Benefits of intratracheal and extrathoracic high-frequency percussive ventilation in a model of capnoperitoneum.

Abdominal inflation with CO2 is used to facilitate laparoscopic surgeries, however, providing adequate mechanical ventilation in this scenario is of major importance during anesthesia management. We characterized high-frequency percussive ventilation (HFPV) in protecting from the gas exchange and respiratory mechanical impairments during capnoperitoneum. In addition, we aimed to assess the difference between conventional pressure-controlled mechanical ventilation (CMV) and HFPV modalities generating the high-frequency signal intratracheally (HFPVi) or extrathoracally (HFPVe). Anesthetized rabbits (n = 16) were mechanically ventilated by random sequences of CMV, HFPVi, and HFPVe. The ventilator superimposed the conventional waveform with two high-frequency signals (5 Hz and 10 Hz) during intratracheal HFPV (HFPVi) and HFPV with extrathoracic application of oscillatory signals through a sealed chest cuirass (HFPVe). Lung oxygenation index ([Formula: see text]/[Formula: see text]), arterial partial pressure of carbon dioxide ([Formula: see text]), intrapulmonary shunt (Qs/Qt), and respiratory mechanics were assessed before abdominal inflation, during capnoperitoneum, and after abdominal deflation. Compared with CMV, HFPVi with additional 5-Hz oscillations during capnoperitoneum resulted in higher [Formula: see text]/[Formula: see text], lower [Formula: see text], and decreased Qs/Qt. These improvements were smaller but remained significant during HFPVi with 10 Hz and HFPVe with either 5 or 10 Hz. The ventilation modes did not protect against capnoperitoneum-induced deteriorations in respiratory tissue mechanics. These findings suggest that high-frequency oscillations combined with conventional pressure-controlled ventilation improved lung oxygenation and CO2 removal in a model of capnoperitoneum. Compared with extrathoracic pressure oscillations, intratracheal generation of oscillatory pressure bursts appeared more effective. These findings may contribute to the optimization of mechanical ventilation during laparoscopic surgery.NEW & NOTEWORTHY The present study examines an alternative and innovative mechanical ventilation modality in improving oxygen delivery, CO2 clearance, and respiratory mechanical abnormalities in a clinically relevant experimental model of capnoperitoneum. Our data reveal that high-frequency oscillations combined with conventional ventilation improve gas exchange, with intratracheal oscillations being more effective than extrathoracic oscillations in this clinically relevant translational model.

Use of Lung Ultrasound in Reducing Radiation Exposure in Neonates with Respiratory Distress: A Quality Management Project.

Background and Objectives: Our quality management project aims to decrease by 20% the number of neonates with respiratory distress undergoing chest radiographs as part of their diagnosis and monitoring. Materials and Methods: This quality management project was developed at Life Memorial Hospital, Bucharest, between 2021 and 2023. Overall, 125 patients were included in the study. The project consisted of a training phase, then an implementation phase, and the final results were measured one year after the end of the implementation phase. The imaging protocol consisted of the performance of lung ultrasounds in all the patients on CPAP (continuous positive airway pressure) or mechanical ventilation (first ultrasound at about 90 min after delivery) and the performance of chest radiographs after endotracheal intubation in any case of deterioration of the status of the patient or if such a decision was taken by the clinician. The baseline characteristics of the population were noted and compared between years 2021, 2022, and 2023. The primary outcome measures were represented by the number of X-rays performed in ventilated patients per year (including the patients on CPAP, SIMV (synchronized intermittent mandatory ventilation), IPPV (intermittent positive pressure ventilation), HFOV (high-frequency oscillatory ventilation), the number of X-rays performed per patient on CPAP/year, the number of chest X-rays performed per mechanically ventilated patient/year and the mean radiation dose/patient/year. There was no randomization of the patients for the intervention. The results were compared between the year before the project was introduced and the 2 years across which the project was implemented. Results: The frequency of cases in which no chest X-ray was performed was significantly higher in 2023 compared to 2022 (58.1% vs. 35.8%; p = 0.03) or 2021 (58.1% vs. 34.5%; p = 0.05) (a decrease of 22.3% in 2023 compared with 2022 and of 23.6% in 2023 compared with 2021). The frequency of cases with one chest X-ray was significantly lower in 2023 compared to 2022 (16.3% vs. 35.8%; p = 0.032) or 2021 (16.3% vs. 44.8%; p = 0.008). The mean radiation dose decreased from 5.89 Gy × cm2 in 2021 to 3.76 Gy × cm2 in 2023 (36% reduction). However, there was an increase in the number of ventilated patients with more than one X-ray (11 in 2023 versus 6 in 2021). We also noted a slight annual increase in the mean number of X-rays per patient receiving CPAP followed by mechanical ventilation (from 1.80 in 2021 to 2.33 in 2022 and then 2.50 in 2023), and there was a similar trend in the patients that received only mechanical ventilation without a statistically significant difference in these cases. Conclusions: The quality management project accomplished its goal by obtaining a statistically significant increase in the number of ventilated patients in which chest radiographs were not performed and also resulted in a more than 30% decrease in the radiation dose per ventilated patient. This task was accomplished mainly by increasing the number of patients on CPAP and the use only of lung ultrasound in the patients on CPAP and simple cases.

