Effects of Lower Rib Expansion Limitation on Maximal Respiratory Pressure and Abdominal Muscle Activity During Maximal Breathing in Healthy Subjects (original) (raw)
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Muscle activity during chest wall restriction and positive pressure breathing in man
Respiration physiology, 1978
The effects of sustained constriction of the rib cage (RCC), constriction of the abdomen (AC) and of breathing against a positive pressure of 10 cms of water (PPB) were studied in four normal subjects with moderate constant hypercapnia. Intercostal electrical activity (Eic) was measured by implanted wire electrodes and diaphragmatic electrical activity (Edia) by oesophageal electrodes. There was no fixed relation between Edia and VT. VT was unaltered during AC and RCC: Edia was unaltered during AC but increased during RCC. The response to PPB without constriction varied: three subjects increased end-expiratory VL with increase in Edia and inspiratory Eic. One subject initially, and one subject after training, maintained end-expiratory VL constant with no change in Edia and an increase in expiratory Eic. When PPB was applied during AC and RCC there was an increase in Edia proportional to end-expiratory lung volume. The overall response to distortion was determined by voluntary choice...
Rib cage mechanics during quiet breathing and exercise in humans
Journal of Applied Physiology, 1997
Kenyon, C. M., S. J. Cala, S. Yan, A. Aliverti, G. Scano, R. Duranti, A. Pedotti, and Peter T. Macklem. Rib cage mechanics during quiet breathing and exercise in humans. J. Appl. Physiol. 83(4): 1242–1255, 1997.—During exercise, large pleural, abdominal, and transdiaphragmatic pressure swings might produce substantial rib cage (RC) distortions. We used a three-compartment chest wall model ( J. Appl. Physiol. 72: 1338–1347, 1992) to measure distortions of lung- and diaphragm-apposed RC compartments (RCp and RCa) along with pleural and abdominal pressures in five normal men. RCp and RCa volumes were calculated from three-dimensional locations of 86 markers on the chest wall, and the undistorted (relaxation) RC configuration was measured. Compliances of RCp and RCa measured during phrenic stimulation against a closed airway were 20 and 0%, respectively, of their values during relaxation. There was marked RC distortion. Thus nonuniform distribution of pressures distorts the RC and marke...
Expiratory Rib Cage Compression in Mechanically Ventilated Subjects: A Randomized Crossover Trial
Respiratory Care, 2013
BACKGROUND: Expiratory rib cage compression (ERCC) has been empirically used by physiotherapists with the rationale of improving expiratory flows and therefore the airway clearance in mechanically ventilated patients. This study evaluates the acute mechanical effects and sputum clearance of an ERCC protocol in ventilated patients with pulmonary infection. METHODS: In a randomized crossover study, sputum production and respiratory mechanics were evaluated in 20 mechanically ventilated subjects submitted to 2 interventions. ERCC intervention consisted of a series of manual bilateral ERCCs, followed by a hyperinflation maneuver. Control intervention (CTRL) followed the same sequence, but instead of the compressive maneuver, the subjects were kept on normal ventilation. Static (C st) and effective (C eff) compliance and total (R tot) and initial (R init) resistance of the respiratory system were measured pre-ERCC (baseline), post-ERCC or CTRL (POST1), and post-hyperinflation (POST2). Peak expiratory flow (PEF) and the flow at 30% of the expiratory tidal volume (flow 30% V T) were measured during the maneuver. RESULTS: ERCC cleared 34.4% more secretions than CTRL (1 [0.5-1.95] vs 2 [1-3.25], P < .01). Respiratory mechanics showed no differences between control and experimental intervention in POST1 for C st , C eff , R tot , and R init. In POST2, ERCC promoted an increase in C st (38.7 ؎ 10.3 vs 42.2 ؎ 12 mL/ cm H 2 O, P ؍ .03) and in C eff (32.6 ؎ 9.1 vs 34.8 ؎ 9.4 mL/cm H 2 O, P ؍ .04). During ERCC, PEF increased by 16.2 L/min (P < .001), and flow 30% V T increased by 25.3 L/min (P < .001) compared with CTRL. Six subjects (30%) presented expiratory flow limitation (EFL) during ERCC. The effect size was small for secretion volume (0.2), C st (0.15), and C eff (0.12) and negligible for R tot (0.04) and R init (0.04). CONCLUSIONS: Although ERCC increases expiratory flow, it has no clinically relevant effects from improving the sputum production and respiratory mechanics in hypersecretive mechanically ventilated patients. The maneuver can cause EFL in some patients. (ClinicalTrials.gov registration NCT01525121).
Journal of Electromyography and Kinesiology, 2016
Central Nervous System modulates the motor activities of all trunk muscles to concurrently regulate the intra-abdominal and intra-thoracic pressures. The study aims to evaluate the effect of inspiratory and expiratory loads on abdominal muscle activity during breathing in healthy subjects. Twenty-three higher education students (21.09 ± 1.56 years; 8 males) breathed at a same rhythm (inspiration: two seconds; expiration: four seconds) without load and with 10% of the maximal inspiratory or expiratory pressures, in standing. Surface electromyography was performed to assess the activation intensity of rectus abdominis, external oblique and transversus abdominis/internal oblique muscles, during inspiration and expiration. During inspiration, transversus abdominis/internal oblique activation intensity was significantly lower with inspiratory load when compared to without load (p = 0.009) and expiratory load (p = 0.002). During expiration, the activation intensity of all abdominal muscles was significantly higher with expiratory load when compared to without load (p < 0.05). The activation intensity of external oblique (p = 0.036) and transversus abdominis/internal oblique (p = 0.022) was significantly higher with inspiratory load when compared to without load. Transversus abdominis/internal oblique activation intensity was significantly higher with expiratory load when compared to inspiratory load (p < 0.001). Transversus abdominis/internal oblique seems to be the most relevant muscle to modulate the intraabdominal pressure for the breathing mechanics.
