scholarly journals MRI Based Evaluation of Mechanical Ventilation and Regional Lung Volumes in Severe Neonatal Bronchopulmonary Dysplasia

2020 ◽  
Author(s):  
K. Gouwens ◽  
N. Higano ◽  
K.T. Marks ◽  
J. Stimpfl ◽  
E. Hysinger ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Bronchopulmonary Dysplasia ◽  
Lung Volumes ◽  
Regional Lung

Regional intrapulmonary gas distribution in awake and anesthetized-paralyzed prone man

1978 ◽  
Vol 45 (4) ◽  
pp. 528-535 ◽  
Author(s):  
K. Rehder ◽  
T. J. Knopp ◽  
A. D. Sessler
Keyword(s):  
Mechanical Ventilation ◽  
Vertical Distribution ◽  
Vertical Gradient ◽  
Phase Iii ◽  
Residual Volume ◽  
Gas Distribution ◽  
Lung Volumes ◽  
Regional Lung ◽  
Residual Capacity ◽  
The Vertical Distribution

The intrapulmonary distribution of inspired gas (ventilation/unit lung volume, VI), functional residual capacity (FRC), closing capacity (CC), and the slope of phase III were determined in five awake and five anesthetized-paralyzed volunteers who were in the prone position with the abdomen unsupported. After induction of anesthesia-paralysis, FRC was less in four of five subjects and CC was consistently less. At FRC there was no difference in the vertical gradient of regional lung volumes between the awake and anesthetized-paralyzed prone subjects. Also, there was no difference in VI between the two states. The normalized slope of phase III decreased consistently with induction of anesthesia-paralysis, but the vertical distribution of a 133Xe bolus inhaled from residual volume was not different between the two states. The data of the study are compatible with 1) a pattern of expansion of the respiratory system during anesthesia-paralysis and mechanical ventilation different than that during spontaneous breathing and 2) a more uniform intraregional distribution of inspired gas and/or a different sequence of emptying during anesthesia-paralysis.

scholarly journals Interaction between regional lung volumes and ventilator-induced lung injury in the normal and endotoxemic lung

2020 ◽  
Vol 318 (3) ◽  
pp. L494-L499 ◽  
Author(s):  
Seiha Yen ◽  
Melissa Preissner ◽  
Ellen Bennett ◽  
Stephen Dubsky ◽  
Richard Carnibella ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Tidal Volume ◽  
Lung Volumes ◽  
Mechanically Ventilated ◽  
Ventilator Induced Lung Injury ◽  
Computed Tomography Images ◽  
Gas Trapping ◽  
Regional Lung ◽  
The Relationship

Both overdistension and atelectasis contribute to lung injury and mortality during mechanical ventilation. It has been proposed that combinations of tidal volume and end-expiratory lung volume exist that minimize lung injury linked to mechanical ventilation. The aim of this study was to examine this at the regional level in the healthy and endotoxemic lung. Adult female BALB/c mice were injected intraperitoneally with 10 mg/kg lipopolysaccharide (LPS) in saline or with saline alone. Four hours later, mice were mechanically ventilated for 2 h. Regional specific end-expiratory volume (sEEV) and tidal volume (sVt) were measured at baseline and after 2 h of ventilation using dynamic high-resolution four-dimensional computed tomography images. The regional expression of inflammatory genes was quantified by quantitative PCR. There was a heterogenous response in regional sEEV whereby endotoxemia increased gas trapping at end-expiration in some lung regions. Within the healthy group, there was a relationship between sEEV, sVt, and the expression of Tnfa, where high Vt in combination with high EEV or very low EEV was associated with an increase in gene expression. In endotoxemia there was an association between low sEEV, particularly when this was combined with moderate sVt, and high expression of IL6. Our data suggest that preexisting systemic inflammation modifies the relationship between regional lung volumes and inflammation and that although optimum EEV-Vt combinations to minimize injury exist, further studies are required to identify the critical inflammatory mediators to assess and the effect of different injury types on the response.

scholarly journals The proteomic response is linked to regional lung volumes in ventilator-induced lung injury

2020 ◽  
Vol 129 (4) ◽  
pp. 837-845
Author(s):  
Seiha Yen ◽  
Yong Song ◽  
Melissa Preissner ◽  
Ellen Bennett ◽  
Richard Wilson ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Complex Interaction ◽  
Lung Volumes ◽  
Ventilator Induced Lung Injury ◽  
Regional Lung ◽  
Altered Regulation ◽  
Proteomic Response

This study provides novel insights into the regional response to mechanical ventilation in the setting of acid-induced lung injury and highlights the complex interaction between tidal stretch and low end-expiratory lung volumes; both of which caused altered regulation of different injury pathways.

scholarly journals Regional Lung Derecruitment and Inflammation during 16 Hours of Mechanical Ventilation in Supine Healthy Sheep

2013 ◽  
Vol 119 (1) ◽  
pp. 156-165 ◽  
Author(s):  
Mauro R. Tucci ◽  
Eduardo L. V. Costa ◽  
Tyler J. Wellman ◽  
Guido Musch ◽  
Tilo Winkler ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Regions Of Interest ◽  
Positive End Expiratory Pressure ◽  
18F Fluorodeoxyglucose ◽  
Positron Emission ◽  
Lung Dysfunction ◽  
Regional Lung ◽  
Net Uptake ◽  
Normal Lungs