Evaluation of lung volumes and gas exchange in surfactant-deficient rabbits between variable and fixed servo pressures during high-frequency jet ventilation.

OBJECTIVE: To investigate a novel servo pressure (SP) setting during high-frequency jet ventilation (HFJV) for a lung protective strategy in a neonatal model of acute respiratory distress. STUDY DESIGN: Comparison of efficacy between variable (standard) and fixed SP settings in a randomized animal study using rabbits (n = 10, mean weight = 1.80 kg) with surfactant deficiency by repeated lung lavages. RESULTS: Rabbits in the fixed SP group had greater peak inspiratory pressure, SP, minute volume, pH, and PaO2, and lower PaCO2 after lung lavage than the variable SP group. Lung volume monitoring with electrical impedance tomography showed that fixed SP reduced the decline of the global lung tidal variation at 30 min after lung lavage (-17.4% from baseline before lavage) compared to variable SP (-44.9%). CONCLUSION: HFJV with fixed SP significantly improved gas exchange and lung volumes compared to variable SP. Applying a fixed SP may have important clinical implications for patients receiving HFJV.

Impact on cerebral hemodynamics of the use of volume guarantee combined with high frequency oscillatory ventilation in a neonatal animal respiratory distress model.

High-frequency oscillatory ventilation (HFOV) is an alternative to conventional mechanical ventilation (CMV). Recently, the use of volume guarantee (VG) combined with HFOV has been suggested as a safe strategy capable of reducing the damage induced by ventilation in immature lungs. However, the possible impact of this new ventilation technique on cerebral hemodynamics is unknown. To evaluate the cerebral hemodynamics effect of HFOV combined with VG in an experimental animal model of neonatal respiratory distress syndrome (RDS) due to surfactant deficiency compared with HFOV and CMV+VG (control group). Eighteen newborn piglets were randomized, before and after the induction of RDS by bronchoalveolar lavage, into 3 mechanical ventilation groups: CMV, HFOV and HFOV with VG. Changes in cerebral oxygen transport and consumption and cerebral blood flow were analyzed by non-invasive regional cerebral oxygen saturation (CrSO2), jugular venous saturation (SjO2), the calculated cerebral oxygen extraction fraction (COEF), the calculated cerebral fractional tissue oxygen extraction (cFTOE) and direct measurement of carotid artery flow. To analyze the temporal evolution of these variables, a mixed-effects linear regression model was constructed. After randomization, the following statistically significant results were found in every group: a drop in carotid artery flow: at a rate of -1.7 mL/kg/min (95% CI: -2.5 to -0.81; p < 0.001), CrSO2: at a rate of -6.2% (95% CI: -7.9 to -4.4; p < 0.001) and SjO2: at a rate of -20% (95% CI: -26 to -15; p < 0.001), accompanied by an increase in COEF: at a rate of 20% (95% CI: 15 to 26; p < 0.001) and cFTOE: at a rate of 0.07 (95% CI: 0.05 to 0.08; p < 0.001) in all groups. No statistically significant differences were found between the HFOV groups. CONCLUSION: No differences were observed at cerebral hemodynamic between respiratory assistance in HFOV with and without VG, being the latter ventilatory strategy equally safe. WHAT IS KNOWN: • Preterm have a situation of fragility of cerebral perfusion wich means that any mechanical ventilation strategy can have a significant influence. High-frequency oscillatory ventilation (HFOV) is an alternative to conventional mechanical ventilation (CMV). Recently, the use of volume guarantee (VG) combined with HFOV has been suggested as a safe strategy capable of reducing the damage induced by ventilation in immature lungs. Several studies have compared CMV and HFOV and their effects at hemodynamic level. It is known that the use of high mean airway pressure in HFOV can cause an increase in pulmonary vascular resistance with a decrease in thoracic venous return. WHAT IS NEW: • The possible impact of VAFO + VG on cerebral hemodynamics is unknown. Due the lack of studies and the existing controversy, we have carried out this research project in an experimental animal model with the aim of evaluating the cerebral hemodynamic repercussion of the use of VG in HFOV compared to the classic strategy without VG.

