Lung behavior during a staircase high-frequency oscillatory ventilation recruitment maneuver.

BACKGROUND: Lung volume optimization maneuvers (LVOM) are necessary to make physiologic use of high-frequency oscillatory ventilation (HFOV), but lung behavior during such maneuvers has not been studied to determine lung volume changes after initiation of HFOV, to quantify recruitment versus derecruitment during the LVOM and to calculate the time to stabilization after a pressure change. METHODS: We performed a secondary analysis of prospectively collected data in subjects < 18 years on HFOV. Uncalibrated respiratory inductance plethysmography (RIP) tracings were used to quantify lung recruitment and derecruitment during the LVOM inflation and deflation. The time constant was calculated according to the Niemann model. RESULTS: RIP data of 51 subjects (median age 3.5 [1.7-13.3] months) with moderate-to-severe pediatric acute respiratory distress syndrome (PARDS) in 85.4% were analyzed. Lung recruitment and derecruitment occurred during the LVOM inflation phase upon start of HFOV and between and within pressure changes. At 90% of maximum inflation pressure, lung derecruitment already started during the deflation phase. Time to stable lung volume (time constant) could only be calculated in 26.2% of all pressure changes during the inflation and in 21.4% during the deflation phase, independent of continuous distending pressure (CDP). Inability to calculate the time constant was due to lack of stabilization of the RIP signal or no change in any direction. CONCLUSIONS: Significant heterogeneity in lung behavior during a staircase incremental-decremental LVOM occurred, underscoring the need for higher initial inflation pressures when transitioning from conventional mechanical ventilation (CMV) and a longer time between pressure changes to allow for equilibration.

Neonatal high frequency ventilation: Current trends and future directions.

High frequency ventilation (HFV) in neonates has been in use for over forty years. Some early HFV ventilators are no longer available, but high frequency oscillatory ventilation (HFOV) and jet ventilators (HFJV) continue to be commonly employed. Advanced HFOV models available outside of the United States are much quieter and easier to use, and are available as options on many conventional ventilators, providing important improvements such as tidal volume measurement and targeting. HFJV excels in treating air leak and non-homogenous lung disease and is often used for other diseases as well. High frequency non-invasive ventilation (hfNIV) is a novel application of HFV that remains under investigation. Similar to bubble CPAP, hfNIV has been applied with a variety of high-frequency ventilators. Efficacy and safety of hfNIV with any device have not yet been established. This article describes the current approaches to these HFV therapies and stresses the importance of understanding how each device works and what disease processes may respond best to the technology employed.

Respiratory function testing for guiding ventilator mode conversion in congenital diaphragmatic hernia.

INTRODUCTION: For patients with a congenital diaphragmatic hernia, conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFOV) are used in initial ventilatory management. HFOV has recently been recommended as a rescue therapy; however, we use HFOV for initial ventilation management, with a preoperative challenge test for CMV conversion and respiratory function testing at the time of CMV conversion. We aimed to compare patient characteristics between CMV conversion- and HFOV-preferred treatment groups. METHODS: Ventilator settings and blood gases were retrospectively evaluated pre- and post-CMV conversion, and respiratory function tests for compliance of the respiratory system (Crs) and for resistance of the respiratory system (Rrs) were performed during the trial to CMV conversion. RESULTS: No differences were observed between the CMV conversion- and HFOV-preferred groups regarding gestational age, birth weight, and observed/expected lung area-to-head circumference ratios. The median Crs (ml/cmH2 O/kg) and Rrs (cmH2 Oï½¥kg/L/s) in the CMV conversion- and HFOV-preferred groups was 0.42 versus 0.53 (p = .44) and 467 versus 327 (p = .045), respectively. The pre and posttrial amount of change in blood gas levels and ventilator parameters in the CMV conversion- and HFOV-preferred groups were as follows: mean airway pressure, -2.0 versus 0 cmH2 O; partial pressure of carbon dioxide, 6.1 versus 2.9 Torr; alveolar-arterial oxygen difference, -39.5 versus -50 Torr; and oxygenation index, -1.0 versus -0.6; respectively. CONCLUSION: Respiratory function tests were useful in tailoring ventilator settings. Patients with high Rrs values responded better to CMV conversion.

Noninvasive Ventilation.

