[Therapeutic efficacy of volume-guaranteed high frequency oscillation ventilation on respiratory failure in preterm infants with a gestational age of 28-34 weeks: a prospective randomized controlled study]. / 容量保证的高频振荡通气模式对胎龄28~34å‘¨æ—©äº§å„¿å‘¼å¸è¡°ç«­ç–—æ•ˆçš„å‰çž»æ€§éšæœºå¯¹ç §ç ”ç©¶.

OBJECTIVES: To investigate the therapeutic efficacy of volume-guaranteed high frequency oscillation ventilation (HFOV-VG) versus conventional mechanical ventilation (CMV) in the treatment of preterm infants with respiratory failure. METHODS: A prospective study was conducted on 112 preterm infants with respiratory failure (a gestational age of 28-34 weeks) who were admitted to the Department of Neonatology, Jiangyin Hospital Affiliated to Medical School of Southeast University, from October 2018 to December 2022. The infants were randomly divided into an HFOV-VG group (44 infants) and a CMV group (68 infants) using the coin tossing method based on the mode of mechanical ventilation. The therapeutic efficacy was compared between the two groups. RESULTS: After 24 hours of treatment, both the HFOV-VG and CMV groups showed significant improvements in arterial blood pH, partial pressure of oxygen, partial pressure of carbon dioxide, and partial pressure of oxygen/fractional concentration of inspired oxygen ratio (P<0.05), and the HFOV-VG group had better improvements than the CMV group (P<0.05). There were no significant differences between the two groups in the incidence rate of complications, 28-day mortality rate, and length of hospital stay (P>0.05), but the HFOV-VG group had a significantly shorter duration of invasive mechanical ventilation than the CMV group (P<0.05). The follow-up at the corrected age of 6 months showed that there were no significant differences between the two groups in the scores of developmental quotient, gross motor function, fine motor function, adaptive ability, language, and social behavior in the Pediatric Neuropsychological Development Scale (P>0.05). CONCLUSIONS: Compared with CMV mode, HFOV-VG mode improves partial pressure of oxygen and promotes carbon dioxide elimination, thereby enhancing oxygenation and shortening the duration of mechanical ventilation in preterm infants with respiratory failure, while it has no significant impact on short-term neurobehavioral development in these infants.

[Prospects and developments in the technologies of high frequency oscillatory ventilation].

The high frequency oscillatory ventilation (HFOV) is characterized with low tidal volume and low mean airway pressure, and can well support the breathing of the patients with respiratory diseases. Since the HFOV was proposed, it has been widely concerned by medical and scientific researchers. About the HFOV, this paper discussed its current research status and prospected its future development in technologies. The research status of ventilation model, mechanisms and ventilation mode were introduced in detail. In the next years, the technologies in developing HFOV will be focused on: to develop the branched high-order nonlinear or volume-depended resistance-inertance-compliance (RIC) ventilation model, to fully understand the mechanisms of HFOV and to achieve the noninvasive HFOV. The development in technologies of HFOV will be beneficial to the patients with respiratory diseases who failed with conventional mechanical ventilation as one of considerable ventilation methods.

High-Frequency Ventilation Modalities as Salvage Therapy for Smoke Inhalation-Associated Acute Lung Injury: A Systematic Review.

BACKGROUND: Smoke inhalation-associated acute lung injury (SI-ALI) is a major cause of morbidity and mortality in victims of fire tragedies. To date, there are no evidence-based guidelines on ventilation strategies in acute respiratory distress syndrome (ARDS) after smoke inhalation. We reviewed the existing literature for clinical studies of salvage mechanical ventilation (MV) strategies in patients with SI-ALI, focusing on mortality and pneumonia as outcomes. METHODS: A systematic search was designed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Risk of bias assessment was performed using the Newcastle-Ottawa Quality Assessment Scale (NOS; 0 to 9 stars), with a score ≥7 being the threshold for inclusion in the meta-analysis. A systematic search strategy was used to search 10 databases. Clinical studies were included in which patients: (1) experienced smoke inhalation, (2) treated with MV, and (3) described a concurrent or historical control group. RESULTS: A total of 226 potentially relevant studies were identified, of which 7 studies on high-frequency percussive ventilation (HFPV) met inclusion criteria. No studies met inclusion for meta-analysis (NOS ≥ 7). In studies comparing HFPV to conventional mechanical ventilation (CMV), mortality and pneumonia incidence improved in 3 studies and remained unchanged in 3 others. No change in ventilator days or ICU length of stay was observed; however, oxygenation and work of breathing improved with HFPV. CONCLUSIONS: Mechanical ventilation in patients with SI-ALI has not been well studied. High-frequency percussive ventilation may decrease in-hospital mortality and pneumonia incidence when compared to CMV. The absence of "good" quality evidence precluded meta-analysis. Based upon low-quality evidence, there was a very weak recommendation that HFPV use may be associated with lower mortality and pneumonia rates in patients with SI-ALI. Given SI-ALI's unique underlying pathophysiology, and its potential implications on therapy, randomized controlled studies are required to ensure that patients receive the safest and most effective care. TRIAL REGISTRATION: The study was registered with PROSPERO International prospective register of systematic reviews (#47015).

