Ventilation and respiratory pattern and timing in resting awake cats

1985 ◽  
Vol 63 (2) ◽  
pp. 148-154 ◽  
Author(s):  
D. B. Jennings ◽  
P. C. Szlyk
Keyword(s):  
Tidal Volume ◽  
Normal Control ◽  
Blood Gases ◽  
Bimodal Distribution ◽  
Inspiratory Flow ◽  
Respiratory Pattern ◽  
Respiratory Drive ◽  
Arterial Blood Gases ◽  
Arterial Blood ◽  
Awake Cats

The purpose of this study was to characterize the variability and patterns of spontaneous respiratory behaviour in awake cats. Respiration was measured in six cats over 80 or 90 min by the plethysmographic technique. In three cats, arterial blood gases were measured. Breath frequency (f) and tidal volume (VT) varied considerably breath-to-breath, although on average, these measurements as well as average ventilation remained relatively constant. The incidence of breath ventilation (VT × 60/TTOT) and VT were distributed unimodally but the incidence of breath f had a bimodal distribution. In the low f range, average f was 22.5 breaths/min, and in the high f range, average f was 41.6 breaths/min. The latter range appeared to be associated with purring. Inspiratory duration (TI) was less than expiratory duration (TE) at low f but exceeded TE at high f. For a given breath ventilation there was a predictable f and VT. At shorter TI (higher f) mean inspiratory flow, an index of central respiratory drive, increased but VT decreased. This study indicates that "normal" control respiratory behaviour in awake cats is better described by the range and pattern of breathing than by average values.

Naloxone alters the early response to an inspiratory flow-resistive load

1989 ◽  
Vol 67 (5) ◽  
pp. 1747-1753 ◽  
Author(s):  
A. T. Scardella ◽  
T. V. Santiago ◽  
N. H. Edelman
Keyword(s):  
Tidal Volume ◽  
Blood Gases ◽  
Inspiratory Flow ◽  
Abdominal Muscles ◽  
Base Line ◽  
Resistive Load ◽  
Endogenous Opioid ◽  
Transdiaphragmatic Pressure ◽  
Arterial Blood ◽  
Gastric Pressure

In a previous study in unanesthetized goats, we demonstrated that cerebrospinal fluid levels of beta-endorphin were significantly elevated after 2.5 h of inspiratory flow-resistive loading. Naloxone (NLX) (0.1 mg/kg) administration partially and transiently reversed the tidal volume depression seen during loading. In the current study, we tested the hypothesis that endogenous opioid elaboration results in depression of respiratory output to the diaphragm. In six studies of five unanesthetized goats, tidal volume (VT), transdiaphragmatic pressure (Pdi), diaphragmatic electromyogram (EMGdi), and arterial blood gases were monitored. A continuous NLX (0.1 mg/kg) or saline (SAL) infusion was begun 5 min before an inspiratory flow-resistive load of 120 cmH2O.l-1.s was imposed. Our data show that the depression of VT induced by the load was prevented by NLX as early as 15 min and persisted for 2 h. At 2 h, Pdi was still 294 +/- 45% of the base-line value compared with 217 +/- 35% during SAL. There was no difference in EMGdi between the groups at any time. However, the augmentation of Pdi was associated with a greater increase in end-expiratory gastric pressure in the NLX group. We conclude that the reduction in VT and Pdi associated with endogenous opioid elaboration is not mediated by a decrease in neural output to the diaphragm, but it appears to be the result of a decrease in respiratory output to the abdominal muscles.

Changes in respiratory pattern and arterial blood gases during sedation with propofol or midazolam in spinal anesthesia

1999 ◽  
Vol 11 (5) ◽  
pp. 375-379 ◽  
Author(s):  
Michiaki Yamakage ◽  
Yasuhiro Kamada ◽  
Masaki Toriyabe ◽  
Yasuyuki Honma ◽  
Akiyoshi Namiki
Keyword(s):  
Spinal Anesthesia ◽  
Blood Gases ◽  
Respiratory Pattern ◽  
Arterial Blood Gases ◽  
Arterial Blood

scholarly journals Tidal Volume, Lung Hyperinflation and Arterial Oxygenation during General Anaesthesia

1993 ◽  
Vol 21 (6) ◽  
pp. 806-810 ◽  
Author(s):  
W. A. Tweed ◽  
W. T. Phua ◽  
K. Y. Chong ◽  
E. Lim ◽  
T. L. Lee
Keyword(s):  
Gas Exchange ◽  
Tidal Volume ◽  
General Anaesthesia ◽  
Blood Gases ◽  
Arterial Oxygenation ◽  
Arterial Blood Gases ◽  
Controlled Ventilation ◽  
Arterial Blood ◽  
Patients At Risk ◽  
Induction Of Anaesthesia

