Respiratory muscle responses to changes in chemoreceptor drive in infants

1990 ◽  
Vol 68 (3) ◽  
pp. 1041-1047 ◽  
Author(s):  
W. A. Carlo ◽  
J. M. DiFiore
Keyword(s):  
Preterm Infants ◽  
Respiratory Muscle ◽  
Muscle Activation ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Obstructive Apnea ◽  
Surface Electrodes ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles ◽  
Muscle Responses

Upper airway muscles and the diaphragm may have different quantitative responses to chemoreceptor stimulation. To compare the respiratory muscle responses to changes in CO2, 10 ventilator-dependent preterm infants (gestational age 28 +/- 1 wk, postnatal age 40 +/- 6 days, weight 1.4 +/- 0.1 kg) were passively hyperventilated to apnea and subsequently hypoventilated. Electromyograms from the genioglossus, alae nasi, posterior cricoarytenoid, and diaphragm were recorded from surface electrodes. Apneic CO2 thresholds of all upper airway muscles (genioglossus 46.8 +/- 4.3 Torr, alae nasi 42.4 +/- 3.6 Torr, posterior cricoarytenoid 41.6 +/- 3.2 Torr) were higher than those of the diaphragm (38.8 +/- 2.6 Torr, all P less than 0.05). Above their CO2 threshold levels, responses of all upper airway muscles appeared proportional to those of the diaphragm. We conclude that nonproportional responses of the respiratory muscles to hypercapnia may be the result of differences in their CO2 threshold. These differences in CO2 threshold may cause imbalance in respiratory muscle activation with changes in chemical drive, leading to upper airway instability and obstructive apnea.

Differences in CO2 threshold of respiratory muscles in preterm infants

1988 ◽  
Vol 65 (6) ◽  
pp. 2434-2439 ◽  
Author(s):  
W. A. Carlo ◽  
R. J. Martin ◽  
J. M. Difiore
Keyword(s):  
Preterm Infants ◽  
Minute Ventilation ◽  
Control Period ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Noninvasive Measurements ◽  
Co2 Rebreathing ◽  
Posterior Cricoarytenoid ◽  
End Tidal ◽  
End Tidal Co2

Because neonatal apnea is frequently associated with airway obstruction, we compared relative changes in activity between various upper airway muscles and the diaphragm during hypercapnic stimulation. The technique of hyperoxic CO2 rebreathing was employed in 17 healthy, sleeping preterm infants studied at a postnatal age of 32 +/- 12 days. Surface diaphragm (DIA) electromyograms (EMGs) were recorded in all infants, and noninvasive measurements of posterior cricoarytenoid (PCA), genioglossus (GG), and alae nasi (AN) EMGs were analyzed in 11, 9, and 8 infants, respectively. During the control period, consistent phasic EMGs were recorded from the DIA in all infants and from the PCA in 8 infants, but from the GG and AN each in only one infant. During CO2 rebreathing, minute ventilation and end-tidal CO2 increased linearly as CO2 rose from 31 +/- 5 to 51 +/- 5 Torr. DIA and PCA EMGs also had proportional and comparable increases throughout rebreathing. In contrast, both GG and AN responses differed from the DIA and PCA (P less than 0.001) and exhibited minimal or absent responses at low levels of hypercapnia. Consistent GG and AN EMGs appeared at comparable levels of end-tidal CO2 (47 +/- 5 and 45 +/- 5 Torr, respectively) and subsequently increased linearly in most infants. We conclude that during CO2 rebreathing the initially delayed and subsequently linear responses of the GG and AN EMGs indicate a high CO2 threshold for these muscles.

Upper airway muscle and diaphragm responses to hypoxia in the piglet

1990 ◽  
Vol 68 (2) ◽  
pp. 672-677 ◽  
Author(s):  
R. J. Martin ◽  
E. van Lunteren ◽  
M. A. Haxhiu ◽  
W. A. Carlo
Keyword(s):  
Muscle Activation ◽  
Upper Airway ◽  
Peripheral Chemoreceptor ◽  
Initial Transient ◽  
Central Inhibition ◽  
Muscle Groups ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles ◽  
Spontaneously Breathing ◽  
Ventilatory Response To Hypoxia

