Pulmonary function during norepinephrine-induced calorigenesis in cold-acclimatized rats

1963 ◽  
Vol 18 (6) ◽  
pp. 1213-1216 ◽  
Author(s):  
Eugene Evonuk ◽  
John P. Hannon

The effects of cold acclimatization on pulmonary function during norepinephrine-induced calorigenesis were studied. Norepinephrine resulted in a marked increase (85%) in the pulmonary minute volume in both the warm- and cold-acclimatized rats. This increase in the warm-acclimatized rats was accomplished entirely by increasing the respiratory rate, whereas in the cold-acclimatized rats, the increase in pulmonary minute volume was achieved for the most part by increasing the tidal volume with a slight increase in respiratory rate. Cold acclimatization was associated with a greater “efficiency of oxygen extraction” before, during, and after the infusion of norepinephrine. pulmonary minute volume; respiratory rate; oxygen extraction Submitted on December 6, 1962

1959 ◽  
Vol 14 (6) ◽  
pp. 914-916 ◽  
Author(s):  
Neil S. Cherniack ◽  
Alvin S. Hyde ◽  
F. W. Zechman

Since difficulty with respiration limits tolerance to transverse acceleration, the effect of this acceleration on different respiratory factors was tested in 15 subjects. Minute volume, respiratory rate, tidal volume, maximum breathing capacity, 0.5-second timed vital capacity and total vital capacity were measured at 3 and 5 g with the subject's trunk perpendicular to the centrifugal force and legs and knees flexed at 90 degrees. Vital capacity was reduced significantly at 3 and 5 g. Maximum breathing capacity was significantly reduced at 5 g. One-half-second timed vital capacity represented an increasing fraction of total vital capacity as acceleration increased. Minute volume and respiratory rate also increased significantly at 5 g while tidal volume was essentially unchanged. Results are obtained which indicate that the nature of the predominant respiratory defect during forward acceleration is restrictive. Of the respiratory parameters measured, vital capacity showed the greatest decrement. Submitted on April 17, 1959


1958 ◽  
Vol 192 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Mary O. Amdur ◽  
Jere Mead

A technique has been described by which tidal volume, intrapleural pressure and rate of flow of gas in and out of the respiratory system can be measured simultaneously in unanesthetized guinea pigs for periods of several hours. These data permit the calculation of the pulmonary flow-resistance and compliance for an experimental animal with normal reflex behavior. The values obtained on 200 normal and 20 tracheotomized animals for tidal volume, respiratory rate, minute volume, resistance and compliance are given.


1994 ◽  
Vol 22 (3) ◽  
pp. 276-280 ◽  
Author(s):  
G. Thomas ◽  
J. Brimacombe

We have assessed the performance of the Dräger Oxylog ventilator at high altitude using a decompression chamber and a lung simulator set to mimic the normal and non-compliant lung. In the normal lung, tidal volume increased by 28% at 2040 metres and by 106% at 9120 metres. A lesser change, but in the opposite direction, occurred in respiratory rate. The net effect was a linear increase in minute volume with altitude. At 2040 and 9144 metres minute volume increased by 13% and by 45%, and rate decreased by 10% and 30% respectively. In the abnormal lung stimulation, similar, but slightly less marked, changes occurred in all variables. These changes are of sufficient magnitude to require frequent observation of tidal volume and respiratory rate during aircraft ascent and descent.


1960 ◽  
Vol 15 (5) ◽  
pp. 838-842 ◽  
Author(s):  
Thomas B. Barnett ◽  
Richard M. Peters

A method is described for maintaining a permanent tracheostomy in dogs. This animal preparation has been used to study the effects of artificially increased respiratory dead space. Trained dogs with tracheostomies have made possible measurements of ventilation without anesthesia. It has been found that additions to the respiratory dead space in the form of tubing of frac34 in. i.d. result in an increase in physiologic dead space of the same magnitude as the volume of tubing added. Increasing the dead space in this manner resulted in an increased minute volume which was accomplished principally by an increase in tidal volume without a significant or consistent change in respiratory rate. Alveolar ventilation remained unchanged even with large additions to the dead space (20–30 cc/kg of animal wt.). Arterial pCO2 was significantly higher in these animals than in the controls. The CO2 tension was similarly elevated when extra dead space of lesser volume (5–20 cc/kg) was allowed to remain on the dogs for more than 48 hours. Submitted on April 13, 1960


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1135
Author(s):  
Anthony P. Addison ◽  
Paul S. Addison ◽  
Philip Smit ◽  
Dominique Jacquel ◽  
Ulf R. Borg

There is considerable interest in the noncontact monitoring of patients as it allows for reduced restriction of patients, the avoidance of single-use consumables and less patient–clinician contact and hence the reduction of the spread of disease. A technology that has come to the fore for noncontact respiratory monitoring is that based on depth sensing camera systems. This has great potential for the monitoring of a range of respiratory information including the provision of a respiratory waveform, the calculation of respiratory rate and tidal volume (and hence minute volume). Respiratory patterns and apneas can also be observed in the signal. Here we review the ability of this method to provide accurate and clinically useful respiratory information.