Systematic Reviews and Randomized clinical trials have shown that the use of noninvasive ventilation (NIV) compared to invasive mechanical ventilation reduces the risk of bronchopulmonary dysplasia and or mortality. Most commonly used NIV modes include nasal continuous positive airway pressure, bi-phasic modes, such as, bi-level positive airway pressure, nasal intermittent positive pressure ventilation, high flow nasal cannula, noninvasive neurally adjusted ventilatory assist, and nasal high frequency ventilation are discussed in this review.

Oscillometry for personalizing continuous distending pressure maneuvers: an observational study in extremely preterm infants.

RATIONALE: Lung recruitment and continuous distending pressure (CDP) titration are critical for assuring the efficacy of high-frequency ventilation (HFOV) in preterm infants. The limitation of oxygenation (peripheral oxygen saturation, SpO2) in optimizing CDP calls for evaluating other non-invasive bedside measurements. Respiratory reactance (Xrs) at 10 Hz measured by oscillometry reflects lung volume recruitment and tissue strain. In particular, lung volume recruitment and decreased tissue strain result in increased Xrs values. OBJECTIVES: In extremely preterm infants treated with HFOV as first intention, we aimed to measure the relationship between CDP and Xrs during SpO2-driven CDP optimization. METHODS: In this prospective observational study, extremely preterm infants born before 28 weeks of gestation undergoing SpO2-guided lung recruitment maneuvers were included in the study. SpO2 and Xrs were recorded at each CDP step. The optimal CDP identified by oxygenation (CDPOpt_SpO2) was compared to the CDP providing maximal Xrs on the deflation limb of the recruitment maneuver (CDPXrs). RESULTS: We studied 40 infants (gestational age at birth = 22+ 6-27+ 5 wk; postnatal age = 1-23 days). Measurements were well tolerated and provided reliable results in 96% of cases. On average, Xrs decreased during the inflation limb and increased during the deflation limb. Xrs changes were heterogeneous among the infants for the amount of decrease with increasing CDP, the decrease at the lowest CDP of the deflation limb, and the hysteresis of the Xrs vs. CDP curve. In all but five infants, the hysteresis of the Xrs vs. CDP curve suggested effective lung recruitment. CDPOpt_SpO2 and CDPXrs were highly correlated (ρ = 0.71, p < 0.001) and not statistically different (median difference [range] = -1 [-3; 9] cmH2O). However, CDPXrs were equal to CDPOpt_SpO2 in only 6 infants, greater than CDPOpt_SpO2 in 10, and lower in 24 infants. CONCLUSIONS: The Xrs changes described provide complementary information to oxygenation. Further investigation is warranted to refine recruitment maneuvers and CPD settings in preterm infants.

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.

Nasal high frequency oscillatory highflow therapy in preterm infants: A randomized crossover trial.

OBJECTIVES: To assess the clinical efficacy, safety, and potential physiological mechanisms of highflow therapy with superimposed high frequency oscillations ("osciflow"). STUDY DESIGN: In this prospective, randomized, single center crossover trial, 30 preterm infants were randomized to receive osciflow or highflow therapy first, each for 180 min. During osciflow, an oscillatory amplitude of 20 mbar and a frequency of 6 Hz were set. The flow rate was 4 L/min during both interventions. Primary outcome was the paired difference in the combined number of desaturations (SpO2 < 80%) and bradycardia (heart rate <80 beats per min) between interventions. Safety outcomes included nasal trauma, pneumothorax and treatment failure, and a pain score was assessed. In 20 infants, electrical impedance tomography (EIT) recordings were performed to evaluate oscillatory (VOsc ) and tidal volumes (VT ) at the lung level. RESULTS: Infants with a mean (SD) postnatal age of 33.1 ± 1.2 weeks were included. The median (IQR) number of episodes of desaturation and bradycardia was 19.5 (6-49) during osciflow and 26 (6-44) during highflow therapy (paired difference -2; IQR -10 to 9; p = .37). There were no differences in safety outcomes and pain scores. During osciflow, EIT recordings showed a signal at 6 Hz, which was not detectable during highflow. Corresponding mean (SD) VOsc /VT ratio was 9% (±5%). CONCLUSIONS: In preterm infants, osciflow did not reduce the number of desaturations and bradycardia compared with highflow therapy. Although VOsc were transmitted to the lung during osciflow, their magnitude was small. Osciflow was safe and well tolerated.

Comparison of clinical outcomes following delivery of budesonide by both vibrating mesh nebulizer and jet nebulizer in premature infants with bronchopulmonary dysplasia.

