Search Results
Results 701 - 750 of 822
< 7 8 9 10 11 12 13 14 15 16 17 >
Axen K - - 1984
Ventilatory responses to graded elastic and resistive loads from 20 quadriplegic men were analyzed. During the 1st, 5th, and 10th consecutively loaded inspirations 1) responses from different subjects ranged from a weak tidal volume defense coupled with an increased breathing frequency to a strong tidal volume defense coupled with a ...
Gimenez M - - 1984
The pattern of breathing during maximal oxygen uptake (Vo2max) was studied in 26 patients with chronic airflow obstruction (CAO), in whom the vital capacity (VC), forced expiratory volume in 1 s (FEV1) and residual volume (RV) were measured. The patients performed, on a cycle ergometer, in a sitting position, a ...
Vanmeenen M T - - 1984
In eleven young healthy subjects, vital capacity was reduced by 30% by thoracic or abdominal strapping and the effects of this on maximal work capacity, ventilation and circulation were examined. During exercise as well as at rest, tidal volume and stroke volume were reduced and respiratory frequency and heart rate ...
Woelfel A - - 1984
Fourteen patients with exercise-induced ventricular tachycardia (VT) underwent serial treadmill testing, and those with reproducible arrhythmia were treated with a beta-adrenergic blocking agent. In 11 patients (79%), VT of similar rate, morphologic characteristics and duration was reproduced on 2 consecutive treadmill tests performed 1 to 14 days apart. Beta blockade ...
Lind F - - 1984
The interrelationships of ventilation (V), tidal volume (VT), inspiratory (T1), expiratory (TE) and total breath (Ttot) durations, mean inspiratory (VT/TI) and expiratory (VT/TE) flows, and lung volumes were studied in normal subjects at rest and during exercise on a cycle ergometer. The ergometric load was increased by 10 W every ...
Lind F G - - 1984
Changes in respiratory drive, as assessed by mouth occlusion pressure (P0.1), and in breathing pattern were studied in 19 healthy subjects who exercised on a cycle ergometer with work loads ranging from loadless pedalling up to the highest load that could be sustained for 4 min. In the P0.1 studies, ...
Katz-Salamon M - - 1984
Ability to judge ventilation (VI) and respiratory rate (RR) was examined in healthy subjects using the standard psychophysical technique of magnitude production. The relationships between objective and subjective magnitudes of VI could be adequately described by power function with the mean exponent 1.9. The mean deviation from the regression line ...
Hornstein D - - 1984
Respiratory responses to a single breath during which a resistive load was applied were studied in 8 conscious subjects. There was an increase in inspiratory time (TI), an increase in end-tidal PCO2 (PETCO2) and a decrease in end-tidal PO2 (PETO2) on the resisted breath. 12 subjects were given a single ...
Dodd D S - - 1984
We studied the dynamic mechanical properties of the chest wall in 7 patients with severe chronic air-flow obstruction (CAO). Measurements were made during quiet breathing at rest and during exercise on a bicycle ergometer at work rates equivalent to 50 and 100% of their maximal work rate (Wmax). The peak ...
Chapman K R - - 1984
To determine whether the rib cage and abdomen-diaphragm contributions to tidal volume (VT) during CO2 rebreathing are affected by postural change, using respiratory inductive plethysmography, we measured in eight healthy volunteers the compartmental VT responses to progressive hypercapnia in both seated and supine postures. The ventilatory, frequency, and VT responses ...
Daubenspeck J A - - 1983
Responses of expiratory duration (TE) and laryngeal aperture to small flow resistance loads (2 and 5 cm H2O/LPS) applied to single expirations were measured using repeated applications in four subjects during quiet breathing. All subjects significantly prolonged TE in response to the higher load and 3 of the 4 showed ...
Hartmann-Andersen F - - 1983
The simple T-piece is frequently used as a weaning system during respirator treatment. It is modified with an expiratory non-compliant reservoir (EnCR), an inspiratory compliant reservoir (ICR) and/or an expiratory one-way valve. The distribution of expiratory gases and rebreathing were studied in a model set-up in the corresponding systems at ...
