High Frequency Mechanical Ventilation Research Articles

PO-1894 Ultrasound is preferable to MRI as imaging modality during high frequency mechanical ventilation

PO-1894 Ultrasound is preferable to MRI as imaging modality during high frequency mechanical ventilation

High-Frequency Ventilation in the Treatment of Acute Respiratory Failure

The need for respiratory therapy can reach 90% depending on the category of the intensive care unit and intensive care unit (ICU). Currently is a wide selection of respiratory therapy methods, including fully controlled mechanical ventilation and assist ventilation. The widespread use of mechanical ventilation and its varieties significantly reduced the mortality of ICU patients. However, the mortality of patients from acute respiratory distress syndrome, nosocomial pneumonia, and newborns with respiratory disorders remains high. High-frequency mechanical ventilation (HFMV) is an alternative treatment for severe respiratory failure, but the frequency of use is not yet sufficient. Three main types of HF ventilation is currently available: high-frequency positive pressure ventilation (HFPPV), high-frequency jet ventilation (HFJV) and high-frequency oscillatory ventilation (HFOV). There is an opportunity to choose a specific mode which will be most applicable for a particular patient. The use of the HFOV method allows the successful treatment of newborns with severe respiratory failure due to primary surfactant deficiency, meconial aspiration or multiple organ failure. Recently high amount of publications appeared on the possibilities of non-invasive HFMV in both adult patients and in pediatrics. This mini-review is devoted to this problem.

Contamination of surgical wound during tracheal resection depending on the mode of mechanical ventilation

To analyze contamination of surgical wound during tracheal resection depending on the mode of mechanical ventilation. There were 976 patients. Circular tracheal resection was made in 396 of these patients. Overall postoperative morbidity was 15.7%, mortality - 0.8%. Bacteriological examination of surgical wound was performed before tracheotomy and after formation of anastomosis depending on the method of mechanical ventilation. Surgical field was sterile before tracheotomy in all cases, contamination was confirmed after tracheotomy in all patients. Minimal contamination was observed in case of apneic oxygenation (100 times less than volumetric mechanical ventilation or high frequency mechanical ventilation). In all cases, several species of pathogenic microorganisms were identified. The number of species was also minimal in case of hypnotic mechanical ventilation. Contamination does not directly affect the development of local purulent-inflammatory process. However, this factor should not be ignored and compliance with all preventive measures is required.

Targeting Notch-activated M1 macrophages attenuate lung tissue damage in a rat model of ventilator induced lung injury.

Ventilator induced lung injury (VILI) may be involved in the activation of alveolar macrophages. The purpose of this study was to investigate the relationship between the Notch signaling pathway and macrophage polarization in VILI. The VILI model was established using rats. Hematoxylineosin staining was used to test the lung tissue morphology. Bicinchoninic acid assay and ELISA were performed to detect protein and tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 levels in bronchoalveolar lavage fluids (BALF), respectively. The ratio of alveolar M1 and M2 macrophages was detected by flow cytometry. The mRNA and protein expression levels of Notch pathway-related proteins were determined using reverse transcription-quantitative PCR and western blotting. The present study found that high-frequency mechanical ventilation could cause pulmonary edema and increase the levels of protein, TNF-α and IL-6 in BALF while decreasing the level of IL-10 in BALF. High-frequency mechanical ventilation also induced polarization of alveolar macrophages to M1. The results also showed a significant increase in the levels of Notch pathway-related proteins including notch intracellular domain, Hes1, Hes5 and Hey1. Injection of N-[N-(3,5-difluorophenylacetyl)-1-alanyl] phenylglycine t-butyl ester could inhibit the Notch pathway and such an inhibition protected lung tissue and reduced lung inflammation caused by mechanical ventilation. After the Notch pathway was inhibited, the level of M1 polarization of macrophages caused by high-frequency mechanical ventilation was reduced. VILI caused pulmonary inflammation and macrophages to polarize to M1 and upregulated the expression levels of Notch pathway-related proteins. The inhibition of Notch pathway also reduced the proportion of M1 macrophages and inflammatory responses.

