Effect of a new respiratory care bundle on bronchopulmonary dysplasia in preterm neonates

Gas transport mechanisms during high-frequency ventilation

By virtue of applying small tidal volumes, high-frequency ventilation is advocated as a method of minimizing ventilator-induced lung injury. Lung protective benefits are established in infants, but not in other patient cohorts. Efforts to improve and extend the lung protection potential should consider how fundamental modes of gas transport can be exploited to minimize harmful tidal volumes while maintaining or improving ventilation.This research investigates different models of gas transport during high-frequency ventilation and discusses the extent to which the gas transport mechanisms are considered in each. The research focuses on the rationale for current ventilation protocols, how they were informed by these models, and investigates alternative protocols that may improve gas transport and lung protection. A review of high-frequency ventilation physiology and fluid mechanics literature was performed, and dimensional analyses were conducted showing the relationship between clinical data and the model outputs. We show that contemporary protocols have been informed by resistor-inductor-capacitor, or network, models of the airway-lung system that are formulated around a ventilation pressure cost framework. This framework leads to clinical protocol selection that ventilates patients at frequencies that excite a resonance in the lung. We extend on these models by considering frequencies that are much higher than resonance which further optimize gas transport in the airway via alternative gas transport mechanisms to bulk advection that operate for very low tidal volumes. Our findings suggest it is unlikely that gas transport is optimally exploited during current approaches to high-frequency ventilation and protocols that differ significantly from those currently in use could achieve ventilation while using very low tidal volumes.

Comparison of High-Frequency Oscillatory Ventilators

BACKGROUND

The performance of high-frequency oscillatory ventilators (HFOV) differs by the waveform generation mode and circuit characteristics. Few studies have described the performance of piston-type HFOV. The present study aimed to compare the amplitude required to reach the target high-frequency tidal volume ([Formula: see text]); determine the relationship between the settings and actual pressure in amplitude or mean airway pressure ([Formula: see text]); and describe the interaction among compliance, frequency, and endotracheal tube (ETT) inner diameter in 4 HFOV models, including Humming X, Vue (a piston type ventilator commonly used in Japan), VN500 (a diaphragm type), and SLE5000 (a reverse jet type).

METHODS

The oscillatory ventilators were evaluated by using a 50-mL test lung with 0.5 and 1.0 mL/cm H2O compliance, [Formula: see text] of 10 cm H2O, frequency of 12 and 15 Hz, and ETT inner diameters 2.0, 2.5, and 3.5 mm. At each permutation of compliance, frequency, and ETT, the target high-frequency [Formula: see text] was increased from 0.5 to 3.0 mL. The change in [Formula: see text] from the ventilator (ventilator [Formula: see text]) to Y-piece (Y [Formula: see text]) and alveolar pressure (alveolar [Formula: see text]) and the change in amplitude from the ventilator (ventilator amplitude) to Y-piece (Y amplitude) and alveolar pressure (alveolar amplitude) were determined at high-frequency [Formula: see text] of 1.0 and 3.0 mL.

RESULTS

To achieve the target high-frequency [Formula: see text], the Humming X and Vue required a higher amplitude than did the SLE5000, but the maximum amplitude in the VN500 was unable to attain a larger high-frequency [Formula: see text]. Ventilator [Formula: see text] and alveolar pressure decreased at the Y-piece with the Humming X and Vue but increased with the SLE5000. The ventilator [Formula: see text] in the VN500 decreased remarkably at a frequency of 15 Hz. The ventilator amplitude in all 4 ventilators decreased while temporarily increasing at the Y-piece in the VN500.

CONCLUSIONS

The actual measured value, such as alveolar [Formula: see text] and high-frequency [Formula: see text], varied according to the type of HFOV system and the inner diameter of the ETT, even with identical settings. Clinicians should therefore determine the setting appropriate to each HFOV model.

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.

The prevention and management strategies for neonatal chronic lung disease

INTRODUCTION

Survival from even very premature birth is improving, but long-term respiratory morbidity following neonatal chronic lung disease (bronchopulmonary dysplasia (BPD)) has not reduced. Affected infants may require supplementary oxygen at home, because they have more hospital admissions particularly due to viral infections and frequent, troublesome respiratory symptoms requiring treatment. Furthermore, adolescents and adults who had BPD have poorer lung function and exercise capacity.

AREAS COVERED

Antenatal and postnatal preventative strategies and management of infants with BPD. A literature review was undertaken using PubMed and Web of Science.