Hodous T K - - 1983
Forty-nine men performed progressive submaximal treadmill exercise to determine the cardiopulmonary and subjective response to added resistance to breathing. Twenty subjects (controls), FEV1/FVC% = 79.2 +/- 1.4 (mean +/- SEM), were compared with 19 mildly obstructed men (OB1), FEV1/FVC% = 66.9 +/- 0.5, and 10 with moderate obstruction (OB2), FEV1/FVC% ...
Burdon J G - - 1983
The responses to exercise were studied in 41 patients with pulmonary fibrosis, in whom vital capacity (VC) was reduced to 62% of predicted normal values. Maximum power output (POmax) was 53% predicted; there was a significant relationship between POmax and VC (r = 0.564). The maximum ventilation achieved during exercise ...
Cotton D J - - 1983
We measured the single breath diffusing capacity for carbon monoxide (DLcoSB) using a three-equation method to describe CO uptake in 10 normal seated subjects who either voluntarily inhaled slowly (0.5 L/sec) to total lung capacity (TLC), or inhaled slowly to TLC with maximal effort through a high inspiratory resistance which ...
Taveira da Silva A M - - 1983
The purpose of our study was to identify central nervous system sites involved in the respiratory depressant effect of drugs that stimulate opioid receptors. Diacetylmorphine (heroin) was administered into several cerebroventricular regions of chloralose-anesthetized cats, while monitoring pulmonary ventilation with a Fleisch pneumotachograph. Administration of heroin (17, 50, 150, and ...
Axen K - - 1983
Ventilatory responses to inspiratory elastic and resistive loads of 67 men were analyzed. During the 1st, 5th, and 10th consecutively loaded breaths 1) individual responses ranged from a rapid-shallow to a slow-deep breathing pattern; 2) strong tidal volume (VT) defenders employed longer inspirations than did weak VT defenders; and 3) ...
Sadler M - - 1983
Vertices are the points in an arborescence which interconnect segments and comprise terminal or pendant vertices (Vp), nodal or branching points and the root point. Branching points may be dichotomous (Vd) or trichomtomous (Vt), etc., and are subdivided into distinct two-dimensional topological entities according to the number of terminal vertices ...
Hudgel D W - - 1983
We previously demonstrated that specific behavioral styles influenced recognition of resistive loads to breathing. However, the basis for this finding remained unclear. Because others have found a relationship between behavioral style and ventilatory drive, we evaluated the relationships among resting ventilatory drive, behavioral style, and recognition of loads to breathing. ...
Sullivan T Y - - 1983
Minute ventilation (VE) and breathing pattern during an abrupt increase in fractional CO2 were compared in 10 normal subjects before and after airway anesthesia. Subjects breathed 7% CO2-93% O2 for 5 min before and after inhaling aerosolized lidocaine. As a result of airway anesthesia, VE and tidal volume (VT) were ...
Clark J M - - 1983
Continuous breath-by-breath measurements of ventilatory parameters were performed during submaximal and maximal treadmill exercise in 21 highly conditioned oarsmen. Average maximum values of O2 uptake, minute ventilation (VI), tidal volume (VT), and respiratory frequency (f) were 6.60 l/min (73.5 ml X kg-1 X min-1), 200 l/min, 3.29 l, and 62 ...
Tallarida G - - 1983
In anesthetized rabbits, rhythmic contractions of the gastrocnemius muscle elicited by stimulating the gastrocnemius nerves (40 trains/min of 0.5-ms rectangular pulses at 2.0-2.5 mult of motor threshold), increased pulmonary ventilation by increasing frequency (f). Expiratory duration (TE) was greatly reduced, while inspiratory time (TI) was much less changed. Mean expiratory ...
Ehrlich, Walter
The cardiopulmonary effects of a peripheral cholinesterase inhibitor (0.025 mg neostigmine i.v. per kg) and inspiratory resistance loading comparable to the inspiratory resistance of a protective respirator mask, were studied comprehensively in 6 intact, awake dogs at rest and during exercise. The aim of this study was to test the ...
Muza S R - - 1983
Previous research indicates that fatiguing static exercise causes hyperventilation and a decrease of end-tidal CO2 partial pressure PETCO2. The objectives of this study were 1) to examine the changes in pattern of breathing during static exercise, and 2) to define the isocapnic ventilatory response. Six healthy males were studied once ...
Oliven A - - 1983
The present study examined the respiratory responses involved in the maintenance of eucapnea during acute airway obstruction in 12 patients with chronic obstructive disease (COPD) and 3 age-matched normal subjects. Acute airway obstruction was produced by application of external flow-resistive loads (2.5 to 30 cm H2O/liter per s) throughout inspiration ...
