The effect of atmospheric CO2 on mammal's ventilatory rate

2013 ◽  
Author(s):  
C. A. Plata ◽  
M. C. Quintero ◽  
J. M. Cordovez
Keyword(s):  
Ventilatory Rate

Pulmonary mechanics during rapid mechanical ventilation in rabbits with saline-lavaged lungs

1986 ◽  
Vol 61 (4) ◽  
pp. 1431-1437 ◽  
Author(s):  
J. J. Perez Fontan ◽  
B. S. Turner ◽  
G. P. Heldt ◽  
G. A. Gregory
Keyword(s):  
Tidal Volume ◽  
Gas Flow ◽  
Transpulmonary Pressure ◽  
Inspiratory Flow ◽  
Pulmonary Mechanics ◽  
Mechanically Ventilated ◽  
Ventilatory Rate ◽  
Residual Capacity ◽  
Pressure Volume Relationship ◽  
Linear Ramp

Infants with respiratory failure are frequently mechanically ventilated at rates exceeding 60 breaths/min. We analyzed the effect of ventilatory rates of 30, 60, and 90 breaths/min (inspiratory times of 0.6, 0.3, and 0.2 s, respectively) on the pressure-flow relationships of the lungs of anesthetized paralyzed rabbits after saline lavage. Tidal volume and functional residual capacity were maintained constant. We computed effective inspiratory and expiratory resistance and compliance of the lungs by dividing changes in transpulmonary pressure into resistive and elastic components with a multiple linear regression. We found that mean pulmonary resistance was lower at higher ventilatory rates, while pulmonary compliance was independent of ventilatory rate. The transpulmonary pressure developed by the ventilator during inspiration approximated a linear ramp. Gas flow became constant and the pressure-volume relationship linear during the last portion of inspiration. Even at a ventilatory rate of 90 breaths/min, 28–56% of the tidal volume was delivered with a constant inspiratory flow. Our findings are consistent with the model of Bates et al. (J. Appl. Physiol. 58: 1840–1848, 1985), wherein the distribution of gas flow within the lungs depends predominantly on resistive factors while inspiratory flow is increasing, and on elastic factors while inspiratory flow is constant. This dynamic behavior of the surfactant-depleted lungs suggests that, even with very short inspiratory times, distribution of gas flow within the lungs is in large part determined by elastic factors. Unless the inspiratory time is further shortened, gas flow may be directed to areas of increased resistance, resulting in hyperinflation and barotrauma.

The Accuracy, Precision and Reliability of Measuring Ventilatory Rate and Detecting Ventilatory Pause by Rainbow Acoustic Monitoring and Capnometry

2013 ◽  
Vol 117 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Michael A. E. Ramsay ◽  
Mohammad Usman ◽  
Elaine Lagow ◽  
Minerva Mendoza ◽  
Emylene Untalan ◽  
...  
Keyword(s):  
Acoustic Monitoring ◽  
Ventilatory Rate

scholarly journals Essential oils of Cunila galioides and Origanum majorana as anesthetics for Rhamdia quelen: efficacy and effects on ventilation and ionoregulation

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Jessyka A. da Cunha ◽  
Cecília Á. Scheeren ◽  
Joseânia Salbego ◽  
Luciane T. Gressler ◽  
Laurício M. Madaloz ◽  
...  
Keyword(s):  
Essential Oils ◽  
Whole Body ◽  
Ventilatory Rate ◽  
Significant Difference ◽  
Rhamdia Quelen ◽  
Origanum Majorana ◽  
Net Fluxes

ABSTRACT This study evaluated anesthetic efficacy and possible effects of the essential oils (EOs) of Cunila galioides (EOC) and Origanum majorana (EOO) on ventilatory rate (VR) and ionoregulation in Rhamdia quelen. In the anesthesia assessments, 50, 100, 200 and 300 μL L-1 EOC and 50, 100, 200, 300, 400 and 500 μL L-1 EOO were tested, and time for induction to sedation and anesthesia stages, as well as recovery, were taken. A second trial employed lower concentrations of both EOs, 10, 25, 50 and 100 μL L-1, in order to verify VR and Na+, K+ and Cl- whole body net fluxes. Sedation was achieved with both oils at 100 µL L-1, and anesthesia at ≥ 200 µL L-1. There was no significant difference between control and EO-treated groups regarding VR, but all fish subjected to 100 µL L-1 EOC died within 2 h of exposure. Overall, ionic loss declined in the presence of the EOs. The EOC at 200 - 300 μL L-1 and EOO at 400 - 500 μL L-1 present the potential to promote fast anesthesia in R. quelen.

