation of abdominal organs into the thorax, resulting in hypoplastic lungs and pulmonary hypertension. The impact of the first cry, a crucial event for lung transition during birth, on CDH patients remains unclear. This study investigated the impact of the first cry during birth on CDH patient survival, along with other prognosis factors. A multi-institutional retrospective study assessed CDH patient characteristics and survival rates by analyzing factors including the first cry, disease severity, birth weight, Apgar scores, oxygenation index (OI) and surgical closure. Among the CDH patients in the study, a positive first cry was linked to 100% survival, regardless of disease severity (p < 0.001). Notably, the presence of a positive first cry did not significantly affect survival rates in patients with worse prognostic factors, such as low birth weight (<2500 g), high CDH severity, low Apgar scores (1 min ≤ 4), high best OI within 24 h after birth (≥8), or those who underwent patch closure. Furthermore, no significant association was found between the first cry and the use of inhaled nitric oxide (iNO) or extracorporeal membrane oxygenation (ECMO). In conclusion, this study suggests that the first cry may not have a negative impact on the prognosis of CDH patients and could potentially have a positive effect.

The use of neurally-adjusted ventilatory assist (NAVA) for infants with congenital diaphragmatic hernia (CDH)

OBJECTIVES

Newborns with congenital diaphragmatic hernia (CDH) can have complex respiratory problems which are worsened by ventilatory induced lung injury. Neurally adjusted ventilator assist (NAVA) is a potentially promising ventilation mode for this population, as it can result in improved patient-ventilator interactions and provision of adequate gas exchange at lower airway pressures.

CONTENT

A literature review was undertaken to provide an overview of NAVA and examine its role in the management of infants with CDH.

SUMMARY

NAVA in neonates has been used in CDH infants who were stable on ventilatory support or being weaned from mechanical ventilation and was associated with a reduction in the level of respiratory support.

OUTLOOK

There is, however, limited evidence regarding the efficacy of NAVA in infants with CDH, with only short-term benefits being investigated. A prospective, multicentre study with long term follow-up is required to appropriately assess NAVA in this population.

Effects of tactile stimulation on spontaneous breathing during face mask ventilation

OBJECTIVE

We sought to determine the effect of stimulation during positive pressure ventilation (PPV) on the number of spontaneous breaths, exhaled tidal volume (VTe), mask leak and obstruction.

DESIGN

Secondary analysis of a prospective, randomised trial comparing two face masks.

SETTING

Single-centre delivery room study.

PATIENTS

Newborn infants ≥34 weeks' gestation at birth.

METHODS

Resuscitations were video recorded. Tactile stimulations during PPV were noted and the timing, duration and surface area of applied stimulus were recorded. Respiratory flow waveforms were evaluated to determine the number of spontaneous breaths, VTe, leak and obstruction. Variables were recorded throughout each tactile stimulation episode and compared with those recorded in the same time period immediately before stimulation.

RESULTS

Twenty of 40 infants received tactile stimulation during PPV and we recorded 57 stimulations during PPV. During stimulation, the number of spontaneous breaths increased (median difference (IQR): 1 breath (0-3); p_adj<0.001) and VTe increased (0.5 mL/kg (-0.5 to 1.7), p_adj=0.028), whereas mask leak (0% (-20 to 1), p_adj=0.12) and percentage of obstructed inflations (0% (0-0), p_adj=0.14) did not change, compared with the period immediately prior to stimulation. Increased duration of stimulation (p_adj<0.001) and surface area of applied stimulus (p_adj=0.026) were associated with a larger increase in spontaneous breaths in response to tactile stimulation.

CONCLUSIONS

Tactile stimulation during PPV was associated with an increase in the number of spontaneous breaths compared with immediately before stimulation without a change in mask leak and obstruction. These data inform the discussion on continuing stimulation during PPV in term infants.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trial Registry (ACTRN12616000768493).

