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Results 451 - 500 of 589
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Jeyaranjan R - - 1987
The purpose of this study was to determine, in man, the contribution of peripheral chemoreceptors to ventilation during constant-load, heavy exercise above anaerobic threshold at sea level, using hyperoxic suppression of peripheral chemoreceptor drive which was obtained by abrupt and surreptitious replacement of inspired air with 100% oxygen for a ...
Smith P D - - 1987
Almitrine bismesylate is a pharmacologically unique respiratory stimulant. It enhances respiration after both acute and chronic administration by acting as an agonist of peripheral chemoreceptors located on the carotid bodies. In comparison with traditional central-acting respiratory stimulants, almitrine has advantages of oral activity, prolonged duration of effect, and an improved ...
Weinger M B - - 1987
To determine if end-tidal carbon dioxide tension (PETCO2) is a clinically reliable indicator of arterial carbon dioxide tension (PaCO2) under conditions of heterogeneous tidal volumes and ventilation-perfusion inequality, we examined the expiratory gases of 25 postcardiotomy patients being weaned from ventilator support with intermittent mandatory ventilation. Using a computerized system ...
Hall J B - - 1987
Discontinuation of mechanical ventilation is too frequently difficult and frustrating for the patient and the clinician alike. With the view that expeditious withdrawal of mechanical support is often a mirror-image exercise requiring reversal of the factors that led to respiratory failure, we begin with a discussion of the various pathophysiologies ...
Casey K - - 1987
1. The threshold of the central chemoreceptors was determined under resting and three exercise conditions in four volunteers. 2. The method used was the hyperoxic, Read rebreathing technique with prior hyperventilation. Plots of resting ventilation vs. carbon dioxide consisted of two straight-line segments of different slopes above and below a ...
Vilozni D - - 1987
Eleven normal adults each performed a ten minute progressive isocapnic hyperventilation (PIHV) test in which ventilatory levels were increased every two minutes. All subjects exhibited mechanical fatigue by failing to maintain the target of 80% of maximum voluntary ventilation (MVV). The mean ventilation at this level was 67.5 +/- 1.4% ...
Miyamoto Y - - 1987
The possible influence of neurogenic factors on respiratory and circulatory responses to continuous static (CSE), rhythmic static (RSE), and dynamic (DE) exercises was studied in 15 healthy young men. Ventilation (VE), oxygen uptake (VO2), cardiac output (Q), and blood pressure (BP) were measured during the steady-state of the exercise. For ...
O'Neill P A - - 1987
The influence of regular exercise on breathlessness and its relationship to ventilation has not been studied previously. We have examined the effects of a training programme on eight patients (5 males, 3 females, mean age 20 years, range 17-27 years) with cystic fibrosis. Eleven minutes of exercise was undertaken each ...
Bouffard Y - - 1986
Pulmonary gas exchange was continuously measured in 13 mechanically ventilated patients during 24 hemodialyses for acute renal failure. Minute-ventilation was maintained constant by controlled ventilation and gas exchange was continuously measured by a mass-spectrometer system. Three groups were compared: a cuprophan membrane with an acetate dialysate; a polyacrilonitrile membrane (PAN) ...
Wells J A - - 1986
The present study was designed to assess differences in compartmental contributions to ventilation between cycle pedaling and treadmill walking. Eight subjects performed submaximal cycle (CE) and treadmill (TM) exercise. The mean maximal work loads were not significantly different between the 2 modes of exercise. Ventilation (VE), oxygen uptake (VO2), and ...
Waldrop T G - - 1986
Recent studies have suggested that descending central command from a hypothalamic site (subthalamic locomotor region) is involved in the control of the respiratory and cardiovascular systems during exercise. The purposes of this study were to determine if this hypothalamic area provides tonic drive to the cardiorespiratory systems and modulates the ...
Leiter J C - - 1986
We have examined the effect of steady-state hyperoxia on the ventilation of sea level (SL) cats and cats acclimatized to simulated high altitude (HA) at 5500 m for three weeks. Three groups of cats were studied. In group I, the ventilatory responses to 10%, 21% and 100% O2 were studied ...