Cardiopulmonary resuscitation of a very preterm infant using high-frequency oscillation ventilation.

We present a novel approach of ventilation, using high-frequency oscillation ventilation (HFOV), during neonatal cardiopulmonary resuscitation (CPR) of a very preterm neonate. This case report highlights the importance of adequate lung inflation, which is a current topic, with neonatal resuscitation guidelines recommending a coordinated 3:1 compression:ventilation ratio during CPR. Our patient, a female infant born at 30 weeks gestational age, weighing 970 g, appeared floppy and apneic following birth in the amniotic sac. Lungs were unfolded and white-out in an x-ray done during resuscitation. The aim was to open lungs effectively using HFOV, instead of positive pressure ventilation, which was used unsuccessfully until the 7th minute of life. Heart rate continuously dropped below 60/min 15 min after birth and chest compressions with asynchronous HFOV were started, adrenalin was administered three times and surfactant was instilled endotracheally twice. It was possible to stabilize the patient after 15 min of CPR, following return of spontaneous circulation. HFOV may have enabled an alternative and rescue option of ventilation during neonatal CPR in this case.

High-frequency oscillatory ventilation in children: A systematic review and meta-analysis.

BACKGROUND: High-frequency oscillatory ventilation (HFOV) is an alternative mechanical ventilation mode proposed to reduce ventilator-induced lung injuries and improve clinical outcomes. The aim of this study was to determine the effects of HFOV compared to conventional mechanical ventilation (CMV) when used in children with hypoxemic respiratory failure. METHODS: The literature search was conducted to identify all studies published before December 2020. Eligible studies included a population aged between 28 days and 18 years old, presented original data from randomized controlled trials (RCTs) or observational studies, compared the use of HFOV with CMV. Meta-analyses of the pooled data were performed by using random-effects models with inverse-variance weighting. RESULTS: A total of 11 studies (2605 cases) were included, most of them evaluating patients with acute respiratory distress syndrome. The mean age of participants was 8.2 months and the mean oxygenation index of those included in the RCTs was 24.4. The effect of HFOV on mortality was not significant, and clinically significant harm or benefit could not be excluded (risk ratio [RR], 0.93; 95% confidence interval [CI], 0.72 to 1.20). No significant difference between groups was found in duration of mechanical ventilation (-2.23; 95% CI, -5.07 to 0.61), treatment failure (RR, 0.28; 95% CI, 0.08 to 1.02), and occurrence of barotrauma (RR, 0.88; 95% CI, 0.39 to 1.99). CONCLUSION: The scarce evidence currently available does not allow us to conclude that HFOV has advantages over CMV and further studies are needed to clarify its role in the treatment of acute hypoxemic respiratory failure in children.

Omphalopagus conjoined twins separation during coronavirus disease-19 pandemic era: A case report.

INTRODUCTION AND IMPORTANCE: Conjoined twin is a rare congenital anomaly characterized by a fusion of certain anatomical structures. Coronavirus-19 (COVID-19) is a new emerging infectious respiratory disease affecting worldwide and potentially leads to acute respiratory distress (ARDS) in children. COVID-19 has reconstructed the healthcare system, including surgical care and decision-making. CASE PRESENTATION: Herein we describe a surgical separation of 2.5 months old omphalopagus conjoined twins, with one of them (Baby A) presenting COVID-19-associated respiratory distress, as well as the challenges faced during the preparation and the execution of the complex surgical procedure. CLINICAL DISCUSSION: Baby A underwent antiviral therapy, oxygen supplementation, and ventilation in the ICU, while baby B remained stable and confirmed negative for SARS-CoV-2. The separation surgery was conducted after baby A had become clinically stable. Defect closure and reconstruction were accomplished. At one week follow-up, Baby A died of lung infection, while baby B remained well after one year. CONCLUSION: The complexity of surgical separation requires careful planning by a multidisciplinary team. Surgical separation of conjoined twins during the pandemic era has not been reported much in the literature, more reports are required to provide further insight.

