Diaphragm length adjustments with body position changes in the awake dog

1989 ◽  
Vol 66 (2) ◽  
pp. 870-875 ◽  
Author(s):  
J. W. Fitting ◽  
P. A. Easton ◽  
R. Arnoux ◽  
A. Guerraty ◽  
A. Grassino

Sonomicrometry was used to measure end-expiratory length and tidal shortening of the costal and crural diaphragm in awake chronically instrumented dogs in the right lateral decubitus, standing, and sitting postures. End-expiratory length did not change significantly in standing but fell by 11.5% for the costal and by 14.4% for the crural segment in sitting, when compared with decubitus position. Tidal shortening of both segments did not change significantly in the three postures. From decubitus to sitting, diaphragmatic electromyogram (EMG) activity increased only in some dogs, not significantly for the group. The inspiratory swing of abdominal pressure was always positive in decubitus and negative in standing and sitting. In the latter two postures, abdominal pressure increased gradually during expiration and fell in inspiration, suggesting a phasic expiratory contraction of abdominal muscles. We conclude that diaphragmatic tidal shortening is maintained in the different postures assumed by the awake dog during resting breathing. It seems that the main compensatory mechanism for changes in diaphragmatic operational length is a phasic expiratory contraction of the abdominal muscles rather than an increase in diaphragmatic EMG activity.

2003 ◽  
Vol 95 (2) ◽  
pp. 810-817 ◽  
Author(s):  
M. Yokoba ◽  
H. G. Hawes ◽  
P. A. Easton

The geniohyoid (Genio) upper airway muscle shows phasic, inspiratory electrical activity in awake humans but no activity and lengthening in anesthetized cats. There is no information about the mechanical action of the Genio, including length and shortening, in any awake, nonanesthetized mammal during respiration (or swallowing). Therefore, we studied four canines, mean weight 28.8 kg, 1.5 days after Genio implantation with sonomicrometry transducers and bipolar electromyogram (EMG) electrodes. Awake recordings of breathing pattern, muscle length and shortening, and EMG activity were made with the animal in the right lateral decubitus position during quiet resting, CO2-stimulated breathing, inspiratory-resisted breathing (80 cmH2O · l-1 · s), and airway occlusion. Genio length and activity were also measured during swallowing, when it shortened, showing a 9.31% change from resting length, and its EMG activity increased 6.44 V. During resting breathing, there was no phasic Genio EMG activity at all, and Genio showed virtually no movement during inspiration. During CO2-stimulated breathing, Genio showed minimal lengthening of only 0.07% change from resting length, whereas phasic EMG activity was still absent. During inspiratory-resisted breathing and airway occlusion, Genio showed phasic EMG activity but still lengthened. We conclude that the Genio in awake, nonanesthetized canines shows active contraction and EMG activity only during swallowing. During quiet or stimulated breathing, Genio is electrically inactive with passive lengthening. Even against resistance, Genio is electrically active but still lengthens during inspiration.


Author(s):  
Kelser De Souza Kock ◽  
Camila Mendes Flor Paz ◽  
Cindy Maximiano Faraco ◽  
Fernando Rodrigues Onofre ◽  
Laís Bruna Ávila De Souza ◽  
...  

Introduction: Body position affects the respiratory mechanics and could be favorable to pulmonary function when combined with respiratory physiotherapy. Objective: Was to compare the ventilatory restriction in respiratory therapy techniques and changes of position. Method: For analysis of lung volume was measured Slow Vital Capacity (SVC) in university students in the positions: sitting, dorsal decubitus (DD), DD with application of maneuver thoracic blockade of the right hemithorax and right lateral decubitus (RLD). In all maneuvers were instructed to perform an inspiration to total lung capacity and slow exhalation to residual volume. Results: It was evaluated 26 subjects with a mean age of 25,5 ± 11 years and mean body mass index of 25 ± 4 kg/m2. The values obtained from SVC sitting, DD, DD with blockade and DLD were respectively 3,5 ± 1,5 liters (87,7 ± 26,8%); 2,9 ± 1,4 liters (75,0 ± 26,5%); 3,0 ± 1,4 liters (75,2 ± 26,2%); 3,5 ± 1,6 liters (88,3 ± 29,4%). Using the SVC in a sitting position as compared, there was no statistical difference in DD (p = 0,024) and DD with position blockade (p = 0,036). There was no significant difference in the DLD (p = 0,459) position. Conclusion: Can conclude that the positions DD and DD with blockade reduced lung volume, whereas DLD position showed no significant difference when compared to sitting position, suggesting that this position is an option favorable position for respiratory therapy.


