Sustained Improvement in Gas Exchange After Negative Pressure Ventilation for 8 Hours Per Day on 2 Successive Days in Chronic Airflow Limitation

1991 ◽  
Vol 144 (2) ◽  
pp. 390-394 ◽  
Author(s):  
Enrique Fernandez ◽  
Paltiel Weiner ◽  
Ephraim Meltzer ◽  
Mary M. Lutz ◽  
David B. Badish ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Negative Pressure ◽  
Airflow Limitation ◽  
Sustained Improvement ◽  
Negative Pressure Ventilation

Negative pressure ventilation decreases inflammation and lung edema during normothermic ex-vivo lung perfusion

2018 ◽  
Vol 37 (4) ◽  
pp. 520-530 ◽  
Author(s):  
Nader S. Aboelnazar ◽  
Sayed Himmat ◽  
Sanaz Hatami ◽  
Christopher W. White ◽  
Mohamad S. Burhani ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Ex Vivo ◽  
Lung Perfusion ◽  
Lung Edema ◽  
Ex Vivo Lung Perfusion ◽  
Negative Pressure Ventilation

Ventilation-perfusion imbalance and chronic obstructive pulmonary disease staging severity

2009 ◽  
Vol 106 (6) ◽  
pp. 1902-1908 ◽  
Author(s):  
Roberto Rodríguez-Roisin ◽  
Mitra Drakulovic ◽  
Diego A. Rodríguez ◽  
Josep Roca ◽  
Joan Albert Barberà ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Forced Expiratory Volume ◽  
Pulmonary Gas Exchange ◽  
Airflow Limitation ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Gold Stage ◽  
Stage 1

Chronic obstructive pulmonary disease (COPD) is characterized by a decline in forced expiratory volume in 1 s (FEV1) and, in many advanced patients, by arterial hypoxemia with or without hypercapnia. Spirometric and gas exchange abnormalities have not been found to relate closely, but this may reflect a narrow range of severity in patients studied. Therefore, we assessed the relationship between pulmonary gas exchange and airflow limitation in patients with COPD across the severity spectrum. Ventilation-perfusion (V̇A/Q̇) mismatch was measured using the multiple inert gas elimination technique in 150 patients from previous studies. The distribution of patients according to the GOLD stage of COPD was: 15 with stage 1; 40 with stage 2; 32 with stage 3; and 63 with stage 4. In GOLD stage 1, AaPo2 and V̇A/Q̇ mismatch were clearly abnormal; thereafter, hypoxemia, AaPo2, and V̇A/Q̇ imbalance increased, but the changes from GOLD stages 1–4 were modest. Postbronchodilator FEV1 was related to PaO2 ( r = 0.62) and PaCO2 ( r = −0.59) and to overall V̇A/Q̇ heterogeneity ( r = −0.48) ( P < 0.001 each). Pulmonary gas exchange abnormalities in COPD are related to FEV1 across the spectrum of severity. V̇A/Q̇ imbalance, predominantly perfusion heterogeneity, is disproportionately greater than airflow limitation in GOLD stage 1, suggesting that COPD initially involves the smallest airways, parenchyma, and pulmonary vessels with minimal spirometric disturbances. That progression of V̇A/Q̇ inequality with spirometric severity is modest may reflect pathogenic processes that reduce both local ventilation and blood flow in the same regions through airway and alveolar disease and capillary involvement.

Augmentation of phrenic neural activity by increased rates of lung inflation

1981 ◽  
Vol 50 (1) ◽  
pp. 149-161 ◽  
Author(s):  
A. I. Pack ◽  
R. G. DeLaney ◽  
A. P. Fishman
Keyword(s):  
Tidal Volume ◽  
Volume Change ◽  
Neural Activity ◽  
Negative Pressure ◽  
Spontaneous Breathing ◽  
Moving Average ◽  
Constant Flow ◽  
Lung Inflation ◽  
Negative Pressure Ventilation ◽  
Single Breath

