Early respiratory system reactance predicts respiratory outcomes in preterm infants: a retrospective, multicentre study.

OBJECTIVE: This multicenter, international, retrospective study aims to investigate whether respiratory system reactance (Xrs) assessed by respiratory oscillometry on the 7th day of life is associated with respiratory outcomes in preterm infants below 32 weeks' gestation. METHODS: Sinusoidal pressure oscillations (2-5 cmH2O peak-to-peak, 10 Hz) were superimposed on the positive end-expiratory pressure (PEEP). We assessed the association of Xrs z-score with the duration of respiratory support using linear regression and with bronchopulmonary dysplasia (BPD, according to Jensen et al. 2019) using logistic regression. We used the likelihood ratio test to evaluate whether Xrs z-score adds significantly to clinical predictors, including gestational age (GA), birth weight (BW) and the National Institute of Child Health and Human Development (NICHD) BPD prediction model. RESULTS: One hundred and thirty-seven infants (median (Q1, Q3) GA=28.43 (26.11, 30.29) weeks) were included; 44 (32%) developed BPD. Xrs z-score was significantly associated with the duration of respiratory support (R2=0.35). Xrs z-score was significantly higher in infants who developed BPD (p<0.001); the optimal cut-off value was 2.6, associated with 77% sensitivity and 80% specificity. In univariable analysis, per z-score increase in Xrs, the OR for BPD increased by 60% and the respiratory support by eight days. In multivariable analysis, Xrs z-score added significantly to the NICHD model and to GA and BW z-score to predict respiratory support duration (p=0.016 and p=0.014, respectively) and BPD development (p=0.003 and p<0.001, respectively). CONCLUSION: Xrs z-score on the 7th day after birth improves the prediction of respiratory outcome in preterm infants.

Neonatal Resuscitation: A Critical Incident Technique Study Exploring Pediatric Registered Nurses' Experiences and Actions.

BACKGROUND: Teamwork during neonatal resuscitation is essential. Situations arise quickly and unexpectedly and are highly stressful, requiring pediatric registered nurses (pRN) to respond effectively and in a structured manner. In Sweden, pRNs work in all pediatric settings including the neonatal intensive care unit. The experience and actions of pRNs are seldom explored, and studies within this area could develop and improve strategies for neonatal resuscitation situations. PURPOSE: To describe pRNs' experiences and actions during neonatal resuscitation. METHODS: A qualitative interview study based on the critical incident technique was performed. Sixteen pRNs from 4 neonatal intensive care units in Sweden were interviewed. RESULTS: Critical situations were divided into 306 experiences and 271 actions. pRNs' experiences were divided into 2 categories: individual- and team-focused experiences. Critical situations were managed by individual- or team-focused actions.Experiences revealed were variation of alarms, psychological impact, parental presence, structured working methods, the team's interactions, professional experience and resource availability, and the impact of the environment. Actions revealed were being prepared, managing the psychological impact, adopting a professional attitude toward parents, working in a structured way, and competence/resource reinforcement. IMPLICATIONS FOR PRACTICE: Developing a structured role distribution within the neonatal resuscitation program and ensuring clear communication in the team during simulation training and in intense situations can increase pRNs' feeling of safety and allow them to further develop their professional role in neonatal resuscitation situations.

Multicenter Experience with Neurally Adjusted Ventilatory Assist in Infants with Severe Bronchopulmonary Dysplasia.

OBJECTIVE: The aim of this study is to determine patterns of neurally adjusted ventilatory assist (NAVA) use in ventilator-dependent preterm infants with evolving or established severe bronchopulmonary dysplasia (sBPD) among centers of the BPD Collaborative, including indications for its initiation, discontinuation, and outcomes. STUDY DESIGN: Retrospective review of infants with developing or established sBPD who were placed on NAVA after ≥4 weeks of mechanical ventilation and were ≥ 30 weeks of postmenstrual age (PMA). RESULTS: Among the 13 sites of the BPD collaborative, only four centers (31%) used NAVA in the management of infants with evolving or established BPD. A total of 112 patients met inclusion criteria from these four centers. PMA, weight at the start of NAVA and median number of days on NAVA, were different among the four centers. The impact of NAVA therapy was assessed as being successful in 67% of infants, as defined by the ability to achieve respiratory stability at a lower level of ventilator support, including extubation to noninvasive positive pressure ventilation or support with a home ventilator. In total 87% (range: 78-100%) of patients survived until discharge. CONCLUSION: We conclude that NAVA can be used safely and effectively in selective infants with sBPD. Indications and current strategies for the application of NAVA in infants with evolving or established BPD, however, are highly variable between centers. Although this pilot study suggests that NAVA may be successfully used for the management of infants with BPD, sufficient experience and well-designed clinical studies are needed to establish standards of care for defining the role of NAVA in the care of infants with sBPD.

