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Results 501 - 550 of 584
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Lundh R - - 1983
Resting lung volume (FRC), airway closure (CC) and ventilation-perfusion relationships, using the multiple inert gas elimination technique, were studied during epidural analgesia. The material consisted of 10 patients, 55-84 years of age. Epidural blockade (9-13 ml mepivacaine-adr, 1/200,000) was instituted to an upper level corresponding to Th3-Th6. Minute ventilation and ...
DiMarco A F - - 1983
In high decerebrate unanaesthetized cats (pre-collicular/pre-mamillary) which developed spontaneous co-ordinated locomotor activity, ventilation, breathing pattern, phrenic nerve, external and internal intercostal electromyogram (e.m.g.) activities were examined. Locomotion was also induced by electrical stimulation of the subthalamic locomotor region and in a few cases the mesencephalic locomotor region. Quadriceps muscle e.m.g. ...
DiRocco P J - - 1983
The purpose of this study was to investigate the physical work capacity of adolescent patients with mild idiopathic scoliosis (less than 60 degrees). Fourteen subjects, who were being treated with a Milwaukee brace, were given a progressive exercise stress test. Ventilatory volume, frequency of breathing, end-tidal PCO2, heart rate, and ...
Prato F S - - 1983
We measured ventilation and static lung volumes in five fit volunteers in the right lateral decubitus position, while they were fully awake and while sedated with diazepam. We also assessed the distributions of ventilation and perfusion in the lungs, using inhalations and intravenous injections of xenon-127. Diazepam, 0.04 mg . ...
Kiley J P - - 1983
To determine the involvement of intrapulmonary chemoreceptors (IPC) in the control of breathing during exercise, it is necessary to hold the PCO2 in the microenvironment of these receptors constant at the resting value. We accomplished this in unanesthetized Pekin ducks by ligating the left pulmonary artery and diverting all of ...
Petrillo G A - - 1983
Mechanical ventilation of paralyzed, pentobarbital-anesthetized adult cats was performed while recording phrenic nerve activity. The periodic changes in lung volume owing to mechanical ventilation affected the rhythm of central respiratory activity, resulting in a variety of regular and irregular patterns of coupling between respiratory system output, monitored by phrenic activity, ...
Visschedijk A H - - 1983
Comparison of diffusive and convective transport equations for O2, CO2 or H2O in the gas-phase shows that for the same gas flux (ml . day-1) and the same pressure difference (Torr) one can substitute an effective air ventilation, VA (ml . day-1), for a given diffusive conductance, G, (ml . ...
Stark R D - - 1983
In six healthy subjects, respiration and the sensation of breathlessness were assessed during submaximal exercise and the subsequent recovery. The overall responses were expressed by the relationship of breathlessness to minute volume. Because of the high subjective component in the assessments, validation of the method in these particular subjects was ...
Favier R - - 1983
The fast component of the ventilatory changes that occur at the transition phases of exercise was studied in awake dogs trained to run on a treadmill. Two questions were examined: firstly, is the fast ventilatory component modified by changes in venous return to the lungs, such as those consecutive either ...
Wasserman D H - - 1983
During steady-state exercise, ventilation increases in proportion to CO2 output (VCO2), regulating arterial PCO2. To characterize the dynamics of ventilatory coupling to VCO2 and O2 uptake (VO2) in the nonsteady-state phase, seven normal subjects performed constant-load cycle ergometry to a series of subanaerobic threshold work rates. Each bout consisted of ...
Szlyk P C - - 1983
The role of the sinoaortic reflexes in the regulation of ventilation during exercise was evaluated in seven awake dogs prepared with chronic tracheostomies and arterial catheters. Each dog ran on a treadmill at several work loads before and after sinoaortic denervation and served as its own control. Minute ventilation in ...
Berk J - - 1983
20 anesthetized mechanically ventilated dogs received an infusion of epinephrine, 2 micrograms/kg/min, for 4 h. 10 dogs were ventilated with air for the entire 4-hour period and 10 were ventilated with oxygen for the first hour and then air for 3 h. During the first hour of the epinephrine infusion ...
Bye P T - - 1983
The question of respiratory factors limiting exercise has been examined in terms of possible limitations arising from the function of gas exchange, the respiratory mechanics, the energetics of the respiratory muscles, or the development of respiratory muscle fatigue. Exercise capacity is curtailed in the presence of marked hypoxia, and this ...
