Respiratory muscle compensation for unilateral or bilateral hemidiaphragm paralysis in awake canines

1994 ◽  
Vol 77 (4) ◽  
pp. 1972-1982 ◽  
Author(s):  
M. Katagiri ◽  
R. N. Young ◽  
R. S. Platt ◽  
T. M. Kieser ◽  
P. A. Easton
Keyword(s):  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Diaphragm Dysfunction ◽  
Nerve Cuff ◽  
Diaphragm Paralysis ◽  
Crural Diaphragm ◽  
Emg Electrodes ◽  
Hemidiaphragm Paralysis

In humans and some animals, the surviving respiratory muscles are able to compensate fully for unilateral, and partially for bilateral, hemidiaphragm paralysis. To examine differential activity of individual respiratory muscles after unilateral or bilateral diaphragm paralysis, length and electromyogram (EMG) of left costal and crural diaphragm segments, parasternal intercostal, and transversus abdominis were measured directly in five awake canines after implantation with sonomicrometry transducers and bipolar EMG electrodes under three conditions: during normal breathing (NOFRZ), after infusion of local anesthetic (bupivacaine) through a cervical phrenic nerve cuff to induce reversible contralateral hemidiaphragm (CNFRZ), and after bilateral diaphragm (BIFRZ) paralysis. From NOFRZ to CNFRZ, costal, crural, parasternal, and transversus abdominis increased shortening and EMG activity to compensate for contralateral diaphragm paralysis, but the increase in activity was not equivalent for each muscle. With BIFRZ, parasternal and transversus abdominis showed further increases in activity, coordinated between both inspiration and expiration. Normalized intrabreath profiles revealed dynamic differences in development of muscle activity within each breath as paralysis worsened. Review of simultaneous muscle activities showed coordinated interactions among the compensating muscles: passive shortening of transversus, and lengthening of costal and crural, coincided with increased active inspiratory shortening of parasternal. We conclude that an integrated strategy of respiratory muscle compensation for unilateral or bilateral diaphragm paralysis occurs among chest wall, abdominal, and diaphragm segmental muscles, with relative contributions of individual muscles adjusted according to the degree of diaphragm dysfunction.

Differential timing of respiratory muscles in response to chemical stimuli in awake dogs

1989 ◽  
Vol 66 (1) ◽  
pp. 392-399 ◽  
Author(s):  
C. A. Smith ◽  
D. M. Ainsworth ◽  
K. S. Henderson ◽  
J. A. Dempsey
Keyword(s):  
Muscle Activation ◽  
Respiratory Muscles ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Inspiratory Time ◽  
Expiratory Muscle ◽  
Inspiratory Activity ◽  
Chemical Stimuli ◽  
Crural Diaphragm ◽  
Differential Timing

We assessed changes in respiratory muscle timing in response to hyperpnea and shortened inspiratory and expiratory times caused by chemoreceptor stimuli in six awake dogs. Durations of postinspiratory inspiratory activity of costal and crural diaphragm (PIIA), the delay in diaphragm electromyogram (EMG) after the initiation of inspiratory airflow, postexpiratory expiratory activity of the transversus abdominis (PEEA), and the delay of abdominal expiratory muscle activity after the initiation of expiratory airflow were measured. In control, four out of six dogs showed PIIA [8–10% of expiratory time (TE)]; all showed delay of diaphragm [19% of inspiratory time (TI)], delay of abdominal muscle activation (21% of TE), and PEEA (24% of TI). Hypercapnia decreased PIIA (4–9% of TE), maintained diaphragm delay at near control values (23% of TI), increased PEEA (36% of TI), eliminated delay of abdominal muscle activation (4% of TE), and decreased end-expiratory lung volume (EELV). Hypocapnic hypoxia increased PIIA (24–25% of TE), eliminated diaphragm delay (3% of TI), eliminated PEEA (3% of TI), reduced delay of abdominal muscle activation (14% of TE), and increased EELV. Most of these effects of hypoxic hypocapnia vs. hypercapnia on the within-breath EMG timing parameters corresponded to differences in the magnitude of expiratory muscle activation. These changes exerted significant influences on flow rates and EELV.

