Search Results
Results 351 - 400 of 1421
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Grimm D R - - 2000
OBJECTIVES: We administered aerosolized histamine to 32 subjects with tetraplegia to determine whether there were differences in spirometric and/or lung volume parameters between responders and nonresponders. RESULTS: Baseline pulmonary function parameters revealed mild to moderate restrictive dysfunction. We found that 25 subjects (78%) were hyperreactive to histamine (mean provocative concentration ...
Suki B - - 2000
In 11 isolated dog lung lobes, we studied the size distribution of recruited alveolar volumes that become available for gas exchange during inflation from the collapsed state. Three catheters were wedged into 2-mm-diameter airways at total lung capacity. Small-amplitude pseudorandom pressure oscillations between 1 and 47 Hz were led into ...
Kessler V - - 2000
OBJECTIVE: Analysis of dynamic respiratory system mechanics is generally based on a resistance-compliance model in which nonlinearities of the respiratory mechanics indices are not considered. The recently developed SLICE method analyzing consecutive volume slices of the tidal volume was used for determination of non-linear volume-dependent respiratory system mechanics. Volume-dependent compliance ...
Aggarwal A N - - 2000
OBJECTIVE: To assess the utility of static lung pressure-volume measurements in identifying and categorizing pulmonary function test defects in survivors of acute respiratory distress syndrome (ARDS). DESIGN: Cross-sectional. SETTING: Pulmonary function laboratory at a tertiary referral hospital in northern India. PATIENTS: Six survivors of ARDS reporting for their first follow-up ...
Villena V - - 2000
The aim of therapeutic thoracentesis (TT) is to aspirate as much pleural fluid as possible. Monitoring pleural pressure (PlP) during TT has been proposed to avoid the adverse effects due to an unintended sharp drop in PlP. The objectives of this study are to ascertain the diagnostic value of the ...
D'Angelo E - - 2000
The purpose of the present investigation was to assess the effect of large tidal volumes and mean lung volumes on the viscoelastic properties of the respiratory system in normal humans; and to verify if in this case the results could be satisfactorily described by a simple linear viscoelastic model of ...
Topulos G P - - 2000
The pressure-volume (P-V) characteristics of the lung microcirculation are important determinants of the pattern of pulmonary perfusion and of red and white cell transit times. Using diffuse light scattering, we measured capillary P-V loops in seven excised perfused dog lobes at four lung volumes, from functional residual capacity (FRC) to ...
Clini E - - 2000
Exhaled nitric oxide (NO) production in stable chronic obstructive pulmonary disease (COPD) has been loosely related to the severity of illness, being significantly reduced in the most severe cases. Pulmonary hypertension is associated with lower NO output from the lung. In this study expired NO was measured in patients with ...
Pieters T - - 2000
STUDY OBJECTIVES: In humans, malnutrition alters the respiratory system in different ways. It impairs the ventilatory drive, decreases respiratory muscle strength and reduces immune competence. In addition, typical emphysema-like changes were demonstrated in starved animals. The presence of emphysema has never been demonstrated in starved humans. Our objective was to ...
Powell L L - - 2000
BACKGROUND: Emphysema is a chronic disease of the lungs with destruction of terminal alveoli and airway obstruction. Lung volume reduction surgery (LVRS) is being investigated for the treatment of emphysema. Increasing resection volumes with LVRS may lead to worsening of carbon monoxide diffusing capacity (Dlco) despite improvement in compliance and ...
Sloots C E - - 2000
The barostat is a device that maintains a constant pressure within an air-filled polyethylene bag by means of a feedback mechanism. The system measures variations in rectal tone by recording changes in the intrarectal pressure and volume. Different procedures, such as ramp distension or intermittent distension, are used to test ...
Nève V - - 2000
We applied to 20 paralyzed ventilated children (0.15 to 14.3 yr, six with acute respiratory distress syndrome [ARDS]) the low-flow inflation (LFI) technique providing quasi-static volume-pressure (V-P) curves and compared the assessment of overdistension (OD) on dynamic and LFI (reference) inspiratory V-P curves. Dynamic curves were obtained at the airway ...
Taube C - - 2000
Expiratory airway collapse is a characteristic feature in patients with chronic obstructive pulmonary disease (COPD). We hypothesized that this collapse might mask the effects of bronchodilators during forced expiration but not during forced inspiration, and that accordingly, the improvement in forced inspiration and not that in forced expiration with bronchodilator ...