Work of breathing at different tidal volume targets in newborn infants with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) results in varying degrees of pulmonary hypoplasia. Volume targeted ventilation (VTV) is a lung protective strategy but the optimal target tidal volume in CDH infants has not previously been studied. The aim of this study was to test the hypothesis that low targeted volumes would be better in CDH infants as determined by measuring the work of breathing (WOB) in CDH infants, at three different targeted tidal volumes. A randomised cross-over study was undertaken. Infants were eligible for inclusion in the study after surgical repair of their diaphragmatic defect. Targeted tidal volumes of 4, 5, and 6 ml/kg were each delivered in random order for 20-min periods with 20-min periods of baseline ventilation between. WOB was assessed and measured by using the pressure-time product of the diaphragm (PTPdi). Nine infants with a median gestational age at birth of 38 + 4 (range 36 + 4-40 + 6) weeks and median birth weight 3202 (range 2855-3800) g were studied. The PTPdi was higher at 4 ml/kg than at both 5, p = 0.008, and 6 ml/kg, p = 0.012.

CONCLUSION

VTV of 4 ml/kg demonstrated an increased PTPdi compared to other VTV levels studied and should be avoided in post-surgical CDH infants.

WHAT IS KNOWN

• Lung injury secondary to mechanical ventilation increases the mortality and morbidity of infants with CDH. • Volume targeted ventilation (VTV) reduces 'volutrauma' and ventilator-induced lung injury in other neonatal intensive care populations.

WHAT IS NEW

• A randomised cross-over trial was carried out investigating the response to different VTV levels in infants with CDH. • Despite pulmonary hypoplasia being a common finding in CDH, a VTV of 5ml/kg significantly reduced the work of breathing in infants with CDH compared to a lower VTV level.

Factors associated with initial tidal volume selection during neonatal volume-targeted ventilation in two NICUs: a retrospective cohort study

OBJECTIVE

To quantify initial tidal volume (VT) during neonatal volume-targeted ventilation (VTV) and to characterize the agreement of initial VT with the limited-evidence available.

STUDY DESIGN

We performed a multi-center retrospective observational cohort study in two Neonatal Intensive Care Units evaluating 313 infants who received VTV as the initial ventilation modality prior to postnatal day 14. We generated descriptive statistics and performed multivariable logistic regression analysis to determine factors associated with initial VT use that agreed with available literature.

RESULTS

154 (49%) infants received an initial VT of 5.0 mL/kg (median 5.0 mL/kg, IQR 5.0-5.1). 45 (14%) infants received an initial VT that was congruent with available literature. A birth weight of 700 -<1250 g was significantly associated with an initial VT in agreement with VT literature (aOR 9.4, 95% CI 1.7-50.4).

CONCLUSIONS

Most infants receive an initial VT of 5.0 mL/kg.

A multi-centre randomised controlled trial of respiratory function monitoring during stabilisation of very preterm infants at birth

AIM

To determine whether the use of a respiratory function monitor (RFM) during PPV of extremely preterm infants at birth, compared with no RFM, leads to an increase in percentage of inflations with an expiratory tidal volume (Vte) within a predefined target range.

METHODS

Unmasked, randomised clinical trial conducted October 2013 - May 2019 in 7 neonatal intensive care units in 6 countries. Very preterm infants (24-27 weeks of gestation) receiving PPV at birth were randomised to have a RFM screen visible or not. The primary outcome was the median proportion of inflations during manual PPV (face mask or intubated) within the target range (Vte 4-8 mL/kg). There were 42 other prespecified monitor measurements and clinical outcomes.

RESULTS

Among 288 infants randomised (median (IQR) gestational age 26⁺² (25⁺³-27⁺¹) weeks), a total number of 51,352 inflations were analysed. The median (IQR) percentage of inflations within the target range in the RFM visible group was 30.0 (18.0-42.2)% vs 30.2 (14.8-43.1)% in the RFM non-visible group (p = 0.721). There were no differences in other respiratory function measurements, oxygen saturation, heart rate or FiO₂. There were no differences in clinical outcomes, except for the incidence of intraventricular haemorrhage (all grades) and/or cystic periventricular leukomalacia (visible RFM: 26.7% vs non-visible RFM: 39.0%; RR 0.71 (0.68-0.97); p = 0.028).

CONCLUSION

In very preterm infants receiving PPV at birth, the use of a RFM, compared to no RFM as guidance for tidal volume delivery, did not increase the percentage of inflations in a predefined target range.

TRIAL REGISTRATION

Dutch Trial Register NTR4104, clinicaltrials.gov NCT03256578.