El-Baz N M - - 1982
Conventional one-lung intermittent positive-pressure ventilation (OL-IPPV) has been a valuable technique during anesthesia for intrathoracic operations. OL-IPPV has been associated with a high incidence of hypoxemia, as a result of the associated intrapulmonary shunt of 21% to 65% of cardiac output. The administration of OL-IPPV requires the use of a ...
Rossing T H - - 1982
Effective gas exchange can be achieved in normal dogs by ventilation at frequencies of 4-20 Hz using stroke volumes (SV) smaller than the anatomic dead space. CO2 elimination is largely a function of tracheal SV-frequency product (Vosc) in anesthetized, paralyzed dogs with normal lungs. To determine the effect of constriction ...
Al-Shway S F - - 1982
Kittens, puppies, cats, and dogs were anesthetized with pentobarbital sodium and tracheotomized. The ventilatory pattern was recorded before, during, and after the delivery of steady flows of room air of 20 or 50 ml X s-1 X kg-1 in the expiratory direction through a cannula inserted just below the larynx. ...
Robertson H T - - 1982
The influence of medroxyprogesterone acetate (MPA) on exercise performance was studied in a double-blind cross-over trial using six normal males to compare the exercise performance changes to those observed in a previous study of exercise responses of female subjects during the follicular and luteal phase of the menstrual cycle. A ...
Field S - - 1982
We measured the oxygen cost of breathing (VO2resp) in 13 patients with cardiorespiratory disease requiring artificial ventilation as the difference between the oxygen consumption during spontaneous respiration (VO2tot) and that during artificial ventilation (VO2nonresp). Average VO2tot was 312 +/- 90 ml/min (mean +/- 1 SD), whereas VO2nonresp was 246 +/- ...
Martin B - - 1982
Although increased ventilation is one of the most readily observed physiological responses to exercise, it is uncertain how severely this hyperpnea stresses the ventilatory muscles. As one approach to this question, we compared short-term maximal running performance in nine subjects with and without prior ventilatory work designed to reduce ventilatory ...
Powell F L - - 1982
We assessed ventilation-perfusion inequality in 8 anesthetized, tidally ventilated geese in terms of continuous V/Q distributions using the multiple inert gas elimination technique modified for cross-current avian lungs (Powell and Wagner, 1982). Thirty-four data sets were collected. Allowing for differences in solubility, high molecular weight gases (Enflurane, SF6) were not ...
Bundgaard A - - 1982
Eleven adult patients with exercise-induced asthma (EIA) were subjected to swimming and bicycle exercise under controlled conditions regarding temperature and relative humidity of the inhaled air, the respiratory frequency, tidal volume, minute ventilation and the accumulated ventilation. Swimming for 6 min was performed on the first day, and the next ...
McEvoy R D - - 1982
Gas exchange was investigated in normal anesthetized dogs during high-frequency, low-tidal volume ventilation (HFV) using the multiple inert gas elimination method. The pattern of inert gas elimination was initially normal during conventional mechanical ventilation. During HFV there was an increase in the difference between the excretion values of acetone and ...
Mognoni P - - 1982
Oxygen consumption, ventilation, and dynamic respiratory work were measured in three male subjects during cycling at 122 and 3500 m above sea level (ASL). At a given ventilation the dynamic respiratory work was 20% less at 3500 m ASL; this change was due to a decrease of airway resistance. At ...
Zapata P - - 1982
The effects of dopamine (DA) antagonists upon resting ventilation and ventilatory reactions to DA, apomorphine, hyperoxia and hypoxia were studied in pentobarbitone-anesthetized cats. Intravenous administration of spiroperidol, haloperidol, perphenazine and chlorpromazine increased resting ventilation, the intensity and duration of the effect being dependent on the dose of the blocker. The ...
Downs J B - - 1982
Respiratory therapy should be directed at underlying pathophysiology, not symptomatology. Mechanical ventilation, oxygen, and CPAP should be administered to patients independently and in appropriate amounts. Removal of each of these therapeutic interventions should occur in a similar fashion. The method for determining optimal mechanical ventilation, oxygen concentration, and CPAP level ...
