Rescue High Frequency Oscillatory Ventilation Research Articles

High-frequency oscillatory ventilation versus conventional ventilation in pediatric patients with acute lung injury: outcomes evaluation

BackgroundWith the development of medical technology and advancements of intensive care units, many types of mechanical ventilators are recruited in the management of acute respiratory distress syndrome (ARDS)/acute lung injury (ALI). We evaluated the outcome of the high-frequency oscillatory ventilation (HFOV) compared to conventional mechanical ventilation (CMV) in pediatric patients with critical respiratory situations mainly ALI or ARDS. A prospective cohort study was performed from 2019 to 2020 in the pediatric intensive care unit (PICU). The following data were recorded: demographic and clinical data, length of PICU stay, mechanical ventilation days, and mortality percentages.ResultsFifty cases who fulfilled the inclusion criteria were divided into two groups, 24 patients on HFOV from the start and the other 26 were admitted on rescue HFOV after the failure of CMV. There was no statistically significant difference between the two groups regarding the age (p = 0.571) and the oxygenation index (OI) (p = 0.651). Early HFOV demonstrated shorter length of PICU stay and fewer days on mechanical ventilation. The mortality rate was less with the application of early HFOV compared to rescue HFOV.ConclusionsEarly admission on HFOV can be a safe option in the management of patients with critical lung situation as ARDS/ALI.

Evaluation of High-Frequency Oscillatory Ventilation as a Rescue Strategy in Respiratory Failure.

The use of high-frequency oscillatory ventilation (HFOV) is backed by sound physiologic rationale, but clinical data on the elective use of HFOV have been largely disappointing. Nonetheless, HFOV is still occasionally used as a rescue mode in patients with severe hypoxemia. The evidence that supports this practice is sparse. This was a retrospective single-center analysis that involved subjects admitted to the medical ICU at Cleveland Clinic, Cleveland, Ohio. We included all adult patients (ages > 18 y) who received rescue HFOV between January 1, 2010, and December 31, 2018, and analyzed their clinical outcomes. A total of 48 subjects were included in the analysis. The most common primary diagnosis was pneumonia (n = 33 [68.8%]), followed by aspiration (n = 6 [12.5%]) and diffuse alveolar hemorrhage (n = 2 [4.2%]). Switching to HFOV improved oxygenation but also increased vasopressor requirements at 3 h. The mortality rate of the study population was 92% (44/48). Our study did not support utilization of HFOV as a "last-ditch" rescue measure in subjects with respiratory failure. The delayed timing of HFOV initiation and its detrimental hemodynamic effects are among the potential reasons for the high mortality rate.

Therapeutic effects and outcomes of rescue high-frequency oscillatory ventilation for premature infants with severe refractory respiratory failure

Despite wide application of high frequency oscillatory ventilation (HFOV) in neonates with respiratory distress, little has been reported about its rescue use in preterm infants. We aimed to evaluate the therapeutic effects of HFOV in preterm neonates with refractory respiratory failure and investigate the independent risk factors of in-hospital mortality. We retrospectively analyzed data collected prospectively (January 2011–December 2018) in four neonatal intensive care units of two tertiary-level medical centers in Taiwan. All premature infants (gestational age 24–34 weeks) receiving HFOV as rescue therapy for refractory respiratory failure were included. A total of 668 preterm neonates with refractory respiratory failure were enrolled. The median (IQR) gestational age and birth weight were 27.3 (25.3–31.0) weeks and 915.0 (710.0–1380.0) g, respectively. Pre-HFOV use of cardiac inotropic agents and inhaled nitric oxide were 70.5% and 23.4%, respectively. The oxygenation index (OI), FiO2, and AaDO2 were markedly increased after HFOV initiation (all p < 0.001), and can be decreased within 24–48 h (all p < 0.001) after use of HFOV. 375 (56.1%) patients had a good response to HFOV within 3 days. The final in-hospital mortality rate was 34.7%. No association was found between specific primary pulmonary disease and survival in multivariate analysis. We found preterm neonates with gestational age < 28 weeks, occurrences of sepsis, severe hypotension, multiple organ dysfunctions, initial higher severity of respiratory failure and response to HFOV within the first 72 h were independently associated with final in-hospital mortality. The mortality rate of preterm neonates with severe respiratory failure remains high after rescue HFOV treatment. Aggressive therapeutic interventions to treat sepsis and prevent organ dysfunctions are the suggested strategies to optimize outcomes.