Tidal volumes at birth as predictor for adverse outcome in congenital diaphragmatic hernia

OBJECTIVE

To assess the predictive value of tidal volume (Vt) of spontaneous breaths at birth in infants with congenital diaphragmatic hernia (CDH).

DESIGN

Prospective study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

Thirty infants with antenatally diagnosed CDH born at Hospital Sant Joan de Déu in Barcelona from September 2013 to September 2015.

INTERVENTIONS

Spontaneous breaths and inflations given in the first 10 min after intubation at birth were recorded using respiratory function monitor. Only expired Vt of uninterrupted spontaneous breaths was included for analysis. Receiver operating characteristics (ROC) analysis was performed and the area under the curve (AUC) was estimated to assess the predictive accuracy of Vt.

MAIN OUTCOME MEASURES

Mortality before hospital discharge and chronic lung disease (CLD) at day 28 of life.

RESULTS

There were 1.233 uninterrupted spontaneous breaths measured, and the overall mean Vt was 2.8±2.1 mL/kg. A lower Vt was found in infants who died (n=14) compared with survivors (n=16) (1.7±1.6 vs 3.7±2.1 mL/kg; p=0.008). Vt was lower in infants who died during admission or had CLD (n=20) compared with survivors without CLD (n=10) (2.0±1.7 vs 4.3±2.2 mL/kg; p=0.004). ROC analysis showed that Vt ≤2.2 mL/kg predicted mortality with 79% sensitivity and 81% specificity (AUC=0.77, p=0.013). Vt ≤3.4 mL/kg was a good predictor of death or CLD (AUC=0.80, p=0.008) with 85% sensitivity and 70% specificity.

CONCLUSION

Vt of spontaneous breaths measured immediately after birth is associated with mortality and CLD. Vt seems to be a reliable predictor but is not an independent predictor after adjustment for observed/expected lung to head ratio and liver position.

Feasibility of Non-invasive Neurally Adjusted Ventilator Assist After Congenital Diaphragmatic Hernia Repair

BACKGROUND

The use of neurally adjusted ventilator assist (NAVA) in congenital diaphragmatic hernia (CDH) patients has been historically deemed unwise, since the trigger for breaths is the electromyographic activity of the diaphragmatic muscle. We report on our NAVA experience in CDH patients.

METHODS

We performed an IRB-approved retrospective review of newborns from 1/1/2012-1/1/2017 at a Level I Children's Surgery Center undergoing CDH repair. Data obtained included demographics, defect type and repair, respiratory support, and outcomes.

RESULTS

Seven infants with CDH were placed on noninvasive-NAVA (NIV-NAVA) after extubation. All seven patients underwent open transabdominal repair, with five requiring patch repair. All survived to discharge, and one year after birth. When we compared this group to a contemporary cohort of patients who also underwent CDH repair, we found no significant differences in birth weight, postmenstrual age, or gender. However, there was a significantly higher need for inhaled nitric oxide (p = 0.002), high frequency oscillatory ventilation (p = 0.016), and extracorporeal membranous oxygenation support (p = 0.045) in the NIV-NAVA cohort.

CONCLUSION

This is the first report of NIV-NAVA being successfully utilized as an adjunct to wean infants from conventional ventilation after CDH repair, even in those who require patch repair or with more significant disease severity.

LEVELS OF EVIDENCE

III- Retrospective Comparative Study.

Reduced oxygen concentration for the resuscitation of infants with congenital diaphragmatic hernia

OBJECTIVE

To evaluate whether infants with congenital diaphragmatic hernia (CDH) can be safely resuscitated with a reduced starting fraction of inspired oxygen (FiO₂) of 0.5.

STUDY DESIGN

A retrospective cohort study comparing 68 patients resuscitated with starting FiO₂ 0.5 to 45 historical controls resuscitated with starting FiO₂ 1.0.

RESULTS

Reduced starting FiO₂ had no adverse effect upon survival, duration of intubation, need for ECMO, duration of ECMO, or time to surgery. Furthermore, it produced no increase in complications, adverse neurological events, or neurodevelopmental delay. The need to subsequently increase FiO₂ to 1.0 was associated with female sex, lower gestational age, liver up, lower lung volume-head circumference ratio, decreased survival, a higher incidence of ECMO, longer time to surgery, periventricular leukomalacia, and lower neurodevelopmental motor scores.