Effect of ventilatory rate on renal venous PGE2 and PGF2 alpha efflux in anesthetized dogs

1982 ◽  
Vol 242 (1) ◽  
pp. F38-F45
Author(s):  
A. J. Lonigro ◽  
D. W. Brash ◽  
A. H. Stephenson ◽  
L. J. Heitmann ◽  
R. S. Sprague
Keyword(s):  
Blood Pressure ◽  
Important Determinant ◽  
Venous Blood ◽  
Plasma Renin ◽  
Normal Range ◽  
Arterial Blood ◽  
Ventilatory Rate ◽  
Arterial Ph ◽  
Anesthetized Dogs ◽  
Arterial Plasma

In anesthetized laparotomized male mongrel dogs with ventilatory rate set at 10 breath.min-1, tidal volume was adjusted so that control arterial pH and PCO2 were within the normal range for unanesthetized dogs. Control renal venous PGE2 and PGF2 alpha concentrations were comparable to those of unanesthetized dogs, namely, 57 +/- 10 and 114 +/- 18 pg.ml-1, respectively. In contrast, control arterial plasma renin activity (PRA), 6.6 +/- 1.2 ng.ml-1.h-1, was considerably greater than in unanesthetized dogs. Stepwise increases in ventilatory rate increased renal venous PGE2 and PGF2 alpha to 109 +/- 18 and 205 +/- 41 pg.ml-1, respectively. Hyperventilation reduced PCO2 and increased pH and PRA but had no effect on renal blood flow, arterial blood pressure, or arterial PGE2 and PGF2 alpha concentrations. When the ventilatory rate was returned to control levels, pH, PCO2, PRA, and renal venous PGE2 and PGF2 alpha concentrations returned to control. Ventilatory rate or some consequence of altering ventilatory rate is, therefore, a determinant of renal venous efflux of PGE2 and PGF2 alpha. Moreover, it may be a more important determinant of "resting" concentrations of prostaglandins in renal venous blood than anesthesia, laparotomy, or PRA.

The Control of Water Loss in Locusta Migratoria Migratorioides R. & F

1968 ◽  
Vol 49 (1) ◽  
pp. 15-29
Author(s):  
J. P. LOVERIDGE
Keyword(s):  
Water Loss ◽  
Water Conservation ◽  
Locusta Migratoria ◽  
Moist Air ◽  
Tracheal System ◽  
Locusta Migratoria Migratorioides ◽  
Ventilatory Rate ◽  
Low Humidity ◽  
Normal Water ◽  
Control Water

1. The rate of total transpiratory water loss from Locusta is proportional to weight and is not affected by activity within the limits possible in an enclosed box. 2. A trend for proportionately less water to be lost at low humidity than at high humidity probably involves active measures to control water loss from the tracheal system. The saving of water is 5 mg./locust/hr. at 0° R.H., 30° C. 3. Experiments involving exposure of locusts to CO2 of different concentrations show that little control over water loss is exerted by the spiracles except in so far as they may influence the type of ventilation. Hyperventilation, predominantly of the tidal type, doubles normal water loss. 4. Between 42 and 45° C. the ventilatory rate increases enormously with con-comitantly greater water loss. 5. Locusts pre-treated in dry air show a 23% reduction in abdominal ventilatory rate and a 25% reduction in water loss over locusts pre-treated in moist air. 6. Ventilatory movements of locusts under conditions of progressive desiccation show decreased rate and amplitude and an increased incidence of discontinuities, which will conserve water. 7. Ventilation and water loss are closely interdependent. The fact that ventilation can be controlled according to water reserves and the humidity of the air is important in water conservation.

Sign in / Sign up

Export Citation Format

Share Document