The neonatal ventilatory response to hypoxia is characterized by initial transient stimulation and subsequent respiratory depression. It is unknown, however, whether this response is also exhibited by the upper airway muscles that regulate nasal, laryngeal, and pharyngeal patency. We therefore compared electromyogram (EMG) amplitudes and minute EMGs for the diaphragm (DIA), alae nasi (AN), posterior cricoarytenoid (PCA), and genioglossus (GG) muscles in 12 anesthetized spontaneously breathing piglets during inhalation of 12% O2 over 10 min. Minute EMG for the DIA responded to hypoxia with an initial transient increase and subsequent return to prehypoxia levels by 10 min. Hypoxia also stimulated all three upper airway muscles. In contrast to the DIA EMG, however, AN, PCA, and GG EMGs all remained significantly above prehypoxia levels after 10 min of hypoxia. We have thus demonstrated that the initial stimulation and subsequent depression of the DIA EMG after 12% O2 inhalation contrast with the sustained increase in AN, PCA, and GG EMGs during hypoxia. We speculate that 1) central inhibition during neonatal hypoxia is primarily distributed to the motoneuron pools regulating DIA activation and 2) peripheral chemoreceptor stimulation and/or central disinhibition induced by hypoxia preferentially influence those motoneuron pools that regulate upper airway muscle activation, causing the different hypoxic responses of these muscle groups in the young piglet.

scholarly journals Ultrasonographic assessment of parasternal intercostal muscles during mechanical ventilation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paolo Formenti ◽  
Michele Umbrello ◽  
Martin Dres ◽  
Davide Chiumello
Keyword(s):  
Mechanical Ventilation ◽  
Ultrasound Imaging ◽  
Muscle Weakness ◽  
Respiratory Muscle ◽  
Muscle Activation ◽  
Invasive Mechanical Ventilation ◽  
Respiratory Muscles ◽  
Course Of Illness ◽  
Intercostal Muscles ◽  
Predictive Parameters

Abstract Although mechanical ventilation is a lifesaving treatment, abundant evidence indicates that its prolonged use (1 week or more) promotes respiratory muscle weakness due to both contractile dysfunction and atrophy. Along with the diaphragm, the intercostal muscles are one of the most important groups of respiratory muscles. In recent years, muscular ultrasound has become a useful bedside tool for the clinician to identify patients with respiratory muscle dysfunction related to critical illness and/or invasive mechanical ventilation. Images obtained over the course of illness can document changes in muscle dimension and can be used to estimate changes in function. Recent evidence suggests the clinical usefulness of ultrasound imaging in the assessment of intercostal muscle function. In this narrative review, we summarize the current literature on ultrasound imaging of the parasternal intercostal muscles as used to assess the extent of muscle activation and muscle weakness and its potential impact during discontinuation of mechanical ventilation. In addition, we proposed a practical flowchart based on recent evidence and experience of our group that can be applied during the weaning phase. This approach integrates multiple predictive parameters of weaning success with respiratory muscle ultrasound.

Force potentiation in respiratory muscles: comparison of diaphragm and sternohyoid

1993 ◽  
Vol 264 (6) ◽  
pp. R1095-R1100 ◽  
Author(s):  
E. Van Lunteren ◽  
H. Vafaie
Keyword(s):  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Rapid Onset ◽  
Force Frequency ◽  
Twitch Force ◽  
Twitch Potentiation ◽  
Early Portion ◽  
Frequency Relationship

Coordinated contraction of thoracic and pharyngeal upper airway respiratory muscles optimizes ventilation, whereas pharyngeal muscle dysfunction may lead to obstructive apneas during sleep. We hypothesized that the force potentiation exhibited by the pharyngeal respiratory muscle, the sternohyoid, in keeping with its faster contractile kinetics, would be greater than that of the thoracic respiratory muscle, the diaphragm. Rat muscles were studied in vitro at 37 degrees C with three force-potentiating protocols: posttetanic twitch potentiation, staircase phenomenon (twitch potentiation), and a classic fatigue paradigm. The sternohyoid had a faster isometric contraction time, a more rightward located force-frequency relationship, and both a more rapid onset and a greater degree of fatigue than the diaphragm. During the early portion of the fatigue protocols, the increase in force was significantly greater for the sternohyoid muscle than the diaphragm (e.g., 33 vs. 3% increase at 20 Hz, P < 0.005). During repetitive twitches at 2, 3, and 5 Hz (staircase test), sternohyoid muscle force increased more than diaphragm force at the higher stimulus frequencies (e.g., by 38 vs. 23% at 5 Hz, P < 0.01). After brief tetanic stimuli, sternohyoid twitch force increased more than diaphragm twitch force (e.g., 73 vs. 14% increase after 125 Hz tetanus, P < 0.005). These data indicate that force potentiation is exhibited by both diaphragm and sternohyoid respiratory muscles, but to different extents, when activated repetitively.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasal and laryngeal reflex responses to negative upper airway pressure

1984 ◽  
Vol 56 (3) ◽  
pp. 746-752 ◽  
Author(s):  
E. van Lunteren ◽  
W. B. Van de Graaff ◽  
D. M. Parker ◽  
J. Mitra ◽  
M. A. Haxhiu ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Moving Average ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Laryngeal Nerve ◽  
Topical Anesthesia ◽  
Inspiratory Activity ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles

The effects of negative pressure applied to just the upper airway on nasal and laryngeal muscle activity were studied in 14 spontaneously breathing anesthetized dogs. Moving average electromyograms were recorded from the alae nasi (AN) and posterior cricoarytenoid (PCA) muscles and compared with those of the genioglossus (GG) and diaphragm. The duration of inspiration and the length of inspiratory activity of all upper airway muscles was increased in a graded manner proportional to the amount of negative pressure applied. Phasic activation of upper airway muscles preceded inspiratory activity of the diaphragm under control conditions; upper airway negative pressure increased this amount of preactivation. Peak diaphragm activity was unchanged with negative pressure, although the rate of rise of muscle activity decreased. The average increases in peak upper airway muscle activity in response to all levels of negative pressure were 18 +/- 4% for the AN, 27 +/- 7% for the PCA, and 122 +/- 31% for the GG (P less than 0.001). Rates of rise of AN and PCA electrical activity increased at higher levels of negative pressure. Nasal negative pressure affected the AN more than the PCA, while laryngeal negative pressure had the opposite effect. The effects of nasal negative pressure could be abolished by topical anesthesia of the nasal passages, while the effects of laryngeal negative pressure could be abolished by either topical anesthesia of the larynx or section of the superior laryngeal nerve. Electrical stimulation of the superior laryngeal nerve caused depression of AN and PCA activity, and hence does not reproduce the effects of negative pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Differential effects of acute cerebellectomy on cough in spontaneously breathing cats

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253060
Author(s):  
M. Nicholas Musselwhite ◽  
Tabitha Y. Shen ◽  
Melanie J. Rose ◽  
Kimberly E. Iceman ◽  
Ivan Poliacek ◽  
...  
Keyword(s):  
Motor Behavior ◽  
Motor Pattern ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Esophageal Pressure ◽  
Adductor Muscle ◽  
Motor Drive ◽  
Mechanical Stimuli ◽  
Posterior Cricoarytenoid ◽  
Spontaneously Breathing

The role of the cerebellum in controlling the cough motor pattern is not well understood. We hypothesized that cerebellectomy would disinhibit motor drive to respiratory muscles during cough. Cough was induced by mechanical stimulation of the tracheobronchial airways in anesthetized, spontaneously breathing adult cats (8 male, 1 female), and electromyograms (EMGs) were recorded from upper airway, chest wall, and abdominal respiratory muscles. Cough trials were performed before and at two time points after total cerebellectomy (10 minutes and >1 hour). Unlike a prior report in paralyzed, decerebrated, and artificially ventilated animals, we observed that cerebellectomy had no effect on cough frequency. After cerebellectomy, thoracic inspiratory muscle EMG magnitudes increased during cough (diaphragm EMG increased by 14% at 10 minutes, p = 0.04; parasternal by 34% at 10 minutes and by 32% at >1 hour, p = 0.001 and 0.03 respectively). During cough at 10 minutes after cerebellectomy, inspiratory esophageal pressure was increased by 44% (p = 0.004), thyroarytenoid (laryngeal adductor) muscle EMG amplitude increased 13% (p = 0.04), and no change was observed in the posterior cricoarytenoid (laryngeal abductor) EMG. Cough phase durations did not change. Blood pressure and heart rate were reduced after cerebellectomy, and respiratory rate also decreased due to an increase in duration of the expiratory phase of breathing. Changes in cough-related EMG magnitudes of respiratory muscles suggest that the cerebellum exerts inhibitory control of cough motor drive, but not cough number or phase timing in response to mechanical stimuli in this model early after cerebellectomy. However, results varied widely at >1 hour after cerebellectomy, with some animals exhibiting enhancement or suppression of one or more components of the cough motor behavior. These results suggest that, while the cerebellum and behavior-related sensory feedback regulate cough, it may be difficult to predict the nature of the modulation based on total cerebellectomy.

Differential response of respiratory muscles to airway occlusion in infants

1985 ◽  
Vol 59 (3) ◽  
pp. 847-852 ◽  
Author(s):  
W. A. Carlo ◽  
M. J. Miller ◽  
R. J. Martin
Keyword(s):  
Total Duration ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Peak Amplitude ◽  
Emg Activity ◽  
Inspiratory Time ◽  
Surface Electrodes ◽  
Airway Occlusion ◽  
The Right ◽  
Respiratory Muscle Activity