Woodcock A A - - 1981
We measured breathlessness and exercise tolerance in 12 patients with chronic airways obstruction, moderate or severe breathlessness, and low or normal arterial carbon dioxide tension, after the patients received dihydrocodeine, alcohol, caffeine, or placebo (through double-blind administration). Forty-five minutes after ingestion, dihydrocodeine had reduced breathlessness by 20 per cent and ...
Cutillo A - - 1981
The effects of moderate exercise on the distribution of inspired gas and efficiency of ventilation were studied by the multibreath nitrogen washout method in three subjects with asymptomatic asthma and 11 patients with chronic obstructive pulmonary disease (COPD). The nitrogen washout curves were analyzed according to a lung model consisting ...
Doust J H - - 1981
Ventilation in steady-state treadmill exercise at five different speeds has been measured in six subjects using an inductance plethysmograph whose calibration is described. A printed passage of 100 words was read aloud during the fifth minute of each exercise period:this took about 30 sec. At each exercise level ventilation was ...
Stark R D - - 1981
1 Healthy volunteers undertook submaximal graded exercise while objective measurements of cardio-respiratory function were made and breathlessness was assessed with serial visual analogue scales. 2 A useful and consistent relationship existed between breathlessness and ventilation for individual subjects. 3 Drugs were examined in this system to test whether they modified ...
Stark R D - - 1981
1. Methods were devised and evaluated for inducing breathlessness by submaximal graded exercise in healthy subjects while objective measurements of cardiorespiratory function were made. Breathlessness was assessed with serial visual analogue scales (VAS), but with various measures to enhance repeatability. 2. A high level of reproducibility was obtained in spite ...
Gabathuler M L - - 1981
The effects of intravenous hydroxyzine and hydroxyzine with naloxone on respiration were determined in man. Drug effect was expressed as the shift in the 20-L intercept of the respiratory response curve measured by a rebreathing technique. The time-effect curve of hydroxyzine was found to be the same for hydroxyzine alone ...
Bundgaard A - - 1981
The degree of post treadmill-running decrease in pulmonary function (Exercise-Induced Asthma) in 11 adult asthmatics was compared with the decrease in pulmonary function followed by resting isocapnic hyperventilation. It was checked that ventilation during the hyperventilation was kept identical to the ventilation during treadmill-running by continuous recording of respiratory frequency, ...
Sivieri E M - - 1981
A closed-circuit fluorocarbon oxygenation system was designed and incorporated into an existing liquid breathing system (LBS) to allow measurement of an animal's oxygen consumption during liquid ventilation. This enabled simultaneous determination of cardiac output by the direct Fick method. A series of seven in-vivo experiments were conducted in which the ...
Saibene F - - 1981
In six dogs trained to wear a mask and to swallow an esophageal balloon, the dynamic work of breathing (Wdyn) was measured while the animals ran on a treadmill at different intensities (7-13 km.h-1,+10%). Wydn (kg.m.min-1) increased with ventilation (VE, 1.min-1) according to Wdyn = 0.308.10(-2) VE2 + 0.0098.10(-2).VE3. However, ...
Bowes G - - 1981
Respiratory activity (diaphragmatic electromyogram) was recorded in six unanesthetized in utero fetal lambs, between 0.7 of gestation and term. Respiratory patterns generated by the fetus showed developmental changes that included 1) an emergence of a periodic modulation of respiratory rate producing alternating active and quite phases (mean cycle length of ...
Barnas G M - - 1981
We studied the effect of increasing colonic temperature (Tc) on respiratory amplitude and frequency at different levels of PICO2 in anesthetized, unidirectionally ventilated cockerels. We also evaluated the relationship between PICO2 and PaCO2. Increased PaCO2 augmented respiratory amplitude and decreased frequency at every Tc. Respiratory amplitude increased as Tc rose ...
Sackner J D - - 1980
The respiratory inductive plethysmograph, a monitor of ventilation that does not require a connection from the airway, was validated against spirometry during moderate exercise using a bicycle ergometer and a treadmill. One hundred seventy-three of 200 breaths during bicycle exercise from 6 young adults and 211 of 242 breaths during ...
