Rationale: There is increasing evidence for a clinical benefit of noninvasive high-frequency oscillatory ventilation (nHFOV) in preterm infants. However, it is still unknown whether the generated oscillations are effectively transmitted to the alveoli. Objectives: To assess magnitude and regional distribution of oscillatory volumes (VOsc) at the lung level. Methods: In 30 prone preterm infants enrolled in a randomized crossover trial comparing nHFOV with nasal continuous positive airway pressure, electrical impedance tomography recordings were performed. During nHFOV, the smallest amplitude to achieve visible chest wall vibration was used, and the frequency was set at 8 hertz. Measurements and Main Results: Thirty consecutive breaths during artifact-free tidal ventilation were extracted for each of the 228 electrical impedance tomography recordings. After application of corresponding frequency filters, Vt and VOsc were calculated. There was a signal at 8 and 16 Hz during nHFOV, which was not detectable during nasal continuous positive airway pressure, corresponding to the set oscillatory frequency and its second harmonic. During nHFOV, the mean (SD) VOsc/Vt ratio was 0.20 (0.13). Oscillations were more likely to be transmitted to the non–gravity-dependent (mean difference [95% confidence interval], 0.041 [0.025–0.058]; P < 0.001) and right-sided lung (mean difference [95% confidence interval], 0.040 [0.019–0.061]; P < 0.001) when compared with spontaneous Vt. Conclusions: In preterm infants, VOsc during nHFOV are transmitted to the lung. Compared with the regional distribution of tidal breaths, oscillations preferentially reach the right and non–gravity-dependent lung. These data increase our understanding of the physiological processes underpinning nHFOV and may lead to further refinement of this novel technique.

CONTEXT: Surfactant nebulization (SN) may offer a safe alternative for surfactant administration in respiratory distress syndrome of preterm infants. OBJECTIVE: To evaluate the efficacy of SN for the prevention of early intubation. DATA SOURCES: Medline, Embase, The Cochrane Library, clinicaltrials.gov, published abstracts, and references of relevant articles were searched through March 23, 2021. STUDY SELECTION: Randomized clinical trials of preterm infants <37 weeks’ gestation comparing SN with noninvasive respiratory support or intratracheal surfactant application. DATA EXTRACTION: Two reviewers extracted data and assessed risk of bias from included studies separately and blinded. Data were pooled by using a fixed-effects model. Subgroups (gestational age, type of nebulizer, surfactant type, and dosage) were evaluated. Primary outcome was intubation rate at 72 hours after birth. RESULTS: Nine studies recruiting 1095 infants met inclusion criteria. SN compared with standard care significantly reduced intubation rate at 72 hours after birth (226 of 565 infants [40.0%] vs 231 of 434 infants [53.2%]; risk ratio [RR]: 0.73, 95% confidence interval [CI]: 0.63–0.84; number needed to treat: 8; 95% CI: 5–14]). Prespecified subgroup analysis identified important heterogeneity: SN was most effective in infants ≥28 weeks' gestation (RR: 0.70, 95% CI: 0.60–0.82), with a pneumatically driven nebulizer (RR: 0.52, 95% CI: 0.40–0.68) and in infants receiving ≥200 mg/kg and animal-derived surfactant (RR: 0.63, 95% CI: 0.52–0.75). No differences in neonatal morbidities or mortality were identified. LIMITATIONS: Quality of evidence was low owing to risk of bias and imprecision. CONCLUSIONS: SN reduced the intubation rate in preterm infants with a higher efficacy for specific subgroups. There was no difference in relevant neonatal morbidities or mortality.

Objective Application of a face mask may induce apnoea and bradycardia, possibly via the trigeminocardiac reflex (TCR). We aimed to describe rates of apnoea and bradycardia in term and late-preterm infants following facemask application during neonatal stabilisation and compare the effects of first facemask application with subsequent applications. Design Subgroup analysis of a prospective, randomised trial comparing two face masks. Setting Single-centre study in the delivery room Patients Infants>34 weeks gestational age at birth Methods Resuscitations were video recorded. Airway flow and pressure were measured using a flow sensor. The effect of first and subsequent facemask applications on spontaneously breathing infants were noted. When available, flow waveforms as well as heart rate (HR) were assessed 20 s before and 30 s after each facemask application. Results In total, 128 facemask applications were evaluated. In eleven percent of facemask applications infants stopped breathing. The first application was associated with a higher rate of apnoea than subsequent applications (29% vs 8%, OR (95% CI)=4.76 (1.41–16.67), p=0.012). On aggregate, there was no change in median HR over time. In the interventions associated with apnoea, HR dropped by 38bpm [median (IQR) at time of facemask application: 134bpm (134–150) vs 96bpm (94–102) 20 s after application; p=0.25] and recovered within 30 s. Conclusions Facemask applications in term and late-preterm infants during neonatal stabilisation are associated with apnoea and this effect is more pronounced after the first compared with subsequent applications. Healthcare providers should be aware of the TCR and vigilant when applying a face mask to newborn infants. Trial registration number ACTRN12616000768493.

Objective Neonatal resuscitation guidelines recommend that newborn infants are stimulated to assist with the establishment of regular respirations. The mode, site of application and frequency of stimulations are not stipulated in these guidelines. The effectiveness of stimulation in improving neonatal transition outcomes is poorly described. Methods We conducted a retrospective review of video recordings of neonatal resuscitation at a tertiary perinatal centre. Four different types of stimulation (drying, chest rub, back rub and foot flick) were defined a priori and the frequency and infant response were documented. Results A total of 120 video recordings were reviewed. Seventy-five (63%) infants received at least one episode of stimulation and 70 (58%) infants were stimulated within the first minute after birth. Stimulation was less commonly provided to infants <30 weeks’ gestation (median (IQR) number of stimulations: 0 (0–1)) than infants born ≥30 weeks’ gestation (1 (1–3); p<0.001). The most common response to stimulation was limb movement followed by infant cry and facial grimace. Truncal stimulation (drying, chest rub, back rub) was associated with more crying and movement than foot flicks. Conclusion Less mature infants are stimulated less frequently compared with more mature infants and many very preterm infants do not receive any stimulation. Most infants were stimulated within the first minute as recommended in resuscitation guidelines. Rubbing the trunk may be most effective but this needs to be confirmed in prospective studies.