Patterns of Use of Adjunctive Therapies in Patients With Early Moderate to Severe ARDS: Insights From the LUNG SAFE Study.

BACKGROUND: Adjunctive strategies are an important part of the management of ARDS. However, their application in clinical practice remains inconsistent. RESEARCH QUESTION: We wished to determine the frequency and patterns of use of adjunctive strategies in patients with moderate to severe ARDS (Pao2/Fio2 [P/F ratio] < 150) enrolled into the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. STUDY DESIGN AND METHODS: The LUNG SAFE study was an international, multicenter, prospective cohort study of patients with severe respiratory failure, conducted in 2014 in 459 ICUs from 50 countries. The primary objective of this substudy was to determine the frequency of use of widely available (neuromuscular blockade, prone position) adjuncts vs adjuncts requiring specialized equipment (extracorporeal membrane oxygenation, inhaled vasodilators, high-frequency ventilation) in patients in the first 48 h of moderate to severe ARDS (P/F ratio < 150). RESULTS: Of 1,146 patients on invasive ventilation with moderate to severe ARDS, 811 patients (71%) received no adjunct within 48 h of ARDS onset. Of 335 (29%) that received adjunctive strategies, 252 (75%) received a single strategy, and 83 (25%) receiving more than one adjunct. Of ARDS nonsurvivors, 67% did not receive any adjunctive strategy in the first 48 h. Most patients (67%) receiving specialized adjuncts did not receive prone positioning or neuromuscular blockade. Patients that received adjuncts were more likely to have their ARDS recognized, be younger and sicker, have pneumonia, be more difficult to ventilate, and be in a European high-income country than those that did not receive adjuncts. INTERPRETATION: Three in 10 patients with moderate to severe ARDS, and only one-third of nonsurvivors, received adjunctive strategies over the first 48 h of ARDS. A more consistent and evidence-driven approach to adjunct use may reduce costs and improve outcomes in patients with moderate to severe ARDS. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02010073; URL: www.clinicaltrials.gov.

An in vitro investigation of the inflammatory response to the strain amplitudes which occur during high frequency oscillation ventilation and conventional mechanical ventilation.

Children randomised in the neonatal period to high frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CMV) in the United Kingdom Oscillation study (UKOS) had superior lung function at 11 to 14 years of age. During HFOV, much smaller tidal volumes, but a higher mean airway distending pressure is delivered, hence, a possible explanation for a volume dependent effect on long term lung function could be an increase in inflammation in response to higher tidal volumes and strains. We tested that hypothesis by assessing interleukin-6 (IL-6) and -8 (IL-8) release from A549 alveolar analogue cells following biaxial mechanical strain applied at 0.5 Hz occurring during conditions mimicking strain during CMV (5-20% strain) and conditions mimicking strain during HFOV (17.5% ±â€¯2.5% strain) for up to 4 h. Cyclic strain of 5-20%, occurring during CMV, increased levels of both IL-6 and IL-8 compared to unstrained controls, while 17.5% ±â€¯2.5% strain, occurring during HFOV, was associated with significantly lower levels of IL-6 (46.31 ±â€¯2.66 versus 56.79 ±â€¯3.73 pg/mL) and IL-8 (1340.2 ±â€¯74.9 versus 2522 ±â€¯248 pg/mL) secretion compared to conditions occurring during CMV at four hours. These results may provide a possible explanation for the superior lung function in 11-14-year-old children who had been supported in the neonatal period by HFOV.

Case Report: Post obstructive pulmonary edema (POPE) Type II following elective adenotonsillectomy requiring novel use of high frequency oscillatory ventilation (HFOV).

This case report describes a previously healthy 14 year-old patient undergoing elective outpatient adenotonsillectomy that was complicated by acute postoperative pulmonary edema requiring 12 hours of high frequency oscillatory ventilation (HFOV) support.  We describe the clinical findings that led us to this rare diagnosis and management of post obstructive pulmonary edema (POPE) Type II, a rare but recognized complication following the surgical relief of an upper airway obstruction. This case is unique in that no previously published case report or review of POPE Type II has described the need for HFOV support.