Effect of inspiratory muscle unloading on arousal responses to CO2 and hypoxia in sleeping dogs

1993 ◽  
Vol 74 (3) ◽  
pp. 1325-1336 ◽  
Author(s):  
R. J. Kimoff ◽  
L. F. Kozar ◽  
F. Yasuma ◽  
T. D. Bradley ◽  
E. A. Phillipson
Keyword(s):  
Rem Sleep ◽  
Respiratory Muscles ◽  
Nrem Sleep ◽  
Inspiratory Muscle ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Arousal Threshold ◽  
Inspiratory Muscles ◽  
Arousal Response ◽  
Muscle Unloading

Chemical respiratory stimuli can induce arousal from sleep, but the specific mechanisms involved have not been established. Therefore, we tested the hypothesis that mechanoreceptor stimuli arising in the ventilatory apparatus have a role in the arousal responses to progressive hypercapnia and hypoxia by comparing arousal responses during spontaneous ventilation with those obtained when the inspiratory muscles were unloaded by mechanical ventilatory assistance. Studies were performed in three trained dogs in which the adequacy of inspiratory muscle unloading was verified by diaphragmatic electromyographic (EMG) recordings. In rapid-eye-movement (REM) sleep the arousal threshold during progressive hypercapnia increased from 68.4 +/- 0.5 (SE) mmHg during spontaneous runs to 72.3 +/- 0.8 mmHg during mechanically assisted runs (P < 0.01). In contrast there were no changes in arousal responses to hypercapnia during non-REM (NREM) sleep or to hypoxia in either NREM or REM sleep. However, during the assisted hypoxic runs, EMG activity of the transversus abdominis muscle was increased compared with the unassisted runs; therefore, the effects on arousal threshold of unloading the inspiratory muscles may have been offset by increased loading of the expiratory muscles. The findings indicate that even in the absence of added mechanical loads, mechanoreceptor stimuli probably arising in the respiratory muscles contribute to the arousal response to hypercapnia during REM sleep.

Postinspiratory activity of costal and crural diaphragm

1999 ◽  
Vol 87 (2) ◽  
pp. 582-589 ◽  
Author(s):  
P. A. Easton ◽  
M. Katagiri ◽  
T. M. Kieser ◽  
R. S. Platt
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Emg Activity ◽  
Expiratory Time ◽  
Equivalent Length ◽  
Centroid Frequency ◽  
Inspiratory Activity ◽  
Crural Diaphragm ◽  
Emg Electrodes

Because the first stage of expiration or “postinspiration” is an active neurorespiratory event, we expect some persistence of diaphragm electromyogram (EMG) after the cessation of inspiratory airflow, as postinspiratory inspiratory activity (PIIA). The costal and crural segments of the mammalian diaphragm have different mechanical and proprioceptive characteristics, so postinspiratory activity of these two portions may be different. In six canines, we implanted chronically EMG electrodes and sonomicrometer transducers and then sampled EMG activity and length of costal and crural diaphragm segments at 4 kHz, 10.2 days after implantation during wakeful, resting breathing. Costal and crural EMG were reviewed on-screen, and duration of PIIA was calculated for each breath. Crural PIIA was present in nearly every breath, with mean duration 16% of expiratory time, compared with costal PIIA with duration −2.6% of expiratory time ( P < 0.002). A linear regression model of crural centroid frequency vs. length, which was computed during the active shortening of inspiration, did not accurately predict crural EMG centroid frequency values at equivalent length during the controlled relaxation of postinspiration. This difference in activation of crural diaphragm in inspiration and postinspiration is consistent with a different pattern of motor unit recruitment during PIIA.