1988 ◽  
Vol 65 (6) ◽  
pp. 2427-2433 ◽  
Author(s):  
G. A. Farkas ◽  
D. F. Rochester

To assess the characteristics and function of the muscles of the anterolateral abdominal wall, we have examined the isometric contractile properties of bundles of canine rectus abdominis (RA) and external oblique (EO) muscles. In addition, we have related the lengths of these muscles measured sonometrically in vivo at supine functional residual capacity (FRC) to in vitro optimal force-producing length (Lo). We also investigated the action of the abdominal muscles on the displacement of costal and crural diaphragm. We found that 1) contraction time of RA was longer and that the RA developed greater force than the EO at submaximal stimulation frequencies; 2) maximal tetanic force and the active length-tension curves were similar in both abdominal muscles; 3) on passive stretch, the compliance of the RA was one-third that of the EO; 4) at supine FRC, the EO is operating at 83% of Lo, whereas the RA is operating at 105% of Lo; 5) stimulation of either RA or EO (abdominal pressure of 15 cmH2O) lengthened the costal and crural diaphragm toward their Lo values, with greater crural excursion occurring than costal. We conclude that the RA is well suited for restraining the abdominal viscera in prone quadrupeds, whereas the EO is better designed to assist expiration. Stimulation of both muscles improves in situ diaphragmatic operating length.


2020 ◽  
Vol 1 (2) ◽  
pp. 112-120
Author(s):  
Senad Burak ◽  
Edin Begic ◽  
Nedim Begic ◽  
Faris Kadic

Background: Sedentary behavior carries the risk of musculoskeletal problems, especially in the lumbosacral region of the spinal column.  According to modern lifestyle, this has begun to be a public health issue. Objective: To point to the health risks of working at the computer and present an ergonomic analysis of the typical and improved position of workers in front of the computer, thereby reducing the chances of emergence occupational diseases. Results:  Changing the position of the subjects led to a change in lumbar pressure from 2,818 N/m2 to 351 N/m2. Software analysis of the changed position indicates that this position is acceptable, both for the lumosacral region of the spine and for the abdominal muscles. Conclusions:  A change in body position will decrease lumbar moment and the load on the lumbosacral region of the spine. Work chair with lumbar support, the right desk height, setting the appropriate position of the monitor, selecting the optimal keyboard and mouse, dividing the workspace into appropriate zones, as well as changing lifestyle and habits should be part of the management of people who spend most of their working time in a sitting position.


Neonatology ◽  
2020 ◽  
Vol 117 (4) ◽  
pp. 467-473
Author(s):  
Doris Cunha-Goncalves ◽  
Anders Nord ◽  
Federico Bianco ◽  
Fabrizio Salomone ◽  
Francesca Ricci ◽  
...  