The outcome of high-frequency oscillatory ventilation in pediatric patients with acute respiratory distress syndrome in an intensive care unit.

BACKGROUND: In adults with acute respiratory distress syndrome (ARDS), high-frequency oscillatory ventilation (HFOV) has been associated with higher mortality rates. Therefore, its use in children with ARDS is still controversial. OBJECTIVES: Evaluate the overall mortality of HFOV in children with ARDS and explore mortality-related risk factors; compare the outcome of using HFOV post-endotracheal intubation early (≤24 hours) versus late (≤24 hours). DESIGN: Retrospective (medical record review) SETTING: Pediatric intensive care unit in a tertiary care center in Saudi Arabia. PATIENTS AND METHODS: Data were collected from medical records of all pediatric patients with ARDS aged one week to 14 years, who were admitted to the pediatric intensive care unit (PICU) from January 2016-June 2019 and who required HFOV. MAIN OUTCOME MEASURES: PICU mortality. SAMPLE SIZE AND CHARACTERISTICS: 135 ARDS patients including 74 females (54.8%), and 61 males (45.2%), with a median age (interquar-tile range) of 35 (72) months. RESULTS: The overall mortality rate was 60.0% (81/135), and most died in the first 28 days in the PICU (91.3%, 74/8). Of non-survivors, 75.3% (61/81) were immunocompromised, and 24.7% (20/81) were immuno-competent patients, 52 (64.2%) received inotropic support, 40 (49.4%) had a bone-marrow transplant (BMT) before HFOV initiation. Although the prone position was used in 20.7% (28/135) to improve the survival rate post-HFOV ventilation, only 28.6% (8/28) survived. In addition, altered code status or chemotherapy reported a significant association with mortality (P<.05). Interestingly, early HFOV initiation (≤24 hours) did not seem to have a high impact on survival compared to late initiation (>24 hours); (57.4% vs. 42.6%, P=.721). CONCLUSION: Immunocompromised and oncology patients, including post-BMT, reported poorer outcomes, and neither the prone position nor early use of HFOV improved outcomes. However, it is recommended to replicate the study in a larger cohort to generalize the results. LIMITATIONS: Retrospective single-center study.

Comparing the effectiveness of single-lumen high-frequency positive pressure ventilation with double-lumen endobronchial tube for the anesthesia management of endoscopic thoracic sympathetic blockade surgery.

OBJECTIVES: In this trial, we aimed to compare anesthetic effectiveness of single lumen tube (SLT) for tracheal intubation with high-frequency positive pressure ventilation (HFPPV) versus classic double lumen tube (DLT) for tracheal intubation in endoscopic thoracic sympathetic blockade surgery. DESIGN: This was a prospective randomized controlled clinical study. SETTING: The study was single-centered and conducted in a university hospital. PARTICIPANTS: There were 135 endoscopic thoracic sympathetic blockade patients in this study. INTERVENTIONS: The patients were randomly allocated either to DLT (n = 67) or SLT (n = 68) groups. In SLT group, the ventilator setting was kept with frequencies that range from 1 to 1.8 Hz (60-110/min). Data regarding anesthesia duration, surgery duration, difficult intraoperative lung deflation, postoperative atelectasis, postoperative pain, postoperative pneumothorax were recorded and compared. All patients were operated by a single experienced surgeon under general anesthesia provided by the same anesthesia team. MEASUREMENTS AND MAIN RESULTS: Both groups were age and gender matched. Among all recorded variables, only anesthesia time was found to be close to statistical significance (P = .059, favoring single lumen). All other parameters were found to be similar between groups. (P < .05). CONCLUSION: We reported that DLT and single lumen tracheal intubation were equally effective for lung deflation during surgery, and SLT with HFPPV ventilation mode during endoscopic thoracic sympathetic blockade surgery provided the surgeon with an adequate and clean workspace with shorter onset of anesthesia. We may suggest the HFPPV technique for uncomplicated surgery groups or where sufficient conditions for DLT cannot be provided in the operating room.

Hemodynamic Effects of a High-Frequency Oscillatory Ventilation Open-Lung Strategy in Critically Ill Children With Acquired or Congenital Cardiac Disease.