Background: This study aimed to compare the efficacy of budesonide inhalation suspension administered via a vibrating mesh nebulizer vs. a jet nebulizer in the treatment of premature infants with bronchopulmonary dysplasia (BPD) undergoing high-frequency oscillatory ventilation (HFOV). Methods: Between July 2020 and July 2022, we retrospectively analyzed the medical records of 36 preterm infants diagnosed with BPD who underwent HFOV. Based on the nebulizer type used, infants were categorized into the vibrating mesh nebulizer group (VMN group) or the jet nebulizer group (JN group). Post-nebulization outcomes, such as the duration of mechanical ventilation, length of stay in the neonatal intensive care unit (NICU), ventilator-associated parameters, and arterial blood gas metrics, were compared between the two groups. Treatment-associated complications were also documented. Results: No significant differences were noted between the VMN and JN groups in terms of mechanical ventilation duration (p = 0.519), NICU length of stay (p = 0.112), ventilator-associated parameters, or complications (p = 0.700). However, after 2 weeks of treatment, the oxygenation index (p = 0.012) and arterial partial pressure of carbon dioxide (p = 0.006) were more favorable in the VMN group compared to the JN group. Conclusion: Among premature infants with BPD on HFOV, for administration of budesonide inhalation suspension resulted in an improved oxygenation index and reduced arterial partial pressure of carbon dioxide when compared to a jet nebulizer, indicating superior therapeutic efficacy.

Noninvasive high frequency oscillatory ventilation versus noninvasive positive pressure ventilation in preterm neonates after extubation: A randomized controlled trial.

BACKGROUND: Weaning from mechanical ventilation is a challenging phase of neonatal respiratory support [1]. Choosing efficient and safe noninvasive modality to prevent re-intubation and choosing the optimal time for weaning are key points for weaning success. The aim of the study is to compare the efficiency and safety of noninvasive high frequency oscillatory ventilation (NHFOV) versus noninvasive positive pressure ventilation (NIPPV) as respiratory support after extubation in preterms with respiratory distress syndrome (RDS). Also, the study compared the lung ultrasound findings between these 2 modalities and assessed the use of lung ultrasound score (LUS) as predictor for extubation outcome. METHODS: This study is a randomized controlled trial conducted on 60 preterm neonates with RDS. Patients were allocated into one of 2 groups: NIPPV or NHFOV as post-extubation noninvasive respiratory support. The 2 groups were compared regarding the incidence of extubation failure within 72 hours from extubation, oxygen needs, duration of application of the noninvasive modality, duration of admission, safety and mortality rate. LUS was assessed pre-extubation and 2 hours post-extubation. RESULTS: The study did not show a statistically significant difference in re-ventilation rate in NHFOV group (23.3%) compared to NIPPV group (30.0%), p = 0.56. Oxygen needs were significantly lower in NHFOV group compared to NIPPV groups (mean FiO2 31.8±6.09 vs 38±0.55, p = 0.007). The duration of the used noninvasive modality, CO2 concentration, LUS, and mortality rate showed statistically insignificant difference between both groups. There was a significant correlation between LUS and extubation outcome. CONCLUSION: NHFOV is a feasible noninvasive modality for respiratory support post-extubation in premature infants. LUS is a good predictor of extubation outcome in neonates.

Point-of-Care Ultrasound versus Chest X-Ray for Determining Lung Expansion Based on Rib Count in High-Frequency Oscillatory Ventilation.

INTRODUCTION: Chest X-ray (CXR) is the most prevalent method for evaluating lung expansion in high-frequency oscillatory ventilation (HFOV). The purpose of this study was to compare the accuracy of chest radiography with point-of-care ultrasound (POCUS) in determining lung expansion. METHODS: This prospective study included newborns who required HFOV and were monitored in a neonatal intensive care unit. A single neonatologist assessed lung expansion with CXR and POCUS to measure the costal level of the right hemidiaphragm and compared the results. RESULTS: A neonatologist performed 55 measurements in 28 newborns with a gestational age of 32 (23.2-39.4) weeks, followed by HFOV. The rib counts obtained from anterior chest ultrasonography and posterior CXR showed a statistically high concordance (r = 0.913, p < 0.001). CONCLUSION: Lung ultrasonography is a reliable method for the evaluation of lung expansion based on rib count in patients with HFOV.