Pauluhn J - - 2000
The pulmonary response of Wistar rats to a cumulative dose of 1 mg/kg body weight of a polymeric alpha,omega-diamine was examined using the intratracheal route of administration. Instillation of the test substance was on days 0 and 7 followed by a 3-month postobservation period. Static and dynamic pulmonary function tests, ...
Wu E Y - - 2000
To determine the role of mediastinal shift after pneumonectomy (PNX) on compensatory responses, we performed right PNX in adult dogs and replaced the resected lung with a custom-shaped inflatable silicone prosthesis. Prosthesis was inflated (Inf) to prevent mediastinal shift, or deflated (Def), allowing mediastinal shift to occur. Thoracic, lung air, ...
Miller M R - - 2000
Previous studies have shown that the added resistance of a mini-Wright peak expiratory flow (PEF) meter reduced PEF by approximately 8% in normal subjects because of gas compression reducing thoracic gas volume at PEF and thus driving elastic recoil pressure. We undertook a body plethysmographic study in 15 patients with ...
Cossette I - - 2000
We studied three professional flautists while playing to determine: (1) what respiratory muscles and percent vital capacity (%VC) were used; (2) how mouth pressure (Pm), embouchure resistance (Rem), embouchure aperture (Aem), flow (V) and velocity (Vel) affect sound loudness (I) and frequency (F). We measured Pm, esophageal, gastric, transdiaphragmatic, transpulmonary ...
Menezes S L - - 2000
OBJECTIVE: Diaphragmatic reconstruction may cause several respiratory changes. The aims of the present study were to evaluate the respiratory changes induced by two methods of diaphragmatic reconstruction. METHODS: Two groups of rats with an experimental diaphragmatic defect were studied. In one group (n = 5), diaphragmatic resection was followed by ...
Kárason S - - 2000
BACKGROUND: Lung mechanics are usually measured using static or quasistatic methods, abandoning normal ventilatory treatment. We have developed a method to calculate the alveolar pressure during dynamic/therapeutic conditions, "the dynostatic pressure" (P(dyn)), using airway pressure (P) measured in the trachea and volume (V) and flow (V) at the Y-piece. METHODS: ...
Kuwahira I - - 2000
OBJECT: The fold plication method is a new operative procedure for lung volume reduction surgery whereby the target area is obliterated by plicating the folded tissue using a knifeless stapler, without the use of bovine pericardium. The effectiveness of this new method was evaluated in patients with advanced pulmonary emphysema. ...
Couëtil L L - - 2000
The purpose of this study was to assess whether our method of inducing forced expiration detects small airway obstruction in horses. Parameters derived from forced expiratory flow-volume (FEFV) curves were compared with lung mechanics data obtained during spontaneous breathing in nine healthy horses, in three after histamine challenge, and in ...
Corsico A - - 2000
According to a recent hypothesis, airway smooth muscle regulates airway calibre mostly at high lung volume, whereas the mucosa and adventitia dimensions dominate at low lung volumes. It was thought that if inhaled steroids decrease the thickness of airway wall in asthma, then forced vital capacity (FVC), which reflects the ...
Gómez-Hospital J A - - 2000
STUDY OBJECTIVES: This study was performed to assess the changes in pulmonary function after a successful percutaneous balloon mitral valvotomy (PBMV) in 23 consecutive patients with symptomatic mitral stenosis. METHODS AND RESULTS: Lung function preprocedure and postprocedure were evaluated by spirometric flow, static pulmonary volumes, and diffusion capacity of the ...
Lai Y L - - 2000
Mice have been widely used in immunologic and other research to study the influence of different diseases on the lungs. However, the respiratory mechanical properties of the mouse are not clear. This study extended the methodology of measuring respiratory mechanics of anesthetized rats and guinea pigs and applied it to ...
Wagers S S - - 2000
We present a case in which the pressure-volume (P-V) curve proved invaluable in the diagnostic workup of a patient. The patient was a 43-year-old man who presented with progressive dyspnea on exertion, restrictive spirometry, exercise desaturation, and an unremarkable CT scan. Because of the unexpected finding of an unremarkable CT ...
