Receipt of high-frequency ventilation is associated with acute kidney injury in very preterm neonates.

BACKGROUND: High-frequency ventilation (HFV) is frequently used in critically ill preterm neonates. We aimed to determine the incidence of acute kidney injury (AKI) in neonates less than 29 weeks gestation who received HFV in the first week of life and to determine if the rates of AKI differed in those who received other forms of respiratory support. METHODS: This retrospective cohort study of 24 international, level III/IV neonatal intensive care units (NICUs) included neonates less than 29 weeks gestation from the AWAKEN study database. Exclusion criteria included the following: no intravenous fluids ≥ 48 h, admission ≥ 14 days of life, congenital heart disease requiring surgical repair at < 7 days of life, lethal chromosomal anomaly, death within 48 h, severe congenital kidney abnormalities, inability to determine AKI status, insufficient data on ventilation, and when the diagnosis of early AKI was unable to be made. Subjects were grouped into three groups based on ventilation modes (CPAP/no ventilation, conventional ventilation, and HFV). RESULTS: The incidence of AKI was highest in the CPAP/no ventilation group, followed by HFV, followed by conventional ventilation (CPAP/no ventilation 48.5% vs. HFV 42.6% vs. conventional ventilation 28.4% (p = 0.009). An increased risk for AKI was found for those on HFV compared to CPAP/no ventilation (HR = 2.65; 95% CI:1.22-5.73). CONCLUSIONS: HFV is associated with AKI in the first week of life. Neonates on HFV should be screened for AKI. The reasons for this association are not clear. Further studies should evaluate the relationship between ventilator strategies and AKI in premature neonates. A higher resolution version of the Graphical abstract is available as Supplementary information.

A review of the utility of high-frequency oscillatory ventilation in burn and trauma ICU patients.

PURPOSE OF REVIEW: The purpose was to examine the utility of high-frequency oscillatory ventilation (HFOV) in trauma and burn ICU patients who require mechanical ventilation, and provide recommendations on its use. RECENT FINDINGS: HFOV may be beneficial in burn patients with smoke inhalation injury with or without acute lung injury/acute respiratory distress syndrome (ARDS), as it improves oxygenation and minimizes ventilator-induced lung injury. It also may have a role in improving oxygenation in trauma patients with blast lung injury, pulmonary contusions, pneumothorax with massive air leak, and ARDS; however, the mortality benefit is unknown. SUMMARY: Although some studies have shown promise and improved outcomes associated with HFOV, we recommend its use as a rescue modality for patients who have failed conventional ventilation.

High-Frequency Oscillatory Ventilation and Ventilator-Induced Lung Injury: Size Does Matter.

OBJECTIVES: The theoretical basis for minimizing tidal volume during high-frequency oscillatory ventilation may not be appropriate when lung tissue stretch occurs heterogeneously and/or rapidly. The objective of this study was to assess the extent to which increased ventilation heterogeneity may contribute to ventilator-induced lung injury during high-frequency oscillatory ventilation in adults compared with neonates on the basis of lung size, using a computational model of human lungs. DESIGN: Computational modeling study. SETTING: Research laboratory. SUBJECTS: High-fidelity, 3D computational models of human lungs, scaled to various sizes representative of neonates, children, and adults, with varying injury severity. All models were generated from one thoracic CT image of a healthy adult male. INTERVENTIONS: Oscillatory ventilation was simulated in each lung model at frequencies ranging from 0.2 to 40 Hz. Sinusoidal flow oscillations were delivered at the airway opening of each model and distributed through the lungs according to regional parenchymal mechanics. MEASUREMENTS AND MAIN RESULTS: Acinar flow heterogeneity was assessed by the coefficient of variation in flow magnitudes across all acini in each model. High-frequency oscillatory ventilation simulations demonstrated increasing heterogeneity of regional parenchymal flow with increasing lung size, with decreasing ratio of deadspace to total acinar volume, and with increasing frequency above lung corner frequency and resonant frequency. Potential for resonant amplification was greatest in injured adult-sized lungs with higher regional quality factors indicating the presence of underdamped lung regions. CONCLUSIONS: The potential for ventilator-induced lung injury during high-frequency oscillatory ventilation is enhanced at frequencies above lung corner frequency or resonant frequency despite reduced tidal volumes, especially in adults, due to regional amplification of heterogeneous flow. Measurements of corner frequency and resonant frequency should be considered during high-frequency oscillatory ventilation management.