OBJECTIVES: To study the hemodynamic consequences of an open-lung high-frequency oscillatory ventilation (HFOV) strategy in patients with an underlying cardiac anomaly with or without intracardiac shunt or primary pulmonary hypertension with severe lung injury. DESIGN: Secondary analysis of prospectively collected data. SETTING: Medical-surgical PICU. PATIENTS: Children less than 18 years old with cardiac anomalies (± intracardiac shunt) or primary pulmonary hypertension. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data from 52 subjects were analyzed, of whom 39 of 52 with cardiac anomaly (23/39 with intracardiac shunt) and 13 of 52 with primary pulmonary hypertension. Fourteen patients were admitted postoperatively, and 26 patients were admitted with acute respiratory failure. Five subjects (9.6%) were canulated for ECMO (of whom four for worsening respiratory status). Ten patients (19.2%) died during PICU stay. Median conventional mechanical ventilation settings prior to HFOV were peak inspiratory pressure 30 cm H 2 O (27-33 cm H 2 O), positive end-expiratory pressure 8 cm H 2 O (6-10 cm H 2 O), and F io2 0.72 (0.56-0.94). After transitioning to HFOV, there was no negative effect on mean arterial blood pressure, central venous pressure, or arterial lactate. Heart rate decreased significantly over time ( p < 0.0001), without group differences. The percentage of subjects receiving a fluid bolus decreased over time ( p = 0.003), especially in those with primary pulmonary hypertension ( p = 0.0155) and without intracardiac shunt ( p = 0.0328). There were no significant differences in the cumulative number of daily boluses over time. Vasoactive Infusion Score did not increase over time. Pa co2 decreased ( p < 0.0002) and arterial pH significantly improved ( p < 0.0001) over time in the whole cohort. Neuromuscular blocking agents were used in all subjects switched to HFOV. Daily cumulative sedative doses were unchanged, and no clinically apparent barotrauma was found. CONCLUSIONS: No negative hemodynamic consequences occurred with an individualized, physiology-based open-lung HFOV approach in patients with cardiac anomalies or primary pulmonary hypertension suffering from severe lung injury.

[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.

Benefits of secretion clearance with high frequency percussive ventilation in tracheostomized critically ill patients: a pilot study.

Clearance of secretions remains a challenge in ventilated patients. Despite high-frequency percussive ventilation (HFPV) showing benefits in patients with cystic fibrosis and neuromuscular disorders, very little is known about its effects on other patient categories. Therefore, we designed a physiological pilot study investigating the effects on lung aeration and gas exchange of short HFPV cycles in tracheostomized patients undergoing mechanical ventilation. Electrical impedance tomography (EIT) was recorded at baseline (T0) by a belt wrapped around the patient's chest, followed by the HFPV cycle lasting 10 min. EIT data was collected again after the HFPV cycle (T1) as well as after 1 h (T2) and 3 h (T3) from T0. Variation from baseline of end-expiratory lung impedance (∆EELI), tidal variation (TIV) and global inhomogeneity index (GI) were computed. Arterial blood was also taken for gas analysis. HFPV cycle significantly improved the ∆EELI at T1, T2 and T3 when compared to baseline (p < 0.05 for all comparisons). The ratio between arterial partial pressure and inspired fraction of oxygen (PaO2/FiO2) also increased after the treatment (p < 0.001 for all comparison) whereas TIV (p = 0.132) and GI (p = 0.114) remained unchanged. Short cycles of HFPV superimposed to mechanical ventilation promoted alveolar recruitment, as suggested by improved ∆EELI, and improved oxygenation in tracheostomized patients with high load of secretion.Trial Registration Prospectively registered on www.clinicaltrials.gov (NCT05200507; dated 6th January 2022).

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.

High-frequency ventilation in preterm infants and neonates.

High-frequency ventilation (HFV) has been used as a respiratory support mode for neonates for over 30 years. HFV is characterized by delivering tidal volumes close to or less than the anatomical dead space. Both animal and clinical studies have shown that HFV can effectively restore lung function, and potentially limit ventilator-induced lung injury, which is considered an important risk factor for developing bronchopulmonary dysplasia (BPD). Knowledge of how HFV works, how it influences cardiorespiratory physiology, and how to apply it in daily clinical practice has proven to be essential for its optimal and safe use. We will present important aspects of gas exchange, lung-protective concepts, clinical use, and possible adverse effects of HFV. We also discuss the study results on the use of HFV in respiratory distress syndrome in preterm infants and respiratory failure in term neonates. IMPACT: Knowledge of how HFV works, how it influences cardiorespiratory physiology, and how to apply it in daily clinical practice has proven to be essential for its optimal and safe use. Therefore, we present important aspects of gas exchange, lung-protective concepts, clinical use, and possible adverse effects of HFV. The use of HFV in daily clinical practice in lung recruitment, determination of the optimal continuous distending pressure and frequency, and typical side effects of HFV are discussed. We also present study results on the use of HFV in respiratory distress syndrome in preterm infants and respiratory failure in term neonates.

