Effects of spontaneous swallows on breathing in awake goats

2002 ◽  
Vol 92 (5) ◽  
pp. 1923-1935 ◽  
Author(s):  
Thom R. Feroah ◽  
H. V. Forster ◽  
Carla G. Fuentes ◽  
Ivan M. Lang ◽  
David Beste ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Tidal Volume ◽  
Onset Time ◽  
Phase Response ◽  
Response Analysis ◽  
Dependent Effect ◽  
Pharyngeal Muscle ◽  
Awake State ◽  
Respiratory Phase

The effects of spontaneous swallows on breathing before, during, and after solitary swallows were investigated in 13 awake goats. Inspiratory (Ti) and expiratory (Te) time and respiratory output were determined from inspiratory airflow [tidal volume (Vt)] and peak diaphragmatic activity (Diapeak). The onset time for 1,128 swallows was determined from pharyngeal muscle electrical activity. During inspiration, the later the swallowing onset, the greater increase in Ti and Vt, whereas there was no significant effect on Te and Diapeak. Swallows in early expiration increased the preceding Ti and reduced Te, whereas later in expiration swallows increased Te. After expiratory swallows, Ti and Vt were reduced whereas minimal changes in Diapeak were observed. Phase response analysis revealed a within-breath, phase-dependent effect of swallowing on breathing, resulting in a resetting of the respiratory oscillator. However, the shift in timing in the breaths after a swallow was not parallel, further demonstrating a respiratory phase-dependent effect on breathing. We conclude that, in the awake state, within- and multiple-breath effects on respiratory timing and output are induced and/or required in the coordination of breathing and swallowing.

Transverse abdominis length changes during eupnea, hypercapnia, and airway occlusion

1988 ◽  
Vol 64 (2) ◽  
pp. 658-665 ◽  
Author(s):  
J. S. Arnold ◽  
M. A. Haxhiu ◽  
N. S. Cherniack ◽  
E. van Lunteren
Keyword(s):  
Electrical Activity ◽  
Tidal Volume ◽  
Abdominal Muscles ◽  
Pentobarbital Sodium ◽  
Airway Occlusion ◽  
Single Breath ◽  
Transverse Abdominis ◽  
Muscle Shortening ◽  
Residual Capacity ◽  
Length Changes

The abdominal muscles accelerate airflow during expiration and may also influence the end-expiratory volume and configuration of the thorax. Although much is known about their electrical activity, the degree to which they change length during the respiratory cycle has not been previously assessed. In the present study we measured respiratory changes in transverse abdominis length using sonomicrometry in 14 pentobarbital sodium-anesthetized supine dogs and compared length changes to simultaneously recorded tidal volume and transverse abdominis electromyograms (EMG). To determine muscle resting length at passive functional residual capacity (LFRC), the animals were hyperventilated to apnea. The transverse abdominis was electrically active in all animals during resting O2 breathing (eupnea). During inspiration the transverse abdominis lengthened above resting length in all 14 dogs by a mean of 3.7 +/- 1.1% LFRC; during expiration the transverse abdominis shortened below resting length in 13 of 14 dogs by a mean of 4.2 +/- 0.9% LFRC. Increasing hyperoxic hypercapnia (produced in 9 animals) progressively heightened transverse abdominis EMG and progressively increased the extent of muscle shortening below resting length (to 12.6 +/- 3.2% LFRC at a PCO2 of 90 Torr). During single-breath airway occlusion substantial inspiratory lengthening of the transverse abdominis occurred, both during O2 breathing and during CO2 rebreathing.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The Light-Perturbed Ru-Catalyzed Belousov−Zhabotinsky Reaction:  Evidence for Photochemically Produced Bromous Acid and Bromide Ions by Phase Response Analysis

2000 ◽  
Vol 104 (46) ◽  
pp. 10783-10788 ◽  
Author(s):  
Ludovit Treindl ◽  
David Knudsen ◽  
Tatsuhito Nakamura ◽  
Takeko Matsumura-Inoue ◽  
Kåre B. Jørgensen ◽  
...  
Keyword(s):  
Phase Response ◽  
Response Analysis ◽  
Bromide Ions ◽  
Belousov Zhabotinsky Reaction

Respiratory responses in reversible diaphragm paralysis

1981 ◽  
Vol 51 (5) ◽  
pp. 1150-1156 ◽  
Author(s):  
M. L. Nochomovitz ◽  
M. Goldman ◽  
J. Mitra ◽  
N. S. Cherniack
Keyword(s):  
Electrical Activity ◽  
Tidal Volume ◽  
Phrenic Nerve ◽  
Respiratory Activity ◽  
Vagus Nerves ◽  
Inspiratory Time ◽  
Transdiaphragmatic Pressure ◽  
Co2 Partial Pressure ◽  
Diaphragm Paralysis ◽  
Before And After