Wolff G - - 1986
Pulmonary gas exchange rates in eight patients after open heart surgery were studied during weaning from the ventilator. We investigated continuous positive pressure ventilation (CPPV), intermittent mandatory ventilation (IMV) and spontaneous breathing with continuous positive airway pressure (CPAP). During each mode of ventilation we measured: CO2 production (VCO2), O2 consumption ...
Trockel U - - 1986
A male adult with exercise-related myalgia and weakness from the age of 17 years, developed contractions after moderate exertion which were electrically silent. Triglyceride loading or prolonged fasting provoked excessive ketosis. His isolated muscle mitochondria had severe blockade of the respiratory chain, particularly of NADH-CoQ reductase. After 1.5 years a ...
Haller R G - - 1986
We evaluated ventilation during cycle exercise in four men lacking myophosphorylase. In submaximal exercise of similar relative intensity, ventilation was higher relative to oxygen uptake in McArdle patients than in normal men. The exercise ventilatory response returned to normal after glucose infusion, by fasting to increase free fatty acid availability ...
O'Neill P A - - 1986
In clinical studies on breathlessness, the relationship between breathlessness and ventilation is a convenient way of summarizing the responses of single subjects or groups of subjects. This relationship is usually based on measurements during progressive exercise. The objective of this study was to determine whether the relationship was maintained in ...
Tobin M J - - 1986
The mechanisms responsible for the marked increase in ventilation at the onset of exercise are incompletely defined. A conditioned response to exercise anticipation has been suggested as an influencing factor, but systematic measurements have not been made during the transition from rest to the time when exercise is anticipated but ...
Stokes G M - - 1986
We have developed a method for quantitatively assessing respiratory control in a group of 10 full-term healthy babies, mean age at test 5 days, by measuring their ventilatory response to added external dead spaces. The dead spaces were equal to 0.5, 1, 2, and 3 anatomic dead spaces (2.2 ml/kg ...
Martin,Bruce J.
Sleep loss appears to influence subsequent exercise in a manner dependent upon the nature of that exercise. To investigate this, the author examined the effect of 24 sleepless hours on the ability to produce and maintain maximal ventilation, a form of exercise involving a limited muscle mass. It was found ...
Gaudy J H - - 1986
In six dogs anaesthetized with Althesin, minute ventilation, respiratory rate, tidal volume, PaO2 and PaCO2 were measured while breathing air (F/O2 = 0.21), and then after correction of hypoxaemia (F/O2 = 0.35), and again while breathing 100% oxygen (F/O2 = 1.00). The administration of 35% oxygen corrected the hypoxaemia (PaO2 ...
Paterson D J - - 1986
To investigate whether ventilation frequency could be entrained to a sub-harmonic of the exercise rhythm, 19 experimentally naive male volunteers were tested during steady state bicycle ergometry and arm cranking under conditions of constant applied workload. Each exercise was performed at two separate ventilatory loads, one within the linear range ...
Munkner T - - 1986
The immediate changes in regional ventilation and pulmonary blood flow were studied in fifteen adults with perennial asthma and in two control persons, who were challenged by moderate exercise on a treadmill or bicycle ergometer. Ventilation was studied before and immediately after the exercise, and again about five min after ...
Robinson N E - - 1985
The primary function of the equine respiratory system is the exchange of oxygen and carbon dioxide at a rate that is matched to metabolism. Gas exchange requires ventilation, distribution of gas within the lung, perfusion of blood through pulmonary capillaries, matching of ventilation and blood flow, diffusion of gases between ...
Heywood L H - - 1985
Concurrent radiographic and electromyographic observations were made in sheep during naturally occurring eructations. The radiographic field extended from the base of the heart to the cranial region of the rumen. Electromyographic recording was from two sites on the caudal thoracic oesophagus within 20-70 mm of the diaphragm. Passage of gas ...
George R J - - 1985
Normal subjects were asked to breathe through an open ended tube while high frequency oscillations were superimposed on tidal breathing via a side arm, either an eight inch (20 cm) loudspeaker or a jet ventilator being used. Both systems were comfortable and well tolerated. Spontaneous minute ventilation fell by 19-46% ...
Cinotti L - - 1985
An interactive software to gate scintigraphic list-mode data collected from ventilation studies using a radioisotope of an inert gas (81mKr) has been developed. It allows the detection of end expiration and end inspiration phases in a time activity curve. It involves six phases: filtering of the curve; preselection of local ...
