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Gallagher C G - - 1989
To assess the effect of the normal respiratory resistive load on ventilation (VE) and respiratory motor output during exercise, we studied the effect of flow-proportional pressure assist (PA) (2.2 cmH2O.l-1.s) on various ventilatory parameters during progressive exercise to maximum in six healthy young men. We also measured dynamic lung compliance ...
Rhodes C G - - 1989
With positron emission tomography, quantitative measurements of regional alveolar and mixed venous concentrations of positron-emitting radioisotopes can be made within a transaxial section through the thorax. This allows the calculation of regional ventilation-to-perfusion (V/Q) ratios by use of established tracer dilution theory and the constant intravenous infusion of 13N. This ...
Schrikker A C - - 1989
The ratio of alveolar ventilations of He and SF6 (VA,He/VA,SF6) was determined in 7 healthy male subjects at rest and at three different levels of exercise on a bicycle ergometer (75, 150 and 225 W). This ratio was calculated from the ratio of the specific ventilations for these gases which ...
Habib M P - - 1989
Ethane quantitated in the expired alveolar gas is a noninvasive measure of free radical activity. This method has been criticized for lack of control of minute ventilation (VE) in spontaneously breathing animals, although ethane, which is poorly soluble in tissues, should not be affected by changes in VE. We measured ...
Aldrich T K - - 1989
We used inspiratory resistive training (IRT) in an effort to improve the respiratory muscle endurance of 27 patients with respiratory failure who had failed repeated weaning attempts using standard techniques. Seven patients had primary neuromuscular diseases; the other 20 had primary lung diseases. All patients had stable respiratory failure, without ...
Prabhakar N R - - 1989
We examined the contribution of the neural elements near the ventral medullary surface (VMS) to the respiratory response caused by 2,4-dinitrophenol (DNP). Two series of experiments were performed on 12 vagotomized and sinoaortic denervated cats. The first series examined the effect of focal cooling of the VMS on the respiratory ...
Jeyaranjan R - - 1989
The purpose of this study was to determine the role of lactic acidosis in the ventilatory response to heavy exercise above anaerobic threshold. Seven subjects ingested either NaHCO3 or CaCO3 at a dose of 300 mg/kg body weight and ran on a motor-driven treadmill at a work load corresponding to ...
Heyrman R M - - 1989
This study evaluates the direct effect of acetate upon ventilation during acetate-haemodialysis. Eight patients with end-stage renal failure who were receiving chronic haemodialysis treatment underwent acetate infusion for 1 h on a day outside a haemodialysis session. Ventilation was continuously measured using respiratory inductance plethysmography, starting 20 min before the ...
Mayers I - - 1989
We hypothesized that during high-frequency oscillatory ventilation (HFOV) of a central bronchopleural fistula (BPF), gas flow through the fistula (Vleak) should vary with ventilatory frequency. In six pentobarbital-anesthetized, open-chested dogs, we inserted a cannula into the left lower lobe bronchus. After 30 min of HFOV at 5 Hz (fistula closed), ...
Jeyaranjan R - - 1989
The purpose of this study was to examine the effects of duration and the concomitant ventilatory drift of heavy exercise on the changes in ventilation following the cessation of exercise. Seven male subjects ran on a motor-driven treadmill at a constant work-rate of 90% of VO2max for either 5 min ...
Teodorescu H - - 1989
The frequency-domain analysis of respiration is used to put in evidence the respiratory reflexes, mainly the acoustical respiratory reflex. Based on the envelope of the spectrum, numerical parameters of the respiration are introduced and applied to determine respiratory patterns. The use of respirograms is also suggested.
Jeyaranjan R - - 1989
The purpose of this study was to determine the effect of altered metabolic acid-base status on the changes in ventilation in the transition from heavy exercise above anaerobic threshold to rest. Seven subjects ingested, in a randomized and blind manner, either NaHCO3 or CaCO3 (placebo) at a dose of 300 ...
Gillespie D J - - 1989
The effect of pleural effusion on lung function and gas exchange has not been adequately defined. We used the multiple "inert" gas technique to study gas exchange and ventilation-perfusion relationships in both the left and the right lateral decubitus positions in a patient with a moderate unilateral (left) pleural effusion. ...
Tobin M J - - 1988
Continuous monitoring of important respiratory indices has the potential for predicting catastrophes and providing an opportunity for the timely institution of lifesaving measures. Arterial oxygenation can be monitored noninvasively using oximetry or transcutaneous oxygen electrodes, while mixed venous oxygenation can be recorded continuously with modified pulmonary artery catheters. A satisfactory ...