[Efficacy of volume-targeted ventilation versus high-frequency oscillatory ventilation in the treatment of neonatal respiratory distress syndrome]. / å®¹é‡ç›®æ ‡é€šæ°”ä¸Žé«˜é¢‘æŒ¯è¡é€šæ°”æ²»ç–—æ–°ç”Ÿå„¿å‘¼å¸çª˜è¿«ç»¼åˆå¾çš„ç–—æ•ˆæ¯”è¾ƒ.

OBJECTIVES: To study the clinical efficacy of volume-targeted ventilation (VTV) versus high-frequency oscillatory ventilation (HFOV) in the treatment of neonatal respiratory distress syndrome (NRDS). METHODS: A retrospective cohort analysis was performed on the medical data of 140 neonates with severe NRDS who were admitted from September 2016 to February 2022, with 55 neonates in the VTV group and 85 in the HFOV group. The neonates in the VTV group received conventional mechanical ventilation and target tidal volume, and those in the HFOV group received HFOV. Arterial blood gas parameters were collected at 48 hours after admission, and related indices during hospitalization were recorded, including mortality rate, duration of invasive mechanical ventilation, duration of oxygen therapy, and the incidence rates of complications. RESULTS: Compared with the VTV group, the HFOV group had significantly lower incidence rates of grade Ⅲ-Ⅳ periventricular-intraventricular hemorrhage and neonatal necrotizing enterocolitis (P<0.05), and there were no significant differences between the two groups in the duration of invasive mechanical ventilation, the duration of oxygen therapy, mortality rate, and the incidence rates of bronchopulmonary dysplasia, hypocapnia, hypercapnia, periventricular leukomalacia, and retinopathy of prematurity (P>0.05). CONCLUSIONS: HFOV has a better clinical efficacy than VTV in the treatment of NRDS.

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

INTRODUCTION: Bronchopulmonary dysplasia (BPD) remains one of the major challenges of extreme prematurity. High-frequency oscillatory ventilation (HFOV) with volume guarantee (HFOV-VG) can be used as an early-rescue ventilation to protect developing lungs. However, the studies exploring the impact of this ventilatory strategy on neonatal respiratory morbidity are very limited. This study aimed at documenting the improvement in respiratory outcomes in mechanically ventilated preterm newborns, after the implementation of a new mechanical ventilation respiratory bundle. METHODS: A prospective, quality improvement study was conducted between January 2012 and December 2018 in a third level NICU in Madrid, Spain. Infants born <32 weeks of gestation with severe respiratory distress syndrome (RDS) and requiring invasive mechanical ventilation were included. The intervention consisted of a new ventilation respiratory care bundle, with HFOV as early rescue therapy using low high-frequency tidal volumes (Vthf) and higher frequencies (15-20 Hz). Criteria for HFOV start were impaired oxygenation or ventilation on conventional ventilation, or peak inspiratory pressures >15 cmH2O. Two cohorts of mechanically ventilated patients were compared, cohort 1 (2012-2013, baseline period) and cohort 2 (2016-2018, after implementation of the new bundle). Clinical outcomes at 36 weeks and 2 years of postmenstrual age were compared between the groups. RESULTS: A total of 216 patients were included, the median gestational age was 26 weeks (IQR 25-28) and median birth weight was 895 g (IQR 720-1160). There were no significant differences in survival between the groups, but patients with the protective ventilation strategy (cohort 2) had higher survival without BPD 2-3 (OR 2.93, 95%CI 1.41-6.05). At 2 years of postmenstrual age, patients in cohort 2 also had a higher survival free of baseline respiratory treatment and hospital respiratory admissions than the control group (adjusted OR 2.33, 95%CI 1.10-4.93, p=.03). The results did not suggest significant differences in neurologic development. CONCLUSIONS: In extreme premature related severe respiratory failure, the use of a lung protective HFOV-VG strategy was proven to be a useful quality improvement intervention in our unit, leading to better pulmonary outcomes at 36 weeks and additional improved respiratory prognosis at two years of age.

Non-invasive high frequency oscillatory ventilation inhibiting respiratory motion in healthy volunteers.