Critical Care Medicine, 2013
Objectives: We investigated the effects of two different types of manual rib cage compression on expiratory flow and mucus clearance during prolonged mechanical ventilation in pigs. Design: Prospective randomized animal study. Setting: Animal research facility, University of Barcelona, Spain. Subjects: Nine healthy pigs. Measurement and Main Results: Pigs were tracheally intubated, sedated, paralyzed, and mechanically ventilated. The animals were prone on a surgical bed in the anti-Trendelenburg position. The experiments were carried out at approximately 60 and 80 hrs from the beginning of mechanical ventilation. Two types of manual rib cage compressions were tested: Hard and brief rib cage compressions synchronized with early expiratory phase (hard manual rib cage compression) and soft and gradual rib cage compressions applied during the late expiratory phase (soft manual rib cage compression). The interventions were randomly applied for 15 min with a 15-min interval between treatments. Respiratory flow and mucus movement were assessed during the interventions. Respiratory mechanics and hemodynamics were assessed prior to and after the interventions. Peak expiratory flow increased to 60.1 ± 7.1 L/min in comparison to 51.2 ± 4.6 L/ min without treatment (p < 0.0015) and 48.7 ± 4.3 L/min with soft manual rib cage compression (p = 0.0002). Similarly, mean expiratory flow increased to 28.4 ± 5.2 L/min during hard manual rib cage compression vs. 15.9 ± 2.2 and 16.6 ± 2.8 L/min without treatment and soft manual rib cage compression, respectively (p = 0.0006). During hard manual rib cage compression, mucus moved toward the glottis (1.01 ± 2.37 mm/min); conversely, mucus moved toward the lungs during no treatment and soft manual rib cage compression, -0.28 ± 0.61 and -0.15 ± 0.95 mm/min, respectively (p = 0.0283). Soft manual rib cage compression slightly worsened static lung elastance and cardiac output (p = 0.0391). Conclusions: Hard manual rib cage compression improved mucus clearance in animals positioned in the anti-Trendelenburg position. The technique appeared to be safe. Conversely, soft manual rib cage compression was not effective and potentially unsafe. These findings corroborate the predominant role of peak expiratory flow on mucus clearance. (Crit Care Med 2013; 41:850-856)
2021
Introduction: Fatigue is defined as a loss in the capacity for developing force and/or velocity of a muscle which is reversible by rest. The aim was to evaluate non-invasively the fatigue and recovery of the inspiratory ribcage muscles during two endurance tests in healthy subjects. Methods: 22 subjects were evaluated before, during and after performing a respiratory endurance test with normocapnic hyperpnea (NH) and inspiratory pressure threshold load (IPTL). Simultaneous measurements of muscle activity (electromyography), tissue oxygenation (NIRS), pressure (nasal inspiratory pressure), and volume (optoelectronic plethysmography) were performed. Results: There was a decrease in the maximum relaxation rate (MRR) and increase in the time constant (τ) after the IPTL test (p <0.05) and a decrease in the peak pressure generated in SNIP after both protocols (p <0.05). Additionally, there was a decrease in shortening velocity and mechanical power only after the IPTL test (p <0.0...
Revista Brasileira de Terapia Intensiva, 2017
Objective: To review the literature on the effects of expiratory rib cage compression on ventilatory mechanics, airway clearance, and oxygen and hemodynamic indices in mechanically ventilated adults. Methods: Systematic review with meta-analysis of randomized clinical trials in the databases MEDLINE (via PubMed), EMBASE, Cochrane CENTRAL, PEDro, and LILACS. Studies on adult patients hospitalized in intensive care units and under mechanical ventilation that analyzed the effects of expiratory rib cage compression with respect to a control group (without expiratory rib cage compression) and evaluated the outcomes static and dynamic compliance, sputum volume, systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, peripheral oxygen saturation, and ratio of arterial oxygen partial pressure to fraction of inspired oxygen were included. Experimental studies with animals and those with incomplete data were excluded.
European Journal of Applied Physiology and Occupational Physiology, 1995
A simple and inexpensive new extensometer for measuring changes in chest wall circumference during human respiratory movements is presented. The instrument detects the delay between ultrasound emission and reception at opposite ends of two rubber tubes encircling the rib cage and abdomen. Assuming a two degree of freedom model of the chest wall and employing an isovolume procedure for determination of volume-motion coefficients, extensometer estimation of tidal volume (VT) from changes of rib cage and abdomen circumference was compared with spirometer measurements at rest and during exercise on a cycle ergometer (55-155 W) in six subjects and, in four of them, on a treadmill (4-12 km" h-1). In three subjects hypercapnic hyperpnoea at rest was also studied. The slopes of the linear relationship between extensometer and spirometer VT (litres) averaged 0.9967 (SD 0.0117) (r 2 = 0.995-0.998; n = 90-143) for cycle ergometer exercise, 1.0072 (SD 0.0078) (r 2 = 0.991-0.998; n = 75-93) for treadmill exercise and 0.9942 (SD 0.0188) (r 2 = 0.997-0.998; n = 18-25) for hypercapnic hyperpnoea. In all instances the slope of the regression line was consistent with the model of the identity line (slope = 1). The changes in end-expiratory lung volume between respiration at rest and during exercise were determined by the extensometers, and were nearly identical (98.4% on average) to those measured with the spirometer (r2= 0.945; n = 24). It is concluded that determination of chest wall circumference with this new instrument is suitable for quantitative measurement of ventilation and lung volume variations in humans under most physiological conditions.