Oscillatory respiratory mechanics on the first day of life improves prediction of respiratory outcomes in extremely preterm newborns.

BACKGROUND: We aimed to evaluate if lung mechanics measured by forced oscillatory technique (FOT) during the first day of life help identify extremely low gestational age newborns (ELGANs) at risk of prolonged mechanical ventilation (MV) and oxygen dependency. METHODS: Positive end-expiratory pressure (PEEP) was increased 2 cmH2O above the clinically set PEEP, then decreased by four 5-min steps of 1 cmH2O, and restored at the clinical value. At each PEEP, FOT measurements were performed bedside during MV. Changes in respiratory mechanics with PEEP, clinical parameters, and chest radiographs were evaluated. RESULTS: Twenty-two newborns (24+4 ± 1+4 wks gestational age (GA); birth weight 653 ± 166 g) on assist/control ventilation were studied. Infants were ventilated for 40 ± 36 d (range 1-155 d), 11 developed severe bronchopulmonary dysplasia (BPD) and one died before 28 d. Early lung mechanics correlated with days on MV, days of respiratory support, and BPD grade. Effects of increasing PEEP on oscillatory reactance assessed by FOT together with GA and radiographic score predicted days on MV (multilinear model, r2 = 0.73). A logistic model considering the same FOT parameter together with GA predicts BPD development. CONCLUSIONS: FOT can be applied bedside in ELGANs, where early changes in lung mechanics with PEEP improve clinical prediction of respiratory outcomes.

Respiratory support of infants born at 22-24 weeks of gestational age.

Lung immaturity and acute respiratory failure are the major problems in the care of extremely preterm infants. Most infants with gestational age (GA) 22-24 weeks will need mechanical ventilation and many will depend on some type of respiratory support, invasive and non-invasive for extended periods. There is ongoing gap in knowledge regarding optimal respiratory support and applying strategies that are effective in more mature populations is not easy or even suitable because lung maturation differs in smaller infants. Better strategies on how to avoid lung damage and to promote growth and development of the immature lung are warranted since increased survival is accompanied by increasing rates of bronchopulmonary dysplasia and concerns over long-standing reductions in lung function. This review focuses on some aspects of respiratory care of infants born at 22-24 weeks of GA.

NIV-NAVA versus NCPAP immediately after birth in premature infants: A randomized controlled trial.

OBJECTIVE: To evaluate whether noninvasive-neurally adjusted ventilatory assist (NIV-NAVA) decrease respiratory efforts compared to nasal continuous positive airway pressure (NCPAP) during the first hours of life. METHODS: Twenty infants born between 28+0 and 31+6 weeks were randomized to NIV-NAVA or NCPAP. Positive end-expiratory pressure was constantly kept at 6 cmH2O for both groups and the NAVA level was 1.0 cmH2O/µV for NIV-NAVA group. The electrical activity of diaphragm (Edi) were recorded for the first two hours. RESULTS: Peak and minimum Edi decreased similarly in both groups (P = 0.98 and P = 0.59, respectively). Leakages were higher in the NIV-NAVA group than in the NCPAP group (P < 0.001). The neural apnea defined as a flat Edi for ≥ 5 s were less frequent in NIV-NAVA group than in NCPAP group (P = 0.046). CONCLUSIONS: Immediately applied NIV-NAVA in premature infants did not reduce breathing effort, measured as peak Edi. However, NIV-NAVA decreased neural apneic episodes compared to NCPAP.

Early volume targeted ventilation in preterm infants born at 22-25 weeks of gestational age.

