Suppression of Ventilatory Muscle Activity in Healthy Subjects and COPD Patients with Negative Pressure Ventilation

CHEST Journal ◽  
1991 ◽  
Vol 99 (5) ◽  
pp. 1186-1192 ◽  
Author(s):  
Francesco Gigliotti ◽  
Roberto Duranti ◽  
Andrea Fabiani ◽  
Mario Schiavina ◽  
Giorgio Scano
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Healthy Subjects ◽  
Negative Pressure Ventilation ◽  
Copd Patients

scholarly journals Maintenance Negative Pressure Ventilation Improves Survival in COPD Patients with Exercise Desaturation

2019 ◽  
Vol 8 (4) ◽  
pp. 562
Author(s):  
Hung-Yu Huang ◽  
Chun-Yu Lo ◽  
Lan-Yan Yang ◽  
Fu-Tsai Chung ◽  
Te-Fang Sheng ◽  
...  
Keyword(s):  
Lung Function ◽  
Negative Pressure ◽  
Significant Risk ◽  
Forced Expiratory Volume ◽  
Walking Distance ◽  
Chronic Obstructive ◽  
Negative Pressure Ventilation ◽  
Risk Of Death ◽  
Copd Patients

Negative pressure ventilation (NPV), when used as an adjuvant to pulmonary rehabilitation, improves lung function, increases exercise capacity, and reduces exacerbations. The aim of this study was to determine whether maintenance NPV improves long-term clinical outcomes and reduces mortality in patients with chronic obstructive pulmonary disease (COPD). Between 2003 and 2009, 341 patients were treated for COPD either with or without hospital-based NPV. We measured forced expiratory volume in one second (FEV1), 6-min walking distance (6MWD), and oxygen saturation by pulse oximetry (SpO2) during a 6-min walk test (6MWT) every 3–6 months. Desaturation (D) during the 6MWT was defined as a reduction in SpO2 of ≥10% from baseline. The NPV group had a better survival outcome than the Non-NPV group. The 8-year survival probabilities for the NPV and Non-NPV groups were 60% and 20%, respectively (p < 0.01). Baseline desaturation was a significant risk factor for death, and the risk of death increased with desaturation severity (SpO2 80~89: hazard ratios (HR) 2.7, 95% confidence interval (CI) 1.4–5.3; SpO2 < 80: HR 3.1, 95% CI 1.3–7.4). The NPV group had a slower decline in lung function and 6MWD. The NPV + D and Non-NPV+D had a threefold and fourfold increase in the risks of all-cause mortality compared with the NPV-ND, respectively. Maintenance non-invasive NPV reduced long-term mortality in COPD patients. The desaturating COPD patients had an increased mortality risk compared with non-desaturating COPD patients.

Upper airway obstruction induced by negative-pressure ventilation in awake healthy subjects

1993 ◽  
Vol 75 (2) ◽  
pp. 546-552 ◽  
Author(s):  
A. Sanna ◽  
C. Veriter ◽  
D. Stanescu
Keyword(s):  
Airway Obstruction ◽  
Negative Pressure ◽  
Healthy Subjects ◽  
Fiber Optic ◽  
Upper Airway ◽  
Upper Airway Obstruction ◽  
Bipolar Electrode ◽  
Upper Airways ◽  
Negative Pressure Ventilation ◽  
Zero Values

Negative-pressure ventilation (NPV) induces sleep-related upper airway obstruction. However, the precise mechanism and site of upper airway obstruction during NPV have not been worked out. We studied seven awake healthy volunteers (23–30 yr old) in an Emerson tank respirator. Subjects had the head outside the iron lung and breathed through a pneumotachograph, which yielded the airflow (V) signal. Supraglottic pressure (Psg) was measured with a catheter with the tip at the retroepiglottic level. Diaphragmatic electromyograms (EMGdi) were obtained from an esophageal bipolar electrode. Tidal volume was measured with an inductance plethysmograph. Measurements were done at -10, -20, and -30 cmH2O. At each pressure run subjects were asked to repeatedly relax or to actively breathe in phase with the respirator. Subjects had been previously trained to relax during NPV. During the relax runs there was no EMGdi activity. Stridor or wheezing occurred in all seven subjects during the relax runs but not during the active runs. Two patterns were associated with NPV during relax runs. One pattern was decreases in both V and Psg followed by zero values of these indexes, which corresponded to an inspiratory narrowing and closure of the glottis. These changes were visualized by fiber-optic bronchoscopy in one subject. The second pattern was a decrease in V and increase in Psg, which corresponded to an inspiratory supraglottic obstruction. In five subjects a supraglottic pattern was observed, whereas in two subjects glottic closure was seen. We conclude that muscular relaxation during NPV produces a decrease in the caliber of the upper airways at the glottic or supraglottic level. An uncoupling of upper airway muscle activity and the diaphragm might be the mechanism responsible for these changes.