An observational, prospective, multicenter study on rescue high-frequency oscillatory ventilation in neonates failing with conventional ventilation.

BackgroundTo achieve gas exchange goals and mitigate lung injury, infants who fail with conventional ventilation (CV) are generally switched to high-frequency oscillatory ventilation (HFOV). Although preferred in many neonatal intensive care units (NICUs), research on this type of rescue HFOV has not been reported recently.MethodsAn online registry database for a multicenter, prospective study was set to evaluate factors affecting the response of newborn infants to rescue HFOV treatment. The study population consisted of 372 infants with CV failure after at least 4 hours of treatment in 23 participating NICUs. Patients were grouped according to their final outcome as survived (Group S) or as died or received extracorporeal membrane oxygenation (ECMO) (Group D/E). Patients’ demographic characteristics and underlying diseases in addition to their ventilator settings, arterial blood gas (ABG) analysis results at 0, 1, 4, and 24 hours, type of device, ventilation duration, and complications were compared between groups.ResultsHFOV as rescue treatment was successful in 58.1% of patients. Demographic and treatment parameters were not different between groups, except that infants in Group D/E had lower birthweight (BW) (1655 ± 1091 vs. 1858 ± 1027 g, p = 0.006), a higher initial FiO2 setting (83% vs. 72%, p < 0.001), and a higher rate of nitric oxide exposure (21.8% vs. 11.1%, p = 0.004) in comparison to infants who survived (Group S). The initial cut-offs for a successful response on ABG were defined as pH >7.065 (OR: 19.74, 95% CI 4.83–80.6, p < 0.001), HCO3 >16.35 mmol/L (OR: 1.06, 95% CI 1.01–1.1, p = 0.006), and lactate level <3.75 mmol/L (OR: 1.09%95 CI 1.01–1.16, p = 0.006). Rescue HFOV duration was associated with retinopathy of prematurity (p = 0.005) and moderate or severe chronic lung disease (p < 0.001), but not with patent ductus arteriosus or intraventricular hemorrhage, in survivors (p > 0.05).ConclusionRescue HFOV as defined for this population was successful in more than half of the patients with CV failure. Although the response was not associated with gestational age, underlying disease, device used, or initial MV settings, it seemed to be more effective in patients with higher BW and those not requiring nitric oxide. Initial pH, HCO3, and lactate levels on ABG may be used as predictors of a response to rescue HFOV.

Rescue High-Frequency Oscillatory Ventilation in Neonatal Respiratory Failure Unresponsive to Conventional Mechanical Ventilation

Background: High-frequency oscillatory ventilation (HFOV) has been shown to result in less lung injury. HFOV is also used in critically ill newborns when conventional mechanical ventilation (CV) fails, especially in units with lack of nitric oxide (NO) and extracorporeal membrane oxygenation. Objectives: There are no recent data on the response of newborns to rescue HFOV (rHFOV) in the literature. The aim of this study was to evaluate the risk factors that affect the response to rHFOV in newborns who had CV failure in respiratory support. Methods: Newborns who still had a respiratory failure in case of CV and switched to rHFOV were grouped as survived and died. The characteristics of the patients such as birth weight (BW), gestational age (GA), and disease, in addition to ventilator settings, arterial blood gas analysis, ventilation duration, and side effects were compared between the groups. Results: 84 patients with a mean GA of 32.1 ± 5.3 weeks and a mean BW of 1901 ± 1135 g were enrolled in the study. The patients were switched to rHFOV at median 28.5 hours of life. Infants who died had lower BW (1345 ± 935 g vs. 2557 ± 1035 g, P = 0.0001) and lower GA (31.7 ± 4.9 weeks vs. 34.8 ± 4.4 weeks, P = 0.03) in comparison with infants who survived. Prematurity (OR: 7.73, 95% CI: 2.1 - 24.7, P = 0.001) and having BW < 1500 g (OR: 7.02, 95% CI: 2.6 - 18.6, P < 0.001) increased mortality significantly. Cut-off values for BW and GA were found to be 1875 g and 32.5 weeks with 75% sensitivity and 78% specificity. There were no differences in the initial ventilation settings between the groups and no correlation between the side effects such as intraventricular hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia could be demonstrated with the duration of rHFOV. Conclusions: rHFOV in case of CV failure is more effective in patients with greater GA and BW, independent of the disease and initial rescue ventilator settings.

