scholarly journals Ultrastructural Study of Alveolar Epithelial Type II Cells by High-Frequency Oscillatory Ventilation

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xiaofei Qin ◽  
Wanhai Fu ◽  
Youwei Zhao ◽  
Qiong Meng ◽  
Chuming You ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Volume ◽  
High Frequency ◽  
High Frequency Oscillatory Ventilation ◽  
Conventional Ventilation ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial ◽  
Volume Strategy ◽  
High Frequency Oscillatory

Alveolar epithelial type II cells (AECIIs) containing lamellar bodies (LBs) are alveolar epithelial stem cells that have important functions in the repair of lung structure and function after lung injury. The ultrastructural changes in AECIIs after high-frequency oscillatory ventilation (HFOV) with a high lung volume strategy or conventional ventilation were evaluated in a newborn piglet model with acute lung injury (ALI). After ALI with saline lavage, newborn piglets were randomly assigned into five study groups (three piglets in each group), namely, control (no mechanical ventilation), conventional ventilation for 24 h, conventional ventilation for 48 h, HFOV for 24 h, and HFOV for 48 h. The lower tissues of the right lung were obtained to observe the AECII ultrastructure. AECIIs with reduced numbers of microvilli, decreased LBs electron density, and vacuole-like LBs deformity were commonly observed in all five groups. Compared with conventional ventilation groups, the decrease in numbers of microvilli and LBs electron density, as well as LBs with vacuole-like appearance and polymorphic deformity, was less severe in HFOV with high lung volume strategy groups. AECIIs were injured during mechanical ventilation. HFOV with a high lung volume strategy resulted in less AECII damage than conventional ventilation.

Nasal High-Frequency Oscillatory Ventilation in Preterm Infants with Moderate Respiratory Distress Syndrome: A Multicenter Randomized Clinical Trial

Neonatology ◽  
2021 ◽  
pp. 1-7
Author(s):  
Xingwang Zhu ◽  
Zhichun Feng ◽  
Chengjun Liu ◽  
Liping Shi ◽  
Yuan Shi ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Distress Syndrome ◽  
Preterm Infants ◽  
High Frequency ◽  
Primary Outcome ◽  
Distress Syndrome ◽  
Invasive Mechanical Ventilation ◽  
Risk Difference ◽  
High Frequency Oscillatory Ventilation ◽  
High Frequency Oscillatory

<b><i>Objective:</i></b> To determine whether nasal high-frequency oscillatory ventilation (NHFOV) as a primary mode of respiratory support as compared with nasal continuous airway pressure (NCPAP) will reduce the need for invasive mechanical ventilation in preterm infants (26<sup>0/7</sup>–33<sup>6/7</sup> weeks of gestational age [GA]) with respiratory distress syndrome (RDS). <b><i>Methods:</i></b> This multicenter randomized controlled trial was conducted in 18 tertiary neonatal intensive care units in China. A total of 302 preterm infants born at a GA of 26<sup>0/7</sup>–33<sup>6/7</sup> weeks with a diagnosis of RDS were randomly assigned to either the NCPAP (<i>n</i> = 150) or the NHFOV (<i>n</i> = 152) group. The primary outcome was the need for invasive mechanical ventilation during the first 7 days after birth. <b><i>Results:</i></b> Treatment failure occurred in 15 of 152 infants (9.9%) in the ­NHFOV group and in 26 of 150 infants (17.3%) in the NCPAP group (95% CI of risk difference: −15.2 to 0.4, <i>p =</i> 0.06). In the subgroup analysis, NHFOV resulted in a significantly lower rate of treatment failure than did NCPAP in the strata of 26<sup>+0/7</sup>–29<sup>+6/7</sup>weeks of GA (11.9 vs. 32.4%, 95% CI of risk difference: −39.3 to −1.7, <i>p =</i> 0.03) and birth weight &#x3c;1,500 g (10.4 vs. 29.6%, 95% CI of risk difference: −33.8 to −4.6, <i>p =</i> 0.01). The rate of thick secretions causing an airway obstruction was higher in the NHFOV group than in the NCPAP group (13.8 vs. 5.3%, 95% CI of risk difference: 1.9–15.1, <i>p =</i> 0.01). No significant differences in other secondary outcomes were found between the NHFOV and NCPAP groups. <b><i>Conclusions:</i></b> NHFOV was not superior to NCPAP with regard to the primary outcome when applied as the primary respiratory support for RDS in infants between 26<sup>+0/7</sup> and 33<sup>+6/7</sup> weeks of GA. In the subgroup analysis, NHFOV seemed to improve effectiveness than NCPAP in preterm infants &#x3c;30 weeks of GA.