Reflex effect of esophageal distension on respiratory muscle activity and pressure

1989 ◽  
Vol 66 (2) ◽  
pp. 536-541 ◽  
Author(s):  
A. Oliven ◽  
M. Haxhiu ◽  
S. G. Kelsen
Keyword(s):  
Motor Activity ◽  
Electrical Activity ◽  
Respiratory Muscle ◽  
Abdominal Cavity ◽  
Respiratory Muscles ◽  
Abdominal Pressure ◽  
Lung Inflation ◽  
Rib Cage ◽  
Expiratory Muscles ◽  
Crural Diaphragm

The electrical activity of the respiratory skeletal muscles is altered in response to reflexes originating in the gastrointestinal tract. The present study evaluated the reflex effects of esophageal distension (ED) on the distribution of motor activity to both inspiratory and expiratory muscles of the rib cage and abdomen and the resultant changes in thoracic and abdominal pressure during breathing. Studies were performed in 21 anesthetized spontaneously breathing dogs. ED was produced by inflating a balloon in the distal esophagus. ED decreased the activity of the costal and crural diaphragm and external intercostals and abolished all preexisting electrical activity in the expiratory muscles of the abdominal wall. On the other hand, ED increased the activity of the parasternal intercostals and expiratory muscles located in the rib cage (i.e., triangularis sterni and internal intercostal). All effects of ED were graded, with increasing distension exerting greater effects, and were eliminated by vagotomy. The effect of increases in chemical drive and lung inflation reflex activity on the response to ED was examined by performing ED while animals breathed either 6.5% CO2 or against graded levels of positive end-expiratory pressure (PEEP), respectively. Changes in respiratory muscle electrical activity induced by ED were similar (during 6.5% CO2 and PEEP) to those observed under control conditions. We conclude that activation of mechanoreceptors in the esophagus reflexly alters the distribution of motor activity to the respiratory muscles, inhibiting the muscles surrounding the abdominal cavity and augmenting the parasternals and expiratory muscles of the chest wall.

Variations in respiratory muscle activity during echolocation when stationary in three species of bat (Microchiroptera: Vespertilionidae)

2001 ◽  
Vol 204 (24) ◽  
pp. 4185-4197
Author(s):  
Winston C. Lancaster ◽  
J. R. Speakman
Keyword(s):  
Muscle Activity ◽  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Pteronotus Parnellii ◽  
Economic Production ◽  
Morphological Adaptations ◽  
The Family ◽  
Respiratory Muscle Activity

SUMMARY Echolocating bats use respiratory muscles to power the production of biosonar vocalisations. The physical characteristics of these calls vary among species of bat, and variations also exist in the timing and patterns of respiratory muscle recruitment during echolocation. We recorded electromyograms from the respiratory muscles of three species of bat (Family Vespertilionidae) while the animals vocalised from stationary positions. Activity was recorded consistently from the lateral abdominal muscles (internal abdominal oblique and transversus abdominis) from all calling bats, but we found much variation within and among species. Bats in the family Vespertilionidae devoted longer periods of expiratory muscle activity to each call than did the mormoopid bat Pteronotus parnellii. These differences correlate negatively with the duration of calls. We suggest that morphological adaptations in some bats may facilitate the economic production of echolocation calls at rest.

Costal and crural diaphragm function during CO2 rebreathing in awake dogs

1993 ◽  
Vol 74 (3) ◽  
pp. 1406-1418 ◽  
Author(s):  
P. A. Easton ◽  
J. W. Fitting ◽  
R. Arnoux ◽  
A. Guerraty ◽  
A. E. Grassino
Keyword(s):  
Inspiratory Flow ◽  
Emg Activity ◽  
Co2 Rebreathing ◽  
Diaphragm Function ◽  
Inspiratory Activity ◽  
Crural Diaphragm ◽  
Emg Electrodes ◽  
Segmental Function