Blaylock R S - - 1985
Two cases of proven bites by the Cape cobra (Naja nivea) are reported. Both patients developed areflexic flaccid paralysis and required ventilation from 2 1/4 and 2 1/2 hours after the bite for 4 1/2 and 7 days respectively. Antivenom is of value before the onset of paralysis but of ...
O'Neill P A - - 1985
The effects of indomethacin on the relationship between breathlessness and minute ventilation during exercise have been determined in a double-blind, randomized study on 6 normal subjects. Indomethacin did not significantly after ventilation or oxygen uptake either at rest or during submaximal exercise. Breathlessness was assessed with visual analogue scales, and, ...
Elliott C G - - 1985
To examine the mechanism of exercise limitation associated with chest wall restriction (CWR), we compared the ramp (1 W/3 s) exercise performance of six untrained subjects with ankylosing spondylitis (AS) and six healthy subjects matched for age and body size. Subjects with AS had CWR (maximum rib cage expansion : ...
O'Neill P A - - 1985
Previous work has left unresolved questions on whether promethazine reduces the sensation of breathlessness. This study was designed to provide a definitive answer and to determine the contributions from promethazine's major pharmacological actions. Twelve healthy subjects participated in a double-blind, within-subject comparison of promethazine and placebo each given acutely by ...
Kuhlmann W D - - 1985
Six Hereford steers were studied before, during, and after short exercise bouts on a motor-driven treadmill (3 degrees incline) at four speeds (1.0, 1.4, 1.8, and 2.2 m X s-1). Oxygen consumption (MO2) and carbon dioxide production (MCO2) were measured by collecting the expired gas. Arterial and mixed venous blood ...
Mohsenifar Z - - 1985
A new method for evaluation of changes in the distribution of pulmonary perfusion and ventilation during exercise was applied to normal male volunteers. Ventilation and perfusion scans were done with the subjects seated on a bicycle ergometer. The resting studies utilized krypton 81 (81mKr) for ventilation and technetium 99m (99mTc) ...
Cockcroft A - - 1985
Nine men with severe chronic obstructive airways disease (COAD), known to desaturate on exercise, performed a 6 min self-paced walk on a treadmill, followed by a bicycle exercise with workloads adjusted to mimic the oxygen consumption achieved on the treadmill. During both exercises, ventilation, oxygen consumption, carbon dioxide production, PaO2, ...
Bender P R - - 1985
It remains unclear whether the hyperpnea of exercise severely stresses the ventilatory musculature. We hypothesized that the ability to ventilate maximally is decreased during and immediately following exhausting exercise. Subjects performed isocapnic maximal voluntary ventilations (60-s MVV) before, during the final minute, and after exhausting treadmill exercise lasting either 3-10 ...
Kanak R - - 1985
We describe a patient with respiratory failure who demonstrated marked increases in O2 consumption (VO2) when breathing with synchronized intermittent mandatory mechanical ventilation (SIMV). When the mode of ventilation was changed to facilitate inspiratory gas flow (pressure-support) during spontaneous breathing, O2 consumption decreased 27 percent. Several important factors contributing to ...
Germain M J - - 1985
The hypoxemia of acetate hemodialysis may result from a decrease in alveolar ventilation (VA) related to a reduction in pulmonary carbon dioxide excretion (VCO2). To test this theory, ventilation was increased by exercise during dialysis on 6 patients and the effect on arterial oxygen tension (PaO2) measured. With hemodialysis the ...
Sinclair M E - - 1984
Two groups of eight patients received infusions of either fentanyl at 3 micrograms kg-1 h-1 or alfentanil at 20 micrograms kg-1 h-1 as supplements to 66% N2O in oxygen anaesthesia, during and after body surface surgery. At the end of surgery, the N2O was reduced to 50% and after measurement ...
Kiley J P - - 1984
The effects of whole body hypothermia on metabolism, blood and medullary acid-base, and respiratory variables were determined in 29 paralyzed, vagotomized and glomectomized cats. Respiratory output was quantified from integrated phrenic nerve activity. Metabolic rate (VCO2) decreased progressively as temperature decreased. When end-tidal PCO2 was kept constant by decreasing artificial ...