<b><i>Introduction:</i></b> The ideal body position during surfactant nebulization is not known. <b><i>Objective:</i></b> The aim of this study was to determine whether body positioning during surfactant nebulization influences surfactant distribution and deposition in the lungs. <b><i>Methods:</i></b> Twenty-four 12- to 36-h-old full-term<b><i></i></b>piglets (1.3–2.2 kg) on nasal continuous positive airway pressure (nCPAP) were randomized into four groups: lateral decubitus with right or left side up, prone or supine positions (<i>n</i> = 6 each). All animals received 200 mg kg<sup>–1</sup> of poractant alfa mixed with 200 MBq of <sup>99m</sup>technetium-nanocolloid via a customized eFlow-Neos investigational vibrating-membrane nebulizer. Surfactant deposition (percentage of the administered dose) was measured by gamma scintigraphy. <b><i>Results:</i></b> Comparing all groups, the mean total lung surfactant deposition was significantly higher in the prone position (32.4 ± 7.7%, <i>p</i> = 0.03). The deposition in this group was higher in the right lung (21.0 ± 8.6 vs. 11.3 ± 5.7%, <i>p</i> = 0.04). When nebulization was performed in the lateral decubitus, most of the surfactant was found in the dependent lung, regardless of which side the piglet lay on (right side up 15.3 ± 1.0 vs. 3.4 ± 1.0%, <i>p</i> = 0.06, and left side up 11.2 ± 9.8 vs. 1.8 ± 0.7%, <i>p</i> = 0.04). <b><i>Conclusions:</i></b> In spontaneously breathing animals on nCPAP, the prone position yielded the highest lung dose. Higher deposition rates in the dependent lung while on lateral decubitus indicates that deposition was also influenced by gravity.


2017 ◽  
Vol 3 ◽  
pp. 233372141770807 ◽  
Author(s):  
Konosuke Sasaki ◽  
Mayu Haga ◽  
Sarina Bao ◽  
Haruka Sato ◽  
Yoshikatsu Saiki ◽  
...  

Objectives: The aim of this study was to evaluate the effect of the supine, left lateral decubitus, and right lateral decubitus positions on autonomic nervous activity in elderly adults by using spectral analysis of heart rate variability (HRV). Method: Forty-five adults aged 73.6 ± 5.7 years were enrolled. After lying in the supine position, all participants moved to the lateral decubitus positions in a random order and maintained the positions for 10 min, while electrocardiographic data were recorded to measure HRV. Results: The lowest heart rate continued for 10 min when participants were in the left lateral decubitus position compared with the other two positions ( p < .001), while the HRV indexes remained unchanged. The low-frequency HRV to high-frequency HRV ratio (LF/HF) for the right lateral decubitus position was significantly lower than that for the other positions. Discussion: The right lateral decubitus position may attenuate sympathetic nerve activity in elderly adults.


Author(s):  
Yi-Liang Kuo ◽  
Chieh-Yu Kao ◽  
Yi-Ju Tsai

The abdominal expansion (AE) strategy, involving eccentric contraction of the abdominal muscles, has been increasingly used in clinical practices; however, its effects have not been rigorously investigated. This study aimed to investigate the immediate effects of the AE versus abdominal drawing-in (AD) strategy on lumbar stabilization muscles in people with nonspecific low back pain (LBP). Thirty adults with nonspecific LBP performed the AE, AD, and natural breathing (NB) strategies in three different body positions. Ultrasonography and surface electromyography (EMG) were, respectively, used to measure the thickness and activity of the lumbar multifidus and lateral abdominal wall muscles. The AE and AD strategies showed similar effects, producing higher EMG activity in the lumbar multifidus and lateral abdominal wall muscles when compared with the NB strategy. All muscles showed higher EMG activity in the quiet and single leg standing positions than in the lying position. Although the AE and AD strategies had similar effects on the thickness change of the lumbar multifidus muscle, the results of thickness changes of the lateral abdominal muscles were relatively inconsistent. The AE strategy may be used as an alternative method to facilitate co-contraction of lumbar stabilization muscles and improve spinal stability in people with nonspecific LBP.