Clinical study of high-frequency oscillatory ventilation in the treatment of pulmonary hemorrhage in newborn infants

Objective To investigate the effects of high frequency oscillatory ventilation in the treatment of neonatal pulmonary hemorrhage curative. Methods 56 neonates with pulmonary hemorrhage were selected, 28 cases in high frequency mechanical ventilation(HFOV) group and 28 cases in conventional mechanical ventilation(CMV) group.On the basis of conventional treatment, the HFOV group received high-frequency mechanical ventilation therapy, the CMV group treated with conventional ventilation.The breathing machine parameters of the two groups were observed and recorded, calculated oxygenation index(OI) and arterial/alveolar oxygen partial pressure ratio(a/APaO2). The duration of pulmonary hemorrhage, the duration of mechanical ventilation, the length of hospital stay, and the duration of oxygen therapy were compared between the two groups. Results Before treatment, there were no statistically differences of in OI and a/APaO2 between the two groups(t1=0.28, P1=0.78; t2=0.47, P2=0.64), 1h treatment later, declining value of the OI and the rising of a/APaO2 in surviving children, and the therapeutic effect of the HFOV group were more obvious than those of the CMV group(t1′=2.14, P1′=0.04; t2′=2.26, P2′=0.03). In the HFOV group, 23 cases cured(82.1%), 5 cases died(17.9%). And in CMV group, 15 cases cured(53.6%), 13 cases died(46.4%). The duration of pulmonary hemorrhage, the duration of mechanical ventilation, the length of the hospital stay, and the duration of oxygen therapy of the HFOV group were significantly lower than those of CMV group, the differences were statistically significant(P=0.046, 0.044, 0.048, 0.035). Conclusion HFOV can better improve oxygenation function in infants with pulmonary hemorrhage, shorten the course of the disease and improve the cure rate, recommend the application and clinical treatment. Key words: High-frequency ventilation; Acute lung injury; Hemorrhage; Infant, newborn

Inhaled Surfactant Therapy in Newborns in Artificial Lung Ventilation

Objective: to evaluate the efficiency of inhaled surfactant therapy in neonatal infants with respiratory failure. Subjects and methods . The trial enrolled 13 premature neonatal infants; their mean gestational age was 31.8±2.8 weeks and the birth weight was 1825±600.9 g. They had a oneminute Apgar score of 4.3±1.4. All the neonates needed mechanical ventilation (MV) at birth because the leading clinical sign was respiratory failure caused by acute intranatal hypoxia, neonatal amniotic fluid aspiration, respiratory distress syndrome (RDS), and cerebral ischemia. Curosurf was injected in a dose of 174.7±21 mg/kg in the infants with neonatal RDS at 35 minutes of life. All the babies included in the study were noted to have severe disease and prolonged MV. After stabilization of their status, the neonates received combination therapy involving surfactantBL inhalation to reduce the duration of MV. The dose of the agent was 75 mg. Results . After surfactantBL inhalation, effective spon taneous respiration occurred in 69.2% of the newborn infants; successful extubation was carried out. The median duration of MV after surfactant BL inhalation was 22 hours (4—68 hours). There were no reintubated cases after inhalation therapy. Following surfactantBL inhalation, 4 (30.8%) patients remained to be on MV as a control regimen; 3 of them had highfre quency MV. SurfactantBL inhalation made it possible to change the respiratory support regimen and to reduce MV parame ters in these babies.

High frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice

We tested the hypothesis that high frequency ventilation affects respiratory system mechanical functions in C57BL/6J and BALB/c mice. We measured respiratory mechanics by the forced oscillation technique over 1h in anesthetized, intubated, ventilated BALB/c and C57BL/6J male mice.We did not detect any change in airway resistance, Rn, tissue damping, G, tissue elastance, H and hysteresivity, eta in BALB/c mice during 1h of ventilation at 150 or at 450 breaths/min; nor did we find a difference between BALB/c mice ventilated at 150 breaths/min compared with 450 breaths/min. Among C57BL/6J mice, except for H, all parameters remained unchanged over 1h of ventilation in mice ventilated at 150 breaths/min. However, after 10 and 30min of ventilation at 450 breaths/min, Rn, and respiratory system compliance were lower, and eta was higher, than their starting value. We conclude that high frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice.