Burdon J G - - 1983
Using open-magnitude scaling, we compared the perceived magnitude of externally added resistive and elastic loads to breathing in normal subjects with that perceived when the background load (i.e., the minimum load of the circuit) was increased by the addition of either resistive or elastic loads of increasing magnitude. The study ...
Esau S A - - 1983
Maximum relaxation rate (MRR) and the time constant of relaxation (tau) of transdiaphragmatic pressure (Pdi) was measured in four male subjects and compared with the high-to-low frequency ratio (H/L) of the diaphragmatic electromyogram (EMG) as a predictor of diaphragmatic fatigue. Pdi and inspiratory time-to-total breath duration ratios (TI/TT) were varied, ...
Hesser C M - - 1983
Mouth occlusion pressure (P0.1), minute ventilation (V), and mean inspiratory and expiratory flows were studied in eight normal subjects at rest and during exercise on a cycle ergometer, the load of which was increased in steps of 10 W every minute. All four variables rose curvilinearly as the load was ...
Iscoe S - - 1983
We measured tidal volume (VT) and inspiratory (TI) and expiratory (TE) durations in five conscious tracheostomized dogs breathing air or 5% CO2 in air either at normal (20 degrees C) or elevated (30 degrees C) ambient temperatures. Respiratory frequency ranged between 16 and 333/min due to changes in both TI ...
Sung R J - - 1983
To elucidate electrophysiologic mechanism of exercise-induced ventricular tachycardia (VT), electrophysiologic studies were performed in 12 patients in whom sustained VT had developed during treadmill exercise testing. Six patients had arteriosclerotic coronary heart disease, 3 had cardiomyopathy, and 3 had no clinical evidence of organic heart disease. All patients had had ...
Citterio G - - 1983
The firing patterns of single diaphragm fibers and electromyographic moving average (M.A.) of diaphragm and parasternal intercostal muscles (P.I.) were studied in rabbits during control and heat tachypnea at nearly constant tidal volume (VT). During tachypnea the percentage of single diaphragm fibers with relatively high values of peak firing rate ...
Chapman K R - - 1983
20 ambulatory asthmatics were questioned regarding their perception of the dyspnea of acute asthmatic attacks; in particular, its relationship to the phase of respiration. 19 (95%) stated that inspiration was more difficult than expiration although 5 (25%) reported that they had been taught that the reverse was 'correct'. In order ...
Folinsbee L J - - 1983
We investigated the breath-by-breath pattern of ventilatory response to bicycle exercise in seven elite male cyclists (VO2max = 71.7 ml X min-1 X kg-1) and ten sedentary males (VO2max = 47.3 ml X min-1 X kg-1) to analyze differences in breathing patterns between individuals with normal and high exercise ventilations ...
Sébert P - - 1983
Ten subjects (five males, five females) were studied in resting conditions. Ventilation (VT, f, TI, TE), heart rate (HR) and RR interval were recorded or measured. Each subject voluntarily breathed with spontaneous frequency at different ratios of his spontaneous tidal volume (VrT). The results show that sinus arrhythmia increases with ...
Lerman Y - - 1983
Twenty subjects wearing protective respirators were studied during submaximal exercise (80% of VO2max) on a treadmill. The protective devices were fitted with canister filters of low expiratory resistance and different inspiratory resistances: (0.3, 1.8, 2.8, 3.4, 3.9, and 4.6 cm H2O X sec/liter). The effect of inspiratory resistance on physical ...
Ballam G O - - 1982
Awake upright White Leghorn roosters (Gallus domesticus) were unidirectionally ventilated. Electromyographic activity from inspiratory and expiratory muscles was recorded to demarcate inspiration and expiration. During inspiration, the rate of inflation of the air sac system was varied while the CO2 concentration of the gas passing through the lungs was maintained ...
Asher M I - - 1982
This study evaluated whether inspiratory muscle training (IMT) could increase inspiratory muscle strength and endurance and exercise performance in 11 patients with cystic fibrosis (CF) with moderately severe airflow limitation. The IMT consisted of breathing through an inspiratory resistance (IR) for 15 min twice daily for 4 wk, preceded or ...