Laroche C M - - 1988
We studied six patients with isolated bilateral paralysis or severe weakness of the diaphragm, present for 2 to 60 months (mean = 25), to document the clinical and respiratory sequelae of the condition. Severe diaphragm dysfunction was confirmed by the demonstration of the very low maximal transdiaphragmatic pressure (Pdi) generated ...
Martins M A - - 1988
The infusion of the hypertonic 7.5% NaCl solution stimulates the afferent vagal innervation of the lungs. In order to verify if this reflex elicits any respiratory mechanical alterations, normovolemic (n = 18) and hypovolemic (n = 18) (20 ml of shed blood/kg) guinea pigs were studied. The animals were assigned ...
Stark G P - - 1988
The authors recently developed an ambulatory system, in which a self-contained respiratory inductive plethysmograph (RIP) was used, to measure noninvasively the volume and time components of breathing. Since it does not use nasal or oral devices, such a system is particularly suitable for use in studying the effects of respiratory ...
Acosta F - - 1988
Weaning patients with chronic obstructive pulmonary disease from mechanical ventilators is occasionally a long and difficult process complicated by the patient's fear of losing his or her breath during the weaning procedure. A case is presented of an anxious 58-year-old man who was taught to relax using biofeedback and progressive ...
Blanco C E - - 1988
We tested the hypothesis that postnatal resetting of the carotid chemoreceptors is initiated by, and is dependent on, the rise in arterial PO2 (PaO2) which normally occurs after birth as air breathing is established. Previous studies had indicated that this resetting takes at least 24 h. We applied a technique ...
Miller T D - - 1988
Four patients were evaluated for persistent dyspnea eight months to four years after inferior vena caval interruption for treatment of pulmonary emboli. Maximal exercise testing with gas-exchange analysis was performed. All patients attained less than 64 percent of predicted maximal oxygen uptake. Peak exercise heart rates were 85 percent or ...
Warner M A - - 1988
The use of high frequency jet ventilation compared to conventional mechanical ventilation during general anesthesia for extracorporeal shock wave lithotripsy of renal or ureteral calculi can reduce stone movement. This decrease in stone movement theoretically lessens the total shock and energy requirements for stone fragmentation and perirenal tissue damage. To ...
Sleigh M A - - 1988
The presence of cilia on epithelia of the respiratory tract was reported more than 150 yr ago, and the two-layer model of mucus transport was put forward more than 50 yr ago. However, it is only in the last 10 yr or so that the motion of mucus-propelling cilia of ...
Shepherd J P - - 1988
Nitrous oxide concentrations have been measured spectrophotometrically in an out-patient clinic to assess pollution during simulated cryosurgery. Unacceptable levels, in excess of 2,000 ppm, were achieved during freezing and thawing and concentrations decreased only to 400 ppm when simple measures were taken to ventilate the clinic. The apparatus required a ...
Arita K I - - 1988
The washout of an insoluble tracer from the lung may be represented by a model with two ventilatory compartments representing poorly and better-ventilated regions. Using boli of a second insoluble gas delivered at a given point during inspirations of a multibreath washout test, the proportions of labeled inspired ventilation reaching ...
Masuda A - - 1988
Nine normal male subjects were studied at three levels of exercise (0, 40, and 80 W). Single vital capacity breath test was applied at rest and during exercise (phases 2 and 3). Minimum minute ventilation found within 4 breaths following the test was compared to the control value. Significant depression ...
Jeyaranjan R - - 1988
Transitions from rest to exercise and vice versa are reported to be associated with instantaneous changes in minute ventilation and the changes in the off-transitions are thought to be the reverses of those in the on-transitions. Such changes have been observed mainly in mild-moderate exercise and their extrapolation to heavy ...
Regensteiner J G - - 1988
Gender differences in resting ventilation and hypoxic ventilatory response (HVR) have been reported. Ventilation and HVR are closely related to changes in metabolic rate in men. However, it is unclear whether there is a comparable relationship between metabolic rate and ventilation or HVR in women. We studied 13 men and ...
Paulev P E - - 1988
Ventilation (VE), cardiac output (Q), oxygen consumption (VO2), carbon dioxide production (VCO2), and end tidal gas tensions (PETO2 and PETCO2) were measured in four healthy men during stepwise, steady state increases in work rate on a bicycle ergometer (25, 50, 75, 100, 125, and 150 W). Both the ventilation equivalent ...
Vercken J B - - 1988
We report a study of an adult with a maltase acid deficiency myopathy. A restrictive respiratory syndrome due to respiratory muscle weakness is associated with paralysis of other muscular groups. In 1982 the patient presented with an alveolar hypoventilation, and mechanical ventilation was required after acute respiratory failure. The patient ...
McDonald N J - - 1988
The oxygen cost of breathing (which is the difference in oxygen consumption measured during controlled ventilation and again during spontaneous ventilation) was measured in 30 patients between the ages of 17 and 96 years at the time of commencement of weaning from mechanical ventilation. There was a significant exponential correlation ...
