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Results 301 - 350 of 591
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Sander J E - - 1995
Broiler embryos and chicks were exposed to formaldehyde vapors (up to 130 ppm) during the final 3 days of incubation. Bacterial load was significantly lower in a formaldehyde-fumigated hatcher than in an unfumigated hatcher. Hatchability was not affected. To determine if exposure to formaldehyde vapors in the hatcher would affect ...
Clark A L - - 1995
BACKGROUND: The exercise limitation of patients with chronic heart failure is associated with an increased ventilatory response during exercise. This is thought to be due, at least in part, to excessive dead space ventilation. METHODS: To assess ventilation perfusion matching, 20 patients with chronic heart failure and eight controls with ...
Shultz J J - - 1995
OBJECTIVE: Active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) utilizes a hand-held suction device with a pressure gauge that enables the operator to compress as well as actively decompress the chest. This new CPR method improves hemodynamic and ventilatory parameters when compared with standard CPR. ACD-CPR is easy to perform but may ...
Bischoff M M - - 1995
Detection of the ventilatory threshold during an incremental load exercise test by eye can be difficult. Although various alternative methods employing information other than the ventilation can be used to assist in determining the ventilatory threshold, they rely on underlying assumptions about the physiological basis for the ventilatory threshold. The ...
Shelledy D C - - 1995
OBJECTIVE: To quantify the ventilatory efficiency of different modes of mechanical ventilation used to achieve full ventilatory support in normal subjects. Modes compared were assist-control, synchronized intermittent mandatory ventilation (SIMV), and SIMV with 10 cm H2O (0.98 kPA) of pressure support. DESIGN: Prospective, randomized blocks repeated measures design. Subjects served ...
Mateika J H - - 1995
During the past 100 years many experimental investigations have been carried out in an attempt to determine the control mechanisms responsible for generating the respiratory responses observed during incremental and constant-load exercise tests. As a result of these investigations a number of different and contradictory control mechanisms have been proposed ...
Norton K I - - 1995
This study investigated the influence of an exercise stimulus on pulmonary ventilation (VE) during severe levels of exercise in a group of ten athletes. The altered ventilation was assessed in relation to its effect on blood gas status, in particular to the incidence and severity of exercise induced hypoxaemia. Direct ...
Wenzel V - - 1994
STUDY OBJECTIVE: To compare the concentration of a rescuer's exhaled O2 and CO2 during mouth-to-mouth ventilation with or without chest compression. DESIGN: Prospective repeated measures study. Simulated one- and two-rescuer cardiopulmonary resuscitation (CPR) was performed as recommended by the American Heart Association. SETTING: University laboratory. PARTICIPANTS: Fifty-five healthcare professionals certified ...
Harty H R - - 1994
To determine whether a dose-dependent relationship exists between the subjective sensation of breathlessness and hypoventilation during steady-state exercise, we measured breathlessness at six levels of volitionally suppressed ventilation. To achieve this, subjects targeted their breathing at 0, 5, 10, 15, 20, and 25% below their spontaneous exercise level. All 12 ...
Malkoff M D - - 1994
Neural control of ventilation is exercised at multiple levels and includes an array of sensors and diverse control areas. Abnormalities in the neural control of ventilation are seen in a variety of pathologic states and illnesses commonly seen in critical care. As is common with any complex system, multiple feedback ...
Javorka K - - 1994
The defensive airway reflexes during high frequency jet ventilation (HFJV) were studied in anaesthetized, non-vagotomized (n = 16) and vagotomized (n = 11) rabbits. The animals were ventilated by a high frequency jet ventilator. Sneezing and coughing were evoked by mechanical stimulation of the airways. During HFJV spontaneous breathing was ...
Criner G J - - 1994
Previous studies have shown that noninvasive positive pressure ventilation (NPPV) improves gas exchange in acute and chronic respiratory failure. However, some patients are unable to tolerate NPPV due to air leaks around the mask, facial discomfort, and claustrophobia. A new mask that covers the entire face (Total, Respironics, Monroeville, Pa), ...