Abstract Background: Lung derecruitment is common during general anesthesia. Mechanical ventilation with physiological tidal volumes could magnify derecruitment, and produce lung dysfunction and inflammation. The authors used positron emission tomography to study the process of derecruitment in normal lungs ventilated for 16 h and the corresponding changes in regional lung perfusion and inflammation. Methods: Six anesthetized supine sheep were ventilated with VT = 8 ml/kg and positive end-expiratory pressure = 0. Transmission scans were performed at 2-h intervals to assess regional aeration. Emission scans were acquired at baseline and after 16 h for the following tracers: (1) 18F-fluorodeoxyglucose to evaluate lung inflammation and (2) 13NN to calculate regional perfusion and shunt fraction. Results: Gas fraction decreased from baseline to 16 h in dorsal (0.31 ± 0.13 to 0.14 ± 0.12, P < 0.01), but not in ventral regions (0.61 ± 0.03 to 0.63 ± 0.07, P = nonsignificant), with time constants of 1.5–44.6 h. Although the vertical distribution of relative perfusion did not change from baseline to 16 h, shunt increased in dorsal regions (0.34 ± 0.23 to 0.63 ± 0.35, P < 0.01). The average pulmonary net 18F-fluorodeoxyglucose uptake rate in six regions of interest along the ventral–dorsal direction increased from 3.4 ± 1.4 at baseline to 4.1 ± 1.5⋅10−3/min after 16 h (P < 0.01), and the corresponding average regions of interest 18F-fluorodeoxyglucose phosphorylation rate increased from 2.0 ± 0.2 to 2.5 ± 0.2⋅10−2/min (P < 0.01). Conclusions: When normal lungs are mechanically ventilated without positive end-expiratory pressure, loss of aeration occurs continuously for several hours and is preferentially localized to dorsal regions. Progressive lung derecruitment was associated with increased regional shunt, implying an insufficient hypoxic pulmonary vasoconstriction. The increased pulmonary net uptake and phosphorylation rates of 18F-fluorodeoxyglucose suggest an incipient inflammation in these initially normal lungs.

Estimation of Mortality Risk in Chronically Ventilated Infants With Bronchopulmonary Dysplasia

PEDIATRICS ◽  
1991 ◽  
Vol 88 (6) ◽  
pp. 1153-1160 ◽  
Author(s):  
Debora W. Overstreet ◽  
J. Craig Jackson ◽  
Gerald van Belle ◽  
William E. Truog
Keyword(s):  
Mechanical Ventilation ◽  
Bronchopulmonary Dysplasia ◽  
Airway Pressure ◽  
Life Support ◽  
Water Pressure ◽  
Accurate Estimation ◽  
Regression Equations ◽  
Bacterial Sepsis ◽  
Mean Airway Pressure ◽  
Predictors Of Mortality

Bronchopulmonary dysplasia is a chronic, sometimes fatal lung disease, which primarily affects premature infants and often leads to a dependence on mechanical ventilation lasting many months. To identify prognostic factors of mortality at 1 and 2 months of age, the authors reviewed the medical records of the 144 neonates admitted to two neonatal intensive care units in Seattle from January 1, 1986, through December 31, 1988, who required mechanical ventilation throughout the first month of life. Likely predictors of mortality were tested by logistic regression analysis. The calculated mean airway pressure at 30 days of age (MAP30) and the diagnosis of bacterial sepsis at any time during the first month of life (Bact0-30) were statistically significant predictors of mortality (P < .001 and P = .018, respectively) and had the lowest deviance in the regression model. The probability of mortality was estimated by 1/(1 + e-x, where x = -6.510 + 0.4588 (MAP30) + 1.475 (Bact0-30), and where MAP30 is expressed as centimeters of water pressure (1 cm H2O = 0.0978 kPa) and the presence or absence of bacteremia is 1 and 0, respectively. The records of the 57 infants who still required mechanical ventilation at 60 days of age were reanalyzed with clinical data available during the first 2 months of life. Mean airway pressure (MAP60) and the fraction of inspired oxygen (F60) at 60 days of age combined to form the best predictors of mortality, where x = -7.668 + 0.2940 (MAP60) + 5.935 (F60). The occurrence of bacterial sepsis during the first 2 months of life, the degree of hypochloremia, and the duration of chronic sedative use were also significant predictors of survival, even controlling of MAP60 and F60. These regression equations allow more accurate estimation of the likelihood of survival for chronically ventilated infants and may facilitate decisions regarding withdrawal or continuation of life support.

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.

scholarly journals Invasive mechanical ventilation and biomarkers as predictors of bronchopulmonary dysplasia in preterm infants

2020 ◽  
Author(s):  
Camila Piqui Nascimento ◽  
Larissa Prado Maia ◽  
Patrícia Terra Alves ◽  
Aline Teodoro de Paula ◽  
Jair Pereira Cunha Junior ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Preterm Infants ◽  
Bronchopulmonary Dysplasia ◽  
Invasive Mechanical Ventilation
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