Studies were conducted in anesthetized paralyzed dogs using a cycle-triggered constant-flow ventilator, which ventilated the animal in phase with the recorded phrenic neural activity. Intermittently tests were performed in which the animal was ventilated with a different airflow for a single breath. Increased airflows, within the range generated during spontaneous breathing, caused an increased rate of rise of the moving average phrenic neurogram and a shortening of the duration of the nerve burst. The magnitude of the increase in the rate of rise of the neurogram was related to the level of inspiratory airflow. Tests with brief pulses of airflow showed that an increase in the rate of rise of the phrenic neurogram could be produced without inflating the lung above the resting tidal volume of the animal. Similar results were obtained with negative-pressure ventilation and the effects were abolished by vagotomy. This vagally mediated augmentation of phrenic neural output may accelerate the inspiratory volume change in the lung during spontaneous breathing at hyperpneic levels.

scholarly journals Diagnosis and validation by computational fluid dynamics of poultry house with negative pressure ventilation

2019 ◽  
Vol 23 (10) ◽  
pp. 761-767
Author(s):  
Gisele C. de A. Cunha ◽  
José P. Lopes Neto ◽  
Dermeval A. Furtado ◽  
Valéria P. Borges ◽  
Elias A. Freire ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Negative Pressure ◽  
Environmental Variables ◽  
Fluid Dynamic ◽  
Air Velocity ◽  
Cfd Simulations ◽  
Heterogeneous Distribution ◽  
Poultry House ◽  
Mean Values ◽  
Negative Pressure Ventilation

ABSTRACT Negative pressure ventilation in poultry houses has been used to enable the correction of their internal microclimates, and studies point to the heterogeneous distribution of air along the aviaries and the inadequacy of the environmental variables to the recommended ranges for thermal comfort of adult birds, especially in the hottest hours of the day. This study aimed to diagnose the facilities of a poultry house in the state of Paraíba, Brazil, regarding the distribution of environmental variables and thermal comfort; develop a computational model and validate it for Computational Fluid Dynamic - CFD simulations. Air temperature (Tair), air relative humidity (RH) and air velocity (Vair) data allowed characterizing the internal environment by comparison with the recommended ranges for each variable and by the temperature-humidity-velocity index (THVI). The poultry house does not provide comfort for the housed adult birds, between 12 and 14 h, with THVI indicating alert and Tair, RH and Vair values outside the recommended ranges; the CFD model for the poultry house was validated with Tair averages collected in the field of 27.75 ± 1.35 ºC and simulated of 27.85 ± 0.55 ºC, mean values of RH collected of 83 ± 12% and simulated of 78 ± 3%, and means of Vair collected of 2.35 ± 1.35 m s-1 and simulated of 2.50 ± 1.50 m s-1.

Negative Pressure Ventilation

CHEST Journal ◽  
1989 ◽  
Vol 95 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Robert D. Levy ◽  
T. Douglas Bradley ◽  
Stephen L. Newman ◽  
Peter T. Macklem ◽  
James G. Martin
Keyword(s):  
Negative Pressure ◽  
Negative Pressure Ventilation

Use of Negative Pressure Ventilation in Pediatric Critical Care

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Cynthia A. Moffitt ◽  
Kathleen Deakins ◽  
Ira Cheifetz ◽  
Jason A. Clayton ◽  
Katherine N. Slain ◽  
...  
Keyword(s):  
Critical Care ◽  
Negative Pressure ◽  
Pediatric Critical Care ◽  
Negative Pressure Ventilation

Negative Pressure Ventilation: New Uses for an Old Technique

1990 ◽  
Vol 1 (2) ◽  
pp. 313-317
Author(s):  
Gloria Sonnesso
Keyword(s):  
Nursing Care ◽  
Negative Pressure ◽  
Respiratory Function ◽  
Upper Airway ◽  
Negative Pressure Ventilation ◽  
Skin Breakdown ◽  
Dependent Patient

Negative pressure ventilation (NPV), a concept that was used in the 1940s through 1950s to support the victims of the polio epidemic, is regaining popularity. It is being used increasingly to intermittently support respiratory function in patients suffering from a variety of diseases. The use of NPV obviates the need for a surgically placed airway (if the patients’ upper airway is intact) and allows the patient to resume many of his or her normal activities. Several types of NPV are available for use and experimentation, and it is strongly recommended that the appropriate type for each patient be chosen. Nursing care of the patient on NPV is essentially the same as that of any chronically ventilator-dependent patient. Issues unique to the patient supported on NPV include: increased potential for aspiration, skin breakdown around the NPV site, and “tank shock.” Nursing plays an important role in identifying patients who may be candidates for NPV. Negative pressure ventilation may allow a formally hospital-bound patient the opportunity to be home with family and friends

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