Two Cases of Pneumatoceles in Mechanically Ventilated Infants.

Pulmonary pneumatocele is a thin-walled, gas-filled space within the lung that usually occurs in association with bacterial pneumonia and is usually transient. The majority of pneumatoceles resolve spontaneously without active intervention, but in some cases they might lead to pneumothorax with subsequent hemodynamic instability. We report two cases presented to the pediatric intensive care unit at the Royal Hospital, Oman with pneumatoceles. The first was a 14-day-old baby who underwent surgical repair of total anomalous pulmonary venous connection (TAPVC) requiring extracorporeal membrane oxygenation (ECMO) support following surgery. He was initially on conventional mechanical ventilation. Seven days after the surgery, he started to develop bilateral pneumatoceles. The pneumatoceles were not regressing and they did not respond to three weeks of conservative management with high-frequency oscillation ventilation (HFOV). He failed four attempts of weaning from HFOV to conventional ventilation. Each time he was developing tachypnea and carbon dioxide retention. Percutaneous intercostal chest drain (ICD) insertion was needed to evacuate one large pneumatocele. Subsequently, he improved and we were able to wean and extubate him. The second case was a two-month-old male admitted with severe respiratory distress secondary to respiratory syncytial virus (RSV) pneumonitis. After intubation, he required a high conventional ventilation setting and within 24 hours he was on HFOV. Conservative management with HFOV was sufficient to treat the pneumatoceles and no further intervention was needed. Our cases demonstrate two different approaches in the management of pneumatoceles in mechanically ventilated children. Each approach was case dependent and could not be used interchangeably.

Ventilación de alta frecuencia oscilatoria en pediatría / High frequency oscillatory ventilation in pediatrics

Mechanical ventilation (MV) is a usual therapy for the management of critically ill children. However its inappropriate use can produce lung injury. Today, the evidence recommends protective ventilation such as strategie low tidal volumes (VT) that minimize injury and thus, high frequency oscillatory ventilation (HFOV) would have a theoretical role. HFOV allows gas exchange using low tidal volumes (1 – 2 ml/kg) and supraphysiologic respiratory frequencies. In pediatrics it comprises 3 – 30 percent of mechanically ventilated patients, most of the time as a rescue therapy in refractory respiratory failure cases where conventional mechanical ventilation fails. Many aspects of HFVO in children remain unclear, theoretical benefits has no solid clinical basis, when is the best time to initiate (early vs rescue mode), which are the optimal settings, and how to monitor lung mechanics. This review examines HFVO theoretical bases, suggest recommendations for its use and considers the available evidence to understand the aspects that are still unclear.

La ventilación mecánica (VM) constituye un apoyo frecuente en el manejo de niños críticamente enfermos, quienes pueden requerirla por diferentes etiologías, entre ellas el síndrome de dificultad respiratoria aguda (SDRA). Sabemos que a pesar de ser un soporte vital, su uso inapropiado puede producir daño inducido por ventilación mecánica (DIVM). En la actualidad, la evidencia recomienda las estrategias de “ventilación protectora”, bajos volúmenes corrientes, que minimicen este daño y es ahí donde la ventilación de alta frecuencia oscilatoria (VAFO) tendría un rol teórico. La VAFO permite el intercambio gaseoso usando pequeños volúmenes corrientes (VT) 1-2 ml /kg y frecuencias respiratorias supra fisiológicas, con la consiguiente disminución del riesgo de atelectrauma, manteniendo el “pulmón abierto” y en la zona de seguridad de la curva presión-volumen. Su uso en pediatría oscila entre el 3 y el 30 por ciento de los pacientes ventilados, la mayoría de las veces como terapia de rescate frente a la falla de la ventilación convencional (VMC) en insuficiencia respiratoria refractaria. Muchos aspectos de la VAFO en pediatría no han sido totalmente esclarecidos; su efecto protector teórico permanece aún sin bases sólidas en el escenario clínico, quienes se benefician de su uso, cuál es el mejor momento para iniciarla (temprana o rescate), cuales son los valores óptimos del oscilador y como monitorear la mecánica pulmonar en VAFO. La presente revisión pretende repasar los conceptos teóricos de la VAFO, formular recomendaciones para su uso y considerar la evidencia disponible que nos permitan dilucidar las interrogantes antes mencionadas.