High-frequency mechanical ventilation principles and practices in the era of lung-protective ventilation strategies.

The term high-frequency ventilation is used to describe a heterogeneous group of ventilation modes that are characterized by high respiratory frequencies and low tidal volumes. The increasing understanding of the pathogenesis of VILI, including concepts such as volutrauma and atelectrauma, has led to a renewed interest in the role of HFV in lung-protective ventilation strategies. Inherent to many modes of HFV are low tidal volumes and small pressure swings during the respiratory cycle, which allow for higher mean airway pressures than those safely achieved with CMV. This has the potential to reduce lung injury by limiting volutrauma, whereas maintaining bigger lung volumes at end-expiration may reduce atelectrauma. Of the various forms of HFV, HFO is the only mode with an active expiration phase. This characteristic, combined with superior gas conditioning, may make HFO a promising ventilatory strategy for adults. Although a significant amount of data exists in the literature to support the application of HFO in infants and children who have acute respiratory failure, clinical data on the use of HFO in adults is only now emerging. Early studies of applying HFO in ARDS patients have demonstrated its safety and benefit in terms of oxygenation. Additionally, limited data exist on the comparison between HFO and CMV in this patient population; however, encouraging preliminary results have been reported. The optimum strategy for the application of HFV, including the timing of HFV initiation, remains unclear.

High frequency mechanical ventilation in the treatment of neonatal respiratory distress.

High frequency mechanical ventilation in the treatment of neonatal respiratory distress.

High Frequency Mechanical Ventilation in Severe Hyaline Membrane Disease

Twenty-four preterm infants with respiratory failure from severe hyaline membrane disease (HMD) received mechanical ventilation at high respiratory frequencies. The average birthweight of the infants was 1244 +/- 301 g, and 7 babies weighed less than 1000 g. The average gestational age was 30 +/- 2 weeks, and 6 infants were born at 28 weeks or less. The method of ventilation included (1) respiratory frequencies of 60--110/min, sometimes with brief manual ventilation at more rapid rates, (2) peak inflation pressures (PIP) of less than 35 cm H2O, (3) inspiratory durations of 0.15--0.25 sec, (4) positive end-expiratory pressure (PEEP) of 4--9 cm H2O, and (5) weaning from mechanical ventilation by reducing tidal volume until peak inflation pressure (PIP) reached 20--25 cm H2O, whereupon respiratory frequency was decreased. PaCO2 was kept at 30--40 torr and PaO2 at 60--80 torr. Of the infants, 22 survived (92%) with few major complications.

High frequency mechanical ventilation in severe hyaline membrane disease an alternative treatment?

Twenty-four preterm infants with respiratory failure from severe hyaline membrane disease (HMD) received mechanical ventilation at high respiratory frequencies. The average birthweight of the infants was 1244 +/- 301 g, and 7 babies weighed less than 1000 g. The average gestational age was 30 +/- 2 weeks, and 6 infants were born at 28 weeks or less. The method of ventilation included (1) respiratory frequencies of 60--110/min, sometimes with brief manual ventilation at more rapid rates, (2) peak inflation pressures (PIP) of less than 35 cm H2O, (3) inspiratory durations of 0.15--0.25 sec, (4) positive end-expiratory pressure (PEEP) of 4--9 cm H2O, and (5) weaning from mechanical ventilation by reducing tidal volume until peak inflation pressure (PIP) reached 20--25 cm H2O, whereupon respiratory frequency was decreased. PaCO2 was kept at 30--40 torr and PaO2 at 60--80 torr. Of the infants, 22 survived (92%) with few major complications.