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

Respiratory Support Strategies for Surgical Neonates: A Review

Neonates with congenital conditions which require surgical management frequently experience respiratory distress. This review discusses the management of pulmonary complications and the respiratory support strategies for four conditions: oesophageal atresia-tracheoesophageal fistula (OA-TOF), congenital diaphragmatic hernia (CDH), congenital lung malformations (CLM), and anterior abdominal wall defects (AWD). Mechanical ventilation techniques which can reduce the risk of ventilator-induced lung injury (VILI) are discussed, as well as the use of non-invasive respiratory support modes. While advances in perioperative respiratory support have improved outcomes in infants with OA-TOF, managing respiratory distress in premature OA-TOF neonates remains a challenge. In CDH infants, a randomised trial has suggested that conventional ventilation may improve outcomes compared to high-frequency ventilation. Echocardiographic assessment is essential in the management of CDH infants with pulmonary hypertension. Lung-protective ventilation settings may lower the rate of postoperative complications in symptomatic CLM infants, but there remains debate regarding the choice of expectant versus surgical management in neonates with asymptomatic CLMs. Infants with AWDs can require ventilation due to pulmonary hypoplasia, but the effects of this on their long-term respiratory health are poorly understood. As surgical techniques continue to evolve and novel ventilation techniques become available, prospective multi-centre studies will be required to define the optimal respiratory support strategies for neonatal surgical conditions that affect lung function.

Comparison of noninvasive and intermittent positive pressure ventilation in treating extremely premature and extremely low birth weight infants

OBJECTIVE

We compared the application value of noninvasive positive pressure ventilation (NIPPV) and intermittent positive pressure ventilation (IPPV) in the treatment of very premature infants and extremely low birth weight infants.

METHODS

Multivariate logistic regression analysis was used to identify factors influencing the transition from noninvasive to invasive ventilation in this infant cohort.

RESULTS

Among extremely preterm infants, 83.3% with gestational age <25 weeks transitioned from noninvasive to invasive ventilation, as did 80.6% of those with birth weight <1000 grams. Multivariate analysis indicated that gestational age <25 weeks, birth weight <1000 grams, and Apgar score ≤7 were significant factors affecting the likelihood of transitioning to invasive ventilation. The survival rate at discharge was 94% for the NIPPV group compared with 89% for the IPPV group. The NIPPV group demonstrated significantly lower rates of complications, shorter weaning times, and reduced lengths of hospital stay compared with the IPPV group.

CONCLUSIONS

Both NIPPV and IPPV effectively improved oxygenation and ventilation in extremely preterm infants. However, NIPPV showed significant advantages in reducing complications, shortening weaning time, and decreasing the hospital stay duration. Prioritizing the use of NIPPV may enhance treatment outcomes and survival quality, providing evidence-based support for clinical practice.

Study protocol for a randomised cross-over trial of Neurally adjusted ventilatory Assist for Neonates with Congenital diaphragmatic hernias: the NAN-C study

BACKGROUND

Neurally adjusted ventilatory assist (NAVA) is a mode of mechanical ventilation that delivers oxygen pressures in proportion to electrical signals of the diaphragm. The proportional assistance can be adjusted by the clinician to reduce the patient's work of breathing. Several case series of infants with congenital diaphragmatic hernias (CDH) have shown that NAVA may reduce oxygenation index and mean airway pressures. To date, no clinical trial has compared NAVA to standard methods of mechanical ventilation for babies with CDH.

METHODS

The aim of this dual-centre randomised cross-over trial is to compare post-operative NAVA with assist control ventilation (ACV) for infants with CDH. If eligible, infants will be enrolled for a ventilatory support tolerance trial (VSTT) to assess their suitability for randomisation. If clinically stable during the VSTT, infants will be randomised to receive either NAVA or ACV first in a 1:1 ratio for a 4-h period. The oxygenation index, respiratory severity score and cumulative sedative medication use will be measured.

DISCUSSION

Retrospective studies comparing NAVA to ACV in neonates with congenital diaphragmatic hernia have shown the ventilatory mode may improve respiratory parameters and benefit neonates. To our knowledge, this is the first prospective cross-over trial comparing NAVA to ACV.

TRIAL REGISTRATION

NAN-C was prospectively registered on ClinicalTrials.gov NCT05839340  Registered on May 2023.