Morice A H - - 2000
The performance of dry powder inhaler (DPI) devices, particularly reservoir DPIs, may be influenced by environmental conditions. This study compared the bronchodilator efficacy and in vitro aerosol characteristics of salbutamol, delivered via a novel reservoir DPI (Clickhaler) and a conventional pressurized metered-dose inhaler (MDI) before and after use of the ...
Tarazona-Santos E - - 2000
This study investigates the relationships among hematological variables, pulmonary function, and age in a sample of high-altitude natives. The following anthropometric and physiological variables were examined in 77 adult Quechua males from the Peruvian Central Andes (Huancavelica, 3,680 m): height, weight, sitting height, chest diameters, chest and abdominal circumferences, forced ...
Mason N P - - 2000
The aims of the present study were to determine the changes in forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1) and peak expiratory flow (PEF), during an ascent to 5,300 m in the Nepalese Himalayas, and to correlate the changes with arterial oxygen saturation measured by pulse ...
Kunst P W - - 2000
OBJECTIVE: A new noninvasive method, electrical impedance tomography (EIT), was used to make pressure-impedance (PI) curves in a lung lavage model of acute lung injury in pigs. The lower inflection point (LIP) and the upper deflection point (UDP) were determined from these curves and from the traditional pressure-volume (PV) curves ...
Dueck R - - 2000
Flow/volume (F/V) spirometry is routinely used for assessing the type and severity of lung disease. Forced vital capacity (FVC) and timed vital capacity (FEV1) provide the best estimates of airflow obstruction in patients with asthma, chronic obstructive pulmonary disease (COPD) and emphysema. Computerized spirometers are now available for early home ...
Chen R - - 2000
We measured the effect of thoracoabdominal configuration on twitch transdiaphragmatic pressure (Pdi, t) in response to supramaximal, transcutaneous, bilateral phrenic nerve shocks in three thin normal men. Pdi, t was measured as a function of lung volume (VL) in the relaxation configuration, at functional residual capacity (FRC), and at the ...
Lahrmann H - - 1999
STUDY OBJECTIVES: The aim of this study was to investigate prospectively the changes in neural drive to the diaphragm in the first year after lung volume reduction surgery (LVRS) in patients with COPD. PATIENTS AND METHODS: In 14 patients with severe emphysema (mean +/- SD; age, 53.7 +/- 8.3 years; ...
Singh B - - 1999
To examine mechanisms responsible for reduced lung volumes (restriction) in asbestos-related pleural fibrosis (APF), we studied diaphragm function and lower rib-cage excursion in 26 subjects with previous asbestos exposure and no evidence of asbestosis. Using posteroanterior (PA) and lateral chest radiographs taken at residual volume and at 25%, 70%, and ...
Vialet R - - 1999
BACKGROUND: In mechanically ventilated patients, inspiration is forced by an externally applied positive pressure whereas expiration remains passive and depends on the time constant of the total respiratory system (tau), which constitutes an important determinant of mechanical ventilation. The end-inspiratory occlusion technique is one of the easiest methods to obtain ...
Cabezas G A - - 1999
OBJECTIVE: To determine the probable bronchodilating effect of dopamine administered by inhalation route in patients with crisis of bronchial asthma and the effect of dopamine on bronchial motor tone. DESIGN AND METHOD: We have studied eighteen (18) patients with crisis of bronchial asthma, ten (10) subjects with bronchial hyperreactivity and ...
Polese G - - 1999
To investigate the changes in respiratory mechanics in patients undergoing cardiac surgery before and after the operation. Prospective physiological study. Operating theatre of the Institute of Cardiac Surgery, Verona, Italy. 8 patients needing heart surgery because of a coronary bypass or mitral valve replacement. We measured respiratory mechanics before and ...
Rodarte J R - - 1999
During dynamic hyperinflation with induced bronchoconstriction, there is a reduction in lung elastic recoil at constant lung volume (R. Pellegrino, O. Wilson, G. Jenouri, and J. R. Rodarte. J. Appl. Physiol. 81: 964-975, 1996). In the present study, lung elastic recoil at control end inspiration was measured in normal subjects ...