Fluctuations in Oxygen Saturation during Synchronized Nasal Intermittent Positive Pressure Ventilation and Nasal High-Frequency Oscillatory Ventilation in Very Low Birth Weight Infants: A Randomized Crossover Trial.

BACKGROUND: Very low birth weight (VLBW) infants on noninvasive ventilation (NIV) experience frequent fluctuations in oxygen saturation (SpO2) that are associated with an increased risk for mortality and severe morbidities. METHODS: In this randomized crossover trial, VLBW infants (n = 22) born 22+3 to 28+0 weeks on NIV with supplemental oxygen were allocated on two consecutive days in random order to synchronized nasal intermittent positive pressure ventilation (sNIPPV) and nasal high-frequency oscillatory ventilation (nHFOV) for 8 h. nHFOV and sNIPPV were set to equivalent mean airway pressure and transcutaneous pCO2. Primary outcome was the time spent within the SpO2 target (88-95%). RESULTS: During sNIPPV, VLBW infants spent significantly more time within the SpO2 target (59.9%) than during nHFOV (54.6%). The proportion of time spent in hypoxemia (22.3% vs. 27.1%) and the mean fraction of supplemental oxygen (FiO2) (29.4% vs. 32.8%) were significantly reduced during sNIPPV, while the respiratory rate (50.1 vs. 42.6) was significantly higher. Mean SpO2, SpO2 above the target, number of prolonged (>1 min) and severe (SpO2 <80%) hypoxemic episodes, parameters of cerebral tissue oxygenation using NIRS, number of FiO2 adjustments, heart rate, number of bradycardias, abdominal distension and transcutaneous pCO2 did not differ between both interventions. CONCLUSIONS: In VLBW infants with frequent fluctuations in SpO2, sNIPPV is more efficient than nHFOV to retain the SpO2 target and to reduce FiO2 exposure. These results demand more detailed investigations into cumulative oxygen toxicities during different modes of NIV over the weaning period, particularly with regard to consequences for long-term outcomes.

The effect of non-invasive high-frequency oscillatory ventilation on the duration of non-invasive respiratory support in late preterm and term infants with transient tachypnea of the newborn: a randomized controlled trial.

Nasal continuous positive airway pressure (nCPAP) is one of the most commonly used non-invasive respiratory support modes in neonates with transient tachypnea of the newborn (TTN). Non-invasive high-frequency oscillatory ventilation (nHFOV) is a non-invasive respiratory support mode that has been increasingly used in neonatal respiratory disorders. This prospective randomized controlled study compared the efficacy of nHFOV and nCPAP in reducing the duration of non-invasive respiratory support. Late preterm and term infants > 34 weeks' gestation were included in the study. The infants were randomly assigned to receive either nHFOV or nCPAP. Treatment was started with standard settings in both groups. Infants who met treatment failure criteria were switched to nasal intermittent mandatory ventilation for further positive-pressure support. A total of 60 infants were included in the study. Thirty of these infants were included in the nHFOV group and 30 were included in the nCPAP group. The median duration of non-invasive respiratory support was not significantly different between the two groups (21 h [IQR: 16-68] for nHFOV vs 15 h [IQR: 11-33] for nCPAP; p = 0.09). However, after adjusting for potential confounders, nHFOV was associated with a shorter duration of non-invasive respiratory support than nCPAP (adjusted mean difference: 16.3 h; 95% CI: 0.7 to 31.9; p = 0.04). nHFOV was well tolerated and did not increase the risk of complications.    Conclusion: Our findings suggest that nHFOV is an effective and safe ventilation mode for late preterm and term neonates with TTN.   Trial registry: Clinicaltrials.gov (NCT03006354). Date of registration: December 30, 2016. What is Known: • nHFOV is a ventilation model that has been increasingly used for the management of RDS. • TTN is one of the most common causes of neonatal respiratory distress. What is New: • nHFOV is associated with shorter duration of non-invasive respiratory support and duration of oxygen support. • nHFOV may be a safe and effective alternative to nCPAP for neonates with TTN.

High-frequency oscillatory ventilation for respiratory failure after congenital heart surgery: a retrospective analysis.