CONCLUSION

Starting FiO₂ 0.5 may be safe for the resuscitation of CDH infants. The need to increase FiO₂ to 1.0 during resuscitation is associated with worse outcomes.

Mask versus Nasal Tube for Stabilization of Preterm Infants at Birth: Respiratory Function Measurements

OBJECTIVE

To compare the nasal tube with face mask as interfaces for stabilization of very preterm infants at birth by using physiological measurements of leak, obstruction, and expired tidal volumes during positive pressure ventilation (PPV).

STUDY DESIGN

In the delivery room, 43 infants <30 weeks gestation were allocated to receive respiratory support by nasal tube or face mask. Respiratory function, heart rate, and oxygen saturation were measured. Occurrence of obstruction, amount of leak, and tidal volumes were compared using a Mann-Whitney U test or a Fisher exact test.

RESULTS

The first 5 minutes after initiation of PPV were analyzed (1566 inflations in the nasal tube group and 1896 inflations in the face mask group). Spontaneous breathing coincided with PPV in 32% of nasal tube and 34% of face mask inflations. During inflations, higher leak was observed using nasal tube compared with face mask (98% [33%-100%] vs 14 [0%-39%]; P < .0001). Obstruction occurred more often (8.2% vs 1.1%; P < .0001). Expired tidal volumes were significantly lower during inflations when using nasal tube compared with face mask (0.0 [0.0-3.1] vs 9.9 [5.5-12.8] mL/kg; P < .0001) and when spontaneous breathing coincided with PPV (4.4 [2.1-8.4] vs 9.6 [5.4-15.2] mL/kg; P < .0001) but were similar during breathing on continuous positive airway pressure (4.7 [2.8-6.9] vs 4.8 [2.7-7.9] mL/kg; P > 0.05). Heart rate was not significantly different between groups, but oxygen saturation was significantly lower in the nasal tube group the first 2 minutes after start of respiratory support.

CONCLUSIONS

The use of a nasal tube led to large leak, more obstruction, and inadequate tidal volumes compared with face mask.

TRIAL REGISTRATION

Trial registration Registered with the Dutch Trial Registry (NTR 2061) and the Australia and New Zealand Clinical Trials Register (ACTRN 12610000230055).

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

Setting the Ventilator in the NICU

Success in providing respiratory support to the neonate requires a clear understanding of the context in which it is being applied. Perhaps more than for any other age group, the array of different situations in which ventilation is applied to the newborn infant is extremely broad, with in each case different pathophysiological disturbances and often the need to use a specific approach to apply ventilation optimally. Table 42.1 provides a list of the more common situations in which conventional ventilation is used in the neonate and includes some considerations regarding ventilator settings for each situation. For each situation, a suggested mode of ventilation is indicated, along with target ranges for positive end-expiratory pressure (PEEP) and tidal volume (V_T). Further discussion of the physiological rationale and available evidence for ventilator settings is set out below.

The administration of 100% oxygen and respiratory drive in very preterm infants at birth

Aim

To retrospectively investigate the changes of SpO₂ and respiratory drive in preterm infants at birth after administration of 100% oxygen.

Methods

Respiratory parameters, FiO₂ and oximetry of infants <32 weeks gestation before and after receiving FiO₂ 1.0 were reviewed during continuous positive airway pressure (CPAP) or positive pressure ventilation (PPV).

Results

Results are given as median (IQR) or percentages where appropriate. Suitable recordings were made in 50 infants (GA 27 (26–29) weeks), 17 received CPAP and 33 PPV. SpO₂ increased rapidly in the first minute after FiO₂ 1.0 and remained stable. The duration of FiO₂ 1.0 tended to be shorter in the CPAP group than in the PPV group (CPAP vs. PPV: 65 (33–105) vs. 100 (40–280) s; p = 0.05), SpO₂ >95% occurred more often in PPV group (53% vs. 69%) and lasted longer (70(40–95) vs. 120(50–202) s). In CPAP group, minute volume increased from 134 (76–265) mL/kg/min 1 minute before to 240 (157–370) mL/kg/min (p<0.01) 1 minute after start FiO₂ 1.0 and remained stable at 2 minutes (252 (135–376) mL/kg/min; ns). The rate of rise to maximum tidal volume increased (from 13.8 (8.0–22.4) mL/kg/s to 18.2 (11.0–27.5) mL/kg/s; p<0.0001) to 18.8 (11.8–27.8) mL/kg/s; ns). In the PPV group respiratory rate increased from 0(0–4) to 9(0–20) at 1 minute (p<0.001) to 23 (0–34) breaths per minute at 2 minutes (p<0.01).