1982 ◽  
Vol 96 (1) ◽  
pp. 325-341
Author(s):  
MALCOLM BURROWS

Simultaneous intracellular recordings have been made from the two expiratory, and from the two inspiratory motor neurones which have their axons in the unpaired median nerves of the thoracic ganglia. Each motor neurone has an axon that branches to innervate muscles on the left and on the right side of one segment. The expiratory neurones studied were those in the meso- and meta-thoracic ganglia which innervate spiracular closer muscles. The depolarizing synaptic potentials underlying the spikes during expiration are common to the two closer motor neurones in a particular segment. Similarly, during inspiration when there are usually no spikes, the hyperpolarizing, inhibitory potentials are also common to both motor neurones. The synaptic input to the neurones can be derived from four interneurones; two responsible for the depolarizing potentials during expiration and two for the inhibitory potentials during inspiration. The inspiratory neurones studied were those in the abdominal ganglia fused to the metathoracic ganglion which innervate dorso-ventral abdominal muscles. During inspiration the two motor neurones of one segment spike at a similar and steady frequency. The underlying synaptic input to the two is common. During expiration, when there are usually no spikes, the hyperpolarizing synaptic potentials are also common to both neurones. In addition they match exactly the depolarizing potentials occurring at the same time in the closer motor neurones. The same set of interneurones could be responsible. No evidence has been revealed to indicate that the two closer, or the two inspiratory motor neurones of one segment are directly coupled by electrical or chemical synapses. The morphology of both types of motor neurone is distinct from that of other motor neurones in these ganglia. Both types branch extensively in both the left and in the right areas of the neuropile.


2018 ◽  
Vol 8 (6) ◽  
pp. 93
Author(s):  
Ghada Shalaby Khalaf Mahran ◽  
Sayed K. Abd-Elshafy ◽  
Manal Mohammed Abd El Neem ◽  
Jehan A. Sayed

Background and objective: Intra-abdominal hypertension (IAH) is a frequent plentiful problem in patients admitted to critical care units. It ranges from a surge incidence of morbidity and mortality to a particular need for nursing health care, so recognition of the occurrence of IAH is a very critical issue for critical care nurses and physician. This study aimed to recognize the effects of various body position with the various head of bed elevation on the intra-abdominal pressure (IAP) in patients with mechanical ventilation.Methods: Design: A non-randomized, prospective observational study was used. Setting: Trauma and general intensive care units at Assuit University Hospitals. Method: In a prospective observational study, during the third day of mechanical ventilation, 60 patients were screened for IAP via a urinary catheter, in two various body positions in three separate degrees of the head of the bed (HOB) elevation (0º, 15º, and 30º). The position was changed at least 4 hours apart over a 24-h period.Results: In lateral recumbence, IAP measurements were significantly elevated compared to supine position, they were 19.70 ± 3.09 mmHg versus 16.00 ± 3.14 (p < .001), 22.80 ± 3.56 mmHg versus 19.03 ± 2.95 (p < .001), and 26.08 ± 3.59 mmHg versus 21.46 ± 2.90 versus (p < .001) at 0º, 15º, and 30º respectively. The mean of IAP difference was 3.7 ± 3.0 mmHg at 0º, 3.8 ± 1.00 mmHg at 15º, and 5.5 ± 1.01 mmHg at 30 º (p < .005).Conclusions: IAP reading is significantly elevated by changing from supine to lateral position especially with HOB elevation and significantly correlated with mortality rate in patients with mechanical ventilation


1978 ◽  
Vol 45 (4) ◽  
pp. 581-589 ◽  
Author(s):  
V. P. Vellody ◽  
M. Nassery ◽  
W. S. Druz ◽  
J. T. Sharp

With a linearized respiratory magnetometer, measurements of anteroposterior and lateral diameters of both the rib cage and the abdomen were made at functional residual capacity and continuously during tidal breathing. Twenty-five subjects with normal respiratory systems were studied in the sitting, supine, lateral decubitus, and prone body positions. When subjects changed from sitting to supine position anteroposterior diameters of both rib cage and abdomen decreased while their lateral diameters increased. Both anteroposterior and lateral tidal excursions of the rib cage decreased; those of the abdomen increased. When subjects turned from supine to lateral decubitus position both anteroposterior diameters increased and the lateral diameters decreased. This was associated with an increase in both lateral excursions and a decrease in the abdominal anteroposterior excursions. Diameters and tidal excursions in the prone position resembled those in the supine position. Diameter changes could be explained by gravitational effects. Differences in tidal excursions accompanying body position change were probably related to 1) differences in the distribution of respiratory muscle force, 2) differences in the activity or mechanical advantage of various inspiratory muscles, and 3) local compliance changes in parts of the rib cage and abdomen.


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