DCO2/PaCO2 correlation on high-frequency oscillatory ventilation combined with volume guarantee using increasing frequencies in an animal model.

To examine the correlation DCO2/PaCO2 on high-frequency oscillatory ventilation (HFOV) combined with volume guarantee (VG) throughout increasing frequencies in two different respiratory conditions, physiological and low compliance. Neonatal animal model was used, before and after a bronchoalveolar lavage (BAL). HFOV combined with VG was used. The frequency was increased from 10 to 20 Hz, and high-frequency tidal volume (VThf) was gradually decreased maintaining a constant DCO2. Arterial partial pressure of carbon dioxide (PaCO2) was evaluated after each frequency and VThf change. Six 2-day-old piglets were studied. A linear decrease in PaCO2 was observed throughout increasing frequencies in both respiratory conditions while maintaining a constant DCO2, showing a significant difference between the initial PaCO2 (at 10 Hz) and the PaCO2 obtained at 18 and 20 Hz. A new DCO2 equation (corrected DCO2) was calculated in order to better define the correlation between DCO2 and the observed PaCO2.Conclusion: The correlation DCO2/PaCO2 throughout increasing frequencies is not linear, showing a greater CO2 elimination efficiency at higher frequencies, in spite of maintaining a constant DCO2. So, using frequencies close to the resonant frequency of the respiratory system on HFOV combined with VG, optimizes the efficiency of gas exchange.What is Known: • The efficacy of CO2removal during high-frequency oscillatory ventilation (HFOV), described as the diffusion coefficient of CO2(DCO2) is related to the square of the high-frequency tidal volume (VThf) and the frequency (f), expressed as DCO2= VThf2× f.What is New: • The correlation between DCO2and PaCO2throughout increasing frequencies is not linear, showing a greater CO2elimination efficiency at higher frequencies. So, using very high frequencies on HFOV combined with volume guarantee optimizes the efficiency of gas exchange allowing to minimize lung injury.

Non-invasive respiratory support for the management of transient tachypnea of the newborn.

BACKGROUND: Transient tachypnea of the newborn (TTN) is characterized by tachypnea and signs of respiratory distress. Transient tachypnea typically appears within the first two hours of life in term and late preterm newborns. Supportive management might be sufficient. Non-invasive (i.e. without endotracheal intubation) respiratory support may, however, be administered to reduce respiratory distress during TTN. In addition, non-invasive respiratory support might improve clearance of lung liquid thus reducing the effort required to breathe, improving respiratory distress and potentially reducing the duration of tachypnea. OBJECTIVES: To assess benefits and harms of non-invasive respiratory support for the management of transient tachypnea of the newborn. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 2), MEDLINE (1996 to 19 February 2019), Embase (1980 to 19 February 2019) and CINAHL (1982 to 19 February 2019). We applied no language restrictions. We searched clinical trial registries for ongoing studies. SELECTION CRITERIA: Randomized controlled trials, quasi-randomized controlled trials and cluster trials on non-invasive respiratory support provided to infants born at 34 weeks' gestational age or more and less than three days of age with transient tachypnea of the newborn. DATA COLLECTION AND ANALYSIS: For each of the included trials, two review authors independently extracted data (e.g. number of participants, birth weight, gestational age, duration of oxygen therapy, need for continuous positive airway pressure [CPAP] and need for mechanical ventilation, duration of mechanical ventilation, etc.) and assessed the risk of bias (e.g. adequacy of randomization, blinding, completeness of follow-up). The primary outcomes considered in this review were need for mechanical ventilation and pneumothorax. We used the GRADE approach to assess the certainty of evidence. MAIN RESULTS: We included three trials (150 infants) comparing either CPAP to free-flow oxygen, nasal intermittent mandatory ventilation to nasal CPAP, or nasal high-frequency percussive ventilation versus nasal CPAP. Due to these different comparisons and to high clinical heterogeneity in the baseline clinical characteristics, we did not pool the three studies. The use of CPAP versus free oxygen did not improve the primary outcomes of this review: need for mechanical ventilation (risk ratio [RR] 0.30, 95% confidence interval [CI] 0.01 to 6.99; 1 study, 64 participants); and pneumothorax (not estimable, no cases occurred). Among secondary outcomes, CPAP reduced the duration of tachypnea as compared to free oxygen (mean difference [MD] -21.10 hours, 95% CI -22.92 to -19.28; 1 study, 64 participants). Nasal intermittent ventilation did not reduce the need for mechanical ventilation as compared with CPAP (RR 4.00, 95% CI 0.49 to 32.72; 1 study, 40 participants) or the incidence of pneumothorax (RR 1.00, 95% CI 0.07 to 14.90; 1 study, 40 participants); duration of tachypnea did not differ (MD 4.30, 95% CI -19.14 to 27.74; 1 study, 40 participants). In the study comparing nasal high-frequency ventilation to CPAP, no cases of mechanical ventilation of pneumothorax occurred (not estimable; 1 study, 46 participants); duration of tachypnea was reduced in the nasal high-frequency ventilation group (MD -4.53, 95% CI -5.64 to -3.42; 1 study, 46 participants). The quality of the evidence was very low due to the imprecision of the estimates and unclear risk of bias for detection bias and high risk of bias for reporting bias. Tests for heterogeneity were not applicable for any of the analyses as no studies were pooled. Two trials are ongoing. AUTHORS' CONCLUSIONS: There is insufficient evidence to establish the benefit and harms of non-invasive respiratory support in the management of transient tachypnea of the newborn. Though two of the included trials showed a shorter duration of tachypnea, clinically relevant outcomes did not differ amongst the groups. Given the limited and low quality of the evidence available, it was impossible to determine whether non-invasive respiratory support was safe or effective for the treatment of transient tachypnea of the newborn.