Conclusion

In preterm infants at birth, a rapid increase in oxygenation, resulting from a transient increase to 100% oxygen might improve respiratory drive, but increases the risk for hyperoxia.

Mask ventilation of preterm infants in the delivery room

OBJECTIVE

To measure tidal volumes (VT) and describe the interactions between spontaneous breaths and positive pressure ventilation (PPV) inflations during stabilisation of preterm infants in the delivery room (DR). We used a respiratory function monitor (RFM) to evaluate the first 5 min of mask respiratory support provided to preterm infants.

STUDY DESIGN

An observational study of infants <32 weeks gestation, born in a single tertiary perinatal centre receiving mask PPV in the DR. PPV was delivered with a round silicone facemask connected to a T-piece device and RFM. The RFM display was not visible to the resuscitator. Respiratory function parameters in the first 5 min after birth were analysed by breath-type (inflations, assisted inflations, spontaneous breaths between PPV, and breaths during continuous positive airway pressure (CPAP)). Parameters measured included VT, peak inspiratory pressure, peak end expiratory pressure and mask leak.

RESULTS

A total of 2605 inflations and breaths from 29 subjects were analysed. Substantial leak was observed during all four breath types with median leaks ranging from 24% to 59%. Median tidal volumes were greater during inflations (8.3 ml/kg) and assisted inflations (9.3 ml/kg) than spontaneous breaths between PPV (3.2 ml/kg) and breaths during CPAP (3.3 ml/kg).

CONCLUSIONS

Facemask leak is large during resuscitation of preterm infants using round silicone masks. Tidal volumes delivered during PPV inflations are much higher than those generated during spontaneous breathing by an infant on CPAP.

Mask versus nasal tube for stabilization of preterm infants at birth: a randomized controlled trial

OBJECTIVE

Positive-pressure ventilation (PPV) using a manual ventilation device and a face mask is recommended for compromised newborn infants in the delivery room (DR). Mask ventilation is associated with airway obstruction and leak. A nasal tube is an alternative interface, but its safety and efficacy have not been tested in extremely preterm infants.

METHODS

An unblinded randomized controlled trial was conducted in Australia, and the Netherlands. Infants were stratified by gestational age (24-25/26-29 weeks) and center. Immediately before birth infants were randomly assigned to receive PPV and/or continuous positive airway pressure with either a nasal tube or a size 00 soft, round silicone mask. Resuscitation protocols were standardized; respiratory support was provided using a T-piece device commencing in room air. Criteria for intubation included need for cardiac compressions, apnea, continuous positive airway pressure >7 cm H2O, and fraction of inspired oxygen >0.4. Primary outcome was endotracheal intubation in the first 24 hours from birth.

RESULTS

Three hundred sixty-three infants were randomly assigned; the study terminated early on the grounds of futility. Baseline variables were similar between groups. Intubation rates in the first 24 hours were 54% and 55% in the nasal tube and face mask groups, respectively (odds ratio: 0.97; 95% confidence interval: 0.63-1.50). There were no important differences in any of the secondary outcomes within the whole cohort or between the 2 gestational age subgroups.

CONCLUSIONS

In infants at <30 weeks' gestation receiving PPV in the DR, there were no differences in short-term outcomes using the nasal tube compared with the face mask.

Noninvasive Monitoring during Interhospital Transport of Newborn Infants

The main indications for interhospital neonatal transports are radiographic studies (e.g., magnet resonance imaging) and surgical interventions. Specialized neonatal transport teams need to be skilled in patient care, communication, and equipment management and extensively trained in resuscitation, stabilization, and transport of critically ill infants. However, there is increasing evidence that clinical assessment of heart rate, color, or chest wall movements is imprecise and can be misleading even in experienced hands. The aim of the paper was to review the current evidence on clinical monitoring equipment during interhospital neonatal transport.