EXPERT OPINION

There are effective preventative strategies which include caffeine, postnatal corticosteroids, vitamin A, and volume guarantee ventilation. Side-effects, however, have appropriately caused clinicians to reduce use of systemically administered corticosteroids to infants only at risk of severe BPD. Promising preventative strategies which need further research are surfactant with budesonide, less invasive surfactant administration (LISA), neurally adjusted ventilatory assist (NAVA) and stem cells. The management of infants with established BPD is under-researched and should include identifying the optimum form of respiratory support on the neonatal unit and at home and which infants will most benefit in the long term from pulmonary vasodilators, diuretics, and bronchodilators.

Lung protection strategy with high-frequency oscillatory ventilation improves respiratory outcomes at two years in preterm respiratory distress syndrome: a before and after, quality improvement study

INTRODUCTION

Bronchopulmonary dysplasia (BPD) remains one of the major challenges of extreme prematurity. High-frequency oscillatory ventilation (HFOV) with volume guarantee (HFOV-VG) can be used as an early-rescue ventilation to protect developing lungs. However, the studies exploring the impact of this ventilatory strategy on neonatal respiratory morbidity are very limited. This study aimed at documenting the improvement in respiratory outcomes in mechanically ventilated preterm newborns, after the implementation of a new mechanical ventilation respiratory bundle.

METHODS

A prospective, quality improvement study was conducted between January 2012 and December 2018 in a third level NICU in Madrid, Spain. Infants born <32 weeks of gestation with severe respiratory distress syndrome (RDS) and requiring invasive mechanical ventilation were included. The intervention consisted of a new ventilation respiratory care bundle, with HFOV as early rescue therapy using low high-frequency tidal volumes (Vthf) and higher frequencies (15-20 Hz). Criteria for HFOV start were impaired oxygenation or ventilation on conventional ventilation, or peak inspiratory pressures >15 cmH₂O. Two cohorts of mechanically ventilated patients were compared, cohort 1 (2012-2013, baseline period) and cohort 2 (2016-2018, after implementation of the new bundle). Clinical outcomes at 36 weeks and 2 years of postmenstrual age were compared between the groups.

RESULTS

A total of 216 patients were included, the median gestational age was 26 weeks (IQR 25-28) and median birth weight was 895 g (IQR 720-1160). There were no significant differences in survival between the groups, but patients with the protective ventilation strategy (cohort 2) had higher survival without BPD 2-3 (OR 2.93, 95%CI 1.41-6.05). At 2 years of postmenstrual age, patients in cohort 2 also had a higher survival free of baseline respiratory treatment and hospital respiratory admissions than the control group (adjusted OR 2.33, 95%CI 1.10-4.93, p=.03). The results did not suggest significant differences in neurologic development.

CONCLUSIONS

In extreme premature related severe respiratory failure, the use of a lung protective HFOV-VG strategy was proven to be a useful quality improvement intervention in our unit, leading to better pulmonary outcomes at 36 weeks and additional improved respiratory prognosis at two years of age.

Lung recruitment in neonatal high-frequency oscillatory ventilation with volume-guarantee

BACKGROUND AND OBJECTIVES

The optimal lung volume strategy during high-frequency oscillatory ventilation (HFOV) is reached by performing recruitment maneuvers, usually guided by the response in oxygenation. In animal models, secondary spontaneous change in oscillation pressure amplitude (ΔPhf) associated with a progressive increase in mean airway pressure during HFOV combined with volume guarantee (HFOV-VG) identifies optimal lung recruitment. The aim of this study was to describe recruitment maneuvers in HFOV-VG and analyze whether changes in ΔPhf might be an early predictor for lung recruitment in newborn infants with severe respiratory failure.

DESIGN AND METHODS

The prospective observational study was done in a tertiary-level neonatology department. Changes in ΔPhf were analyzed during standardized lung recruitment after initiating early rescue HFOV-VG in preterm infants with severe respiratory failure.

RESULTS

Twenty-seven patients were included, with a median gestational age of 24 weeks (interquartile range [IQR]: 23-25). Recruitment maneuvers were performed, median baseline mean airway pressure (mPaw) was 11 cm H₂ O (IQR: 10-13), median critical lung opening mPaw during recruitment was 14 cm H₂ O (IRQ: 12-16), and median optimal mPaw was 12 cm H₂ O (IQR: 10-14, p < 0.01). Recruitment maneuvers were associated with an improvement in oxygenation (FiO₂ : 65.0 vs. 45.0, p < 0.01, SpO2/FiO₂ ratio: 117 vs. 217, p < 0.01). ΔPhf decreased significantly after lung recruitment (mean amplitude: 23.0 vs. 16.0, p < 0.01).

CONCLUSION

In preterm infants with severe respiratory failure, the lung recruitment process can be effectively guided by ΔPhf on HFOV-VG.