Precision radiotherapy needs to manage organ movements to prevent critical organ injury. The purpose of this study is to examine the feasibility of motion control of the lung by suppressing respiratory motion. The non-invasive high frequency oscillatory ventilation (NIHFOV) is a technique commonly used in the protection of lung for patients with acute lung disease. By using a very high respiratory frequency and a low tidal volume, NIHFOV allows gas exchange, maintains a constant mean airway pressure and minimizes the respiratory movements. We tested healthy volunteers NIHFOV to explore the optimal operational parameter setting and the best possible motion suppression achievable. This study was conducted with the approval of Institutional Review Boards of the Wuwei Cancer hospital (approval number: 2021-39) and carried out in accordance with Declaration of Helsinki. The study comprises two parts. Twenty three healthy volunteers participated in the first part of the study. They had 7 sessions of training with the NIHFOV. The duration of uninterrupted, continuous breathing under the NIHFOV and the optimal operational machine settings were defined. Eight healthy volunteers took part in the second part of the study and underwent 4-dimensional CT (4DCT) scanning with and without NIHFOV. Their respiratory waveform under free breathing (FB) and NIHFOV were recorded. The maximum range of motion of the diaphragm from the two scannings was compared, and the variation of bilateral lung volume was obtained to evaluate the impact of NIHFOV technique on lung volume. The following data were collected: comfort score, transcutaneous partial pressure of oxygen (PtcO2), transcutaneous partial pressure of carbon dioxide (PtcCO2), and pulse rate. Data with and without NIHFOV were compared to evaluate its safety, physiological impacts and effect of lung movement suppression. All the volunteers completed the training sessions eventlessly, demonstrating a good tolerability of the procedure. The median NIHFOV-on time was 32 min (22-45 min), and the maximum range of motion in the cephalic-caudal direction was significantly reduced on NIHFOV compared with FB (1.8 ± 0.8 cm vs 0.3 ± 0.1 cm, t = - 3.650, P = 0.003); the median range of motion was only 0.3 ± 0.1 cm on NIHFOV with a good reproducibility. The variation coefficient under NIHFOV of the right lung volume was 2.4% and the left lung volume was 9.2%. The PtcO2 and PtcCO2 were constantly monitored during NIHFOV. The medium PtcCO2 under NIHFOV increased lightly by 4.1 mmHg (interquartile range [IQR], 4-6 mmHg) compared with FB (t = 17.676, P < 0.001). No hypercapnia was found, PtcO2 increased significantly in all volunteers during NIHFOV (t = 25.453, P < 0.001). There was no significant difference in pulse rate between the two data sets (t = 1.257, P = 0.233). NIHFOV is easy to master in healthy volunteers to minimize respiratory movement with good tolerability and reproducibility. It is a feasible approach for lung motion control and could potentially be applied in accurate radiotherapy including carbon-ion radiotherapy through suppression of respiratory movement.

Clinical application of bronchial high-frequency ventilation in 2-port thoracoscopic segmentectomy.

To evaluate the safety and clinical application of a computer-aided surgery system (CAS) combined with high-frequency bronchial ventilation in 2-port thoracoscopic anatomical segmentectomy. A total of 301 patients who underwent 2-port thoracoscopic segmentectomy between January 1, 2019 and March 1, 2022 in the 960th Hospital of the People's Liberation Army and the Department of Thoracic Surgery of Zibo Municipal Hospital were retrospectively analyzed. The experimental and control groups were created according to the different methods of appearing the intersegmental plane of the lung. The experimental group comprised 152 patients who underwent CAS reconstruction combined with high-frequency ventilation, and the control group comprised 149 patients who underwent CAS reconstruction combined with expansion collapse. The characteristics of the patients, including age, sex, smoking history, forced expiratory volume in 1 second/forced vital capacity, Maximal ventilation, diameter of pulmonary nodules, intraoperative blood loss, postoperative drainage volume, drainage tube removal time, length of hospital stay after extubation, postoperative complication rate, operation time and appearance time of the intersegmental plane, were compared between the 2 groups. All patients completed the operation between high-frequency bronchial ventilation and expansion collapse group. There was no significant difference in Forced expiratory volume in 1 second/Forced vital capacity [(101.05 ±â€…11.86) vs (101.86 ±â€…11.61)], maximum expiratory volume [(86.36 ±â€…17.59 L) vs (85.28 ±â€…17.68 L)], the diameter of lung nodules [(13.61 ±â€…3.51 cm) vs (13.21 ±â€…3.41 cm)], intraoperative blood loss [(47.50 ±â€…45.90 mL) vs (48.49 ±â€…34.65 mL)], postoperative drainage volume [(425.16 ±â€…221.61 mL) vs (444.70 ±â€…243.72 mL)], drainage tube removal time [(3.88 ±â€…1.85 days) vs (3.43 ±â€…1.81 days)], or postoperative hospital stay [(6.07 ±â€…2.14 days) vs (5.82 ±â€…1.88 days) between the experimental group and the control group (P > .05)]. There were significant differences in operation time [(95.05 ±â€…26.85 min) vs (117.85 ±â€…31.70 min), P = .017] and intersegmental plane appearance time [(2.37 ±â€…1.03 min) vs (14.20 ±â€…3.23 min), P < .001]. High-frequency bronchial ventilation is safe and feasible when used in quickly and accurately identifying the intersegmental plane and is worthy of clinical application in 2-port thoracoscopic segmentectomy.