If costal and crural diaphragm segments can perform as separate muscles, then CO2-stimulated ventilation may elicit differential segmental function. We studied diaphragm segmental length, shortening, and electromyogram (EMG) activity in 10 awake dogs chronically implanted with sonomicrometer transducers and EMG electrodes. During CO2 rebreathing, segmental shortening and EMG activity per whole tidal breath progressively increased, but segmental responses could not be differentiated at any level of CO2. With increasing CO2, resting end-expiratory length of both diaphragm segments increased. During the complete intrabreath inspiratory-expiratory cycle, costal and crural diaphragm revealed distinctive segmental function. At rest, crural shortening exceeded costal shortening in earliest inspiration, costal and especially crural shortening persisted into early expiration, and EMG activity of the crural segment was greater than that of the costal segment in earliest inspiration and showed more end-inspiratory/early expiratory [post-inspiratory inspiratory activity (PIIA)] activity. During CO2-stimulated breathing, neither segment shortened during the inspiratory flow of earliest inspiration. During CO2 rebreathing, shortening of the crural segment exceeded that of the costal segment during early inspiration and outlasted costal shortening during expiration; for both segments, shortening persisted after termination of inspiratory airflow. With increased CO2, EMG activity of the crural segment preceded that of the costal segment in earliest inspiration and was dominant into expiration, whereas costal EMG activity terminated abruptly with inspiratory flow. Thus, costal EMG PIIA was not evident during hypercapnia, whereas crural EMG PIIA was significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Costal and crural diaphragm function during panting in awake canines

1994 ◽  
Vol 77 (4) ◽  
pp. 1983-1990 ◽  
Author(s):  
P. A. Easton ◽  
T. Abe ◽  
R. N. Young ◽  
J. Smith ◽  
A. Guerraty ◽  
...  
Keyword(s):  
High Frequency ◽  
Minute Ventilation ◽  
Respiratory Muscles ◽  
Thermal Regulation ◽  
High Frequency Ventilation ◽  
Emg Activity ◽  
Dry Heat ◽  
Frequency Ventilation ◽  
Crural Diaphragm ◽  
Segmental Function

During natural panting for thermal regulation, the pattern of activation of the major respiratory muscles, including costal and crural diaphragm segments, is not known. We measured diaphragm segmental length, shortening, and electromyographic (EMG) activity in five chronically implanted canines awake and breathing spontaneously at rest and during a mild dry heat stress. During panting, minute ventilation increased fourfold from 5.07 l/min and respiratory rate increased from 16.9 to 192.8 breaths/min or 3.2 Hz. During panting, end-expiratory length of both costal and crural segments decreased, concurrent with significant increases in end-expiratory EMG. With the onset of panting, tidal costal shortening decreased significantly from 6.29% of end-expiratory length to 3.54%, whereas crural shortening decreased from 6.04 to 2.46%. Meanwhile, segmental EMG tended to increase during panting. During panting, intrabreath costal and crural segmental function revealed differential activation; the costal segment shortened in concert with inspiratory flow, whereas peak crural shortening occurred in expiration, almost 180 degrees out of phase with costal. The divergence in segmental shortening during panting was accompanied by a lesser shift in timing of segmental EMG. In the awake spontaneously panting canine, asynchronous costal and crural shortening may enhance gas mixing in a manner analogous to high-frequency ventilation.