Reproducibility and responsiveness of a noninvasive EMG technique of the respiratory muscles in COPD patients and in healthy subjects

2004 ◽  
Vol 96 (5) ◽  
pp. 1723-1729 ◽  
Author(s):  
Marieke L. Duiverman ◽  
Leo A. van Eykern ◽  
Peter W. Vennik ◽  
Gerard H. Koëter ◽  
Eric J. W. Maarsingh ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Healthy Subjects ◽  
Respiratory Muscles ◽  
Emg Activity ◽  
Chronic Obstructive ◽  
Abdominal Muscles ◽  
Breathing Patterns ◽  
Obstructive Pulmonary Disease ◽  
Intercostal Muscles ◽  
Copd Patients

In the present study, we assessed the reproducibility and responsiveness of transcutaneous electromyography (EMG) of the respiratory muscles in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects during breathing against an inspiratory load. In seven healthy subjects and seven COPD patients, EMG signals of the frontal and dorsal diaphragm, intercostal muscles, abdominal muscles, and scalene muscles were derived on 2 different days, both during breathing at rest and during breathing through an inspiratory threshold device of 7, 14, and 21 cmH2O. For analysis, we used the logarithm of the ratio of the inspiratory activity during the subsequent loads and the activity at baseline [log EMG activity ratio (EMGAR)]. Reproducibility of the EMG was assessed by comparing the log EMGAR values measured at test days 1 and 2 in both groups. Responsiveness (sensitivity to change) of the EMG was assessed by comparing the log EMGAR values of the COPD patients to those of the healthy subjects at each load. During days 1 and 2, log EMGAR values of the diaphragm and the intercostal muscles correlated significantly. For the scalene muscles, significant correlations were found for the COPD patients. Although inspiratory muscle activity increased significantly during the subsequent loads in all participants, the COPD patients displayed a significantly greater increase in intercostal and left scalene muscle activity compared with the healthy subjects. In conclusion, the present study showed that the EMG technique is a reproducible and sensitive technique to assess breathing patterns in COPD patients and healthy subjects.

Four-week Negative Pressure Ventilation Improves Respiratory Function in Severe Hypercapnic COPD Patients

CHEST Journal ◽  
1994 ◽  
Vol 105 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Francesco Gigliotti ◽  
Alessandro Spinelli ◽  
Roberto Duranti ◽  
Massimo Gorini ◽  
Patrizio Goti ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Respiratory Function ◽  
Negative Pressure Ventilation ◽  
Copd Patients

Noninvasive negative pressure ventilation improves survival of COPD patients with exercise desaturation

2018 ◽  
Author(s):  
Hung Yu Huang ◽  
Te-Fang Sheng ◽  
Chee Jen Chang ◽  
Lan-Yan Yang ◽  
Chun-Hua Wang ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Negative Pressure Ventilation ◽  
Copd Patients

Ventilatory and diaphragmatic EMG changes during negative-pressure ventilation in healthy subjects

1988 ◽  
Vol 64 (6) ◽  
pp. 2272-2278 ◽  
Author(s):  
D. O. Rodenstein ◽  
G. Cuttitta ◽  
D. C. Stanescu
Keyword(s):  
High Pressure ◽  
Tidal Volume ◽  
Negative Pressure ◽  
Healthy Subjects ◽  
Normal Subjects ◽  
Cortical Activity ◽  
Assisted Ventilation ◽  
Phase Lock ◽  
Negative Pressure Ventilation ◽  
Low Pressures

To evaluate the response of normal subjects to assisted ventilation, we studied 6 naive healthy subjects before and during negative-pressure ventilation (NPV) with "low" (-10 cmH2O) and "high" (-30 cmH2O) pressures in an Emerson tank respirator. Ventilation was measured with an inductive plethysmograph (Respitrace), and diaphragmatic electromyogram (DEMG) was studied with a bipolar esophageal electrode. During NPV a 1:1 phase lock was observed between subjects and iron lung frequency in all subjects. Tidal volume increased in most subjects, more with high than with low pressures (P less than 0.05), whereas DEMG increased, decreased, or showed no change. Postinspiratory inspiratory diaphragmatic activity (PIIA) significantly increased during high-pressure NPV and was accompanied by an increase in tonic DEMG in one-half of the subjects. Voluntary relaxation resulted in a decrease in DEMG and PIIA. We suggest that cortical activity can explain persistency of active breathing during negative-pressure ventilation.

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