Impaired pulmonary oxygen (O2) exchange is common during general anaesthesia but there is no clinical unanimity as to methods of prevention or treatment. We studied 14 patients at risk for pulmonary dysfunction because of increased age, obesity, cigarette smoking, or chronic lung disease. Pulmonary O2 exchange was measured during four conditions of ventilation: awake spontaneous, conventional tidal volume (CVT, 7 ml.kg-1) or high tidal volume (HVT, 12 ml.kg-1) controlled ventilation, and five min after manual hyperinflation (H1) of the lungs. The F1O2 was controlled at 0.5, and FETCO2 was kept constant by adding dead space during HVT. Eight patients were ventilated with N2O/O2 and six with air/O2. Arterial blood gases were used to calculate the (A-a)DO2. In seven patients (A-a)DO2 worsened after induction of anaesthesia, while in seven there was no change or an improvement. Manual HI significantly reduced (A-a)DO2, but changing tidal volume (VT) had no effect. Using a multivariate model to predict O2 exchange, obesity and type of surgery were significantly associated with worsening, while level of VT and inspiratory gas (N2O or N2) were not significant predictors. Thus patient and surgical factors were more important determinants of pulmonary gas exchange during anaesthesia than were tidal volume or inspiratory gas. Manual HI is a simple and effective manoeuvre to improve gas exchange.

Effect of naloxone on ventilation in newborn rabbits

1981 ◽  
Vol 50 (4) ◽  
pp. 713-717 ◽  
Author(s):  
T. A. Hazinski ◽  
M. M. Grunstein ◽  
M. A. Schlueter ◽  
W. H. Tooley
Keyword(s):  
Blood Gases ◽  
Postnatal Life ◽  
Respiratory Drive ◽  
Arterial Blood Gases ◽  
Inspiratory Time ◽  
Ether Anesthesia ◽  
Respiratory Effect ◽  
Artery Cannulation ◽  
Arterial Blood ◽  
Before And After

Endorphins have been isolated from amniotic fluid and cord blood of mammals. To determine if these agents influence ventilation after birth, we measured ventilation (VE), tidal volume, inspiratory time, and respiratory frequency (f) in 19 rabbit pups before and after administration of naloxone (NLX), an endorphin antagonist. Tracheostomy and carotid artery cannulation were performed under light ether anesthesia. After 30-90 min for recovery the pups were placed in a body plethysmograph. Rectal temperature was kept at 37 +/- 0.5 degrees C. After 15 min of control measurements we infused saline, which had no respiratory effect. NLX (4 microgram/g) was then infused and measurements continued for 30 min. In 6 of 7 pups less than or equal to 4 days old, VE increased to 140-180% of control values and remained elevated for the remainder of the study period. Increased VE was due solely to increased f. By contrast, only 1 of 12 pups greater than or equal to 5 days old responded in this fashion. This difference was significant (P less than 0.005). Arterial blood gases were measured before and after NLX in 10 pups. In those pups who increased their ventilation after NLX, arterial CO2 tension fell and pH rose above pre-NLX values (P less than 0.05) for both variables). Blood gases of the group whose ventilation was uneffected remained unchanged. These results indicate that early in postnatal life endorphins probably modulate central respiratory drive in rabbits but that these agents become less important with maturation.

Effects of carotid body denervation on respiratory pattern of awake cats

1979 ◽  
Vol 46 (6) ◽  
pp. 1127-1131 ◽  
Author(s):  
H. Gautier ◽  
M. Bonora
Keyword(s):  
Tidal Volume ◽  
Carotid Body ◽  
Inspiratory Flow ◽  
Respiratory Pattern ◽  
Oxygen Breathing ◽  
Before And After ◽  
Inspiratory Activity ◽  
The Mean ◽  
Awake Cats ◽  
Carotid Body Denervation

Eight awake cats have been studied before and after carotid denervation during air and oxygen breathing, and during hypercapnia. Analysis of the variables that characterize the spirogram shows that carotid denervation consistently results in a decrease of the mean inspiratory flow (VT/TI), causing a decrease in tidal volume (VT) and ventilation with a relative alveolar hypercapnia. In carotid-denervated animals, inhalation of oxygen results in an increase in ventilation due to an augmentation of VT/TI and VT and a relative hypocapnia. TI does not significantly change in the different conditions whereas TE is significantly affected. TE seems therefore to be more closely related to the rate of rise of inspiratory activity than to inspiratory duration.

scholarly journals Short-Term Effects of Humidification Devices on Respiratory Pattern and Arterial Blood Gases During Noninvasive Ventilation

2012 ◽  
Vol 57 (11) ◽  
pp. 1879-1886 ◽  
Author(s):  
François Lellouche ◽  
Claudia Pignataro ◽  
Salvatore Maurizio Maggiore ◽  
Emmanuelle Girou ◽  
Nicolas Deye ◽  
...  
Keyword(s):  
Noninvasive Ventilation ◽  
Blood Gases ◽  
Respiratory Pattern ◽  
Arterial Blood Gases ◽  
Short Term ◽  
Arterial Blood ◽  
Humidification Devices ◽  
Short Term Effects
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