Oxygen cost of resistive-loaded breathing in quadriplegia

1992 ◽  
Vol 73 (3) ◽  
pp. 825-831 ◽  
Author(s):  
H. Manning ◽  
F. D. McCool ◽  
S. M. Scharf ◽  
E. Garshick ◽  
R. Brown
Keyword(s):  
Chest Wall ◽  
Energy Cost ◽  
Regression Line ◽  
Normal Subjects ◽  
Oxygen Cost ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Residual Capacity ◽  
Loaded Breathing ◽  
The Mean

We hypothesized that, in quadriplegia, chest wall distortion would increase the energy cost of ventilation. To assess this, we measured the oxygen cost of breathing (VO2 resp) and changes in chest wall configuration during inspiratory resistive-loaded breathing tasks in five quadriplegic and five normal subjects. Each subject performed three breathing tasks that spanned a range of work rates (Wtot). Configurational changes of the abdomen and upper, lower, and transverse rib cage were assessed with magnetometers. We found that 1) in both groups, VO2resp increased linearly with Wtot over the range of tasks performed, 2) the mean slope of the regression line of VO2resp vs. Wtot was greater for quadriplegic than for normal subjects (3.7 +/- 0.8 vs. 2.0 +/- 0.7 ml O2/J, P less than 0.01), 3) efficiency of breathing (Wtot/VO2resp) was less for quadriplegic than for normal subjects (1.9 +/- 0.6 vs. 3.5 +/- 1.4%, P less than 0.001), 4) during inhalation, upper and lower rib cages behaved similarly in the two groups, but the quadriplegic subjects had a decrease in transverse rib cage and a much greater increase in abdomen than normal subjects, and 5) functional residual capacity decreased in normal but not in quadriplegic subjects during the breathing tasks. We conclude that the lesser efficiency of breathing in quadriplegia may be related to the elastic work of chest wall distortion, shorter mean operational diaphragm length, and possibly differences between normal and quadriplegic subjects in mechanical advantage of available inspiratory muscles.

Dissociation between diaphragmatic and rib cage muscle fatigue

1988 ◽  
Vol 64 (3) ◽  
pp. 959-965 ◽  
Author(s):  
J. W. Fitting ◽  
T. D. Bradley ◽  
P. A. Easton ◽  
M. J. Lincoln ◽  
M. D. Goldman ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Normal Subjects ◽  
Breathing Patterns ◽  
Recruitment Pattern ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Resistive Breathing ◽  
Emg Power Spectrum ◽  
The Mean ◽  
Substantial Degree

To assess rib cage muscle fatigue and its relationship to diaphragmatic fatigue, we recorded the electromyogram (EMG) of the parasternal intercostals (PS), sternocleidomastoid (SM), and platysma with fine wire electrodes and the EMG of the diaphragm (DI) with an esophageal electrode. Six normal subjects were studied during inspiratory resistive breathing. Two different breathing patterns were imposed: mainly diaphragmatic or mainly rib cage breathing. The development of fatigue was assessed by analysis of the high-to-low (H/L) ratio of the EMG. To determine the appropriate frequency bands for the PS and SM, we established their EMG power spectrum by Fourier analysis. The mean and SD for the centroid frequency was 312 ± 16 Hz for PS and 244 ± 48 Hz for SM. When breathing with the diaphragmatic patterns, all subjects showed a fall in H/L of the DI and none had a fall in H/L of the PS or SM. During rib cage emphasis, four out of five subjects showed a fall in H/L of the PS and five out of six showed a fall in H/L of the SM. Four subjects showed no fall in H/L of the DI; the other two subjects were unable to inhibit diaphragm activity to a substantial degree and did show a fall in H/L of the DI. Activity of the platysma was minimal or absent during diaphragmatic emphasis but was usually strong during rib cage breathing. We conclude that fatigue of either the diaphragm or the parasternal and sternocleidomastoid can occur independently according to the recruitment pattern of inspiratory muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Human Chest Wall Function during Epidural Anesthesia

1996 ◽  
Vol 85 (4) ◽  
pp. 761-773 ◽  
Author(s):  
David O. Warner ◽  
Mark A. Warner ◽  
Erik L. Ritman
Keyword(s):  
Chest Wall ◽  
Functional Residual Capacity ◽  
Muscle Activity ◽  
Respiratory Muscle ◽  
Sensory Level ◽  
Wall Function ◽  
Rib Cage ◽  
Residual Capacity ◽  
The Mean ◽  
Respiratory Muscle Activity