Current views of complications associated with neonatal ventilation.

Infants born prematurely require external respiratory support device like ventilation for the purpose of life saving. However, these ventilation machines have complications that sometimes unfortunately result in morbidity. New ventilation techniques have been developed to prevent morbidity, but have yet to be fully evaluated. The present review article would discuss current aspects of this life saving gear especially for pediatric patients in clinical setting. Besides basic ventilation apparatus, advancements in the filed like proportional assist ventilation, volume targeted ventilation would be discussed.

Ambient Noise Production by High-Frequency Neonatal Ventilators.

OBJECTIVE: To assess sound levels of 4 high-frequency neonatal ventilators to determine whether there is a safety benefit in using modern high-frequency ventilators compared with older models. STUDY DESIGN: We performed a bench study comparing noise production of the Sensormedics 3100A Oscillator, Bunnell Life Pulse Jet Ventilators Model 203 and Model 204, and Dräger VN500 in high-frequency mode. A wide range of ventilation settings was examined. All measurements were performed in triplicate using a high-fidelity sound meter, with data analyzed using ANOVA and regression analyses. RESULTS: The Dräger ventilator was quietest overall, with average sound levels of 49.8 ± 0.49 dB across all settings. The average noise from the Sensormedics was 53.6 ± 2.01 dB, for Bunnell Model 203 was 54.1 ± 1.09 dB, and for Bunnell Model 204 was 53.7 ± 1.45 dB. Adjustments made to frequency/rate and mean airway pressure/positive end-expiratory pressure had minimal effect on noise, and increasing amplitude/peak inspiratory pressure resulted in significantly more noise by all ventilators. At all settings, the Sensormedics and Bunnell ventilators were louder than the Dräger, and the difference became greater as amplitude/peak inspiratory pressure was increased. CONCLUSIONS: The Dräger VN500 in high-frequency mode produces significantly less noise that both the Sensormedics and Bunnell ventilators. These data suggest that using the Dräger VN500 as a high-frequency ventilator may reduce the potential for adverse outcomes created by ventilator noise.

Predictors of Respiratory Improvement 1 Week after Ligation of Patent Ductus Arteriosus in Preterm Infants.