The effect of end-expiratory occlusion on respiratory muscle activity was studied in 10 unsedated preterm infants during sleep. Electromyograms (EMG) of the upper airway were recorded from surface electrodes placed over the submental (SM) area; diaphragm (DIA) EMGs were obtained with identical electrodes over the right subcostal margin. Phasic SM EMG accompanied 56 +/- 36% of breaths during spontaneous breathing and increased to 80 +/- 26% (P less than 0.05) on the first inspiratory effort after occlusion. Occlusion increased peak amplitude (P less than 0.001) and total duration (P less than 0.005) of the SM EMG without significant changes in its initial rate of rise. In contrast, only the total duration of the DIA EMG increased (P less than 0.005) during occlusion. Inspiratory time increased from 470 +/- 120 to 720 +/- 210 ms (P less than 0.001) during the first occluded effort, but expiratory time did not change. With sustained occlusion, peak amplitude of the SM EMG progressively increased, but DIA EMG only significantly increased by the third occluded effort. Pharyngeal patency was invariably maintained throughout the induced airway occlusions. Sharp bursts of SM EMG activity coincided with resolution of spontaneous obstructive apneic episodes in four infants. The immediate increase in SM EMG associated with airway occlusion may be a mechanism that prevents the development of obstructive apnea.

Activation of upper airway muscles before onset of inspiration in normal humans

1980 ◽  
Vol 49 (4) ◽  
pp. 638-642 ◽  
Author(s):  
K. P. Strohl ◽  
M. J. Hensley ◽  
M. Hallett ◽  
N. A. Saunders ◽  
R. H. Ingram
Keyword(s):  
Animal Studies ◽  
Muscle Activation ◽  
Minute Ventilation ◽  
Upper Airway ◽  
Stage Ii ◽  
Direct Proportion ◽  
Co2 Levels ◽  
Normal Humans ◽  
Co2 Level ◽  
Upper Airway Muscles

Animal studies have shown activation of upper airway muscles prior to inspiratory efforts of the diaphragm. To investigate this sequence of activation in humans, we measured the electromyogram (EMG) of the alae nasi (AN) and compared the time of onset of EMG to the onset of inspiratory airflow, during wakefulness, stage II or III sleep (3 subj), and CO2-induced hyperpnea (6 subj). During wakefulness, the interval between AN EMG and airflow was 92 +/- 34 ms (mean +/- SE). At a CO2 level of greater than or equal to 43 Torr, the AN EMG to airflow was 316 +/- 38 ms (P < 0.001). During CO2-induced hyperpnea, the AN EMG to airflow interval and AN EMG magnitude increased in direct proportion to CO2 levels and minute ventilation. During stages II and III of sleep, the interval between AN EMG and airflow increased when compared to wakefulness (P < 0.005). We conclude that a sequence of inspiratory muscle activation is present in humans and is more apparent during sleep and during CO2-induced hyperpnea than during wakefulness.

Alae Nasi Activation (Nasal Flaring) Decreases Nasal Resistance in Preterm Infants

PEDIATRICS ◽  
1983 ◽  
Vol 72 (3) ◽  
pp. 338-343 ◽  
Author(s):  
Waldemar A. Carlo ◽  
Richard J. Martin ◽  
Eugene N. Bruce ◽  
Kingman P. Strohl ◽  
Avroy A. Fanaroff
Keyword(s):  
Pressure Drop ◽  
Preterm Infants ◽  
Upper Airway ◽  
Skin Surface ◽  
Nasal Resistance ◽  
Active Sleep ◽  
Quiet Sleep ◽  
Surface Electrodes ◽  
Pharyngeal Pressure ◽  
Nasal Pressure

The effect of alae nasi activation on nasal resistance in a group of healthy preterm infants was measured. Alae nasi activity was determined via the alae nasi electromyogram obtained from skin surface electrodes during both active and quiet sleep. Nasal resistance was calculated from airflow measured with a mask pneumotachograph and transnasal pressure drop obtained by simultaneous measurement of nasal pressure via a catheter inserted in one nostril and mask pressure. The percentage of breaths accompanied by phasic alae nasi activity was higher during active sleep than during quiet sleep (43% ± 10% v 14% ± 6%; P &lt; .005), and hypercapnic stimulation (4% CO2 inhalation) significantly increased the incidence of phasic alae nasi activity to comparable levels in both sleep states (82% ± 8% in active sleep and 82% ± 9% in quiet sleep). Elevation of tonic alae nasi activity also occurred more frequently during active sleep (P &lt; .05). The presence of either phasic or elevated tonic alae nasi activity decreased nasal resistance by 23% ± 4% during active sleep and 21% ± 3% during quiet sleep. This reduction in nasal resistance resulted in either a lower transnasal pressure during inspiration, a higher peak inspiratory airflow, or a combination of the two. Alae nasi activity may be an important mechanism that facilitates ventilation by reducing nasal resistance, and it may help stabilize the upper airway by preventing the development of large negative pharyngeal pressure during inspiration.

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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