Damato S - - 1988
Using a double-blind cross-over design, a single oral dose of 100 mg almitrine bismethylate and placebo were administered to 7 patients with chronic airflow limitation. In all patients, arterial blood gases at rest, ventilation and breathing pattern at rest and on exercise were measured before and 3 h after administration. ...
Tipton M J - - 1987
Twelve healthy male subjects performed three 10-min head-out immersions in water at 10 degrees C. The responses of the subjects to immersion were recorded under three conditions: a) Control condition (CC)--torso and limbs exposed; b) Torso protected/limbs exposed condition (TPC); and c) Limbs protected/torso exposed condition (LPC). Results showed that ...
Brisson G R - - 1987
Selective face ventilation, known to interfere with bloodstreamed temperature signals, should alter exercise-induced prolactinemic (PRL) responses if, as recently suggested, the latter responses are associated with body temperature increases generated by working muscles. To test this hypothesis, 15 trained adult male and female volunteers were submitted to 45-min hyperthermic treadmill ...
Lane R - - 1987
1. Nine normal subjects performed 6 min, constant-workload, exercise tests on a bicycle ergometer at either a 'high workload' or at a 'low workload'. During the first 'high workload' test their spontaneous breathing pattern was recorded on to magnetic tape. During one subsequent 'high workload' test and one 'low workload' ...
Corriveau M L - - 1987
Hydralazine has been shown to increase minute ventilation, alveolar ventilation, and arterial partial pressure of oxygen (PaO2) after short-term administration in patients with chronic obstructive pulmonary disease and pulmonary hypertension. The effects of orally administered hydralazine on ventilation and blood gas values were evaluated after six to 18 months of ...
Matthews J I - - 1987
Several microprocessor exercise physiology systems have been introduced recently. Comparison of the data output between these systems and more traditional nonautomated systems has not been reported extensively. Twelve normal adult men were exercised in random sequence on different days on a Sensormedics MMC Horizon system, the Medical Graphics Corporation System ...
Casey K - - 1987
1. The change in ventilation at the start of exercise was determined during both hyperoxic rebreathing and air breathing in four volunteers. 2. In order to differentiate between the effects of limb-movement frequency and exercise load in terms of oxygen uptake, three treadmill exercises were tested: E1, at an oxygen ...
Madsen F - - 1987
Tidal breathing during bronchial challenge shows both between- and within-subject variation. A challenge protocol permitting controlled ventilation was designed in order to improve repeatability of the method. Twenty-five patients were challenged twice with an interval of 2 h. The 2 min ventilation was kept constant at each concentration administered. During ...
Cornish J D - - 1987
Eighteen neonates 33 to 42 wk gestational age with severe respiratory failure were referred for extracorporeal membrane oxygenation (ECMO). Sixteen ultimately met the ECMO criteria, of whom 15 were first offered high-frequency oscillatory ventilation (HFOV). Seven responded to HFOV alone and did not require ECMO treatment. Eight of the nine ...
Alt E - - 1987
Several studies have shown that the capability for exercise can be increased in patients with pacemakers by means of adjusting the rate. Respiration is one of the parameters considered for rate control. The aim of our study was to determine how respiratory parameters such as ventilation, tidal volume, and respiratory ...
Anholm J D - - 1987
To determine the increment in cardiac output and in O2 consumption (Vo2) from quiet breathing to maximal sustained ventilation, Vo2 and cardiac output were measured using an acetylene rebreathing technique in five subjects. Cardiac output and Vo2 were measured multiple times in each subject at rest and during sustained maximal ...
Kolton M - - 1987
We ventilated seven mongrel dogs with high frequency oscillatory ventilation (HFO) at frequencies from 3 to 30 Hz. At each frequency, the tidal volume required to achieve isocapnia (VTiso) was measured by plethysmography. In an individual dog, VTiso could be related to frequency by an equation of the form VTiso ...
Lane R - - 1987
Nine patients with chronic obstructive airways disease performed a 6 min self-paced walk (breathing air) on a treadmill and then identical (but operator-controlled) treadmill walks breathing either air or supplemental oxygen sufficient to just prevent arterial oxygen desaturation during the exercise. During the exercises, ventilation was recorded and patients recorded ...
Girotti M J - - 1987
We compared the effects of high frequency jet ventilation (HFV), conventional ventilation (CMV), and spontaneous breathing (SB) on regional pulmonary blood flows (QLLL), standard cardiopulmonary measurements and the serum levels of the first generation metabolites of prostacyclin (6-keto-PGF1 alpha) and thromboxane A2 (TxB2) in established left lower lobe pseudomonas aeruginosa ...
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% ...
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