Application of High-Frequency Oscillation Ventilation Combined With Volume Guarantee in Preterm Infants With Acute Hypoxic Respiratory Failure After Patent Ductus Arteriosus Ligation.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of high-frequency oscillation ventilation combined with volume guarantee (HFOV-VG) in preterm infants with acute hypoxemic respiratory failure (AHRF) after patent ductus arteriosus ligation. METHODS: We retrospectively analyzed the clinical data of 41 preterm infants, who were ventilated for AHRF after patent ductus arteriosus ligation between January 2020 and January 2022. HFOV alone was used in 20 of the 41 infants, whereas HFOV-VG was used in the other 21 infants. RESULTS: There was no statistically significant difference in the demographic information and baseline characteristics of preterm infants included in the study. The average frequency tidal volume (VThf) of the HFOV-VG group was lower than that of the HFOV group (2.6 ± 0.6 mL versus 1.9 ± 0.3 mL, P < .001). In addition, the incidence of hypocapnia and hypercapnia in infants supported with HFOV-VG was significantly lower (15 versus 8, P < .001; 12 versus 5, P < .001). Furthermore, the duration of invasive ventilation in the HFOV-VG group also was lower than in the HFOV group (3.7 ± 1.2 days versus 2.1 ± 1.0 days, P < .01). CONCLUSION: Compared with HFOV alone, HFOV-VG decreases VThf levels and reduces the incidence of hypercapnia and hypocapnia in preterm infants with acute hypoxic respiratory failure after patent ductus arteriosus ligation.

Expiratory high-frequency percussive ventilation: a novel concept for improving gas exchange.

BACKGROUND: Although high-frequency percussive ventilation (HFPV) improves gas exchange, concerns remain about tissue overdistension caused by the oscillations and consequent lung damage. We compared a modified percussive ventilation modality created by superimposing high-frequency oscillations to the conventional ventilation waveform during expiration only (eHFPV) with conventional mechanical ventilation (CMV) and standard HFPV. METHODS: Hypoxia and hypercapnia were induced by decreasing the frequency of CMV in New Zealand White rabbits (n = 10). Following steady-state CMV periods, percussive modalities with oscillations randomly introduced to the entire breathing cycle (HFPV) or to the expiratory phase alone (eHFPV) with varying amplitudes (2 or 4 cmH2O) and frequencies were used (5 or 10 Hz). The arterial partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2) were determined. Volumetric capnography was used to evaluate the ventilation dead space fraction, phase 2 slope, and minute elimination of CO2. Respiratory mechanics were characterized by forced oscillations. RESULTS: The use of eHFPV with 5 Hz superimposed oscillation frequency and an amplitude of 4 cmH2O enhanced gas exchange similar to those observed after HFPV. These improvements in PaO2 (47.3 ± 5.5 vs. 58.6 ± 7.2 mmHg) and PaCO2 (54.7 ± 2.3 vs. 50.1 ± 2.9 mmHg) were associated with lower ventilation dead space and capnogram phase 2 slope, as well as enhanced minute CO2 elimination without altering respiratory mechanics. CONCLUSIONS: These findings demonstrated improved gas exchange using eHFPV as a novel mechanical ventilation modality that combines the benefits of conventional and small-amplitude high-frequency oscillatory ventilation, owing to improved longitudinal gas transport rather than increased lung surface area available for gas exchange.

