Responses of Diaphragm and External Oblique Muscles to Flow-resistive Loads During Sleep

Abstract

Although it is generally agreed that rapid respiratory compensation for externally applied inspiratory loads is impaired or absent during sleep, the individual components of the "load-compensating reflex" may not be inhibited by sleep to the same degree. We studied the effect of inspiratory flow-resistive loading (18 cm H2O/L/s) for two consecutive breaths on inspiratory (diaphragm) and expiratory (external oblique) muscle activity, and respiratory timing, in six awake and sleeping goats. During the first loaded breath in the awake state, peak integrated diaphragmatic electromyogram activity (EMGdi) increased 16.7 +/- 3.9% (p less than 0.01), peak integrated external oblique EMG activity (EMGeo) increased 21.0 +/- 7.5% (p less than 0.001), and electrical inspiratory time (Ti) increased 18.1 +/- 2.1% (p less than 0.01). In contrast, loading did not significantly change peak EMGdi or EMGeo on the first or second breaths in any sleep state. However, Ti was significantly increased during loading in all sleep states (p less than 0.01) to a similar degree seen during wakefulness. Loading did not significantly alter electrical expiratory time. No significant differences were noted between the first and second loaded breaths. We conclude that the reflex increases in peak EMG of both inspiratory and expiratory muscles in response to inspiratory flow-resistive loading during the awake state are absent during all stages of sleep; however, one aspect of load compensation, prolongation of Ti, is preserved during sleep and aids in maintaining tidal volume.

The effect of tracheal occlusion on respiratory load compensation: Changes in neurons containing inhibitory neurotransmitter in the nucleus of the solitary tract in conscious rats

“…During occlusions, conscious rats did not respond to ITTO in the beginning of the occlusions (O1 and O2), but behaviorally increased their expiration only by O3 and then returned to normal breathing immediately after the removal of occlusions demonstrating that the load compensation response in conscious animals might be affected by consciousness and behavior. These results are different from previous studies (Calabrese et al, 1998; Forster et al, 1994; Hutt et al, 1991; Phillipson, 1974; Watts et al, 1997) that have only used single breath loads during one phase of breathing (inspiration or expiration) or one entire breath. However, in the present study, consecutive sustained respiratory loads to both inspiration and expiration were presented in conscious animals for up to 2–3 sec that could cause an aversive sensation.…”

“…behavior load compensation. In addition, ITTO was used to elicit load compensation responses in this study whereas previous studies used external respiratory loads to generate load compensation (Calabrese et al, 1998; Forster et al, 1994; Hutt et al, 1991; Phillipson, 1974; Watts et al, 1997). In fact, ITTO is a more appropriate method to simulate patients with respiratory obstructive diseases compared to external respiratory load since it reduces airflow intrinsically without changing lung compliance.…”

“…Conscious newborn lambs responded to a single expiratory load by dilating the larynx and prolonging Te, followed by a return to baseline during the post-load breath (Watts et al, 1997). Application of two consecutive external inspiratory loads to conscious goats caused prolonged Ti and augmented respiratory output during the two loaded breaths (Hutt et al, 1991). In awake ponies, sustained external inspiratory loads for 4 minutes resulted in an increase in Ti, decrease in Te and augmentation of diaphragm activity during the first loaded breath and only had minimal changes after first loaded breath (Forster et al, 1994).…”

Effects of Right Sidelying Respiratory Left Adductor Pull Back Exercise on Improving Hip Biomechanics in Participants With a Tendency to Stand on Right Side

“…When the large padding is placed between the ankle and the foot, it relaxes, inhibits, or lengthens the paraspinals, and induces left femoral internal rotation. The left posterior hip capsule and the ischiofemoral ligament are pushed even more into a lengthened position as a result of compensating for a left anterior internal chain arrangement [12,[24][25][26]. This active technique also guides the respiratory structures and pushes them into a mechanical advantage so that they can work efficiently.…”

Ventilatory neural drive in chronically hypercapnic patients with COPD: effects of sleep and nocturnal noninvasive ventilation

“…https://doi.org/10.1183/16000617.0069-2022 mechanism in murine models [78]. This hypercapnia-mediated increase in contractility may potentiate airways resistance and load in hypercapnic COPD patients, which in turn could further increase ventilatory drive through mechanosensory afferent pathways [79]. In addition, cellular and molecular changes within the diaphragm contribute to mechanical limitations in chronic hypercapnic respiratory failure.…”