Background Although epidural anesthesia (EA) can significantly disrupt the function of the respiratory system, data concerning its effects on respiratory muscle activity and the resulting motion of the chest wall are scarce. This study aimed to determine the effects of lumbar EA on human chest wall function during quiet breathing. Methods Six persons were studied while awake and during mid-thoracic (approximately a T6 sensory level) and high (approximately a T1 sensory level) lumbar EA produced by either 2% lidocaine (two persons) or 1.5% etidocaine (four persons) with 1:200,000 epinephrine. Respiratory muscle activity was measured using fine-wire electromyography electrodes. Chest wall configuration during high EA was determined using images of the thorax obtained by three-dimensional, fast computed tomography. The functional residual capacity was measured using a nitrogen dilution technique. Results High EA abolished activity in the parasternal intercostal muscles of every participant but one, whereas the mean phasic activity of the scalene muscles was unchanged. High EA significantly decreased the inspiratory volume displacement of the rib cage compared with intact breathing but did not have a significant effect on diaphragm displacement. Therefore, high EA decreased the percentage contribution of rib cage expansion to inspiratory increases in thoracic volume (delta Vth) (from 27 +/- 2 [MSE] to 10 +/- 11% of delta Vth). Paradoxic rib cage motion during inspiration (i.e., a net inward motion during inspiration) developed in only one participant. High EA substantially increased the functional residual capacity (by 295 +/- 89 ml), with a significant net caudad motion of the end expiratory position of the diaphragm. In addition, high EA significantly decreased the volume of liquid in the thorax at end expiration in five of the six participants, a factor that also contributed to the increase in functional residual capacity in these persons. Conclusions Rib cage expansion continues to contribute to tidal volume during high EA in most subjects, even when most of the muscles of the rib cage are paralyzed; the mean phasic electrical activity of unblocked respiratory muscles such as scalenes does not increase in response to rib cage muscle paralysis produced by EA; and high EA increases the functional residual capacity, an increase produced in most participants by a caudad motion of the diaphragm and a decrease in intrathoracic blood volume.

Triangularis sterni muscle use in supine humans

1987 ◽  
Vol 62 (3) ◽  
pp. 919-925 ◽  
Author(s):  
A. De Troyer ◽  
V. Ninane ◽  
J. J. Gilmartin ◽  
C. Lemerre ◽  
M. Estenne
Keyword(s):  
Normal Subjects ◽  
Abdominal Muscle ◽  
Abdominal Muscles ◽  
Neural Activation ◽  
Trained Subjects ◽  
Rib Cage ◽  
Residual Capacity ◽  
External Oblique ◽  
Head Flexion ◽  
Static Head

The electrical activity of the triangularis sterni (transversus thoracis) muscle was studied in supine humans during resting breathing and a variety of respiratory and nonrespiratory maneuvers known to bring the abdominal muscles into action. Twelve normal subjects, of whom seven were uninformed and untrained, were investigated. The electromyogram of the triangularis sterni was recorded using a concentric needle electrode, and it was compared with the electromyograms of the abdominal (external oblique and rectus abdominis) muscles. The triangularis sterni was usually silent during resting breathing. In contrast, the muscle was invariably activated during expiration from functional residual capacity, expulsive maneuvers, “belly-in” isovolume maneuvers, static head flexion and trunk rotation, and spontaneous events such as speech, coughing, and laughter. When three trained subjects expired voluntarily with considerable recruitment of the triangularis sterni and no abdominal muscle activity, rib cage volume decreased and abdominal volume increased. These results indicate that unlike in the dog, spontaneous quiet expiration in supine humans is essentially a passive process; the human triangularis sterni, however, is a primary muscle of expiration; and its neural activation is largely coupled with that of the abdominals. The triangularis sterni probably contributes to the deflation of the rib cage during active expiration.

Effects of body position change on thoracoabdominal motion

1978 ◽  
Vol 45 (4) ◽  
pp. 581-589 ◽  
Author(s):  
V. P. Vellody ◽  
M. Nassery ◽  
W. S. Druz ◽  
J. T. Sharp
Keyword(s):  
Supine Position ◽  
Muscle Force ◽  
Body Position ◽  
Tidal Breathing ◽  
Position Change ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Residual Capacity ◽  
Lateral Decubitus ◽  
Local Compliance

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.

