Effects of tonic vagal input on breathing pattern in newborn rabbits

1985 ◽  
Vol 59 (1) ◽  
pp. 223-228 ◽  
Author(s):  
T. Trippenbach ◽  
G. Kelly ◽  
D. Marlot
Keyword(s):  
Breathing Pattern ◽  
Minute Ventilation ◽  
Vagal Activity ◽  
Respiratory Effects ◽  
Tracheal Pressure ◽  
Negative Pressure Breathing ◽  
Lung Deflation ◽  
Reflex Stimulation ◽  
Cardiac Receptors ◽  
Respiratory Reflex

Respiratory effects of positive and negative pressure breathing were studied in 1- and 4-day-old rabbit pups anesthetized with ketamine (50 mg/kg, im) and acepromazine (3 mg/kg, im). We recorded tidal volume (VT), tracheal pressure (Ptr), and integrated diaphragmatic EMG (DiEMG). Inspiratory (TI) and expiratory time (TE) were measured from the records of DiEMG. During breathing with increased Ptr by 1 or 2 cmH2O, VT, minute ventilation (VE), and respiratory rate (f) decreased. Changes in f relied on a TE prolongation. Neither DiEMG nor its rate of rise (DiEMGt) were affected. Except for VT decrease during positive Ptr, all other effects disappeared after vagotomy. Our results indicate that an increase in tonic vagal activity interacts with the mechanisms controlling TE and has no effect on depth and duration of inspiration. When Ptr decreased by 1 and 2 cmH2O, VE increased due to an increase in f. Increase in f relied on shortening of both TI and TE; the TE effect being more pronounced. DiEMG and DiEMGt also increased. Adverse effects of lung deflation and vagotomy strongly suggest that the respiratory reflex stimulation due to decrease in Ptr does not rely on inhibition of the slowly adapting stretch receptor activity. Therefore other excitatory vagal inputs must be responsible for this response. We propose two vagally mediated inputs: the irritant and/or the cardiac receptors.

Mechanics of the respiratory system and breathing pattern during sleep in normal humans

1984 ◽  
Vol 56 (1) ◽  
pp. 133-137 ◽  
Author(s):  
D. W. Hudgel ◽  
R. J. Martin ◽  
B. Johnson ◽  
P. Hill
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Breathing Pattern ◽  
Minute Ventilation ◽  
Transpulmonary Pressure ◽  
Dynamic Compliance ◽  
Face Mask ◽  
Esophageal Pressure ◽  
Rapid Eye Movement ◽  
Airflow Resistance

The purposes of this investigation were to describe the changes in 1) dynamic compliance of the lungs, 2) airflow resistance, and 3) breathing pattern that occur during sleep in normal adult humans. Six subjects wore a tightly fitting face mask. Flow and volume were obtained from a pneumotachograph attached to the face mask. Transpulmonary pressure was calculated as the difference between esophageal pressure obtained with a balloon and mask pressure. At least 20 consecutive breaths were analyzed for dynamic compliance, airflow resistance, and breathing pattern during wakefulness, non-rapid-eye-movement stage 2 and rapid-eye-movement (REM) sleep. Dynamic compliance did not change significantly. Airflow resistance increased during sleep; resistance was 3.93 +/- 0.56 cmH2O X 1–1 X s during wakefulness, 7.96 +/- 0.95 in stage 2 sleep, and 8.66 +/- 1.43 in REM sleep (P less than 0.02). By placing a catheter in the retroepiglottic space and thus dividing the airway into upper and lower zones, we found the increase in resistance occurred almost entirely above the larynx. Decreases in tidal volume, minute ventilation, and mean inspiratory flow observed during sleep were not statistically significant.

Effect of pulmonary arterial PCO2 on breathing pattern

1988 ◽  
Vol 64 (5) ◽  
pp. 1844-1850 ◽  
Author(s):  
E. R. Schertel ◽  
D. A. Schneider ◽  
L. Adams ◽  
J. F. Green
Keyword(s):  
Breathing Pattern ◽  
Minute Ventilation ◽  
Blood Gases ◽  
Middle Level ◽  
Positive Pressure ◽  
Breathing Patterns ◽  
Arterial Pco2 ◽  
Anesthetized Dogs ◽  
Steady State Levels ◽  
Pulmonary Arterial

