Parasternal Intercostal, Costal and Crural Diaphragm Neural Activation During Hypercapnia

Author(s):  
Giovanni Tagliabue ◽  
Michael Sukjoon Ji ◽  
Jenny V. Suneby Jagers ◽  
Dan J. Zuege ◽  
John B. Kortbeek ◽  
...  

Background Parasternal intercostal is an obligatory inspiratory muscle working in coordination with the diaphragm, apparently sharing a common pathway of neural response. This similarity has attracted clinical interest, promoting parasternal as a non-invasive alternative to the diaphragm, to monitor central neural respiratory output. However, this role may be confounded by the distinct and different functions of costal and crural diaphragm. Given the anatomic location, parasternal activation may significantly impact chest wall via both mechanical shortening or as a "fixator" for the chest wall. Either mechanical function of parasternal may also impact differential function of costal and crural. Objectives During eupnea and hypercapnia, 1) compare the intensity of neural activation of parasternal, with costal and crural diaphragm; 2)examine parasternal recruitment and changes in mechanical action during progressive hypercapnia, including muscle baseline length and shortening. Methods In 30 spontaneously breathing canines, awake without confounding anesthetic, we measured directly both electrical activity of parasternal, costal, and crural diaphragm, and corresponding mechanical shortening of parasternal, during eupnea and hypercapnia. Results During eupnea and hypercapnia, parasternal and costal diaphragm share a similar intensity of neural activation, while both differ significantly from crural diaphragm activity. The shortening of parasternal increases significantly with hypercapnia, without change in baseline end-expiratory length. Conclusion Parasternal shares an equivalent intensity of neural activation with costal, but not crural, diaphragm. Parasternal maintains and increases its active inspiratory shortening during augmented ventilation, despite high levels of diaphragm recruitment. Throughout hypercapnic ventilation, parasternal contributes mechanically - it is not relegated to chest wall fixation.

2019 ◽  
Vol 126 (4) ◽  
pp. 1117-1128 ◽  
Author(s):  
Tetsunori Ikegami ◽  
Michael Ji ◽  
Naoyuki Fujimura ◽  
Jenny V. Suneby Jagers ◽  
Teresa M. Kieser ◽  
...  

In humans and other mammals, isocapnic hypoxia sustained for 20–60 min exhibits a biphasic ventilation pattern: initial increase followed by a significant ventilatory decline (“roll-off”) to a lesser intermediate plateau. During sustained hypoxia, the mechanical action and activity of the diaphragm have not been studied; thus we assessed diaphragm function in response to hypoxic breathing. Thirteen spontaneously breathing awake canines were exposed to moderate levels of sustained isocapnic hypoxia lasting 20–25 min (80 ± 2% pulse oximeter oxygen saturation). Breathing pattern and changes in muscle length and electromyogram (EMG) activity of the costal and crural diaphragm were continuously recorded. Mean tidal shortening and EMG activity of the costal and crural diaphragm exhibited an overall biphasic pattern, with initial brisk increase followed by a significant decline ( P < 0.01). Although costal and crural shortening did not differ significantly with sustained hypoxia, this equivalence in segmental shortening occurred despite distinct and differing EMG activities of the costal and crural segments. Specifically, initial hypoxia elicited a greater costal EMG activity compared with crural ( P < 0.05), whereas sustained hypoxia resulted in a lesser crural EMG decline/attenuation than costal ( P < 0.05). We conclude that sustained isocapnic hypoxia elicits a biphasic response in both ventilation and diaphragmatic function and there is clear differential activation and contribution of the two diaphragmatic segments. This different diaphragm segmental action is consistent with greater neural activation of costal diaphragm during initial hypoxia, then preferential sparing of crural activation as hypoxia is sustained. NEW & NOTEWORTHY In humans and other mammals, during isocapnic hypoxia sustained for 20–60 min ventilation exhibits a biphasic pattern: initial increase followed by significant ventilatory decline (“roll-off”). During sustained hypoxia, the function of the diaphragm is unknown. This study demonstrates that the diaphragm reveals a biphasic action during the time-dependent hypoxic “roll-off” in ventilation. These results also highlight that the two diaphragm segments, costal and crural, show differing, distinctive contributions to diaphragm function during sustained hypoxia.