Inspiratory muscles during exercise: a problem of supply and demand

1988 ◽  
Vol 64 (6) ◽  
pp. 2482-2489 ◽  
Author(s):  
P. Leblanc ◽  
E. Summers ◽  
M. D. Inman ◽  
N. L. Jones ◽  
E. J. Campbell ◽  
...  
Keyword(s):  
Lung Volume ◽  
Static Pressure ◽  
Total Lung Capacity ◽  
Supply And Demand ◽  
Normal Subjects ◽  
Esophageal Pressure ◽  
Maximum Exercise ◽  
Lung Capacity ◽  
Inspiratory Muscles ◽  
Residual Capacity

The capacity of inspiratory muscles to generate esophageal pressure at several lung volumes from functional residual capacity (FRC) to total lung capacity (TLC) and several flow rates from zero to maximal flow was measured in five normal subjects. Static capacity was 126 +/- 14.6 cmH2O at FRC, remained unchanged between 30 and 55% TLC, and decreased to 40 +/- 6.8 cmH2O at TLC. Dynamic capacity declined by a further 5.0 +/- 0.35% from the static pressure at any given lung volume for every liter per second increase in inspiratory flow. The subjects underwent progressive incremental exercise to maximum power and achieved 1,800 +/- 45 kpm/min and maximum O2 uptake of 3,518 +/- 222 ml/min. During exercise peak esophageal pressure increased from 9.4 +/- 1.81 to 38.2 +/- 5.70 cmH2O and end-inspiratory esophageal pressure increased from 7.8 +/- 0.52 to 22.5 +/- 2.03 cmH2O from rest to maximum exercise. Because the estimated capacity available to meet these demands is critically dependent on end-inspiratory lung volume, the changes in lung volume during exercise were measured in three of the subjects using He dilution. End-expiratory volume was 52.3 +/- 2.42% TLC at rest and 38.5 +/- 0.79% TLC at maximum exercise.

Changes in lung volume and rib cage configuration with abdominal binding in quadriplegia

1986 ◽  
Vol 60 (4) ◽  
pp. 1198-1202 ◽  
Author(s):  
F. D. McCool ◽  
B. M. Pichurko ◽  
A. S. Slutsky ◽  
M. Sarkarati ◽  
A. Rossier ◽  
...  
Keyword(s):  
Total Lung Capacity ◽  
Normal Subjects ◽  
Tidal Range ◽  
Dilution Technique ◽  
Inspiratory Capacity ◽  
Rib Cage ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Helium Dilution ◽  
Combined Data

Previous studies suggest that abdominal binding may affect the interaction of the rib cage and the diaphragm over the tidal range of breathing in quadriplegia. To determine whether abdominal binding influences rib cage motion over the entire range of inspiratory capacity, we used spirometry and the helium-dilution technique to measure functional residual capacity (FRC), inspiratory capacity, and total lung capacity (TLC) in eight quadriplegic and five normal subjects in supine, tilted (37 degrees), and seated positions. Combined data in all three positions indicated that, with abdominal binding, FRC and TLC decreased in normal subjects [delta FRC = -0.33 + 0.151 (SD) P less than 0.01); delta TLC = -0.16 + 0.121, P less than 0.05]. In quadriplegia there was also a reduction in FRC with binding (delta FRC = -0.32 + 0.101, P less than 0.001). However, TLC increased in quadriplegia (delta TLC = 0.07 + 0.061, P less than 0.025). In an additional six quadriplegic and five normal subjects, we used magnetometers to define the influences of abdominal binding on rib cage dimensions and TLC. In quadriplegia, rib cage dimensions were increased at TLC with abdominal binding, whereas there was no change in normals. Our data suggest that this inspiratory effect of abdominal binding on augmenting rib cage volume in quadriplegia is greater than the effect of impeding diaphragm descent, and thus abdominal binding produces a net increase in TLC in quadriplegia.

Effect of thoracoabdominal breathing patterns on inspiratory effort sensation

1987 ◽  
Vol 62 (4) ◽  
pp. 1665-1670 ◽  
Author(s):  
J. W. Fitting ◽  
D. A. Chartrand ◽  
T. D. Bradley ◽  
K. J. Killian ◽  
A. Grassino
Keyword(s):  
Normal Subjects ◽  
Motor Command ◽  
Esophageal Pressure ◽  
Inspiratory Effort ◽  
Breathing Patterns ◽  
Borg Scale ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Main Variable ◽  
Unique Relationship

The respiratory sensations evoked by added inspiratory loads are currently thought to be largely mediated by the activity of the inspiratory muscles. Because of the differences in proprioceptors and in afferent and efferent innervations among the inspiratory muscles, we hypothesized that the sensation evoked by a given load would be different when the motor command is directed mainly to rib cage muscles or mainly to the diaphragm. To test this hypothesis, we studied six normal subjects breathing against several inspiratory resistances while emphasizing the use of rib cage muscles, or the diaphragm, or a combination of both. At the end of 10 loaded breaths the subjects rated the perceived magnitude of inspiratory effort on a Borg scale. A linear and unique relationship (r = 0.96 +/- 0.02; P less than 0.001) was found between the sensation and esophageal pressure (Pes) in the three thoracoabdominal breathing patterns. We conclude that the level of Pes, whether generated mainly by the rib cage muscles or the diaphragm, is the main variable related to the sensation of inspiratory effort under external inspiratory loads.