BACKGROUND: Early hypocapnia in preterm infants is associated with intraventricular hemorrhage (IVH) and bronchopulmonary dysplasia (BPD). Volume targeted ventilation (VTV) has been shown to reduce hypocapnia in preterm infants. Less is known of VTV in infants born at <26 weeks gestational age (GA). OBJECTIVES: Our aim was to investigate the short- and long-term effects of early VTV as compared to pressure limited ventilation (PLV) in extremely preterm infants on the incidence of hypocapnia, days on ventilatory support, IVH, and BPD. STUDY DESIGN: A retrospective observational study of 104 infants born at 22-25 weeks GA (mean ± SD; 24+0 ± 1+1 GA; birth weight 619 ± 146 g), ventilated with either VTV (n = 44) or PLV (n = 60) on their first day of life. Ventilatory data and blood gases were collected at admission and every fourth hour during the first day of life, together with perinatal characteristics and outcomes. RESULTS: Peak inflation pressure (PIP) was lower in the VTV-group than in the PLV-group during the first 20 h of life (p < .05), without any difference in respiratory rate or FiO2 . Incidence of hypocapnia (PaCO2 < 4.5 kPa) was lower with VTV than PLV during the first day of life (32% vs. 62%; p < .01). Infants in the VTV-group were more frequently extubated at 24 h (30% vs. 13%; p < .05). IVH Grade ≥3, BPD, and time on mechanical ventilation did not differ between the groups. CONCLUSIONS: VTV is safe to apply in infants born at <26 GA and was observed to result in a lower incidence of hypocapnia compared to infants ventilated by PLV, without any differences in outcomes.

Proportional assist and neurally adjusted ventilation: Clinical knowledge and future trials in newborn infants.

Different types of patient triggered ventilator modes have become the mainstay of ventilation in term and preterm newborn infants. Maintaining spontaneous breathing has allowed for earlier weaning and the additive effects of respiratory efforts combined with pre-set mechanical inflations have reduced mean airway pressures, both of which are important components in trying to avoid lung injury and promote normal lung development. New sophisticated modes of assisted ventilation have been developed during the last decades where the control of ventilator support is turned over to the patient. The ventilator detects the respiratory effort and adjusts ventilatory assistance proportionally to each phase of the respiratory cycle, thus enabling the patient to have full control of the start, the duration and the amount of ventilatory assistance. In this paper we will review the literature on the ventilatory modes of proportional assist ventilation and neurally adjusted ventilatory assistance, examine the different ways the signals are analyzed, propose future studies, and suggest ways to apply these modes in the clinical environment.

Skin conductance measurements as pain assessment in newborn infants born at 22-27 weeks gestational age at different postnatal age.

BACKGROUND: To assess pain or stress in newborn infants submitted to intensive care is important but difficult, as different observational pain scales are not always reliable in premature infants. As an indicator of pain, skin conductance (SC) measurements have detected increased sweating in newborn infants >28 gestational age (GA) submitted to heel lancing. OBJECTIVE: To measure SC during heel lancing and routine care in newborn infants, born at 22 to 27 GA, with special relation to postnatal age (PNA). METHODS: In six infants <28+0 GA and 4 infants ≥28+0 GA spontaneous SC activity and behavioural state (Neonatal Pain Agitation and Sedation Scale (N-PASS)) was measured before, during and after each intervention. Measurements were repeated in each patient at different PNA. RESULTS: Baseline SC prior to intervention took longer time to stabilise and was higher in <28 than in ≥28+0 PNA. The combination of heel lancing and squeezing gave an increased SC in <28 PNA, whereas heel lancing alone gave the same SC response in ≥28+0 PNA. A possibly continued immature response in SC measurements was not observed. Oral glucose admission prior to heel lancing increased SC. Routine care did not give any changes in SC. Except during orogastric tube placement no signs of discomfort or pain could be detected by the neonatal pain, agitation and sedation scale (N-PASS) in <28 PNA. CONCLUSION: Changes in SC could be detected in infants at <28+0 PNA and related to the combination of heel lancing and squeezing. A maturational development of the SC was observed in infants born <28 GA. SC seems to be able to differentiate between pain and discomfort.