The effects of diaphragm paralysis on respiratory activity were assessed in 13 anesthetized, spontaneously breathing dogs studied in the supine position. Transient diaphragmatic paralysis was induced by bilateral phrenic nerve cooling. Respiratory activity was assessed from measurements of ventilation and from the moving time averages of electrical activity recorded from the intercostal muscles and the central end of the fifth cervical root of the phrenic nerve. The degree of diaphragm paralysis was evaluated from changes in transdiaphragmatic pressure and reflected in rib cage and abdominal displacements. Animals were studied both before and after vagotomy breathing O2, 3.5% CO2 in O2, or 7% CO2 in O2. In dogs with intact vagi, both peak and rate of rise of phrenic and inspiratory intercostal electrical activity increased progressively as transdiaphragmatic pressure fell. Tidal volume decreased and breathing frequency increased as a result of a shortening in expiratory time. Inspiratory time and ventilation were unchanged by diaphragm paralysis. These findings were the same whether O2 or CO2 in O2 was breathed. After vagotomy, no significant change in phrenic or inspiratory intercostal activity occurred with diaphragm paralysis in spite of increased arterial CO2 partial pressure. Ventilation and tidal volume decreased significantly, and respiratory timing was unchanged. These results suggest that mechanisms mediated by the vagus nerves account for the compensatory increase in respiratory electrical activity during transient diaphragm paralysis. That inspiratory time is unchanged by diaphragm paralysis whereas the rate or rise of phrenic nerve activity increases suggest that reflexes other than the Hering-Breuer reflex contribute to the increased respiratory response.

scholarly journals Neurally Adjusted Ventilatory Assist in Critically Ill Postoperative Patients: A Crossover Randomized Study

2010 ◽  
Vol 113 (4) ◽  
pp. 925-935 ◽  
Author(s):  
Yannael Coisel ◽  
Gerald Chanques ◽  
Boris Jung ◽  
Jean-Michel Constantin ◽  
Xavier Capdevila ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Gas Exchange ◽  
Electrical Activity ◽  
Tidal Volume ◽  
Critically Ill ◽  
Neurally Adjusted Ventilatory Assist ◽  
Exchange Effects ◽  
Ventilatory Parameters ◽  
Ventilatory Assist ◽  
Ventilation Modes

Background Neurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation that delivers ventilatory assist in proportion to the electrical activity of the diaphragm. This study aimed to compare the ventilatory and gas exchange effects between NAVA and pressure support ventilation (PSV) during the weaning phase of critically ill patients who required mechanical ventilation subsequent to surgery. Methods Fifteen patients, the majority of whom underwent abdominal surgery, were enrolled. They were ventilated with PSV and NAVA for 24 h each in a randomized crossover order. The ventilatory parameters and gas exchange effects produced by the two ventilation modes were compared. The variability of the ventilatory parameters was also evaluated by the coefficient of variation (SD to mean ratio). Results Two patients failed to shift to NAVA because of postoperative bilateral diaphragmatic paralysis, and one patient interrupted the study because of worsening of his sickness. In the other 12 cases, the 48 h of the study protocol were completed, using both ventilation modes, with no signs of intolerance or complications. The Pao2/Fio2 (mean ± SD) ratio in NAVA was significantly higher than with PSV (264 ± 71 vs. 230 ± 75 mmHg, P < 0.05). Paco2 did not differ significantly between the two modes. The tidal volume (median [interquartile range]) with NAVA was significantly lower than with PSV (7.0 [6.4-8.6] vs. 6.5 [6.3-7.4] ml/kg predicted body weight, P < 0.05).Variability of insufflation airway pressure, tidal volume, and minute ventilation were significantly higher with NAVA than with PSV. Electrical activity of the diaphragm variability was significantly lower with NAVA than with PSV. Conclusions Compared with PSV, respiratory parameter variability was greater with NAVA, probably leading in part to the significant improvement in patient oxygenation.

scholarly journals Isochron-Based Phase Response Analysis of Circadian Rhythms

2006 ◽  
Vol 91 (6) ◽  
pp. 2131-2141 ◽  
Author(s):  
Rudiyanto Gunawan ◽  
Francis J. Doyle
Keyword(s):  
Circadian Rhythms ◽  
Phase Response ◽  
Response Analysis

Lung-Air-Sac Anatomy and Respiratory Pressures in the Bird

1972 ◽  
Vol 57 (2) ◽  
pp. 543-550
Author(s):  
JOHN H. BRACKENBURY
Keyword(s):  
Steady State ◽  
Tidal Volume ◽  
Pressure Wave ◽  
Airway Resistance ◽  
Equilibrium Distribution ◽  
Wave Form ◽  
Pressure Waves ◽  
Air Sacs ◽  
Maximum Value ◽  
Respiratory Phase

1. Regardless of its tidal volume an individual air sac shows a respiratory pressure-wave which is similar to that of every other sac. These is a process of pressure equilibration within the lung-air-sac system involving very short-lived streams of air between air sacs, whose significance becomes larger as pressure accelerations become bigger; and when a steady state has been achieved in any respiratory phase the pressure wave becomes normalized in all parts of the system. 2. Small pressure differentials between sacs are part of the equilibrium distribution of pressure within the lung-air-sac system. They result from differences in the resistance path through the lung to each sac, and differences in their respective tidal volumes. Their wave-form closely resembles that of the parent pressure waves and has a maximum value of one-tenth their value. 3. In general, the bronchial pathways to the posterior sacs have greater resistances to air flow than those to the anterior sacs. 4. During vocalization pressures in the coelom and air sacs exceed normal respiratory pressures by about 40 times. Airway resistance vastly increases as the syringeal membranes begin to vibrate.

Sign in / Sign up

Export Citation Format

Share Document