Epstein R A - - 1980
Ventrilatory requirement was assessed in 15 critically ill neonates on a total of 31 occasions. All were either currently receiving mechanical ventilation or had had mechanical ventilation in the recent past. Minute ventilation, respiratory frequency, carbon dioxide production (VCO2) and arterial blood PaCO2 were measured. Dead space-to-tidal volume ratios (VD/VT) ...
Kumazawa T - - 1980
In anesthetized, vagotomized, paralyzed, and artificially ventilated dogs, naloxone effects on respiratory responses induced by thin-fiber muscular afferents were studied by recording phrenic nerve discharges. Naloxone augmented respiratory outputs, before, during, and after the stimulation. Two different types were found in the returning phase of the respiratory response by thin-fiber ...
Robertson C H CH - - 1980
Two computerized methods of measuring ventilation from four pairs magnetometers placed anteroposteriorly (AP) and laterally on the rib cage and abdomen were compared with a method that employs two pairs of magnetometers placed AP on the rib cage and abdomen. This comparison showed that the most accurate method of measuring ...
Saxena R - - 1980
In dogs anaesthetised with pentobarbitone sodium raising the body temperature from 37 degrees C during mild exercise increased the rate of respiration and pulmonary ventilation but decreased the tidal volume. Cold blocking the vagi during the exercise resulted in decrease in respiration rate and minute ventilation, but increase in tidal ...
Nag P K - - 1980
The cardio-respiratory performance of five subjects was studied in relation to two types of agricultural work, on germinating seedlings and threshing. Manual operations were compared with some simple implements. Transplanting of seedlings demanded 17.4 l/min (BTPS) pulmonary ventilation and 0.618 l/min (STPD) oxygen uptake. With the IRRI and the CRRI ...
Pachalski A - - 1980
The aim of this paper was to study the effect of swimming training on the cardio-respiratory system of paraplegics. The observation of 60 paraplegics (34 males and 26 females) was carried out during the three years experiment. To measure a cardio-respiratory efficiency level we used Skibinski's cardio-respiratory index (SCRI). After ...
Solomon W R - - 1980
Effects of window air-conditioner operation on intramural particle levels were assessed in the bedrooms of 20 homes and in 10 outpatient clinic examining rooms during late summer periods. At each site, pollen and spore collections in the mechanically cooled room and a normally ventilated counterpart were compared using volumetric impactors. ...
Mortola J P - - 1980
Tracheal dimensions have been measured in a variety of newborn mammals ranging in body mass (M) from mouse to dolphin. Both tracheal diameter and tracheal length are nearly proportional to the cube root of M (M0.36 and M0.34, respectively). Tracheal volume is proportional to M1.07, and assuming that dead space ...
Kinney J M - - 1980
Normal subjects and surgical patients were studied with a noninvasive canopy-spirometer system which provides prolonged measurements of gas exchange and pattern of breathing. Values for normal subjects agreed with published values. Twenty-nine patients undergoing uncomplicated elective operation had a mean preoperative minute ventilation of 3.44 +/- 0.84 L/min/m2, a VO2 ...
Snyder E W - - 1980
Electrographic seizure activity was recorded shortly following naxolone injections in artificially ventilated, methadone-treated stump-tailed macaques. Plasma-methadone concentrations prior to seizure activity were many times higher than those that have produced respiratory depression and death in nonventilated monkeys. The duration of seizure activity was clearly related to the dose of naloxone. ...
Mohsenifar Z - - 1980
8 healthy dogs were anesthetized with a continuous infusion of pentobarbital (1 mg/kg/h) and were weakened but not paralyzed by intravenous succinylcholine (1 mg/kg/h). They were then studied during alternating periods of spontaneous breathing and assisted ventilation (IPPB). After succinylcholine, there was a significant increase in PaCO2, no significant change ...
Lipscomb D J - - 1980
A computer model of human respiration is of value for teaching the basic principles of respiratory physiology to students. An extension of this educational use is in the theoretical exploration of the relative importance of individual factors which may be contributing to disordered function in common clinical problems. For example, ...
Rehder K - - 1979
Distributions of ventilation and perfusion relative to Va/Q were determined in seven young healthy volunteers (24-33 yr) while they were either in the supine or right lateral decubitus position. The subjects were studied first awake and then while anesthetized-paralyzed and breathing 30% oxygen and again while breathing 100% oxygen. In ...
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