We studied breathing patterns and tidal volume (VT)-inspiratory time (TI) relationships at three steady-state levels of pulmonary arterial PCO2 (PpCO2) in 10 anesthetized dogs. To accomplish this we isolated and then separately pump perfused the pulmonary and systemic circulations, which allowed us to control blood gases in each circuit independently. To ventilate the lungs at a rate and depth determined by central drive, we used an electronically controlled positive-pressure ventilator driven by inspiratory phrenic neural activity. Expiratory time (TE) varied inversely with PpCO2 over the range of PpCO2 from approximately 20 to 80 Torr. VT and TI increased with rising PpCO2 over the range from approximately 20 to 45 Torr but did not change further as PpCO2 was raised above the middle level of approximately 45 Torr. Thus minute ventilation increased as a function of TE and VT as PpCO2 was increased over the lower range and increased solely as a function of TE as PpCO2 was increased over the upper range. The VT-TI relationship shifted leftward on the time axis as PpCO2 was lowered below the middle level but did not shift in the opposite direction as PpCO2 was raised above the middle level. In addition to its effect on breathing pattern, we found that pulmonary hypocapnia depressed inspiratory drive.

Cardiorespiratory transfer during sleep: a study in healthy young men

1995 ◽  
Vol 269 (3) ◽  
pp. H952-H958 ◽  
Author(s):  
P. Van de Borne ◽  
P. Biston ◽  
M. Paiva ◽  
H. Nguyen ◽  
P. Linkowski ◽  
...  
Keyword(s):  
Breathing Pattern ◽  
Sleep Stages ◽  
Vagal Activity ◽  
Deep Sleep ◽  
Rapid Eye Movement Sleep ◽  
Nocturnal Sleep ◽  
Healthy Men ◽  
Consistent Increase ◽  
Respiratory Modulation ◽  
Light Sleep

This study tested the concept that changes in breathing parameters account for modifications in respiratory-related blood pressure (BP) and R-R interval (RRI) variability during nocturnal sleep. BP (Finapres), electrocardiogram, respiration (Respitrace), and polygraphic sleep recordings were recorded continuously in 13 healthy men aged 18-37 yr. The transfer characteristics identified by coherence and gain measures between the calibrated thoraco-abdominal motion and the respiratory-related BP and RRI variability evidenced a consistent increase during transitions from wake to light sleep and from light to deep sleep but returned to waking levels during rapid-eye-movement sleep (P < 0.0001). These changes were related to the specific modifications occurring in the respiratory rate, tidal volume, and ribcage-to-abdominal motion ratio during the different sleep stages (0.28 < r < 0.39; P < 0.0001). This study demonstrates 1) that modifications in the breathing pattern account for 8-15% of the variance in the cardiorespiratory transfer, and 2) that respiratory modulation of vagal activity is not the main mechanism controlling the magnitude of the respiratory-related BP and RRI variability during sleep.

Ventilatory adjustments during sustained mechanical loading in conscious humans

1983 ◽  
Vol 55 (4) ◽  
pp. 1211-1218 ◽  
Author(s):  
K. Axen ◽  
S. S. Haas ◽  
F. Haas ◽  
D. Gaudino ◽  
A. Haas
Keyword(s):  
Mechanical Loading ◽  
Breathing Pattern ◽  
Minute Ventilation ◽  
Ventilatory Responses ◽  
Frequency Responses ◽  
Group Response ◽  
Resistive Loading ◽  
Elastic Loading ◽  
Resistive Loads ◽  
Load Size

Ventilatory responses to inspiratory elastic and resistive loads of 67 men were analyzed. During the 1st, 5th, and 10th consecutively loaded breaths 1) individual responses ranged from a rapid-shallow to a slow-deep breathing pattern; 2) strong tidal volume (VT) defenders employed longer inspirations than did weak VT defenders; and 3) individual frequency responses were mediated by changes in inspiratory and/or expiratory timing. Thus the group response was qualitatively similar on the 1st, 5th, and 10th loaded breaths. Quantitatively, however, the group's mean minute ventilation increased throughout each episode owing to progressively larger tidal volumes coupled with equal breathing frequencies. During elastic loading this amplified VT defense was achieved by stronger inspirations with no systematic changes in timing, whereas during resistive loading it was achieved both by stronger and longer inspirations. Inspiring 5% CO2 induced a degree of hypercapnia exceeding that accompanying mechanical loading and yet elicited a comparatively modest enhancement of respiratory output. These findings suggest that in conscious humans 1) repeated mechanical loading activates neural load-compensating mechanisms; 2) the range of these neural adjustments varies with both load size and type; and 3) the stimulus to initiate this behavior is largely nonchemical.