Duffin J - - 1994
This article presents the author's views about the neural drives to breathing during exercise. Two hypotheses are developed, the first being that the rapid changes in ventilation at the start and end of exercise are due to a fast neural drive whose magnitude is related to the frequency of limb ...
Ahmed M - - 1994
Many of the factors that appear to cause Cheyne-Stokes Breathing (CSB) in sleeping patients with congestive heart failure (CHF) are present during wakefulness. We studied the stability of ventilatory pattern in nine awake CHF patients (left ventricular ejection fraction 9-48%) who demonstrated CSB only while asleep and compared results with ...
Saunders K B - - 1994
A 37 year old patient with chronic active hepatitis progressing to cirrhosis presented with increasing breathlessness and was found to be hypoxic with finger clubbing. A progressive exercise study with measurement of oxygen saturation (SaO2) showed abnormally high ventilation and desaturation to 81% at 100 W. Serial studies over nearly ...
Vilozni D - - 1994
The present study describes the use of simple video games for a 5-week regimen of respiratory muscle training in 15 patients with Duchenne muscular dystrophy (DMD) at various stages of the disease. The games were re-arranged to be operated and driven by the respiratory efforts of the patient and to ...
Listello D - - 1994
STUDY OBJECTIVE: To examine the incidence, clinical impact, and predictors of reintubation following unplanned extubation (UE) in ICU patients. DESIGN: Retrospective data collection of prospectively identified consecutive cases of UE. SETTING: The adult Medical, Coronary, Surgical, Cardiac Surgery, and Neuroscience ICUs of a University Medical Center. PATIENTS: Eighty-one episodes of ...
Grinton S F - - 1994
In the normal aging population, there is no evidence that ventilation limits exercise. At all ages, normal persons have adequate ventilation during exercise to avoid arterial hypoxemia. Despite adequate oxygenation, however, indirect evidence suggests that with normal aging the loss of elastic recoil and reductions in maximal expiratory flow may ...
Cotes J E - - 1994
A standardised method of scoring respiratory disability based on measurement and/or estimation of maximal oxygen uptake has recently been developed by the European Society for Clinical Respiratory Physiology. In the present study, we wanted to determine how the results obtained using this objective method compared with those by the more ...
Nielsen O W - - 1994
Stout et al. (J. Appl. Physiol. 38:913-918, 1975) suggested an open-circuit multibreath (MB) inert gas method for determining pulmonary capillary blood flow (Qc) in anesthetized dogs receiving artificial ventilation. In the present work we investigated the accuracy and reproducibility of the MB method in nine healthy human subjects at spontaneous ...
Chassard D - - 1994
OBJECTIVE: In mechanically ventilated patients, pulmonary gas exchange was investigated during the administration of total parenteral nutrition containing medium-chain triglycerides or long-chain triglycerides as fat emulsions. DESIGN: Prospective, randomized, crossover trial (two lipid infusion periods of 8 hrs). SETTING: Intensive care unit in a university hospital. PATIENTS: Six mechanically ventilated ...
Clark A L - - 1994
BACKGROUND: Measurement of variables of metabolic gas exchange during exercise is widely used to assess the severity of heart failure. The variables derived however, are potentially dependent on motivation of the patient and duration of exercise. METHODS: The data from exercise tests in 23 patients with exertional breathlessness were analysed ...
Whyte K F - - 1994
Our objective was to examine the changes in regional ventilation during histamine-induced bronchoconstriction in stable asthma. We measured regional ventilation by a new method which measures regional distribution of inhaled 127Xe during tidal breathing by a gated method and, by simultaneously measuring 99mTc counts from labelled macroaggregates, allowed for changes ...
Miyamura M - - 1994
When exercise starts, various cardiorespiratory adjustments take place for accommodating the greatly increased metabolic requirements. A rapid response in ventilation (Phase I) may be at least useful for preventing oxygen deficiency and for increasing alveolar ventilation, oxygen tension, and oxygen uptake even if it is minimal. But why is the ...
Nink M - - 1994
Previous experimental and clinical studies clearly demonstrated that exogenously administered CRH possesses respiratory properties. Until now, these effects were investigated using human (h) CRH in both healthy volunteers and patients under long-term respiration. We now compared the effects of hCRH with those of ovine (o) CRH in ten healthy young ...
