Novel Ventilation Strategies to Reduce Adverse Pulmonary Outcomes

High-frequency oscillatory ventilation with volume guarantee in infants: a systematic review

BACKGROUND

This systematic review was designed to assess the efficacy and safety of high-frequency oscillatory ventilation (HFOV) combined with volume guarantee (VG) in infants compared with HFOV alone.

METHODS

We searched for electronic databases to find studies using HFOV-VG or HFOV for respiratory support in infants from the database creation to October 20, 2024. Two evaluators independently screened the literature, extracted data, and evaluated quality. Meta-analysis was performed using Rev man 5.3 software on survival-free BPD at grades 2 and 3 (SF-BPD), the incidence of BPD, mortality, duration of invasive ventilation, length of hospital stays, and complications in both groups.

RESULTS

The review included 11 studies (three randomized controlled trials, one non-randomized controlled trial, and seven observational studies) with 785 participants. Data analysis showed that HFOV-VG could increase SF-BPD in preterm infants (OR 3.15, 95%CI 1.66-5.98) without reducing the overall incidence of BPD compared with HFOV alone. HFOV-VG may offer advantages in shortening the duration of MV and total hospital stay, potentially reducing mortality and the incidence of air leak syndrome.

CONCLUSIONS EXISTING

Studies showed that HFOV-VG had certain advantages in improving oxygenation and stable ventilation to protect neonatal lungs. HFOV-VG could increase SF-BPD in preterm infants with GA < 32 weeks without reducing the overall incidence of BPD compared with HFOV alone.

IMPACT

Existing evidence suggested that HFOV-VG ventilation strategies could increase SF-BPD in preterm infants with GA < 32 weeks without reducing the overall incidence of BPD compared with HFOV alone. HFOV-VG ventilation strategy has certain advantages in improving oxygenation and stable ventilation to protect neonatal lungs. The effects of HFOV-VG vs. HFOV in neonates remain to be further validated by additional large sample, multicenter RCTs.

Neonatal Sequential Organ Failure Assessment Score Predicts Respiratory Outcomes in Preterm Newborns with Late-Onset Sepsis: A Retrospective Study

INTRODUCTION

Neonatal sequential organ failure assessment (nSOFA) score predicts mortality in preterm newborns. The aim of the study was to assess whether nSOFA score could predict respiratory outcomes in preterm infants with late-onset sepsis (LOS).

METHODS

This retrospective, observational, single-center study enrolled infants with gestational age <32 weeks born between January 2016 and June 2023 who experienced an episode of LOS during NICU stay. The primary outcome was death or bronchopulmonary dysplasia (BPD); secondary outcomes were BPD, death or mechanical ventilation (MV) on day 5 after the onset of LOS, and MV on day 5 after the onset of LOS. The nSOFA score was assessed at the onset of LOS and after 6 ± 1, 12 ± 3, and 24 ± 3 h.

RESULTS

Neonatal SOFA score was significantly higher in patients who developed each outcome versus those who did not at all timings. Maximal nSOFA score during the first 24 h after onset of LOS was an independent predictive factor for death or BPD (p = 0.007), BPD (p = 0.009), and death or MV on day 5 (p = 0.009), areas under the curve (AUC) were 0.740 (95% CI: 0.656-0.828), 0.700 (95% CI: 0.602-0.800), and 0.800 (95% CI: 0.710-0.889), respectively. Maximal nSOFA score also predicted moderate to severe BPD (p = 0.019) and death or moderate to severe BPD (p < 0.001). Maximal nSOFA ≥4 was associated with odds ratio (OR) of 7.37 (95% CI: 2.42-22.44) for death or BPD, 4.86 (95% CI: 1.54-15.28) for BPD, and 7.99 (95% CI: 3.47-18.36) for death or MV on day 5. AUC of the predicting model was 0.895 (95% CI: 0.801-0.928) for BPD, 0.897 (95% CI: 0.830-0.939) for death or BPD, 0.904 (95% CI: 0.851-0.956) for MV on day 5, 0.923 (95% CI: 0.892-0.973) for death or MV on day 5.

CONCLUSION

Maximal nSOFA score during the first 24 h after the onset of LOS predicts respiratory outcomes and allows identification of patients who may crucially benefit from lung-protective measures.