Breuer-Hering inflation reflex and breathing pattern in anesthetized humans and cats

1981 ◽  
Vol 51 (5) ◽  
pp. 1162-1168 ◽  
Author(s):  
H. Gautier ◽  
M. Bonora ◽  
J. H. Gaudy
Keyword(s):  
Tidal Volume ◽  
Breathing Pattern ◽  
Respiratory Activity ◽  
Human Subjects ◽  
Threshold Curve ◽  
Ventilatory Pattern ◽  
Tracheal Pressure ◽  
Switch Mechanism

In nine cats and nine human subjects anesthetized with alfaxalone, respiratory activity and tracheal pressure were recorded prior to and during occlusion of the airway at end inspiration or end expiration. Lung inflations at the end of expiration were also performed. In addition, the ventilatory pattern was analyzed during hypercapnia. The results show that occlusions at the end of inspiration or inflations provoked an apnea in both cats and humans. However, concomitant with increases in tidal volume during hypercapnia, inspiratory duration decreased in cats and did not change in human subjects. These results indicate that the Breuer-Hering reflex, which delays the onset of inspiration during inflation was equally operative in cats and humans. In contrast, the “Breuer-Hering threshold curve,” which accounts for the off-switch“ of inspiration was different in cats and humans. Thus, in summary, the Breuer-Hering inflation reflex is operative in human subjects, but it does not seem to be involved in the control of the inspiratory off-switch mechanism during increases respiratory activity resulting from hypercapnia.

Time course of ozone-induced changes in breathing pattern in healthy exercising humans

2007 ◽  
Vol 102 (2) ◽  
pp. 688-697 ◽  
Author(s):  
Edward S. Schelegle ◽  
William F. Walby ◽  
William C. Adams
Keyword(s):  
Time Course ◽  
Breathing Pattern ◽  
Human Subjects ◽  
Minute Ventilation ◽  
Cumulative Exposure ◽  
Healthy Human ◽  
Percent Change ◽  
Atropine Treatment ◽  
Induced Changes ◽  
Time To Onset

We examined the time course of O3-induced changes in breathing pattern in 97 healthy human subjects (70 men and 27 women). One- to five-minute averages of breathing frequency (fB) and minute ventilation (V̇e) were used to generate plots of cumulative breaths and cumulative exposure volume vs. time and cumulative exposure volume vs. cumulative breaths. Analysis revealed a three-phase response; delay, no response detected; onset, fB began to increase; response, fB stabilized. Regression analysis was used to identify four parameters: time to onset, number of breaths at onset, cumulative inhaled dose of ozone at onset of O3-induced tachypnea, and the percent change in fB. The effect of altering O3 concentration, V̇e, atropine treatment, and indomethacin treatment were examined. We found that the lower the O3 concentration, the greater the number of breaths at onset of tachypnea at a fixed ventilation, whereas number of breaths at onset of tachypnea remains unchanged when V̇e is altered and O3 concentration is fixed. The cumulative inhaled dose of O3 at onset of tachypnea remained constant and showed no relationship with the magnitude of percent change in fB. Atropine did not affect any of the derived parameters, whereas indomethacin did not affect time to onset, number of breaths at onset, or cumulative inhaled dose of O3 at onset of tachypnea but did attenuate percent change in fB. The results are discussed in the context of dose response and intrinsic mechanisms of action.

Effect of respiratory apparatus on respiration

1984 ◽  
Vol 57 (2) ◽  
pp. 475-480 ◽  
Author(s):  
C. Weissman ◽  
J. Askanazi ◽  
J. Milic-Emili ◽  
J. M. Kinney
Keyword(s):  
Tidal Volume ◽  
Duty Cycle ◽  
Breathing Pattern ◽  
Minute Ventilation ◽  
Inspiratory Flow ◽  
Percentage Increase ◽  
Breathing Patterns ◽  
Normal Volunteers ◽  
Abdominal Operation ◽  
Respiratory Apparatus

A mouthpiece plus noseclip (MP & NC) is frequently used in performing measurements of breathing patterns. Although the effects the apparatus exerts on breathing patterns have been studied, the mechanism of the changes it causes remains unclear. The current study examines the effects on respiratory patterns of a standard (17-mm-diam) MP & NC during room air (RA) breathing and the administration of 2 and 4% CO2 in normal volunteers and in patients 2–4 days after abdominal operation. When compared with values obtained with a noninvasive canopy system, the MP & NC induced increases in minute ventilation (VE), tidal volume (VT), and mean inspiratory flow (VT/TI), but not frequency (f) or inspiratory duty cycle, during both RA and CO2 administration. The percentage increase in VE, VT, and VT/TI caused by the MP & NC decreased as the concentration of CO2 increased. During RA breathing, the application of noseclip alone resulted in a decrease in f and an increase in VT, but VE and VT/TI were unchanged. The changes were attenuated during the administration of 2 and 4% CO2. Reducing the diameter of the mouthpiece to 9 mm abolished the alterations in breathing pattern observed with the larger (17-mm) diameter MP.