Hirsch J A - - 1982
Steady-state breathing patterns on mouthpiece and noseclip (MP) and face mask (MASK) during air and chemostimulated breathing were obtained from pneumotachometer flow. On air, all 10 subjects decreased frequency (f) and increased tidal volume (VT) on MP relative to that on MASK without changing ventilation (VE), mean inspiratory flow (VT/TI), ...
Trippenbach T - - 1982
Effects of chest compressions on the pattern of breathing were studied in pentobarbital anaesthetized 9- to 11-day-old kittens before and after vagotomy. The chest was compressed by means of a micrometer at three levels (T1-4, T6-8, T9-11). In intact and vagotomized kittens, the group mean values of inspiratory time (tI), ...
Savoy J - - 1982
We compared resting breathing patterns in twelve normal humans before and after administration of aerosols of normal saline and 4% lidocaine. Experiments were performed in random order on two consecutive days in single blind fashion. At the time of the experiments, neither the subjects nor the people who analyzed the ...
Szekely O - - 1982
This study was conducted to differentiate the ventilatory and metabolic response to supine exercise at low levels (VO2 less than 1000 ml/min) from the well-documented response to high level upright exercise. Further, the respiratory cycle during exercise is analysed in terms of inspiratory time, flow and expiratory time as well ...
Harber P - - 1982
Air-purifying respirators impose several loads on breathing. The effects of inspiratory flow resistance, respiratory dead space such as that of a full-face mask, and moderate exercise and maximal exercise were assessed alone and in combination in nine normal volunteers. There were significant effects on respiratory timing variables (e.g., inspiratory time, ...
Weissman C - - 1982
The effect of sitting and supine posture on breathing patterns and gas exchange during room air breathing and administration of 2 and 4% CO2 was studied in nine normal subjects using a noninvasive canopy system. During air breathing minute ventilation (VE) was 21% (P less than 0.005) higher in the ...
Hedner T - - 1982
The respiratory activity in newborn preterm (29 days gestation) rabbits was studied after administration of thyrotropic releasing hormone. Intraperitoneal injection induced an increase in respiratory frequency (f) and a decrease in tidal volume (VT) resulting in a slight increase in pulmonary ventilation (VE). These effects were seen in parallel to ...
Henderson-Smart D J - - 1982
1. Direct simultaneous recordings from chronically implanted electrodes in different parts of the diaphragm were made in young lambs in which laryngeal adductor (thyroarytenoideus) and intercostal electromyograms, airflow, tracheal pressure and electrocorticogram and electro-oculograms for behavioural state were also recorded.2. An asynchrony of diaphragmatic contraction occurred which was dependent on ...
Robinson E P - - 1982
We studied the effects of running on ventilatory muscle strength and endurance in 11 adults enrolled in a physical fitness program. Twelve healthy volunteers were used as a control group. Maximum expiratory pressure (Paomax), maximum voluntary ventilation (MVV), peak inspiratory flow, forced expiratory volume in 1 s, forced vital capacity, ...
Macklem P T - - 1982
The diaphragm consists of two separate muscles, the costal and crural parts, with different segmental innervation and different action on the rib cage. Diaphragmatic endurance is determined by the balance between energy supply and demand. Both an increase in demand and a decrease in supply of energy lead to diaphragmatic ...
Connellan S J - - 1982
The effects of 10 mg of nebulized salbutamol on lung mechanics and exercise tolerance in 10 patients with severe airflow obstruction are described. All patients were previously considered to have irreversible airflow obstruction as demonstrated by little or no improvement in expiratory flow rates either during a corticosteroid trial or ...
Iber C - - 1982
Ventilatory and timing responses to repetitive and sustained inspiratory resistive loading were assessed in six naive male subjects during wakefulness (AW) and non-REM sleep (NREM). In five of six subjects, tidal volume (VT) was maintained or increased with repetitive five-breath loading periods during wakefulness. In these five subjects, mouth occlusion ...
Axen K - - 1982
Load compensation in 29 cervical cord-injured men was inferred from the difference between actual first-breath responses to graded elastic and resistive loads and those calculated assuming identical respiratory muscle pressure (Pmus) wave forms in the unloaded and loaded states (i.e., the passive prediction). At every load, respiratory frequency (f) and ...
< 7 8 9 10 11 12 13 14 15 16 17 >