OBJECTIVE: To characterize preterm infants that demonstrates respiratory improvement 7 days after ligation of a patent ductus arteriosus (PDA). STUDY DESIGN: We performed a 2-phase study of preterm infants (birthweight <1500 g between 2010 and 2016). We first did a retrospective analysis using regression modeling of ligation population. We then performed a case-control study comparing a ligation group with infants matched by gestational age, postnatal age, and preligation respiratory condition (ventilator mode, mean airway pressure [MAP], and fraction of inspired oxygen [FiO2]). Respiratory improvement was defined as either extubation, downgrading of ventilatory mode, reduction in MAP >25%, or decrease in FiO2 >25%. RESULTS: Forty-five (42%) of 107 preterm infants (gestational age 25.5 ± 1.7 weeks) with ligation showed respiratory improvement at 7 days. Infants on high frequency ventilation (HFV) were more likely to have respiratory improvement (aOR 5.03, 95% CI [1.14-22.18]). In matched-control analysis of 89 pairs, there was no difference in respiratory improvement. Among infants on HFV, the ligation group had an increase in MAP during 3 days prior to ligation. For infants on conventional ventilation, the ligation group had higher MAP and FiO2 than the control group during the first 2-3 postoperative days. CONCLUSIONS: Among infants undergoing PDA ligation, those on HFV were more likely to have respiratory improvement in the first week, possibly because of the prevention of further respiratory deterioration. For infants on conventional ventilation, ligation was associated with higher respiratory support in the immediate postligation period without respiratory benefits at 7 days. As HFV was used as a rescue mode, our findings suggest that those with worse lung disease may achieve greater short term benefit from PDA ligation.

Lung Lavage with Dilute Surfactant vs. Bolus Surfactant for Meconium Aspiration Syndrome.

OBJECTIVE: To compare the effectiveness of lung lavage with surfactant vs. bolus surfactant treatment in meconium aspiration syndrome (MAS). PATIENTS AND METHODS: This randomized controlled trial included newborns ventilated with MAS. In lavage group (n = 17) 30 ml/kg of diluted porcine surfactant was instilled into the lung. In bolus group (n = 16) porcine surfactant (100 mg/kg) was administered as bolus. Respiratory outcomes and mortality were compared between groups. RESULTS: Duration of respiratory support was found to be similar between lavage and bolus groups (3 vs. 3.5 days, p = 0.36). Death or requirement for extracorporeal membrane oxygenation (ECMO) was 12% vs. 6%; respectively (RR: 2, 95% CI 0.16-24.48; p = 1.0). Duration of oxygen therapy, high-frequency ventilation or inhaled nitric oxide requirement did not differ among the groups. CONCLUSION: Lung lavage did not show any advantage over bolus therapy on duration of respiratory support. The incidence of pneumothorax and surfactant re-administration decreased nonsignificantly in lavage group. CLINICAL TRIAL REGISTRATION: We registered the trial to ClinicalTrials.gov (http://clinicaltrials.gov) under identifier NCT02041546. REGISTRY NAME: Lung Lavage With Dilute Poractant Alfa for Meconium Aspiration Syndrome.

[Research advances in noninvasive high-frequency oscillatory ventilation in neonates].

Noninvasive ventilation is an important respiratory management technique for the treatment of mild or moderate respiratory failure in the neonatal intensive care unit. Its reasonable application can effectively avoid the use of invasive ventilation and related complications. Recent studies have found that noninvasive high-frequency oscillatory ventilation has the advantages of both nasal continuous positive airway pressure and high-frequency ventilation and can rapidly improve oxygenation, effectively remove carbon dioxide, and improve respiratory failure. Therefore, it is considered a new and effective noninvasive ventilation mode. There are many studies on the rational use, efficacy, and safety of noninvasive high-frequency oscillatory ventilation in neonates around the world. This article reviews the advances in the clinical studies on noninvasive high-frequency oscillatory ventilation in neonates.

Mechanical ventilation for children.

PURPOSE OF REVIEW: The aim of this review is to analyze innovative data pertaining to the clinical use of mechanical ventilation for children. RECENT FINDINGS: The optimal definition and treatment of pediatric acute respiratory distress syndrome, the application of innovative ventilation modes in children to optimize child/ventilator interaction, and pediatric noninvasive ventilation, including specific interfaces, have been recently evaluated in the literature. SUMMARY: Despite the improvement observed in the last decades in the treatment of pediatric acute respiratory failure and the diffusion of innovative modes of mechanical ventilation, there are no clear and consistent guidelines for the use of mechanical ventilation for children. In several areas data are still lacking, and in many others they are extrapolated from studies performed in adults; the direct evaluation of results obtained from studies specific to the pediatric population is therefore crucial.

Individualized lung recruitment during high-frequency ventilation in preterm infants is not associated with lung hyperinflation and air leaks.