Respiratory Care of Big Data Communication to Prevent Respiratory Tract Infection Nursing Analysis of Patients with Heart Failure

Heart failure is the final stage of the development of heart disease, with a high mortality and disability rate. It poses a serious threat to human health and brings tremendous pressure to human society. Preventing respiratory infections in patients with heart failure is also the first priority of care. This article is aimed at studying the nursing analysis of respiratory tract care based on big data exchanges to prevent respiratory tract infections in patients with heart failure. This article uses benchmark and sample collection. Studies have shown that for Pseudomonas aeruginosa, its resistance to ampicillin, amoxicillin/clavulanic acid, cefazolin, cefuroxime, ceftriaxone, cefotaxime, and cefoxitin has reached more than 80%. It is also suitable for piperacillin, ticarcillin/clavulanic acid, piperacillin/tazobactam, cefepime, aztreonam, gentamicin, tobramycin, ciprofloxacin, and levofloxacin. The resistance rate of stars is within 10%-30%. These antibiotics are effective and can be used for clinical treatment. The drug resistance rates of ceftazidime, imipenem, meropenem, and amikacin were all lower than 10%, and the drug resistance rates of ceftazidime and imipenem were much lower than those reported in the 2016 literature. These antibiotics have become the most effective drugs for the treatment of Pseudomonas aeruginosa infections. Basically, good communication of respiratory care data is realized, thereby preventing respiratory care analysis of patients with heart failure.

High-frequency Ventilation

High-frequency ventilation (HFV) is an alternative to conventional mechanical ventilation, with theoretic benefits of less risk of ventilator lung injury and more effectivity in washout CO₂. Previous clinical studies have not demonstrated advantages of HFV in preterm infants compared with conventional ventilation, so rescue HFV has been used when severe respiratory insufficiency needs aggressive ventilator settings in immature infants. Today it is possible to measure, set directly, and fix tidal volume, which can protect the immature lung from large volumes and fluctuations of the tidal volume. This strategy can be used in preterm infants with respiratory failure needing invasive ventilation.

Target volume-guarantee in high-frequency oscillatory ventilation for preterm respiratory distress syndrome: Low volumes and high frequencies lead to adequate ventilation

BACKGROUND AND OBJECTIVES

Respiratory distress syndrome (RDS) and ventilation-induced lung injury lead to significant morbidity in preterm infants. High-frequency oscillatory ventilation with volume-guarantee (HFOV-VG) has been used as a rescue therapy and might lead to lower rates of death and bronchopulmonary dysplasia, especially when using low tidal volumes and high frequencies. The aim of the study was to define HFOV-VG parameters leading to adequate ventilation in the first 72 h of preterm RDS using a low volume and high-frequency strategy.

DESIGN AND METHODS

Retrospective cohort study in a tertiary-level neonatology unit. Infants <32 weeks with severe respiratory insufficiency needing HFOV-VG were included. Patients were ventilated following a standard mechanical ventilation aiming for low tidal volumes and high frequencies. Clinical data, perinatal characteristics and high-frequency parameters corresponding with adequate ventilation were recorded.

RESULTS

116 patients were included. Median gestational age was 25 weeks (interquartile range [IQR] = 24-27), median birth weight 724 g (IQR = 600-900 g). HFOV-VG was started at 2 h, median high-frequency tidal volume was 1.63 ml/kg (IQR = 1.44-1.84) and median frequency was 16 Hz (IQR = 15-18). Weight-adjusted tidal volumes did not depend on gestational age, antenatal corticosteroids nor chorioamnionitis, and were inversely correlated with frequencies (R ²  = -0.10, p = .001).

CONCLUSION

HFOV-VG can reach adequate ventilation at high frequencies when using adequate volumes, providing a feasible ventilation strategy that might be of help in preterm infants with RDS.

BPD treatments: The never-ending smorgasbord

Despite important advances in neonatal care, rates of bronchopulmonary dysplasia (BPD) have remained persistently high. Numerous drugs and ventilator strategies are used for the prevention and treatment of BPD. Some, such as exogenous surfactant, volume targeted ventilation, caffeine, and non-invasive respiratory support, are associated with modest but important reductions in rates of BPD and long-term respiratory morbidities. Many other therapies, such as corticosteroids, diuretics, nitric oxide, bronchodilators and anti-reflux medications, are widely used despite conflicting, limited or no evidence of efficacy and safety. This paper examines the range of therapies used for the prevention or treatment of BPD. They are classified into those supported by evidence of effectiveness, and those which are widely used despite limited evidence or unclear risk to benefit ratios. Finally, the paper explores emerging therapies and approaches which aim to prevent or reduce BPD and long-term respiratory morbidity.