Diaphragmatic electromyography in infants: an overview of possible clinical applications

Preterm infants often experience breathing instability and a hampered lung function. Therefore, these infants receive cardiorespiratory monitoring and respiratory support. However, the current respiratory monitoring technique may be unreliable for especially obstructive apnea detection and classification and it does not provide insight in breathing effort. The latter makes the selection of the adequate mode and level of respiratory support difficult. Electromyography of the diaphragm (dEMG) has the potential of monitoring heart rate (HR) and respiratory rate (RR), and it provides additional information on breathing effort. This review summarizes the available evidence on the clinical potential of dEMG to provide cardiorespiratory monitoring, to synchronize patient-ventilator interaction, and to optimize the mode and level of respiratory support in the individual newborn infant. We also try to identify gaps in knowledge and future developments needed to ensure widespread implementation in clinical practice. IMPACT: Preterm infants require cardiorespiratory monitoring and respiratory support due to breathing instability and a hampered lung function. The current respiratory monitoring technique may provide unreliable measurements and does not provide insight in breathing effort, which makes the selection of the optimal respiratory support settings difficult. Measuring diaphragm activity could improve cardiorespiratory monitoring by providing insight in breathing effort and could potentially have an important role in individualizing respiratory support in newborn infants.

Variability for Age at Successful Extubation in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

The objective of this study was to characterize clinical factors associated with successful extubation in infants with congenital diaphragmatic hernia.

STUDY DESIGN

Using the Children's Hospitals Neonatal Database, we identified infants with congenital diaphragmatic hernia from 2017 to 2020 at 32 centers. The main outcome was age in days at the time of successful extubation, defined as the patient remaining extubated for 7 consecutive days. Unadjusted Kaplan-Meier and multivariable Cox proportional hazards ratio equations were used to estimate associations between clinical factors and the main outcome. Observations occurred through 180 days after birth.

RESULTS

There were 840 eligible neonates with a median gestational age of 38 weeks and birth weight of 3.0 kg. Among survivors (n = 693), the median age at successful extubation was 15 days (interquartile range [IQR]: 8-29 days, 95th percentile: 71 days). For nonsurvivors (n = 147), the median age at death was 21 days (IQR: 11-39 days, 95th percentile: 110 days). Center (adjusted hazards ratio: 0.22-15, P < .01), low birth weight, intrathoracic liver position, congenital heart disease, lower 5-minute Apgar score, lower pH upon admission to Children's Hospitals Neonatal Database center, and use of extracorporeal support were independently associated with older age at successful extubation. Tracheostomy was associated with multiple failed extubations.

CONCLUSION

Our findings suggest that infants who have not successfully extubated by about 3 months of age may be candidates for tracheostomy with chronic mechanical ventilation or palliation. The variability of timing of successful extubation among our centers supports the development of practice guidelines after validating clinical criteria.

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.

Respiratory Support of Infants With Congenital Diaphragmatic Hernia

Optimisation of respiratory support of infants with congenital diaphragmatic hernia (CDH) is critical. Infants with CDH often have severe lung hypoplasia and abnormal development of their pulmonary vasculature, leading to ventilation perfusion mismatch. It is vital that lung protective ventilation strategies are employed during both initial stabilisation and post-surgical repair to avoid ventilator induced lung damage and oxygen toxicity to prevent further impairment to an already diminished gas-exchanging environment. There is a lack of robust evidence for the routine use of surfactant therapy during initial resuscitation of infants with CDH and thus administration cannot be recommended outside clinical trials. Additionally, inhaled nitric oxide has been shown to have no benefit in reducing the mortality rates of infants with CDH. Other therapeutic agents which beneficially act on pulmonary hypertension are currently being assessed in infants with CDH in randomised multicentre trials. The role of novel ventilatory modalities such as closed loop automated oxygen control, liquid ventilation and heliox therapy may offer promise for infants with CDH, but the benefits need to be determined in appropriately designed clinical trials.

[Research advances in validity of predictors for extubation outcome in children receiving invasive mechanical ventilation]

The development of invasive mechanical ventilation technology provides effective respiratory support for critically ill children. However, respiratory support is not the end of treatment as the ultimate goal is successful extubation in children. At present, some evaluation indicators before extubation including rapid shallow breathing index, maximal inspiratory pressure, and work of breathing are of high clinical value in predicting adult extubation outcome, but their evidence of evidence-based medicine is not sufficient in the field of pediatric intensive care. This paper reviews the current research on the validity of predictors for extubation outcomes in children. It shows that there is still a lack of indicators with good sensitivity and specificity for assessment before extubation in children. The studies are still in a small-sample size and single-center stage. Therefore, how to optimize evaluation before extubation and improve the success rate of extubation is the direction of joint efforts of doctors in the pediatric intensive care unit and rehabilitation medicine department.