INTRODUCTION: Pulmonary complications such as acute respiratory distress syndrome and refractory respiratory failure have been major causes of morbidity and mortality after cardiac surgery in children. Patients are usually transitioned to either high-frequency oscillatory ventilation (HFOV) or extracorporeal membrane oxygenation (ECMO) as "salvage therapy" when the maximal medical management and controlled mechanical ventilation (CMV) become ineffective. MATERIAL AND METHODS: A retrospective review of paediatric patients who underwent congenital heart surgery and developed cardiorespiratory failure during their stay in a paediatric cardiac ICU, refractory to maximal CMV, was performed in the study. The outcomes assessed were respiratory variables such as SpO 2 , RR, oxygenation index (OI), P/F ratio, and ABG parameters in CMV and HFOV as predictors of survival. RESULTS: Twenty-four children with cardiorespiratory failure were candidates for a transition to either HFOV ( n = 15) or VA ECMO ( n = 9) for refractory hypoxaemia; of these 24 patients, 13 (54.16%) survived. PaO2 showed a significant improvement in the survivors (P = 0.03). Improvement in the PaO 2 /FiO 2 (P/F ratio) after initiation of HFOV was associated with survival ( P < 0.001). pH, PaCO 2 , HCO 3 , FiO 2 , Paw, RR/Amp, SpO 2 , and OI also showed improvements in survivors but these were not statistically significant. The HFOV survivors had longer mechanical ventilation and ICU stay than non-survivors ( P = 0.13). CONCLUSIONS: HFOV was associated with improved gas exchange for paediatric patients who developed post-cardiac surgery refractory respiratory failure. HFOV can be considered as rescue therapy where ECMO has major financial implications.

HFOV in inhalational injury associated ARDS with broncho-pleural fistula - An old friend to the rescue: Case report.

Introduction: Patients with acute respiratory distress syndrome (ARDS) on mechanical ventilation often require high inspiratory pressure and positive end-expiratory pressure (PEEP). However, effective ventilation becomes difficult in cases where a large air leak develops in patients. The management of such a case requires improvisation and the adoption of special ventilation strategies. Case and outcomes: We present a case study of a burn patient with airway involvement, developing ARDS and who developed a bronchopleural fistula (BPF) leading to failure of conventional ventilation. He was managed successfully with high-frequency oscillatory ventilation (HFOV) and finally discharged. Conclusion: HFOV is a feasible option for ventilating patients with BPF when conventional ventilation fails. At a time when HFOV has largely been relegated to obsolescence, we hope to re-emphasize its relevance under particular circumstances.

[Efficacy of noninvasive high-frequency oscillatory ventilation versus nasal intermittent positive pressure ventilation as post-extubation respiratory support in preterm infants: a Meta analysis]. / æ— åˆ›é«˜é¢‘æŒ¯è¡é€šæ°”ä¸Žç»é¼»é—´æ­‡æ­£åŽ‹é€šæ°”ä½œä¸ºæ—©äº§å„¿æ‹”ç®¡åŽå‘¼å¸æ”¯æŒç–—æ•ˆæ¯”è¾ƒçš„Meta分析.

OBJECTIVES: To systematically evaluate the efficacy and safety of noninvasive high-frequency oscillatory ventilation (NHFOV) versus nasal intermittent positive pressure ventilation (NIPPV) as post-extubation respiratory support in preterm infants. METHODS: China National Knowledge Infrastructure, Wanfang Data, Chinese Journal Full-text Database, China Biology Medicine disc, PubMed, Web of Science, and the Cochrane Library were searched for articles on NHFOV and NIPPV as post-extubation respiratory support in preterm infants published up to August 31, 2022. RevMan 5.4 software and Stata 17.0 software were used for a Meta analysis to compare related indices between the NHFOV and NIPPV groups, including reintubation rate within 72 hours after extubation, partial pressure of carbon dioxide (PCO2) at 6-24 hours after switch to noninvasive assisted ventilation, and the incidence rates of bronchopulmonary dysplasia (BPD), air leak, nasal damage, periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP). RESULTS: A total of 9 randomized controlled trials were included. The Meta analysis showed that compared with the NIPPV group, the NHFOV group had significantly lower reintubation rate within 72 hours after extubation (RR=0.67, 95%CI: 0.52-0.88, P=0.003) and PCO2 at 6-24 hours after switch to noninvasive assisted ventilation (MD=-4.12, 95%CI: -6.12 to -2.13, P<0.001). There was no significant difference between the two groups in the incidence rates of complications such as BPD, air leak, nasal damage, PVL, IVH, and ROP (P>0.05). CONCLUSIONS: Compared with NIPPV, NHFOV can effectively remove CO2 and reduce the risk of reintubation, without increasing the incidence of complications such as BPD, air leak, nasal damage, PVL, and IVH, and therefore, it can be used as a sequential respiratory support mode for preterm infants after extubation.