Evaluating manual inflations and breathing during mask ventilation in preterm infants at birth

OBJECTIVE

To investigate inflations (initial sustained inflations and consecutive inflations) and breathing during mask ventilation in preterm infants at birth.

STUDY DESIGN

Resuscitation of infants <32 weeks' gestation receiving mask ventilation at birth were recorded. Recorded waveforms were divided into inflations (sustained and consecutive inflations), breaths in between inflations, breaths coinciding with an inflation, and breaths on continuous positive airway pressure (during evaluation moments in between and after ventilation) and expiratory tidal volume (V(Te)) was compared. Inflations were analyzed for leak, low V(Te) (<2.5 mL/kg), high V(Te) (>15 mL/kg in sustained inflations, >10 mL/kg in consecutive inflations), and airway obstruction.

RESULTS

In 27 infants, we analyzed 1643 inflations, 110 breaths in between inflations, 133 breaths coinciding with an inflation, and 1676 breaths on continuous positive airway pressure. A large mask leak frequently resulted in low V(Te). Breathing during positive pressure ventilation occurred in 24 of 27 infants (89%). Median (IQR) V(Te) of inflations, breaths in between inflations, and breaths coinciding with an inflation were 0.8 mL/kg (0.0-5.6 mL/kg), 2.8 mL/kg (0.7-4.6 mL/kg), and 3.9 mL/kg (0.0-7.7 mL/kg) during sustained inflations and 3.7 mL/kg (1.4-6.7 mL/kg), 3.3 mL/kg (2.1-6.6 mL/kg), and 4.6 mL/kg (2.1-7.8 mL/kg) during consecutive inflations, respectively. The V(Te) of breaths were significantly lower than the V(Te) of inflations or breaths coinciding with an inflation.

CONCLUSIONS

We often observed large leak and low V(Te), especially during sustained inflations. Most preterm infants breathe when receiving mask ventilation and this probably contributed to the stabilization of the infants after birth.

Respiratory function monitor guidance of mask ventilation in the delivery room: a feasibility study

OBJECTIVE

To investigate whether using a respiratory function monitor (RFM) during mask resuscitation of preterm infants reduces face mask leak and improves tidal volume (V(T)).

STUDY DESIGN

Infants receiving mask resuscitation were randomized to have the display of an RFM (airway pressure, flow, and V(T) waves) either visible or masked.

RESULT

Twenty-six infants had the RFM visible, and 23 had the RFM masked. The median mask leak was 37% (IQR, 21%-54%) in the visible RFM group and 54% (IQR, 37%-82%) in the masked RFM group (P = .01). Mask repositioning was done in 19 infants (73%) of the visible group and in 6 infants (26%) of the masked group (P = .001). The median expired V(T) was similar in the 2 groups. Oxygen was provided to 61% of the visible RFM group and 87% of the RFM masked group (P = .044). Continuous positive airway pressure use was greater in the visible RFM group (73% vs 43%; P = .035). Intubation in the delivery room was done in 21% of the visible group and in 57% of the masked group (P = .035).

CONCLUSION

Using an RFM was associated with significantly less mask leak, more mask adjustments, and a lower rate of excessive V(T).

Providing PEEP during neonatal resuscitation: which device is best?

AIM

The study aims to compare three commonly used neonatal resuscitation devices, the Laerdal self-inflating bag with a positive end expiratory pressure (PEEP) valve, a T-piece resuscitator (T-piece) and a flow-inflating bag to provide peak inflation pressure (PIP) and PEEP.

METHODS

Participants were asked to use each device to give positive pressure ventilation to a modified neonatal mannequin via a face mask to achieve 40-60 inflations per minute, aiming for a PIP/PEEP of 30/5 cm H₂O. A manometer was visible to participants with each device. PIP, PEEP, percentage leak at the face mask and expired tidal volume were measured using a hot-wire anemometer. We analysed 20 inflations from each participant for each device.

RESULTS

Fifty participants provided PIP and PEEP with each device. The T-piece was the most accurate and consistent. The flow-inflating bag had the most variation. The leak was lowest with the self-inflating bag and PEEP and highest with the flow-inflating bag, but all had wide variation.

CONCLUSION

Each device was able to provide PIP and PEEP when used appropriately. When compared with other resuscitation devices, the T-piece provided the most accurate and consistent PIP and PEEP.