Schrijen F - - 1984
Changes at the beginning of isometric and dynamic low level exercise were studied in 23 patients with chronic lung disease. Ventilation, oxygen consumption and vascular pressures in systemic and pulmonary circulation were continuously monitored, and cardiac output was measured by thermodilution every minute. Circulatory changes took place suddenly at the ...
Groeger J S - - 1984
The consensus of available studies indicates that high-frequency jet ventilation (HFJV) can adequately ventilate animals in respiratory failure, although a clear superiority to volume-cycled ventilation (VCV) cannot be established. HFJV is probably useful in the presence of airway disruption and in tracheal or pulmonary surgery. Clinical trials and additional bench ...
Sanders A B - - 1984
A study was undertaken to determine the pattern of arterial blood gas (ABG) concentration in the canine model undergoing prolonged cardiopulmonary resuscitation (CPR) from fibrillatory arrest, and to determine the importance of acid base abnormalities in predicting resuscitation. Ventricular fibrillation was induced electrically in 12 dogs. CPR was begun at ...
Javaheri S - - 1984
During acute respiratory acidosis increments in cisternal cerebrospinal fluid (CSF) [HCO3-] approximate decrements in CSF [Cl-] with CSF [Na+] remaining unchanged; the mechanisms mediating this reciprocal anionic relationship are unclear. In the present study we investigated the effects of DIDS (4,4'-diisothiocyano-disulfonic stilbene), a known inorganic anion exchange blocker, on CSF ...
Sladen A - - 1984
One hundred patients were ventilated with high-frequency jet ventilation (HFJV) during the initial 24-h postoperative period in the surgical and neurosurgical ICUs. Eighty-three were successfully weaned, 2 could not be ventilated adequately with HFJV, and 15 with criteria of acute respiratory failure received HFJV for up to 21 days. A ...
Tajiri J - - 1984
The feasibility of the thermodilution technique to measure cardiac output (CO) during positive pressure ventilation was assessed in 12 critically ill patients. An indicator (5 ml of 5% glucose in cold water) was injected at the mid and end of the inspiratory and expiratory phases of mechanical ventilation to see ...
GÅ‚owicki K - - 1984
The relative effect of the temperature on respiratory rhythm generation was studied in muscle-relaxed, artificially ventilated and bilaterally vagotomized rabbits under general anaesthesia (urethane and chloralose). Hypercapnia was produced during normothermia (38.8 +/- 0.6 degrees C) and hyperthermia (40.5 +/- 0.3 degrees C). The basic physiological parameters, efferent phrenic nerve ...
Bergsholm P - - 1984
Seizure duration in unilateral electroconvulsive therapy (ECT) was recorded by means of EEG in an intraindividual comparison under different alveolar O2- and CO2-concentrations. Hypocapnia induced by hyperventilation to an alveolar CO2-concentration of 2% (2 kPa) resulted in a highly significant increase in seizure duration compared to a normal CO2 of ...
Brusasco V - - 1984
The efficiency of oxygenation and the uniformity of the distribution of regional ventilation (Vr) to regional perfusion (Qr) along the vertical and horizontal axes was compared in anesthetized dogs between conventional mechanical ventilation (CMV) and high-frequency ventilation (HFV) at 5.8, 15.0, and 29.8 Hz. Both CMV and HFV were adjusted ...
Martin B J - - 1984
Although minute ventilation (VE) exhibits marked increases during heavy rhythmic exercise utilizing a large muscle mass, the extent to which this hyperpnea stresses the respiratory muscles remains controversial. In an attempt to resolve this matter, we measured arterial blood lactate concentration during seated isocapnic reproduction of peak exercise ventilation. This ...
O'Neill P A - - 1984
The effects of ICI 118,587 and atenolol on the responses to submaximal exercise and on breathlessness were studied in six healthy subjects. Atenolol reduced heart rate at rest and during exercise whereas ICI 118,587 increased resting heart rate but caused a small reduction in the highest heart rate achieved during ...
Nunn P P - - 1984
A double-blind, placebo-controlled, crossover study of the effects on regional lung function of oral almitrine bismesylate at a dose of 3 mg X kg-1, was carried out in six patients with severe chronic airflow obstruction. Oxygen saturation (SaO2) was measured by ear-lobe oximetry and ventilation (VE) by inductance plethysmography. Radionuclide ...
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