Importance of inspiratory muscle tone in maintenance of FRC in the newborn

1981 ◽  
Vol 51 (4) ◽  
pp. 830-834 ◽  
Author(s):  
J. Lopes ◽  
N. L. Muller ◽  
M. H. Bryan ◽  
A. C. Bryan
Keyword(s):  
Muscle Tone ◽  
Inspiratory Muscle ◽  
Rapid Eye Movement Sleep ◽  
Sleep State ◽  
Quiet Sleep ◽  
Rib Cage ◽  
Surface Electrodes ◽  
Inspiratory Muscles ◽  
Residual Capacity ◽  
Behavioral Criteria

The importance of inspiratory muscle tone in the maintenance of functional residual capacity (FRC) in newborns was studied in eight premature infants with birth weights of 1,166 +/- 217 g and gestational age 29 +/- 1.9 wk (mean +/- SD). Rib cage and abdominal anteroposterior diameters were monitored with magnetometers, and electromyograms of the diaphragm and intercostal muscles were recorded with surface electrodes. Sleep state was monitored using electrooculogram and behavioral criteria. We assessed the decrease in tonic activity of the inspiratory muscles and the fall in end-expiratory lung volume during apnea compared with the period just preceding apnea. A total of 98 apneas were analyzed. In all instances a decrease in diaphragmatic and intercostal tone was associated with a decrease in the anteroposterior diameter of both rib cage and abdomen, indicating a fall in FRC. These changes were more marked during quiet sleep than during rapid-eye-movement sleep (P less than 0.01). Our results suggest that inspiratory muscle tone is a major determinant of FRC in the newborn.

Breathing Patterns and Regional Ventilation Distribution in Tetraplegic Patients and in Normal Subjects

1972 ◽  
Vol 42 (2) ◽  
pp. 117-128 ◽  
Author(s):  
B. Bake ◽  
A. R. Fugl-Meyer ◽  
G. Grimby
Keyword(s):  
Tidal Volume ◽  
Cervical Spinal Cord ◽  
Regional Distribution ◽  
Normal Subjects ◽  
Airway Disease ◽  
Breathing Patterns ◽  
Rib Cage ◽  
Small Airway Disease ◽  
Residual Capacity ◽  
Traumatic Transection

1. The regional distribution of ventilation was studied with 133Xe techniques in the sitting position in six patients with complete traumatic transection of the cervical spinal cord, 3–40 months after the lesion, and in four normal subjects. The relative contributions of the rib cage and abdomen to ventilation were determined from chest-wall motions. 2. Total lung capacity (TLC) was decreased and residual volume increased in the patients. After correction for the decreased TLC, the distribution of the regional functional residual capacity in the tetraplegic patients was similar to that of the normal subjects. In the patients, where the abdomen contributed to about half of the tidal volume, decreased ventilation of basal regions was demonstrated from measurements of regional tidal volumes (Vtr) and regional 133Xe wash-in curves. 3. The distribution of ventilation in normal persons, however, was not changed by varying the relative contributions of the rib cage and abdomen to the tidal volume, as shown from Vtr and regional 133Xe wash-out measurements. 4. The results in the tetraplegic patients are interpreted as evidence of ‘small airway disease’, presumably from infection of the air way and impairment of the cough.

Rib cage distortion during voluntary and involuntary breathing acts

1985 ◽  
Vol 58 (5) ◽  
pp. 1703-1712 ◽  
Author(s):  
F. D. McCool ◽  
S. H. Loring ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Relative Motion ◽  
Spontaneous Breathing ◽  
Normal Subjects ◽  
Esophageal Pressure ◽  
Transmural Pressure ◽  
Muscle Coordination ◽  
Rib Cage ◽  
Gastric Pressure ◽  
Natural Breathing

We examined chest wall and rib cage configuration in seven normal subjects during a variety of breathing maneuvers. Magnetometers were used to measure lower rib cage anteroposterior, lower rib cage transverse, upper rib cage anteroposterior, and abdomen anteroposterior diameters. Changes of these diameters were recorded during voluntary maneuvers, rebreathing, reading, and “natural” breathing. Relative motion of the rib cage and abdomen was displayed with the rib cage represented by the product of its lower anteroposterior and transverse diameters. During spontaneous breathing the rib cage and chest wall are near their relaxation configuration. During chemically driven ventilation the chest wall and rib cage progressively depart from this configuration. Much greater distortions of the chest wall and rib cage occurred during some voluntary maneuvers. Additionally, esophageal pressure and gastric pressure were measured during voluntary distortion of the rib cage. Substantial changes in lower rib cage shape occurred during voluntary maneuvers when compared with spontaneous breaths at the same transmural pressure. We conclude that the unitary behavior of the rib cage in normal subjects requires muscle coordination.

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