Mallios V J - - 1994
Previous studies have shown the existence of an ideal respiratory rate (fR) for a given ventilation at which the respiratory work rate (J.s-1) is minimum. The purpose of the present study was to measure the effect of fR, tidal volume and breathing pattern on the respiratory work per breath and ...
Mateika J H - - 1994
These experiments examined the effect of hypoxia and hyperoxia on ventilation, lactate concentration and electromyographic activity during an incremental exercise test in order to determine if coincident chances in ventilation and electromyographic activity occur during an incremental exercise test, despite an enhancement or reduction of peripheral chemoreceptor activity. In addition, ...
Mateika J H - - 1994
These experiments examined the changes in ventilation at the start and end of exercise. Six subjects walked on a treadmill at two work rates above and two below that corresponding to their first ventilatory thresholds, for three durations. The subjects also exercised at the lowest and highest work rates while ...
Mateika J H - - 1994
These experiments examined the effect of metabolic acidosis, induced as a result of dynamic exercise, on ventilation, lactate concentration and electromyographic activity. Seven subjects performed two consecutive incremental exercise tests until volitional exhaustion was achieved. The two tests were identical and were separated by a 7-min period of light exercise. ...
Bach J R - - 1993
Pulmonary complications are major causes of morbidity and mortality for patients with severe expiratory muscle weakness. The purpose of this study was to compare peak cough expiratory flows (PCEFs) during unassisted and assisted coughing and review the long-term use of mechanical insufflation-exsufflation (MI-E) for 46 neuromuscular ventilator users. These individuals ...
Haouzi P - - 1993
Ventilation and cardiac output subside gradually following cessation of exercise, which is commonly linked to the slow wash-out of materials from the recovering muscles. The effect of hindering the removal of the metabolic products of heavy cycle exercise on the kinetics of ventilation and gas exchange was studied in 5 ...
Thomas S H - - 1993
Ultrasonic nebulizers may be particularly suitable for the administration of therapeutic aerosols to patients undergoing mechanical ventilation, but the amount of aerosol that reaches the patients' respiratory tract during ultrasonic nebulization has not been adequately studied. The delivery through an endotracheal tube of nebulized aerosols labeled with 99mTechnetium human serum ...
Tucker K J - - 1993
This investigation was designed to test the hypothesis that active compression-decompression resuscitation is able to independently provide improved levels of minute ventilation when compared to high-impulse manual cardiopulmonary resuscitation (CPR). Eight adult beagles (10-15 kg) were studied after induction of ventricular fibrillation. Single 1-min CPR trials were performed while arterial ...
Berg R A - - 1993
BACKGROUND: Prompt initiation of bystander cardiopulmonary resuscitation (CPR) improves survival. Basic life support with mouth-to-mouth ventilation and chest compressions is intimidating, difficult to remember, and difficult to perform. Chest compressions alone can be easily taught, easily remembered, easily performed, adequately taught by dispatcher-delivered telephone instruction, and more readily accepted by ...
Wang P M - - 1993
The thickness of the pleural space was measured by fluorescence video-microscopy during mechanical ventilation in anesthetized paralyzed rabbits. A transparent parietal pleural window was made in the fourth or sixth intercostal space near midchest by dissection of intercostal muscle and endothoracic fascia. Fluorescence-labeled (fluorescein isothiocyanate) dextran solution (1 ml) was ...
Leach C L - - 1993
OBJECTIVE: To determine the efficacy of perfluorocarbon-associated gas exchange (partial liquid ventilation) in respiratory distress syndrome. DESIGN: Prospective, randomized, controlled study. SETTING: State University of New York at Buffalo, School of Medicine and Biomedical Sciences. SUBJECTS: Eleven premature lambs with respiratory distress syndrome, delivered by cesarean section. INTERVENTIONS: Five lambs ...
Wood R A - - 1993
To further characterize airborne cat allergen and a newly established cat challenge facility, airborne Fel d I levels and particle size distributions were studied in both the cat challenge room and home environments under different conditions of ventilation and physical activity. In the cat room, there has been a dramatic ...