Setting Mean Airway Pressure during High-frequency Oscillatory Ventilation According to the Static Pressure–Volume Curve in Surfactant-deficient Lung Injury

2003 ◽  
Vol 99 (6) ◽  
pp. 1313-1322 ◽  
Author(s):  
Thomas Luecke ◽  
Juergen P. Meinhardt ◽  
Peter Herrmann ◽  
Gerald Weisser ◽  
Paolo Pelosi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Lung Volume ◽  
High Frequency ◽  
Airway Pressure ◽  
Static Pressure ◽  
High Frequency Oscillatory Ventilation ◽  
Mean Airway Pressure ◽  
Oscillatory Ventilation ◽  
Hemodynamic Variables ◽  
High Frequency Oscillatory

Background Numerous studies suggest setting positive end-expiratory pressure during conventional ventilation according to the static pressure-volume (P-V) curve, whereas data on how to adjust mean airway pressure (P(aw)) during high-frequency oscillatory ventilation (HFOV) are still scarce. The aims of the current study were to (1) examine the respiratory and hemodynamic effects of setting P(aw) during HFOV according to the static P-V curve, (2) assess the effect of increasing and decreasing P(aw) on slice volumes and aeration patterns at the lung apex and base using computed tomography, and (3) study the suitability of the P-V curve to set P(aw) by comparing computed tomography findings during HFOV with those obtained during recording of the static P-V curve at comparable pressures. Methods Saline lung lavage was performed in seven adult pigs. P-V curves were obtained with computed tomography scanning at each volume step at the lung apex and base. The lower inflection point (Pflex) was determined, and HFOV was started with P(aw) set at Pflex. The pigs were provided five 1-h cycles of HFOV. P(aw), first set at Pflex, was increased to 1.5 times Pflex (termed 1.5 Pflex(inc)) and 2 Pflex and decreased thereafter to 1.5 times Pflex and Pflex (termed 1.5 Pflex(dec) and Pflex(dec)). Hourly measurements of respiratory and hemodynamic variables as well as computed tomography scans at the apex and base were made. Results High-frequency oscillatory ventilation at a P(aw) of 1.5 Pflex(inc) reestablished preinjury arterial oxygen tension values. Further increase in P(aw) did not change oxygenation, but it decreased oxygen delivery as a result of decreased cardiac output. No differences in respiratory or hemodynamic variables were observed when comparing HFOV at corresponding P(aw) during increasing and decreasing P(aw). Variation in total slice lung volume (TLVs) was far less than expected from the static P-V curve. Overdistended lung volume was constant and less than 3% of TLVs. TLVs values during HFOV at Pflex, 1.5 Pflex(inc), and 2 Pflex were significantly greater than TLVs values at corresponding tracheal pressures on the inflation limb of the static P-V curve and located near the deflation limb. In contrast, TLVs values during HFOV at decreasing P(aw) (i.e., 1.5 Pflex(dec) and Pflex(dec)) were not significantly greater than corresponding TLV on the deflation limb of the static P-V curves. The marked hysteresis observed during static P-V curve recordings was absent during HFOV. Conclusions High-frequency oscillatory ventilation using P(aw) set according to a static P-V curve results in effective lung recruitment, and slice lung volumes during HFOV are equal to those from the deflation limb of the static P-V curve at equivalent pressures.

Pulmonary Mechanics in Preterm Neonates With Respiratory Failure Treated With High-Frequency Oscillatory Ventilation Compared With Conventional Mechanical Ventilation

PEDIATRICS ◽  
1991 ◽  
Vol 87 (4) ◽  
pp. 487-493
Author(s):  
Soraya Abbasi ◽  
Vinod K. Bhutani ◽  
Alan R. Spitzer ◽  
William W. Fox
Keyword(s):  
Mechanical Ventilation ◽  
Bronchopulmonary Dysplasia ◽  
High Frequency ◽  
Conventional Mechanical Ventilation ◽  
High Frequency Oscillatory Ventilation ◽  
Preterm Neonates ◽  
High Frequency Ventilation ◽  
Pulmonary Mechanics ◽  
Frequency Ventilation ◽  
High Frequency Oscillatory

Pulmonary mechanics were measured in 43 preterm neonates (mean ± SD values of birth weight 1.2 ± 0.3 kg, gestational age 30 ± 2 weeks) with respiratory failure who were concurrently randomly assigned to receive conventional mechanical ventilation (n = 22) or high-frequency ventilation (n = 21). The incidence of bronchopulmonary dysplasia was comparable in the two groups (high-frequency ventilation 57%, conventional ventilation 50%). Pulmonary functions were determined at 0.5, 1.0, 2.0, and 4.0 weeks postnatal ages. Data were collected while subjects were in a nonsedated state during spontaneous breathing. These sequential data show similar patterns of change in pulmonary mechanics during high-frequency ventilation and conventional mechanical ventilation irrespective of gestational age, birth weight stratification, or bronchopulmonary dysplasia. There was no significant difference in the pulmonary functions with either mode of ventilation during the acute phase (≤4 weeks) of respiratory disease. When evaluated by the clinical diagnosis of bronchopulmonary dysplasia, the pulmonary data suggested a less severe dysfunction in the high-frequency oscillatory ventilation-treated bronchopulmonary dysplasia group compared with the conventional mechanical ventilation-treated group. These results indicate that high-frequency oscillatory ventilation in preterm neonates does not reduce the risk of acute lung injury; however, the magnitude of the pulmonary dysfunction in the first 2 weeks of life merits a reevaluation.

Comparison of four methods of lung volume recruitment during high frequency oscillatory ventilation

2009 ◽  
Vol 35 (11) ◽  
Author(s):  
Anastasia Pellicano ◽  
David G. Tingay ◽  
John F. Mills ◽  
Stephen Fasulakis ◽  
Colin J. Morley ◽  
...  
Keyword(s):  
Lung Volume ◽  
High Frequency ◽  
High Frequency Oscillatory Ventilation ◽  
Oscillatory Ventilation ◽  
Lung Volume Recruitment ◽  
High Frequency Oscillatory
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