Rescue high-frequency oscillatory ventilation combined with intermittent mandatory ventilation for infants with acute respiratory distress syndrome after congenital heart surgery.

BACKGROUND: This study aimed to evaluate the efficacy and safety of high-frequency oscillation ventilation combined with intermittent mandatory ventilation in infants with acute respiratory distress syndrome after congenital heart surgery. METHODS: We retrospectively analysed the clinical data of 32 infants who were ventilated due to acute respiratory distress syndrome after congenital heart surgery between January, 2020 and January, 2022. We adopted high-frequency oscillation ventilation combined with intermittent mandatory ventilation as the rescue ventilation mode for infants who were failing conventional mechanical ventilation. RESULTS: After rescue high-frequency oscillation ventilation combined with intermittent mandatory ventilation, the dynamic compliance (Cdyn), PaO2 and PaO2/FiO2 ratio of the infants improved compared with conventional mechanical ventilation (p < 0.05). Moreover, high-frequency oscillation ventilation combined with intermittent mandatory ventilation resulted in a significant decrease in arterial-alveolar oxygen difference (AaDO2), FiO2, and oxygenation index (p < 0.05). No significant effect on haemodynamic parameters was observed. Moreover, no serious complications occurred in the two groups. CONCLUSION: Rescue high-frequency oscillation ventilation combined with intermittent mandatory ventilation significantly improved oxygenation in infants who failed conventional mechanical ventilation for acute respiratory distress syndrome after congenital heart surgery. Thus, this strategy is considered safe and feasible. However, further studies must be conducted to confirm the efficacy and safety of high-frequency oscillation ventilation combined with intermittent mandatory ventilation as a rescue perioperative respiratory support strategy for CHD.

Patent ductus arteriosus ligation under high-frequency oscillatory ventilation in two critically ill pre-mature newborns.

Information on the use of high-frequency oscillatory ventilation in neonatal surgeries is very rare. In this report, we discuss two pre-term infants who had to receive high-frequency oscillatory ventilation as a rescue treatment due to severe pre-maturity. These two cases underwent successful bedside patent ductus arteriosus ligation under high-frequency oscillatory ventilation, and this shows us that patent ductus arteriosus ligation can be performed successfully in neonates even under high-frequency oscillatory ventilation.

Clinical characteristics and outcomes in neonates with perinatal acute respiratory distress syndrome in China: A national, multicentre, cross-sectional study.

Background: Neonatal acute respiratory distress syndrome (NARDS) was defined in 2017 and the epidemiological data remain unknown. Our objective was to explore aetiological factors, clinical characteristics and outcomes in patients with perinatal NARDS. Methods: A multicentre, prospective, cross-sectional study was performed in 58 tertiary neonatal intensive care units in China from Jan 1, 2018 to June 30, 2019. Neonates diagnosed with NARDS were included. Primary outcomes were aetiological factors, clinical characteristics and outcomes. Binary logistic regression and multivariate cox proportional regression were performed to identify independent predictors for bronchopulmonary dysplasia (BPD) and/or death or single death. This study was registered with ClinicalTrials.Gov, NCT03311165. Findings: Among 70,013 admitted neonates, the incidence of NARDS was 1.44% (1005). The cumulative incidences were 65.6%, 86.7%, 94.1% within one, two and three days after birth. The median gestational age and birth weight were 36.4 weeks and 2700 g. Three main aetiological triggers included pneumonia (58.1%), asphyxia (24.3%) and early-onset sepsis (EOS) (21.3%). BPD and/or death was observed in 213 (21.2%) infants, consisting 104 (10.3%) BPD and 126 (12.6%) deaths. The numbers of mild, moderate and severe NARDS were 537 (53.4%), 286 (28.4%) and 182 (18.2%). Two or more doses of surfactant was associated with increased mortality as compared with one or less doses of surfactant (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.20-3.10, P = 0.006). Similarity also appeared in the comparison between EOS and non-EOS triggers (OR 1.57, 95% CI 1.06-2.33, P = 0.023). Interpretation: NARDS incidence was 1.44% and the three main aetiologies were pneumonia, asphyxia and EOS. The cumulative incidences were 65.6%, 86.7%, and 94.1% within one, two and three days after birth. Our results suggested that two or more doses of surfactant increased mortality compared with one or less doses of surfactant. Funding: The National Clinical Research Center of China and Clinical Medical Study Program of Children's Hospital of Chongqing Medical University (NCRC-2019-GP-13) and Natural Science Foundation of Chongqing (cstc2020jcyj-msxmX0197).