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

BACKGROUND AND OBJECTIVES: The optimal lung volume strategy during high-frequency oscillatory ventilation (HFOV) is reached by performing recruitment maneuvers, usually guided by the response in oxygenation. In animal models, secondary spontaneous change in oscillation pressure amplitude (ΔPhf) associated with a progressive increase in mean airway pressure during HFOV combined with volume guarantee (HFOV-VG) identifies optimal lung recruitment. The aim of this study was to describe recruitment maneuvers in HFOV-VG and analyze whether changes in ΔPhf might be an early predictor for lung recruitment in newborn infants with severe respiratory failure. DESIGN AND METHODS: The prospective observational study was done in a tertiary-level neonatology department. Changes in ΔPhf were analyzed during standardized lung recruitment after initiating early rescue HFOV-VG in preterm infants with severe respiratory failure. RESULTS: Twenty-seven patients were included, with a median gestational age of 24 weeks (interquartile range [IQR]: 23-25). Recruitment maneuvers were performed, median baseline mean airway pressure (mPaw) was 11 cm H2 O (IQR: 10-13), median critical lung opening mPaw during recruitment was 14 cm H2 O (IRQ: 12-16), and median optimal mPaw was 12 cm H2 O (IQR: 10-14, p < 0.01). Recruitment maneuvers were associated with an improvement in oxygenation (FiO2 : 65.0 vs. 45.0, p < 0.01, SpO2/FiO2 ratio: 117 vs. 217, p < 0.01). ΔPhf decreased significantly after lung recruitment (mean amplitude: 23.0 vs. 16.0, p < 0.01). CONCLUSION: In preterm infants with severe respiratory failure, the lung recruitment process can be effectively guided by ΔPhf on HFOV-VG.

High-frequency oscillatory ventilation versus conventional ventilation in the respiratory management of term neonates with a congenital diaphragmatic hernia: a retrospective cohort study.

Conventional mechanical ventilation (CMV) has been recommended as the first-line mode of respiratory support for neonates born with a congenital diaphragmatic hernia (CDH). However, older studies suggested that protective high-frequency oscillatory ventilation (HFOV) with low-mean airway pressure (MAP) may limit lung injury. We aimed to compare low-MAP HFOV with CMV in neonates with CDH in terms of patient outcomes. This retrospective cohort study was conducted in two French neonatal intensive care units: center 1 mainly used CMV, and center 2 mainly used HFOV with a low MAP. All term neonates with CDH born between 2010 and 2018 in these two centers were included. The primary outcome was the duration of oxygen therapy. Secondary outcomes were survival and duration of mechanical ventilation. A total of 170 patients (105 in center 1, 65 in center 2) were included. In center 2, 96% of patients were ventilated with HFOV versus 19% in center 1. After adjustment for perinatal data, there was no significant difference regarding duration of oxygen therapy (SHR 0.83, 95% CI [0.55-1.23], p = 0.35) or survival (HR 1.73, 95% CI [0.64-4.64], p = 0.28). Center 2 patients required longer mechanical ventilation and sedation. CONCLUSION: First-line mode of mechanical ventilation was not associated with the duration of oxygen therapy or survival in neonates with CDH. WHAT IS KNOWN: • Recommendations were given in favour of using the conventional mechanical ventilation in first intention in neonates with a congenital diaphragmatic hernia, since High frequency oscillation (HFO) has been associated with a higher morbidity. WHAT IS NEW: • No differences between HFO and conventional mechanical ventilation were observed concerning the length of oxygen supply and the survival..

Effect of High-Frequency Oscillatory Ventilation, Combined With Prone Positioning, in Infants With Acute Respiratory Distress Syndrome After Congenital Heart Surgery: A Prospective Randomized Controlled Trial.

OBJECTIVES: This study aimed to evaluate the effect of high-frequency oscillatory ventilation, (HFOV) combined with prone positioning, on oxygenation and pulmonary ventilation in infants with acute respiratory distress syndrome (ARDS) after congenital heart surgery. DESIGN: A randomized controlled trial. SETTING: A single-center study at a tertiary teaching hospital. PARTICIPANTS: Patients with postoperative ARDS after congenital heart disease were divided randomly into the following 2 groups: HFOV combined with prone position (HFOV-PP), and HFOV combined with supine position (HFOV-SP). INTERVENTIONS: The primary outcomes were the PaO2/FIO2 ratio and the oxygenation index after the intervention, and the secondary outcomes were respiratory variables, hemodynamics, complications, and other short-term outcomes. RESULTS: Sixty-five eligible infants with ARDS were randomized to either the HFOV-PP (n = 32) or HFOV-SP (n = 33) group. No significant difference in baseline data was found between the 2 groups (p > 0.05). Oxygenation was improved in both groups after HFOV intervention. Compared with the HFOV-SP group, the HFOV-PP group had significantly increased PaO2/FIO2 and oxygenation index and a shorter duration of invasive ventilation and length of cardiac intensive care unit stay. No serious complications occurred in the 2 groups. CONCLUSION: HFOV-PP significantly improved oxygenation in infants with ARDS after cardiac surgery and had no serious complications.