1985 ◽  
Vol 58 (4) ◽  
pp. 1157-1163 ◽  
Author(s):  
D. Gross ◽  
A. Zidulka ◽  
C. O'Brien ◽  
D. Wight ◽  
R. Fraser ◽  
...  

We investigated the effects of high-frequency chest wall compression (HFCWC) on peripheral and tracheal mucus clearance in anesthetized spontaneously breathing dogs. HFCWC was achieved by oscillating the pressure in a thoracic cuff with a piston pump. Regional lung retention of a technetium-99m sulfur colloid aerosol was monitored with a gamma camera. A peripheral mucus clearance index (PMCI) was defined for each region of interest. The tracheal mucus clearance rate (TMCR) was determined by bronchoscopic visualization of marker particle transport. Phase I: In seven dogs, 30 min of HFCWC at 13 Hz with peak cuff pressure (Pcuff) 100–120 cmH2O was found to significantly enhance PMCI in regions immediately under the cuff. (delta PMCI = 24.4 +/- 4.6 in the basal peripheral region.) Phase II: Because of subpleural hemorrhage in phase I, the effect of HFCWC on TMCR at various Pcuff levels was studied in five dogs. The enhancement of TMCR by HFCWC reached a plateau level at Pcuff = 50 cmH2O. Phase III: HFCWC at 13 Hz with Pcuff = 50–60 cmH2O was found to significantly enhance PMCI in five dogs without the consequence of hemorrhage. Correlations were found between the enhancement of PMCI and TMCR by HFCWC. These results demonstrate that HFCWC is effective in enhancing both peripheral and central mucus clearance in dogs and safe when moderate pressures are applied.


1990 ◽  
Vol 69 (2) ◽  
pp. 438-442 ◽  
Author(s):  
D. Negrini ◽  
M. I. Townsley ◽  
A. E. Taylor

The hydraulic conductivity (Lp) of the parietal pleura was measured in vivo in spontaneously breathing anesthetized dogs in either the supine (n = 8) or the prone (n = 7) position and in an excised portion of the chest wall in which the pleura and its adjacent tissue were intact (n = 3). A capsule was glued to the exposed parietal pleura after the intercostal muscles were removed. The capsule was filled with either autologous plasma or isotonic saline. Transpleural fluid flow (V) was measured at several transpleural hydrostatic pressures (delta P) from the rate of meniscus movement within a graduated pipette connected to the capsule. Delta P was defined as the measured difference between capsule and pleural liquid pressures. The Lp of the parietal pleura was calculated from the slope of the line relating V to delta P by use of linear regression analysis. Lp in vivo averaged 1.36 X 10(-3) +/- 0.45 X 10(-3) (SD) ml.h-1.cmH2O-1.cm-2, regardless of whether the capsule was filled with plasma or saline and irrespective of body position. This value was not significantly different from that measured in the excised chest wall preparation (1.43 X 10(-3) +/- 1.1 X 10(-3) ml.h-1.cmH2O-1.cm-2). The parietal pleura offers little resistance to transpleural protein movement, because there was no observed difference between plasma and saline. We conclude that because the Lp for intact parietal pleura and extrapleural interstitium is approximately 100 times smaller than that previously measured in isolated stripped pleural preparations, removal of parietal pleural results in a damaged preparation.


2017 ◽  
Vol 11 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Wilfredo De Jesus Rojas ◽  
Cheryl L. Samuels ◽  
Traci R. Gonzales ◽  
Katrina E. McBeth ◽  
Aravind Yadav ◽  
...  