Hyperinflation with intrinsic PEEP and respiratory muscle blood flow

1994 ◽  
Vol 77 (5) ◽  
pp. 2440-2448 ◽  
Author(s):  
Y. Kawagoe ◽  
S. Permutt ◽  
H. E. Fessler
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Fold Increase ◽  
Transversus Abdominis ◽  
Resistive Load ◽  
Transdiaphragmatic Pressure ◽  
Circulatory Effects ◽  
Inspiratory Work

Increased end-expiratory lung volume and intrinsic positive end-expiratory pressure (PEEP) are common in obstructive lung disease, especially during exacerbations or exercise. This loads the respiratory muscles and may also stress the circulatory system, causing a reduction or redistribution of cardiac output. We measured the blood flow to respiratory muscles and systemic organs using colored microspheres in 10 spontaneously breathing anesthetized tracheotomized dogs. Flows during baseline breathing (BL) were compared with those during hyperinflation (HI) induced by a mechanical analogue of airway closure and with those during an inspiratory resistive load (IR) that produced an equivalent increase in inspiratory work and time-integrated transdiaphragmatic pressure. Cardiac output was unchanged during IR (3.19 +/- 0.27 l/min at BL, 3.09 +/- 0.34 l/min during IR) but was reduced during HI (2.14 +/- 0.29 l/min; P < 0.01). Among the organs studied, flow was unaltered by IR but decreased to the liver and pancreas and increased to the brain during HI. For the respiratory muscles, flow to the diaphragm increased during IR. However, despite a 1.9-fold increase in inspiratory work per minute and a 2.5-fold increase in integrated transdiaphragmatic pressure during HI, blood flow to the diaphragm was unchanged and flow to the scalenes and sternomastoid fell. The only respiratory muscle to which flow increased during HI was the transversus abdominis, an expiratory muscle. We conclude that the circulatory effects of hyperinflation in this model impair inspiratory muscle perfusion and speculate that this may contribute to respiratory muscle dysfunction in hyperinflated states.

Respiratory Muscle Interaction

Physiology ◽  
1993 ◽  
Vol 8 (3) ◽  
pp. 121-124 ◽  
Author(s):  
M Decramer
Keyword(s):  
Chest Wall ◽  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Transversus Abdominis ◽  
Quiet Breathing ◽  
Expiratory Muscles

Breathing requires a coordinated contraction of different respiratory muscles. During quiet breathing in upright humans, the diaphragm, parasternal intercostals, and scalenes contract and interact to displace the chest wall along its relaxation line. The most important expiratory muscles, triangularis sterni and transversus abdominis, do not contribute to quiet breathing.

scholarly journals Differential respiratory muscle recruitment induced by clonidine in awake goats

1998 ◽  
Vol 84 (4) ◽  
pp. 1198-1207 ◽  
Author(s):  
Michael S. Hedrick ◽  
Melinda R. Dwinell ◽  
Patrick L. Janssen ◽  
Josue Pizarro ◽  
Gerald E. Bisgard
Keyword(s):  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Transversus Abdominis ◽  
Muscle Recruitment ◽  
Breathing Cycle ◽  
Peripheral Chemoreceptor ◽  
Inspiratory Muscles ◽  
Tonic Activation ◽  
Expiratory Muscles

The purpose of this study was to test the hypothesis that dysrhythmic breathing induced by the α2-agonist clonidine is accompanied by differential recruitment of respiratory muscles. In adult goats ( n = 14) electromyographic (EMG) measurements were made from inspiratory muscles (diaphragm and parasternal intercostal) and expiratory muscles [triangularis sterni (TS) and transversus abdominis (Abd)]. EMG of the thyroarytenoid (TA) muscle was used as an index of upper airway (glottal) patency. Peak EMG activities of all spinal inspiratory and expiratory muscles were augmented by central and peripheral chemoreceptor stimuli. Phasic TA was apparent in the postinspiratory phase of the breathing cycle under normoxic conditions. During dysrhythmic breathing episodes induced by clonidine, TS and Abd activities were attenuated or abolished, whereas diaphragm and parasternal intercostal activities were unchanged. There was no tonic activation of TS or Abd EMG during apneas; however, TA activity became tonic throughout the apnea. We conclude that 1) α2-adrenoceptor stimulation results in differential recruitment of respiratory muscles during respiratory dysrhythmias and 2) apneas are accompanied by active glottic closure in the awake goat.

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