UNLABELLED: Lung recruitment during high-frequency ventilation (HFV) in preterm infants with respiratory distress syndrome (RDS) has been associated with an increased risk of lung hyperinflation and air leaks. Individualizing the lung recruitment procedure to the severity of lung disease of each patient might reduce these risks. In this prospective cohort study, we evaluated chest X-ray (CXR) characteristics during individualized oxygenation-guided lung recruitment with HFV in preterm infants with RDS, before and after surfactant therapy. Two pediatric radiologists scored radiolucency, the presence of lung hyperinflation, and/or air leaks following lung recruitment during HFV in 69 infants before and 39 infants after surfactant treatment. Following lung recruitment, the median radiolucency score was 2, with 44 (64 %) infants having a score ≤2. Only mild to moderate hyperinflation was seen in 13 (19 %) infants, with no air leaks. After the surfactant, the radiolucency score improved in 62 % of 39 paired CXRs (p < 0.001). Mild to moderate hyperinflation was seen in nine (24 %) patients. During the entire admission, only four (6 %) of the patients developed air leaks. CONCLUSION: The risk of significant hyperinflation and air leaks is low when using an individualized oxygenation-guided recruitment procedure during HFV in preterm infants with RDS. WHAT IS KNOWN: • Lung recruitment during high-frequency ventilation in preterm infants with respiratory distress syndrome is associated with an increased risk of lung hyperinflation and air leaks. What is New: • The risk of lung hyperinflation and air leaks is low when using an individualized oxygenation-guided lung recruitment procedure during high-frequency ventilation in preterm infants with respiratory distress syndrome.

High-Frequency Oscillatory Ventilation in Pediatric Acute Lung Injury: A Multicenter International Experience.

OBJECTIVE: We aim to describe current clinical practice, the past decade of experience and factors related to improved outcomes for pediatric patients receiving high-frequency oscillatory ventilation. We have also modeled predictive factors that could help stratify mortality risk and guide future high-frequency oscillatory ventilation practice. DESIGN: Multicenter retrospective, observational questionnaire study. SETTING: Seven PICUs. PATIENTS: Demographic, disease factor, and ventilatory and outcome data were collected, and 328 patients from 2009 to 2010 were included in this analysis. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Patients were classified into six cohorts based on underlying diagnosis. We used univariate analysis to identify factors associated with mortality risk and multivariate logistic regression to identify independent predictors of mortality risk. An oxygenation index greater than 35 and immunocompromise exhibited the greatest predictive power (p < 0.0001) for increased mortality risk, and respiratory syncytial virus was associated with lowest mortality risk (p = 0.003). Differences in mortality risk as a function of oxygenation index were highly dependent on primary underlying condition. A trend toward an increase in oscillator amplitude and frequency was observed when compared with historical data. CONCLUSIONS: Given the number of centers and subjects included in the database, these findings provide a robust description of current practice regarding the use of high-frequency oscillatory ventilation for pediatric hypoxic respiratory failure. Patients with severe hypoxic respiratory failure and immunocompromise had the highest mortality risk, and those with respiratory syncytial virus had the lowest. A means of identifying the risk of 30-day mortality for subjects can be obtained by identifying the underlying disease and oxygenation index on conventional ventilation preceding the initiation of high-frequency oscillatory ventilation.

Controversies in the Management of Severe ARDS: Optimal Ventilator Management and Use of Rescue Therapies.

Groundbreaking research into the pathophysiology of the adult acute respiratory distress syndrome (ARDS) and the prevention of ventilator-induced lung injury has led to dramatic improvements in survival. Investigations over the last two decades have revolved around the development of rescue therapies that can be used for patients with severe ARDS and refractory hypoxemia. To date, the techniques of using high levels of positive end-expiratory pressure (PEEP), prompt institution of neuromuscular blockade, and early prolonged prone positioning have been shown to reduce mortality in patients with severe ARDS. PEEP titration using transpulmonary pressure estimations assisted by esophageal manometry has been shown to result in a substantial improvement in oxygenation. Extracorporeal membrane oxygenation (ECMO) has been used increasingly since the mid-2000s in part due to the H1N1 epidemic. A major randomized controlled trial conducted during this period showed a significant mortality benefit for patients with severe ARDS who were referred to a center with ECMO capabilities. The routine use of inhaled nitric oxide for patients with severe ARDS has not been shown to lead to more than a transient and limited improvement in oxygenation, which may hinder its use as a sole rescue therapy. Finally, recent studies have found that the routine use of high-frequency oscillatory ventilation in severe ARDS does not result in decreased mortality, although the technique has not been specifically investigated as rescue therapy for severe refractory hypoxemia.