It Is Too Early to Declare Early or Late Rescue High-Frequency Oscillatory Ventilation Dead

It Is Too Early to Declare Early or Late Rescue High-Frequency Oscillatory Ventilation Dead

Rescue High-Frequency Oscillatory Ventilation for Congenital Diaphragmatic Hernia: What about Lung Histopathology and Necropsy Findings?

Introduction. It is not yet a resolved issue whether HFOV (high-frequency oscillatory ventilation), used as primary mode or as rescue ventilation, has benefit over conventional mechanical ventilation for CDH (congenital diaphragmatic hernia) patients treatment. Purpose. To evaluate the success rate of rescue HFOV for CDH, and the histological characteristics of the lungs, at the autopsy of the deceased patients. Material and Methods. Out of 80 CDH patients, 10 were treated with rescue HFOV. The success of HFOV, histological exam of the lungs of deceased patients, and data on the followup of discharged patients were assessed. Results. Rescue HFOV was started between two hours and four days of life. The success rate of rescue HFOV was 20% (2/10). Autopsy findings along with pulmonary hypoplasia included coarctation of aorta (n=1), pneumonia (n=3), meconium aspiration (n=2), hyaline membranes (n=2), severe muscular hypertrophy of medium and small diameter lung arteries (n=1), severe lung hypoplasia (n=1), pleural effusions (n=2), haemorrhagic diatesis (n=2), and signs of overwhelming sepsis (n=1). The five-years follow up of the two survivors revealed normal growth and neurodevelopment. Conclusions. The results of this study support the idea that rescue HFOV may increase survival of CDH patients, when conventional mechanical ventilation fails.

Rescue high frequency oscillation in neonates with acute respiratory failure

The aim was to study the efficacy of rescue High Frequency Oscillatory Ventilation (HFOV) in improving the oxygenation and ventilation in neonates with acute respiratory failure after failing Conventional Mechanical Ventilation (CMV). Primary outcome was short term oxygenation, lung recruitment, and ventilation and secondary outcome studied was survival. 675 babies were ventilated and 97 of them received HFOV. HFOV significantly improved oxygenation index, alveolar-arterial oxygen gradient, pH, PCO2, PO2 and caused better lung recruitment within 2 hours. Fifty seven babies (58.77%) survived and the mortality was more in <28 weeks, babies with pulmonary hemorrhage, sepsis and CDH.

High-frequency oscillatory ventilation and pediatric cardiac surgery: Yes, we can!

In the previous issue of Critical Care, Bojan and colleagues reported their experiences with high-frequency oscillatory ventilation (HFOV) after pediatric cardiac surgery. A total of 120 patients were treated with HFOV on the day of surgery, thus excluding rescue HFOV use. The main finding of the authors was that the duration of mechanical ventilation was significantly shorter in patients in whom HFOV was initiated on the day of surgery. Especially interesting about this work is that the authors used HFOV when there was evidence of pulmonary hypertension or right ventricular (RV) failure in their patients. This is an interesting approach as it is often assumed that high intra-thoracic pressures increase RV afterload and thus may enhance RV dysfunction. The findings of Bojan and colleagues may be explained by the fact that they were able to decrease the pulmonary vascular resistance by finding a proper balance between atelectasis and overdistension of the lung. It can be argued that it is possible to do so by applying positive end-expiratory pressure. But, at the same time, this may coincide with the delivery of high inspiratory pressures (>30 cm H2O). As HFOV is, in fact, a continuous positive airway pressure system, its advantage is that it is possible to maintain sufficient lung volume without large injurious pressure swings. Although the observations by Bojan and colleagues need to be confirmed in a prospective randomized trial, they have provided arguments not to rule out the early use of HFOV in pediatric cardiac surgery patients.