Uren N G - - 1993
BACKGROUND: The inability to match lung perfusion to ventilation because of a reduced cardiac output on exercise contributes to reduced exercise capacity in chronic heart failure. OBJECTIVE: To quantify ventilation to perfusion matching at rest and at peak exercise in patients with chronic heart failure and relate this to haemodynamic ...
Diaz C E - - 1993
Patients with neuromuscular disease can display paradoxic motion of the rib cage (RC) and abdomen (AB), which increases the work of breathing and predisposes to respiratory muscle fatigue. Long-term mechanical ventilation can reverse chronic hypercapnea and decrease the work of breathing in these patients. Changes in chest wall motion (CWM) ...
Forse R A - - 1993
This study compared gas exchange measurements obtained by using a mask, mouthpiece, and ventilated canopy in 30 normal, healthy volunteers. The ventilated canopy and its gas analyzers had an accuracy for oxygen consumption of 98.0 +/- 0.8% and for carbon dioxide production of 100.1 +/- 1.1%. The study indicates that ...
Clark A L - - 1993
The aim of this study was to test the hypothesis that the increased ventilation to carbon dioxide production relationship on exercise associated with chronic cardiac failure may be due in part to changes in respiratory pattern, causing an increase in anatomical dead space ventilation. In order to assess the effect ...
Samet J M - - 1993
The rate of ventilation and route of breathing (i.e., nasal versus oronasal) are potential determinants of pollutant doses to target sites in the lung. However, the lack of accurate methods for ambulatory measurement of ventilation has hindered estimation of exposure and dose in freely ranging individuals, complicating the interpretation of ...
Hsia C C - - 1993
Exercise capacity is significantly impaired in postpneumonectomy patients who have relatively normal remaining lungs. Our objectives are to determine (1) the nature and extent of mechanical ventilatory abnormalities and oxygen cost of breathing in such patients, and (2) the efficacy of a selective respiratory muscle training program in improving ventilatory ...
Tissot S - - 1993
Measurement of the nutrient oxidation rate with 13C as a tracer requires knowledge of the value of its coefficient of fractional recovery in the expired gas (FR). We measured FR in nine intensive care patients who were mechanically ventilated and received total parenteral nutrition. NaH13CO3 was administered at a priming ...
Lane R - - 1993
1. A previous study showed that when combined with exercise in normal subjects, hypercapnic and hypoxic ventilatory stimuli did not have a specific effect on the intensity of the sensation of breathlessness in addition to their stimulation of ventilation. The aim of the present study was to assess the significance ...
Perera E R - - 1993
A 76-yr-old man underwent carinal resection for squamous cell carcinoma through the right posterolateral thoracotomy approach. Ventilation was maintained by the use of two high-frequency jet ventilators, each attached to a separate catheter during the time of resection and reconstruction of the tracheal carina. These catheters were introduced through the ...
Clark A L - - 1992
OBJECTIVES: The aim of this study was to analyze the relation between ventilation and carbon dioxide production and the control of ventilation in patients with chronic heart failure. BACKGROUND: Patients with chronic heart failure exhibit an increased ventilatory response to exercise. Ventilation is closely linked to carbon dioxide production, producing ...
Demediuk B H - - 1992
Breathlessness induced by hypercapnia may be related to the sensation of respiratory effort or to the central or peripheral effects of CO2. To examine the relationship among breathlessness, respiratory effort, and hypercapnia, we studied eight normal naive subjects. By using a visual feedback system, subjects maintained a constant ventilation of ...
Tuxen D V - - 1992
Mechanical ventilation causes significant morbidity and mortality in patients with severe asthma. Hypoventilation may reduce this morbidity and mortality, but indicators to guide the degree of hypoventilation are unclear. We used a measure of pulmonary hyperinflation to assess the degree of airflow obstruction and to guide the extent and duration ...
Todd D A - - 1992
We used scanning electron microscopy (SEM) and light microscopy (LM) to study the recovery of tracheal epithelium in newborn lambs damaged by high frequency flow interrupted ventilation (HFFIV) at low inspired humidity (30%). Newborn lambs were mechanically ventilated for 6 h, allowed to recover and subsequently killed at 2, 7 ...
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