Teramoto S - - 1999
We evaluated variations in spirometric indices (i.e., forced vital capacity [FVC], peak expiratory flow [PEF], and forced expiratory volume in 1 sec [FEV1]) and static respiratory muscle pressures (i.e., maximum static inspiratory pressure [PImax] and maximum static expiratory pressure [PEmax]) within a span of 12 hr in 60 healthy elderly ...
Sanna A - - 1999
We studied chest wall kinematics and respiratory muscle action in five untrained healthy men walking on a motor-driven treadmill at 2 and 4 miles/h with constant grade (0%). The chest wall volume (Vcw), assessed by using the ELITE system, was modeled as the sum of the volumes of the lung-apposed ...
Ranieri V M - - 1999
OBJECTIVE: Cardiopulmonary bypass (CPB) is associated with abnormalities of lung function characterized by an increase in static elastance of the respiratory system. We examined the following: a) the effects of CPB on the total inspiratory volume-pressure (V-P) relationship of the respiratory system; b) the relative contribution of the chest wall ...
Polkey M I - - 1999
Functional magnetic stimulation (FMS) of the thoracic nerve roots to simulate cough has been suggested as a treatment approach in patients unable to voluntarily activate the abdominal muscles. However, factors that could influence the efficacy of FMS in clinical use have not been evaluated. In the present investigation we studied ...
Lorino A M - - 1999
This study was designed to determine the responses of lung volume and respiratory resistance (Rrs) to decreasing levels of continuous negative airway pressure (CNAP). Twenty normal subjects were studied in the basal state and under CNAP levels of -5, -10, and -15 hPa. Rrs was measured by the forced oscillation ...
Nava S - - 1999
BACKGROUND: Idiopathic pulmonary fibrosis is an inflammatory disease which leads to chronic ventilatory insufficiency and is characterised by a reduction in pulmonary static and dynamic volumes. It has been suggested that lung elastance may also be abnormally increased, particularly in end stage disease, but this has not been systematically tested. ...
Chou K C - - 1999
BACKGROUND: The effect of body position on diffusing capacity and its components, membrane diffusing capacity (Dm) and pulmonary capillary blood volume (Vc), in patients with chronic obstructive pulmonary disease (COPD) has remained elusive. This study was designed to evaluate the effect of body position on diffusing capacity for carbon monoxide ...
Chen J C - - 1999
Lung volume reduction surgery (LVRS) has shown promising results in severe emphysema. However, intraoperative indicators are needed to define optimal resection volumes. Diffusing capacity (DLCO) worsens with larger LVRS and may correlate with pulmonary artery (PA) pressure. We hypothesized that there would be a greater increase in PA pressures with ...
Kárason S - - 1999
BACKGROUND: Airway pressure measurements above the endotracheal tube will be distorted because of endotracheal tube resistance. To separate lung and chest wall compliance, esophageal pressure is conventionally measured with an air-filled balloon catheter, which is difficult to insert in unconscious patients. We have developed a methodology with fluid-filled catheters for ...
Zerahn B - - 1999
This study aimed to determine the relationship between improvement in lung function and changes in transthoracic electrical bioimpedance (TEB) after thoracentesis in patients with pleural effusions. Fifteen patients with pleural effusions due to either malignant (n = 8) or cardiac (n = 7) diseases were included. Pulmonary function was assessed ...
Bersten A D - - 1999
OBJECTIVE: To describe and evaluate clinically applicable approaches to measurement of respiratory mechanics in critically ill patients. DATA SOURCES: Methodological and evaluation studies of respiratory mechanics in critically ill patients from relevant MEDLINE searches. SUMMARY OF REVIEW: In ventilated subjects clinically important respiratory system mechanics can be measured using airway ...
Ratnovsky A - - 1999
A system for noninvasive assessment of an all-inclusive function of respiratory muscles at different lung volumes is presented. The apparatus was based on the interrupter technique and facilitated simultaneous measurements of mouth pressure and airflow rate during dynamic or quasistatic manoeuvres. In this study, mouth pressure values were continuously acquired ...
Fujimoto K - - 1999
In twelve patients with severe emphysema who underwent lung volume reduction surgery (LVRS), we assessed the results of dyspnea scale, pulmonary function, 6-minute walk distance (6MD), and thoracic movement prior to and 6 months following LVRS. Postoperatively, forced expiratory volume (FEV1), maximum inspiratory mouth pressures (MIP), maximum expiratory mouth pressures ...
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