Background: Nasal non-invasive-ventilation (Nasal NIV) is a mode of ventilatory support providing positive pressure to patients via a nasal interface. The RAM Cannula is an oxygen delivery device that can be used as an alternative approach to deliver positive pressure. Together they have been successfully used to provide respiratory support in neonatal in-patient settings. Objective: To describe the outpatient use of Nasal NIV/RAM Cannula as a feasible alternative for home respiratory support in children with chronic respiratory failure. Methods: We performed a retrospective case series of 18 children (4 months to 19 years old) using the Nasal NIV/RAM Cannula in the Pediatric Pulmonary Clinic at the McGovern Medical School, UTHealth (2014-16). Consideration for Nasal NIV/RAM Cannula utilization included: inability to wean-off in-patient respiratory support, comfort for dyspnea, intolerability of conventional mask interfaces and tracheostomy avoidance. Results: Average age was 7 years. 50% were Caucasian, 38% African-American and 11% Hispanics. Pulmonary disorders included: chest wall weakness (38%), central control abnormalities (33%), obstructive lung disease (16%) and restrictive lung disease (11%). Indications for Nasal NIV/RAM Cannula initiation included: CPAP/BPAP masks intolerability (11%), dyspnea secondary to chest wall weakness (38%) and tracheostomy avoidance (50%). Average length of use of Nasal NIV/RAM Cannula was 8.4 months. Successful implementation of Nasal NIV/Ram Cannula was 94%. One patient required a tracheostomy following the use of Nasal NIV/RAM Cannula. Significant decrease in arterial PaCO2 pre and post Nasal NIV/RAM cannula initiation was notable (p=0.001). Conclusion: Outpatient use of Nasal NIV/RAM Cannula may prove to be a feasible and save treatment alternative for children with chronic respiratory failure, chest wall weakness, dyspnea and traditional nasal/face mask intolerance to avoid tracheostomy.


1989 ◽  
Vol 67 (2) ◽  
pp. 655-662 ◽  
Author(s):  
J. Sprung ◽  
C. Deschamps ◽  
R. D. Hubmayr ◽  
B. J. Walters ◽  
J. R. Rodarte

A biplane videofluorographic system was used to track the position of metallic markers affixed to the abdominal surface of the left hemidiaphragm in supine anesthetized dogs. Regional shortening was determined from intermarker distances of rows of markers placed along muscle bundles in the ventral, middle, and dorsal regions of the costal diaphragm and of one row on the crural diaphragm. Considerable variability of regional shortening was seen in a given row, which was reproducible on repeat study in individual dogs but which differed between mechanical ventilation and spontaneous breathing. There were no consistent patterns among dogs. Regional shortening obtained from the change in length of rows extending from chest wall to central tendon showed no consistent differences among dogs during spontaneous breathing. At equal tidal volumes, all regions (except the ventral costal diaphragm) shortened more during spontaneous breathing than during mechanical ventilation.


2019 ◽  
Vol 8 (9) ◽  
pp. 1387 ◽  
Author(s):  
Marta Delsoglio ◽  
Najate Achamrah ◽  
Mette M. Berger ◽  
Claude Pichard

Indirect calorimetry (IC) is considered as the gold standard to determine energy expenditure, by measuring pulmonary gas exchanges. It is a non-invasive technique that allows clinicians to personalize the prescription of nutrition support to the metabolic needs and promote a better clinical outcome. Recent technical developments allow accurate and easy IC measurements in spontaneously breathing patients as well as in those on mechanical ventilation. The implementation of IC in clinical routine should be promoted in order to optimize the cost–benefit balance of nutrition therapy. This review aims at summarizing the latest innovations of IC as well as the clinical indications, benefits, and limitations.


2018 ◽  
Vol 40 (2) ◽  
pp. 298-313 ◽  
Author(s):  
Karishma Chhabria ◽  
Karen Plant ◽  
Oliver Bandmann ◽  
Robert N Wilkinson ◽  
Chris Martin ◽  
...  

Neurovascular coupling (through which local cerebral blood flow changes in response to neural activation are mediated) is impaired in many diseases including diabetes. Current preclinical rodent models of neurovascular coupling rely on invasive surgery and instrumentation, but transgenic zebrafish coupled with advances in imaging techniques allow non-invasive quantification of cerebrovascular anatomy, neural activation, and cerebral vessel haemodynamics. We therefore established a novel non-invasive, non-anaesthetised zebrafish larval model of neurovascular coupling, in which visual stimulus evokes neuronal activation in the optic tectum that is associated with a specific increase in red blood cell speed in tectal blood vessels. We applied this model to the examination of the effect of glucose exposure on cerebrovascular patterning and neurovascular coupling. We found that chronic exposure of zebrafish to glucose impaired tectal blood vessel patterning and neurovascular coupling. The nitric oxide donor sodium nitroprusside rescued all these adverse effects of glucose exposure on cerebrovascular patterning and function. Our results establish the first non-mammalian model of neurovascular coupling, offering the potential to perform more rapid genetic modifications and high-throughput screening than is currently possible using rodents. Furthermore, using this zebrafish model, we reveal a potential strategy to ameliorate the effects of hyperglycemia on cerebrovascular function.


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