Relationship between Cr and breathing pattern in mechanically ventilated patients

1994 ◽  
Vol 77 (6) ◽  
pp. 2703-2708 ◽  
Author(s):  
H. Burnet ◽  
M. Bascou-Bussac ◽  
C. Martin ◽  
Y. Jammes
Keyword(s):  
Linear Regression ◽  
Tidal Volume ◽  
Multiple Linear Regression ◽  
Breathing Pattern ◽  
Minute Ventilation ◽  
Respiratory Frequency ◽  
Upper Airways ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Ventilated Patients

In mechanically ventilated patients the natural gas-conditioning process of the upper airways is bypassed by the use of an endotracheal tube or a tracheostomy. We hypothesized that under these conditions the breathing pattern may greatly influence the convective respiratory heat loss (Cr). Cr values were computed from minute ventilation (VE) and inspiratory and expiratory gas temperatures, which were measured in six patients under mechanical ventilation for the management of cranial trauma. In each patient the effects of 11–20 different breathing patterns were investigated. Relationships between Cr and VE and between combined tidal volume and respiratory frequency were obtained by simple and multiple linear regression methods, respectively. Comparison of the standard errors of estimate indicated that multiple linear regression gives the best fit. Thus, Cr was highly dependent on the breathing pattern and was not related only to VE. For the same VE value, Cr was higher when VE was achieved with high tidal volume and low respiratory frequency. These data are consistent with previous studies in which thermal exchanges through the upper airways were taxed by hyperventilation of frigid air.

Role of Vagal Airway Reflexes in Control of Ventilation in Pulmonary Fibrosis

1981 ◽  
Vol 61 (6) ◽  
pp. 781-784 ◽  
Author(s):  
J. Savoy ◽  
S. Dhingra ◽  
N. R. Anthonisen
Keyword(s):  
Pulmonary Fibrosis ◽  
Breathing Pattern ◽  
Minute Ventilation ◽  
Arterial Oxygen ◽  
Control Subjects ◽  
Cough Response ◽  
Before And After ◽  
The Mean ◽  
Breath Cycle

1. in 10 patients with pulmonary fibrosis and in seven control subjects, we measured the pressure at the mouth 0.1 s after onset of an inspiration against occluded airway (P0.1), minute ventilation (VI), breathing frequency (fr), tidal volume (VT), inspiratory duration (Tl) and calculated the mean inspiratory flow (VT/Tl) and the fraction of the breath cycle devoted to inspiration (Tl/Ttot.). in the patients measurements were made at normal arterial oxygen saturations (Sao2), before and after lignocaine airway anaesthesia. 2. Efficacy of airway anaesthesia was tested by the cough response to citric acid inhalation. 3. in pulmonary fibrosis P0.1, f1 and VT/Tl were greater than in the control subjects, VT and Tl, were smaller and Tl/Ttot. and VI were not different. 4. Effective airway anaesthesia did not modify P0.1 and breathing pattern parameters observed in pulmonary fibrosis. 5. These results suggest that airway receptors do not contribute to a major extent to the control of breathing in pulmonary fibrosis.

scholarly journals Changes in respiratory function following the intramuscular administration of etorphine to boer goats (Capra hircus)

2001 ◽  
Vol 72 (3) ◽  
Author(s):  
P.E. Buss ◽  
D.G.A. Meltzer
Keyword(s):  
Respiratory Function ◽  
Minute Ventilation ◽  
Minute Volume ◽  
Capra Hircus ◽  
Physiological Effects ◽  
Physiological Changes ◽  
Respiratory Effects ◽  
Physiological Dead Space ◽  
Boer Goats ◽  
Dead Space Ventilation

The physiological effects on respiratory function of etorphine (M99, Logos Agvet) (30 µg/kg) administered intramuscularly were determined in boer goats. The goats were habituated to the experimental procedures so that respiratory function could be determined while the animals stood quietly at rest. This enabled the physiological changes induced by etorphine to be measured and compared with those obtained before administration of the immobilising drug. The effectiveness of diprenorphine (M5050, Logos Agvet) (3 mg/1 mg etorphine) as an antagonist of the physiological changes induced by the etorphine treatment was also determined. Etorphine depressed respiratory function, which resulted in a decrease in PaO2 and an increase in PaCO2. These changes were limited and occurred as a result of decreases in respiratory minute volume and alveolar minute ventilation caused by a decrease in respiratory rate. The physiological shunt fraction did not change significantly but there was a significant decrease in percentage physiological dead space ventilation. It was not possible to determine how effectively diprenorphine reversed the respiratory effects due to etorphine.

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