Noninvasive high-frequency oscillatory ventilation versus nasal intermittent positive pressure ventilation for preterm infants as an extubation support: A systematic review and meta-analysis.

OBJECTIVE: We aimed to explore whether noninvasive high-frequency oscillatory ventilation (NHFOV) could reduce the incidence of reintubation compared with nasal intermittent positive pressure ventilation (NIPPV) in the postextubation phase of preterm infants. METHODS: Randomized controlled trials of NHFOV versus NIPPV were searched in PubMed, EMBASE, Cochrane Central, and MEDLINE. Meta-analysis was performed using Review Manager 5.3. RESULTS: Four randomized controlled trials including 1138 preterm infants were included in this study. Compared with NIPPV, NHFOV reduced the incidence of reintubation in the post-extubation phase of preterm infants (p = 0.01, RR = 0.72, 95% confidence interval (CI): 0.56∼0.94), and no heterogeneity was found in the four studies (p = 0.55, I2 = 0%). In the sensitivity analysis, the result showed that there was no significant difference in the incidence of reintubation between NHFOV and NIPPV after excluding one study (p = 0. 05, RR = 0.76 95% CI: 0.58∼1.00), and no heterogeneity was found in the other three studies (p = 0.95, I2 = 0%). There was no statistical difference between NHFOV and NIPPV in BPD, air leak, IVH (≥Grade III) and mortality. CONCLUSION: Among mechanically ventilated preterm infants, compared with NIPPV, NHFOV was potentially beneficial to reduce the incidence of reintubation after extubation and did not increase the risk of complications.

Risk factors for failure of nasal high frequency oscillatory ventilation as initial therapy in very low birth weight infants with respiratory distress syndrome / 中国新生儿科杂志

Objective:To study the risk factors of failure using nasal high frequency oscillatory ventilation (nHFOV) as initial therapy in the treatment of respiratory distress syndrome (RDS) in very low birth weight infants (VLBWIs).Methods:From January 2018 to December 2021, VLBWIs with RDS initially supported by nHFOV in NICU of our hospital were retrospectively analyzed. They were assigned into success and failure groups according to the ventilation efficacy. Demographic data and clinical outcomes of the two groups were compared. Risk factors of initial nHFOV failure were analyzed using binary Logistic regression method.Results:A total of 135 infants were included, including 103 in the success group and 32 in the failure group. The initial nHFOV failure rate was 23.7%. The failure group had lower pH (7.26±0.09 vs. 7.33±0.08) and PaO 2 [61.0 (49.6, 77.2) mmHg vs. 83.6 (64.4, 99.0) mmHg] than the success group ( P<0.05) and higher PaCO 2 than the success group [49.0 (42.3, 58.1) mmHg vs. 43.4 (36.0, 50.0) mmHg] ( P<0.05). Using PaCO 2 as predictor, the area under the curve (AUC) was 0.682 (95% CI 0.575-0.788) and the cut-off value was 44.8 mmHg for nHFOV failure and the AUC was 0.716 (95% CI 0.615-0.817) and the cut-off value was 67.1 mmHg for nHFOV success. The incidences of early onset sepsis (EOS), shock within 3 d and hemodynamically significant patent ductus arteriosus (hsPDA) in the failure group were significantly higher than the success group (40.6% vs. 7.8%, 53.1% vs. 2.9%, 31.3% vs. 13.6%, P<0.05, respectively). Binary logistic regression analysis found that PaO 2<67.1 mmHg ( OR=5.458,95% CI 1.730-17.220) on the first blood gas analysis and shock within 3 d ( OR=26.585,95% CI 3.854-183.396) were independent risk factors for initial nHFOV failure ( P<0.05). Conclusions:The failure of initial nHFOV is correlated with the first blood gas parameters, EOS, hsPDA and shock within 3 d. Shock within 3 d and low PaO 2(<67.1 mmHg) were independent risk factors for initial nHFOV failure.