2020 ◽  
pp. 100063
Author(s):  
Susana Baixauli-Alacreu ◽  
Celia Padilla-Sánchez ◽  
David Hervás-Marín ◽  
Inmaculada Lara-Cantón ◽  
Alvaro Solaz-García ◽  
...  

PEDIATRICS ◽  
1959 ◽  
Vol 24 (2) ◽  
pp. 181-193
Author(s):  
C. D. Cook ◽  
P. J. Helliesen ◽  
L. Kulczycki ◽  
H. Barrie ◽  
L. Friedlander ◽  
...  

Tidal volume, respiratory rate and lung volumes have been measured in 64 patients with cystic fibrosis of the pancreas while lung compliance and resistance were measured in 42 of these. Serial studies of lung volumes were done in 43. Tidal volume was reduced and the respiratory rate increased only in the most severely ill patients. Excluding the three patients with lobectomies, residual volume and functional residual capacity were found to be significantly increased in 46 and 21%, respectively. These changes correlated well with the roentgenographic evaluation of emphysema. Vital capacity was significantly reduced in 34% while total lung capacity was, on the average, relatively unchanged. Seventy per cent of the 61 patients had a signficantly elevated RV/TLC ratio. Lung compliance was significantly reduced in only the most severely ill patients but resistance was significantly increased in 35% of the patients studied. The serial studies of lung volumes showed no consistent trends among the groups of patients in the period between studies. However, 10% of the surviving patients showed evidence of significant improvement while 15% deteriorated. [See Fig. 8. in Source Pdf.] Although there were individual discrepancies, there was a definite correlation between the clinical evaluation and tests of respiratory function, especially the changes in residual volume, the vital capacity, RV/ TLC ratio and the lung compliance and resistance.


1989 ◽  
Vol 66 (2) ◽  
pp. 613-621 ◽  
Author(s):  
P. A. Easton ◽  
J. W. Fitting ◽  
R. Arnoux ◽  
A. Guerraty ◽  
A. E. Grassino

If sonomicrometry transducers could be implanted permanently into the diaphragm, direct measurements of costal and crural length and shortening could be made during recovery from the laparotomy and then indefinitely in an awake, non-anesthetized mammal. We report results from six canines in which we successfully implanted transducers onto the left hemidiaphragm through a midline laparotomy and measured segmental shortening and ventilation at intervals through 22 days of postoperative recovery. After laparotomy, breathing pattern, including tidal volume, respiratory rate and mean inspiratory flow, stabilized by the 4th postoperative day (POD). Tidal shortening of costal and crural segments increased from 1.82 and 1.45% of end-expiratory length (%LFRC) on the 2nd POD to 5.32 and 8.56% LFRC, respectively, after a mean of 22 POD. Segmental shortening did not stabilize until 10 POD, and the recovery process displayed a sequence of segmental motions: lengthening, biphasic inspiratory lengthening-shortening, and increasing simple shortening. Three weeks after implantation, costal and crural segments were stable and shortening 5.32 and 8.56% LFRC, respectively, and capable of shortening 49% LFRC with maximal phrenic stimulation. In a pair of recovered animals, the initial postoperative dysfunction did not recur after a subsequent, simple laparotomy. At postmortem examination, the chronically implanted sonomicrometer transducers were found to have evoked only a thin fibrotic capsule within the diaphragm.


2020 ◽  
Vol 57 (1) ◽  
pp. 64-68
Author(s):  
Verônica Lourenço WITTMER ◽  
Rozy Tozetti LIMA ◽  
Michele Coutinho MAIA ◽  
Halina DUARTE ◽  
Flávia Marini PARO

ABSTRACT BACKGROUND: Liver cirrhosis is a highly prevalent disease that, at an advanced stage, usually causes ascites and associated respiratory changes. However, there are few studies evaluating and quantifying the impact of ascites and its relief through paracentesis on lung function and symptoms such as fatigue and dyspnea in cirrhotic patients. OBJECTIVE: To assess and quantify the impact of acute reduction of ascitic volume on respiratory parameters, fatigue and dyspnea symptoms in patients with hepatic cirrhosis, as well as to investigate possible correlations between these parameters. METHODS: Thirty patients with hepatic cirrhosis and ascites who underwent the following pre and post paracentesis evaluations: vital signs, respiratory pattern, thoracoabdominal mobility (cirtometry), pulmonary function (ventilometry), degree of dyspnea (numerical scale) and fatigue level (visual analog scale). RESULTS: There was a higher prevalence of patients classified as CHILD B and the mean MELD score was 14.73±5.75. The comparison of pre and post paracentesis parameters evidenced after paracentesis: increase of predominantly abdominal breathing pattern, improvement of ventilatory variables, increase of the differences obtained in axillary and abdominal cirtometry, reduction of dyspnea and fatigue level, blood pressure reduction and increased peripheral oxygen saturation. Positive correlations found: xiphoid with axillary cirtometry, degree of dyspnea with fatigue level, tidal volume with minute volume, Child “C” with higher MELD score, volume drained in paracentesis with higher MELD score and with Child “C”. We also observed a negative correlation between tidal volume and respiratory rate. CONCLUSION: Since ascites drainage in patients with liver cirrhosis improves pulmonary volumes and thoracic expansion as well as reduces symptoms such as fatigue and dyspnea, we can conclude that ascites have a negative respiratory and symptomatological impact in these patients.


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