Weaning from mechanical ventilation and assessment of extubation readiness

Tremendous advancements in neonatal respiratory care have contributed to the improved survival of extremely preterm infants (gestational age ≤ 28 weeks). While mechanical ventilation is often considered one of the most important breakthroughs in neonatology, it is also associated with numerous short and long-term complications. For those reasons, clinical research has focused on strategies to avoid or reduce exposure to mechanical ventilation. Nonetheless, in the extreme preterm population, 70-100% of infants born 22-28 weeks of gestation are exposed to mechanical ventilation, with nearly 50% being ventilated for ≥ 3 weeks. As contemporary practices have shifted towards selectively reserving mechanical ventilation for those patients, mechanical ventilation weaning and extubation remain a priority yet offer a heightened challenge for clinicians. In this review, we will summarize the evidence for different strategies to expedite weaning and assess extubation readiness in preterm infants, with a particular focus on extremely preterm infants.

Invasive and non-invasive ventilatory strategies for early and evolving bronchopulmonary dysplasia

In the age of surfactant and antenatal steroids, neonatal care has improved outcomes of preterm infants dramatically. Since the early 2000's neonatologists have strived to decrease bronchopulmonary dysplasia (BPD) by decreasing ventilator-associated lung injury and utilizing many novel modes of non-invasive respiratory support. After the initial success with nasal continuous positive airway pressure, it was established that discontinuing invasive ventilation early in favor of non-invasive respiratory support is the most effective way to reduce the incidence of BPD. In this review, we discuss the management of the preterm lung from the time of delivery, through the phases of respiratory distress syndrome (early BPD) and then evolving BPD. The goal remains to optimize respiratory support of the preterm lung while minimizing ventilator-associated lung injury and oxygen toxicity. A multidisciplinary approach involving the medical team and family is quintessential in reaching this goal and involves adequate respiratory support, optimizing nutrition and fluid balance as well as preventing infections.

Efficacy of perinatal pharmacotherapeutic actions for survival of very preterm newborn rabbits at 26-day gestation

Investigation of the pathophysiology of lung impairment and protection in very preterm neonates at birth requires adequate experimental models. This study aimed to elucidate the efficacy and mechanism of perinatal pharmacotherapeutic action in postnatal survival of very preterm rabbits. Pregnant New Zealand White rabbits on 25-day gestation (term 31 days) were given dexamethasone (D), or sham injection as control (C), and cesarean delivered 24 hours later on day 26. Newborns were anesthetized, intratracheally intubated, randomly received either saline or porcine surfactant (S), allocated to four groups (C, S, D, and DS), and ventilated with low tidal volume. Under the identical protocol, another four groups were added with nitric oxide (N) inhalation (CN, SN, DN, and DSN). Survival length, lung mechanics, histopathology, and pathobiology of lung tissue were measured for benefits and injury patterns. DSN had the longest median survival time (ST50, 10.3 h), whereas C had the shortest (3.5 h), with remaining groups in-between. The survival was mainly benefited by S, when additive effects with D and/or N were discernible, by improved lung mechanics and alveolar aeration, ameliorated lung injury severity and pneumothorax, and augmented lung phospholipid pools, with DSN being the most optimal. Variable mRNA expression profiles of alveolar epithelia-associated cytokines and inflammatory mediators further characterized injury and response patterns as phenotyping conditioned in pharmacotherapeutic actions. In conclusion, the combined regimens of perinatal medications achieved remarkable survival in very preterm rabbits with lung protective ventilation strategy, offering a unique model in investigation of very preterm birth-associated respiratory physiology and morbidities.NEW & NOTEWORTHY By establishing a very preterm rabbit model with 26-day gestation (term 31 days), optimal survival length for 50% of animals in groups was achieved by comparing regimens of combined antenatal glucocorticoids, postnatal surfactant and inhaled nitric oxide, with a low tidal volume ventilation strategy. The efficacies of pharmacotherapeutic action were associated with significantly improved lung mechanics, ameliorated lung injury and pneumothorax, and enhanced surfactant phospholipid metabolism, along with variable mRNA expression profiles characterizing the response patterns.

Respiratory support strategies in the prevention and treatment of bronchopulmonary dysplasia

Neonates who are born preterm frequently have inadequate lung development to support independent breathing and will need respiratory support. The underdeveloped lung is also particularly susceptible to lung injury, especially during the first weeks of life. Consequently, respiratory support strategies in the early stages of premature lung disease focus on minimizing alveolar damage. As infants grow and lung disease progresses, it becomes necessary to shift respiratory support to a strategy targeting the often severe pulmonary heterogeneity and obstructive respiratory physiology. With appropriate management, time, and growth, even those children with the most extreme prematurity and severe lung disease can be expected to wean from respiratory support.