Nasal high-frequency oscillation ventilation in neonates: a survey in five European countries.

UNLABELLED: Nasal high-frequency oscillation ventilation (nHFOV) is a non-invasive ventilation mode that applies an oscillatory pressure waveform to the airways using a nasal interface. nHFOV has been shown to facilitate carbon dioxide expiration, but little is known about its use in neonates. In a questionnaire-based survey, we assessed nHFOV use in neonatal intensive care units (NICUs) in Austria, Switzerland, Germany, the Netherlands, and Sweden. Questions included indications for nHFOV, equipment used, ventilator settings, and observed side effects. Of the clinical directors of 186 NICUs contacted, 172 (92 %) participated. Among those responding, 30/172 (17 %) used nHFOV, most frequently in premature infants <1500 g (27/30) for the indication nasal continuous positive airway pressure (nCPAP) failure (27/30). Binasal prongs (22/30) were the most common interfaces. The median (range) mean airway pressure when starting nHFOV was 8 (6-12) cm H2O, and the maximum mean airway pressure was 10 (7-18) cm H2O. The nHFOV frequency was 10 (6-13) Hz. Abdominal distension (11/30), upper airway obstruction due to secretions (8/30), and highly viscous secretions (7/30) were the most common nHFOV side effects. CONCLUSION: In a number of European NICUs, clinicians use nHFOV. The present survey identified differences in nHFOV equipment, indications, and settings. Controlled clinical trials are needed to investigate the efficacy and side effects of nHFOV in neonates.

Acute respiratory distress syndrome in a child with severe epileptic disorder treated successfully by extracorporeal membrane oxygenation: a case report.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is now a candidate therapy for children with acute respiratory failure. CASE PRESENTATION: We report our experience of using central ECMO therapy for acute respiratory distress syndrome followed by seizure in a 15-month-old girl with a severe epileptic disorder. Her respiratory distress was refractory to standard medical treatment and mechanical ventilatory support. Her condition was complicated by development of a pneumothorax. The patient was successfully weaned off ECMO and discharged without deterioration of her neurological status. CONCLUSION: The successful outcome in this case resulted from the central ECMO, which enabled "lung rest" and adequate cerebral blood flow. In skilled ECMO facilities, early implementation of ECMO would give some advantages to patients such as the one presented here. Given the invasiveness and the ease of the procedure, introduction of dual-lumen catheters adequately sized for pediatric patients in Japan is required.

[Clinical efficacy of preferred use of high-frequency oscillatory ventilation in treatment of neonatal pulmonary hemorrhage].

OBJECTIVE: To investigate the clinical efficacy and safety of preferred use of high-frequency oscillatory ventilation (HFOV) in the treatment of neonatal pulmonary hemorrhage. METHODS: The clinical efficacy of preferred use of HFOV (preferred use group) and rescue use of HFOV after conventional mechanical ventilation proved ineffective (rescue use group) in the treatment of 26 cases of neonatal pulmonary hemorrhage was retrospectively analyzed. The oxygenation index (OI), pulmonary hemorrhage time, hospitalization time, ventilation time, oxygen therapy time, complications, and outcome of the two groups were compared. RESULTS: Compared with the rescue use group, the preferred use group had significantly lower IO values at 1, 6, 12, 24, 48, and 72 hours after treatment (P<0.05). Compared with the rescue use group, the preferred use group had a significantly lower incidence of ventilator associated pneumonia (VAP) (P<0.05) and a significantly higher cure rate (P<0.05). There were no statistically significant differences in the incidences of pneumothorax, intracranial hemorrhage, and digestive tract hemorrhage between the two groups (P>0.05). Compared with those in the rescue use group, children who survived in the preferred use group had significantly shorter pulmonary hemorrhage time, hospitalization time, ventilation time, and oxygen therapy time (P<0.05). CONCLUSIONS: Compared with the rescue use of HFOV, preferred use of HFOV can better improve oxygenation function, reduce the incidence of VAP, shorten the course of disease, and increase cure rate while not increasing the incidence of adverse effects.

Efficacy and adverse events of high-frequency oscillatory ventilation in adult patients with acute respiratory distress syndrome: a meta-analysis.