A practical guide to neonatal volume guarantee ventilation

A recent systematic review and meta-analysis shows that volume-targeted ventilation (VTV) compared with pressure-limited ventilation (PLV) reduce death and bronchopulmonary dysplasia, pneumothorax, hypocarbia and severe cranial ultrasound abnormalities. In this paper, we present published research and our experience with volume guarantee (VG) ventilation, a VTV mode available on the Dräger Babylog 8000plus and VN500 ventilators. The VG algorithm measures the expired tidal volume (V(T)) for each inflation and adjusts the peak inflating pressure for the next inflation to deliver a V(T) set by the clinician. The advantage of controlling expired V(T) is that this is less influenced by endotracheal tube leak than inspired V(T). VG ventilation can be used with an endotracheal tube leak up to ∼50%. Initial set V(T) for infants with respiratory distress syndrome should be 4.0 to 5.0 ml kg(-1). The set V(T) should be adjusted to maintain normocapnoea. Setting the peak inflating pressure limit well above the working pressure is important to enable the ventilator to deliver the set V(T), and to avoid frequent alarms. This paper provides a practical guide on how to use VG ventilation.

Oxygenation with T-piece versus self-inflating bag for ventilation of extremely preterm infants at birth: a randomized controlled trial

OBJECTIVE

To investigate whether infants < 29 weeks gestation who receive positive pressure ventilation (PPV) immediately after birth with a T-piece have higher oxygen saturation (SpO₂) measurements at 5 minutes than infants ventilated with a self inflating bag (SIB).

STUDY DESIGN

Randomized, controlled trial of T-piece or SIB ventilation in which SpO₂ was recorded immediately after birth from the right hand/wrist with a Masimo Radical pulse oximeter, set at 2-second averaging and maximum sensitivity. All resuscitations started with air.

RESULTS

Forty-one infants received PPV with a T-piece and 39 infants received PPV with a SIB. At 5 minutes after birth, there was no significant difference between the median (interquartile range) SpO₂ in the T-piece and SIB groups (61% [13% to 72%] versus 55% [42% to 67%]; P = .27). More infants in the T-piece group received oxygen during delivery room resuscitation (41 [100%] versus 35 [90%], P = .04). There was no difference in the groups in the use of continuous positive airway pressure, endotracheal intubation, or administration of surfactant in the delivery room.

CONCLUSION

There was no significant difference in SpO₂ at 5 minutes after birth in infants < 29 weeks gestation given PPV with a T-piece or a SIB as used in this study.

Respiratory function monitoring to reduce mortality and morbidity in newborn infants receiving resuscitation

BACKGROUND

A respiratory function monitor is routinely used in neonatal intensive care units to continuously measure and display airway pressures, tidal volume and leak during ventilation. During positive pressure ventilation in the delivery room, clinical signs are used to monitor the effectiveness of ventilation. The additional use of a respiratory function monitor during positive pressure ventilation in the delivery room might help to improve the effectiveness of ventilation.

OBJECTIVES

To determine whether the use of a respiratory function monitor in addition to clinical assessment compared to clinical assessment alone in newborn infants resuscitated with positive pressure ventilation reduces mortality and morbidity.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2010), MEDLINE (January 1996 to March 2010), EMBASE (January 1980 to March 2010) and CINAHL (January 1982 to March 2010). Clinical trials registers and the abstracts of the Society for Pediatric Research and the European Society for Pediatric Research were searched from 2004 to 2009. No language restrictions were applied.

SELECTION CRITERIA

We planned to include randomised and quasi-randomised controlled trials and cluster trials that compared the use of a respiratory function monitor in addition to clinical assessment, compared to clinical assessment alone, in newborn infants resuscitated with positive pressure ventilation.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated the search results against the selection criteria. Data extraction and risk of bias assessment were not performed because there were no studies that met our inclusion criteria.

MAIN RESULTS

No studies were found meeting the criteria for inclusion in this review

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the efficacy and safety of a respiratory function monitor in addition to clinical assessment during positive pressure ventilation at neonatal resuscitation. Randomised clinical trials comparing positive pressure ventilation with and without a respiratory function monitor in addition to clinical assessment at neonatal resuscitation are warranted.