Rescue high frequency oscillatory ventilation vs conventional ventilation for infants with severe pulmonary dysfunction born at or near term.

Pulmonary disease is a major cause of mortality and morbidity in term and near term infants. Conventional ventilation (CV) has been used for many years but may lead to lung injury, require the subsequent use of more invasive treatment such as extra corporeal membrane oxygenation (ECMO), or result in death. There are some studies indicating that high frequency oscillatory ventilation (HFOV) may be more effective in these infants as compared to CV. The objective of this review is to determine if HFOV, as compared to conventional ventilation, reduces mortality and morbidity in term or near term infants with intractable lung disease without an increase in adverse effects. Standard search methods of the Cochrane Neonatal Review group were used. These included searches of the Oxford Database of Perinatal Trials, MEDLINE, EMBASE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, and journal hand searching by the Cochrane Collaboration. Randomized or quasi-randomized trials comparing HFOV and CV in term or near term infants with intractable respiratory failure were included in this review. The standard methods of the Cochrane Neonatal Review Group were used. The investigators separately extracted, assessed and coded all data for each study. Any disagreement was resolved by discussion. Data were synthesized using relative risk (RR) and risk difference (RD). Only one trial met the inclusion criteria. This rescue trial of 81 infants showed no evidence of a reduction in mortality at 28 days [RR 0.51 (0.05, 5.43)] or in failed therapy on the assigned mode of ventilation requiring cross-over to the other mode [RR 0.73 (0.47, 1.13)]. There were no significant differences in the numbers of patients requiring extracorporeal membrane oxygenation [RR 2.05 (0.85, 4.92)], days on a ventilator, days in oxygen or days in hospital. There are no data from randomized controlled trials supporting the routine use of rescue HFOV in term or near term infants with severe pulmonary dysfunction. The area is complicated by diverse pathology in such infants and by the occurrence of other interventions (surfactant, inhaled nitric oxide, inotropes). Randomized controlled trials are needed to establish the role of rescue HFOV in near term and term infants with pulmonary dysfunction before widespread use of this mode of ventilation in such infants.

Efficacité et limites de la ventilation par oscillations à haute fréquence après échec de la ventilation conventionnelle chez des prématurés atteints de maladie des membranes hyalines sévère

Conflicting reports of high-frequency oscillatory ventilation (HFOV) use as an alternative to conventional mechanical ventilation have been published. This retrospective study has evaluated the efficacy and safety of rescue HFOV in preterm infants with severe hyaline membrane disease (HMD) after the failure of conventional mechanical ventilation (CMV). All newborns hospitalized in our neonatal intensive care unit (NICU) from 10.1.1993 to 15.4.1995 with CMV failure, defined as the need for more than 55% FiO2 without any improvement for at least six hours, have been retrospectively studied. The infants were shared according to the absence (Gr I) or the presence (Gr II) of persistent pulmonary hypertension of neonate (PPHN) in addition to HMD before HFOV. Gestational age (GA) was 29.2 +/- 3.7 weeks (mean +/- SD) in Gr I and 30.3 +/- 2.8 in Gr II. Birth weight was 1379 +/- 750 g and 1471 +/- 612 g, respectively. As soon as three hours after the onset of HFOV in both groups, a dramatic improvement was observed with a FiO2 drop from 82 +/- 20% to 64.8 +/- 25.5% (P < 0.01). Among the infants, 62% survived without any major disability and 28% died (46% in Gr II vs 12% in Gr I, P < 0.01). A trend towards a worsening of pre-existing brain lesions has been noticed. An increased risk of mortality was observed when a secondary worsening in O2 requirements occurred 24 hours after the onset of HFOV, despite an initial significant improvement. SGA was also associated with a poor prognosis (46% of the deaths vs 29% for AGA infants, P < 0.05). HFOV has been successfully used in premature infants with severe respiratory disease and failure of CMV. Criteria of poor prognosis were PPHN and SGA, or a secondary worsening in oxygen requirements after initial improvement. A trend towards aggravation of pre-existing brain lesions has been noticed after HFOV. This aggravation is more frequent when PPHN is associated with HMD. This observation suggests caution for HFOV use when these conditions are present in premature infants.