INTRODUCTION: Theoretically, high-frequency oscillatory ventilation (HFOV) achieves all goals of a lung-protective ventilatory mode and seems ideal for the treatment of adult patients with acute respiratory distress syndrome (ARDS). However, its effects on mortality and adverse clinical outcomes remain uncertain given the paucity of high-quality studies in this area. This meta-analysis was performed to evaluate the efficacy and adverse events of HFOV in adults with ARDS. METHODS: We searched PubMed, EMBASE and Cochrane Central Register of Controlled Trials through February 2014 to retrieve randomized controlled trials of HFOV in adult ARDS patients. Two independent reviewers extracted data on study methods, clinical and physiological outcomes and adverse events. The primary outcome was 30-day or hospital mortality. Risk of bias was evaluated with the Cochrane Collaboration's tool. Mortality, oxygenation and adverse effects of HFOV were compared to those of conventional mechanical ventilation. A random-effects model was applied for meta-analysis. RESULTS: A total of five trials randomly assigning 1,580 patients met inclusion criteria. Pooled data showed that HFOV significantly improved oxygenation on day one of therapy (four studies; 24% higher; 95% confidence interval (CI) 11 to 40%; P <0.01). However, HFOV did not reduce mortality risk (five studies; risk ratio (RR) 1.04; 95% CI 0.83 to 1.31; P = 0.71) and two early terminated studies suggested a harmful effect of HFOV in ARDS (two studies; RR 1.33; 95% CI 1.09 to 1.62; P <0.01). Safety profiles showed that HFOV was associated with a trend toward increased risk of barotrauma (five studies; RR 1.19; 95% CI 0.83 to 1.72; P = 0.34) and unfavorable hemodynamics (five studies; RR 1.16; 95% CI 0.97 to 1.39; P = 0.12). CONCLUSIONS: HFOV improved oxygenation in adult patients with ARDS; however, it did not confer a survival benefit and might cause harm in the era of lung-protective ventilation strategy. The evidence suggests that HFOV should not be a routine practice in ARDS and further studies specifically selecting patients for this ventilator mode should be pursued.

Is high-frequency oscillatory ventilation more effective and safer than conventional protective ventilation in adult acute respiratory distress syndrome patients? A meta-analysis of randomized controlled trials.

INTRODUCTION: Comprehensively evaluating the efficacy and safety of high-frequency oscillatory ventilation (HFOV) is important to allow clinicians who are using or considering this intervention to make appropriate decisions. METHODS: To find randomized controlled trials (RCTs) comparing HFOV with conventional mechanical ventilation (CMV) as an initial treatment for adult ARDS patients, we searched electronic databases (including PubMed, MedLine, Springer Link, Elsevier Science Direct, ISI web of knowledge, and EMBASE) with the following terms: "acute respiratory distress syndrome", "acute lung injury", and "high frequency oscillation ventilation". Additional sources included reference lists from the identified primary studies and relevant meta-analyses. Two investigators independently screened articles and extracted data. Meta-analysis was conducted using random-effects models. RESULTS: We included 6 RCTs with a total of 1,608 patients in this meta-analysis. Compared with CMV, HFOV did not significantly reduce the mortality at 30 or 28 days. The pooled relative risk (RR) was 1.051 (95% confidence interval (CI) 0.813 to 1.358). ICU mortality was also not significantly reduced in HFOV group, with a pooled RR of 1.218 (95% CI 0.925 to 1.604). The pooled effect sizes of HFOV for oxygenation failure, ventilation failure and duration of mechanical ventilation were 0.557 (95% CI 0.351 to 0.884), 0.892 (95% CI 0.435 to 1.829) and 0.079 (95% CI -0.045 to 0.203), respectively. The risk of barotrauma and hypotension were similar between the CMV group and HFOV group, with a RR of 1.205 (95% CI 0.834 to 1.742) and a RR of 1.326 (95% CI 0.271 to 6.476), respectively. CONCLUSIONS: Although HFOV seems not to increase the risk of barotrauma or hypotension, and reduces the risk of oxygenation failure, it does not improve survival in adult acute respiratory distress syndrome patients.

Mechanical ventilation in the newborn; a simplified approach. Part 2: High-frequency ventilation.

High frequency oscillatory ventilation (HFOV) is becoming an increasingly popular intervention in the neonatal intensive care unit. This article will attempt to explain the principles of HFOV. It is inherently more difficult to become skilled in this technique than in other forms of mechanical ventilation, so caution is warranted.