Rescue high frequency oscillatory ventilation versus conventional ventilation for pulmonary dysfunction in preterm infants.

This section is under preparation and will be included in the next issue. Experimental studies suggest that high frequency oscillatory ventilation (HFOV) reduces pulmonary injury during mechanical ventilation. The main objective of this review is to test the hypothesis that by use of HFOV as compared to conventional ventilation (CV) it may be possible to rescue preterm infants with very severe lung disease and so at high risk of pulmonary air leak (PAL), without adverse effects. A search was carried out for all randomized controlled trials from MEDLINE using the MeSH and text terms, "high frequency ventilation", "high frequency oscillatory ventilation", " oscillatory ventilation" from the years 1980 to 1997. EMBASE, the Oxford Database of Perinatal Trials and trials identified by the Neonatal Review Group of the Cochrane Collaboration were also reviewed. Information was also sought from experts in the field, cross references from studies and proceedings of recent meetings. Randomized controlled trials of HFOV vs CV as rescue therapy in preterm infants with severe pulmonary dysfunction. The standard review method of the Neonatal Review Group was used. This includes independent quality assessment and data extraction by the second author. Relative risk (RR), risk difference (RD) and number needed to treat (NNT) were used. Only one trial was found and this showed a reduction in any new pulmonary air leak (PAL) [RR 0.73 (0.55,0.96), RD -0.174 (-0.321,-0.027)]. The number of infants that need to be treated (NNT) to prevent one infant having any PAL is six (95% CI 3, 37). There is no difference in the rate of PIE or of gross pulmonary air leak, such as pneumomediastinum or pneumothorax. Mortality and the use of IPPV at 30 days was similar in the HFOV and CV groups. The rate of intraventricular hemorrhage (IVH) of any grade is increased in infants treated with HFOV, RR 1.77 (1.06,2.96), RD 0.156 (0.020, 0. 291). Thus for every six infants (95% CI 3, 50) given rescue HFOV, one IVH of any grade is caused. There is a stronger but non-significant trend towards an increase in the more severe grades 3 or 4 IVH. There is insufficient information on the use of rescue HFOV to make recommendations for practice. The small amount of data that exists suggest that harm might outweigh any benefit. Any future use of HFOV as rescue therapy for preterm infants with severe RDS should be within randomized controlled trials and address important outcomes such as longer term pulmonary and neurological function.

Oscillatory ventilation for infants with respiratory distress syndrome--survey of current practice in the UK.

A questionnaire survey identified 55 neonatal units in the UK currently providing high frequency oscil latory ventilation (HFOV) for respiratory distress syndrome (RDS). Criteria used to select infants for both rescue and elective HFOV were found to vary widely between units. Personal clinical experience was the most common factor determining these criteria.

High-frequency Oscillatory Ventilation as Rescue Therapy in Sick Preterm Neonates (≤1250 g): Outcome and Its Prediction

In their recent article, Paranka et al showed the lack of improvement in oxygenation after 6 hours of high-frequency oscillatory ventilation (HFOV) was associated with failure of HFOV and treatment with extracorporeal membrane oxygenation in term infants with severe respiratory failure. Rescue HFOV has also been used in treating critically ill very low birth weight infants with respiratory failure. We retrospectively reviewed the outcome of 52 preterm infants (gestation ≤30 weeks, birth weight ≤1250 g) treated with rescue HFOV in the Neonatal Intensive Care Unit, Royal Alexandra Hospital, Edmonton, Canada, between October 1988 through August 1993.