Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Data from the present study indicate a change in the pattern of chest wall muscle recruitment and improved ventilation with pursed-lip breathing (PLB) in COPD. Pursed lip breathing led to increased rib cage and accessory muscle recruitment during inspiration and expiration, increased abdominal muscle recruitment during expiration, decreased duty cycle of the inspiratory muscles and respiratory rate, and improved SaO2. In addition, PLB resulted in no change in pressure across the diaphragm and a less fatiguing breathing pattern of the diaphragm. Changes in chest wall muscle recruitment and respiratory temporal parameters concomitant with the increased SaO2 indicate a mechanism of improving ventilation with PLB while protecting the diaphragm from fatigue in COPD. Alterations in the pattern of respiratory muscle recruitment with PLB may be associated also with the amelioration of dyspnea. Further investigation is necessary to explore the relationship between the pattern of respiratory muscle recruitment during PLB and dyspnea.
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PMID:The pattern of respiratory muscle recruitment during pursed-lip breathing. 172 14

The literature dealing with the magnitude, mechanism and effects of reduced FRC in the perioperative period is reviewed. During general anaesthesia FRC is reduced by approximately 20%. The reduction is greater in the obese and in patients with COPD. The most likely mechanism is the loss of inspiratory muscle tone of the muscles acting on the rib cage. Gas trapping is an additional mechanism. Lung compliance decreases and airways resistance increases, in large part, due to decreased FRC. The larynx is displaced anteriorly and elongated, making laryngoscopy and intubation more difficult. The change in FRC creates or increases intrapulmonary shunt and areas of low ventilation to perfusion. This is due to the occurrence of compression atelectasis, and to regional changes in mechanics and airway closure which tend to reduce ventilation to dependent lung zones which are still well perfused. Abdominal and thoracic operations tend to increase shunting further. Large tidal volume but not PEEP will improve oxygenation, although both increase FRC. Both FRC and vital capacity are reduced following abdominal and thoracic surgery in a predictable pattern. The mechanism is the combined effect of incisional pain and reflex dysfunction of the diaphragm. Additional effects of thoracic surgery include pleural effusion, cooling of the phrenic nerve and mediastinal widening. Postoperative hypoxaemia is a function of reduced FRC and airway closure. There is no real difference among the various methods of active lung expansion in terms of the speed of restoration of lung function, or in preventing postoperative atelectasis/pneumonia. Epidural analgesia does not influence the rate of recovery of lung function, nor does it prevent atelectasis/pneumonia.
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PMID:Perioperative functional residual capacity. 180 4

In the present study, we assessed the occurrence of respiratory muscle rest during long lasting INPV runs using a pneumowrap ventilator at different pressure levels. We measured two indices of diaphragmatic activity: transdiaphragmatic pressure and the electrical activity of the diaphragm. Five healthy volunteers and six COPD patients were studied during spontaneous breathing and during 30-minute runs of INPV at a pressure of -2, -15 and -30 cmH2O. Ventilation, rib cage and abdomen motion were measured by inductive plethysmography; Pdi was obtained as the difference between gastric and esophageal pressures; Edi was recorded with surface electrodes. About 10 minutes of INPV (adaptation phase) were needed to obtain stable values in all the variables recorded. Ventilation increased in both groups up to threefold by increasing the negative pressure applied, this being due to changes in tidal volume. Changes in Pga swings mainly accounted for the reduction in Pdi that became negative during the run at -30 cmH2O. In both groups, Edi, after adaptation, showed no change during INPV at -2 cmH2O but a progressive reduction from control, during INPV at -15 and -30 cmH2O. We conclude that INPV by a pneumowrap ventilator can induce partial respiratory muscle rest in normal subjects and COPD patients.
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PMID:Diaphragmatic rest during negative pressure ventilation by pneumowrap. Assessment in normal and COPD patients. 211 51

We assessed the accuracy of the respiratory inductive plethysmograph in the supine position to spirometry by the two-body position, least squares calibration and single-body position, isovolume calibration procedures. The comparison was carried out simultaneously in normal subjects breathing naturally and with voluntarily controlled abdominal or thoracic breathing, and in patients with COPD breathing naturally and with voluntarily controlled abdominal breathing patterns. In both groups, there was no significant difference in estimation of tidal volume between the 2 calibration procedures for the various breathing patterns. There was greater deviation from spirometric tidal volume values for both calibration methods in patients with COPD during abdominal than during natural breathing. In the normal subjects, agreement between the rib cage and abdominal partitioning of tidal volume for both calibration methods was good, but in the patients with COPD there was greater variability. In normal subjects, over a wide range of rib cage and abdominal compartmental contributions to tidal volume, either calibration procedure appears satisfactory. For patients with COPD, if large changes occur in the distribution of rib cage and abdominal contributions to tidal volume, then validation of respiratory inductive plethysmography to spirometry must be rechecked.
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PMID:Accuracy of respiratory inductive plethysmograph over wide range of rib cage and abdominal compartmental contributions to tidal volume in normal subjects and in patients with chronic obstructive pulmonary disease. 646 70

We measured the breathing pattern of normal subjects, asymptomatic smokers, asymptomatic and symptomatic asthmatic patients, and patients with chronic obstructive pulmonary disease, restrictive lung disease, primary pulmonary hypertension and anxiety state utilizing respiratory inductive plethysmography. Respiratory rate was increased above the normal in smokers and in patients with COPD, restrictive lung disease and pulmonary hypertension, but remained normal in asthmatic patients. Inspiratory times (T1) of one second or less often occurred in patients with COPD, restrictive lung disease, and pulmonary hypertension. Smokers and patients with symptomatic asthma, COPD, restrictive lung disease and pulmonary hypertension showed heightened respiratory center drive as reflected by elevated mean inspiratory flow (VT/TI). Fractional inspiratory time was reduced to a variable extent in smokers, symptomatic asthmatic patients and patients with COPD, and was a weak indicator of airways obstruction. Patients with COPD often had major fluctuations of expiratory timing, periodic fluctuations of end-expiratory level, and asynchrony between rib cage and abdominal movements. Chronic anxiety was characterized by frequent sighs; episodic rapid rates alternating with apneas were less common. We conclude that analysis of breathing patterns provides diagnostic discrimination among normal subjects and disease states.
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PMID:Breathing patterns. 2. Diseased subjects. 688 4

Using computed tomography we assessed rib cage dimensions at the levels of Th4, Th6, Th8, and Th10 in seven supine patients with COPD who were severely obstructed (FEV1, 25 +/- 7% of predicted) and hyperinflated (FRC, 234 +/- 34% of predicted) and seven matched normal control subjects. The midsagittal anteroposterior (AP) diameter, the maximal AP diameter of the right and left hemithorax, and the maximal transverse (T) diameter were measured on scans obtained at relaxed TLC, FRC, and RV. At each volume, AP diameters were invariably 2 to 3 cm greater in patients with COPD than in normal subjects, but no significant differences in T diameters were found. When compared at a given absolute lung volume, T diameters at all thoracic levels and AP diameters at Th4-6 were smaller in patients with COPD than in normal subjects; in contrast, at Th8-10, AP diameters were similar in the two groups. We conclude that the marked hyperinflation of patients with severe COPD produces complex changes in rib cage dimensions: (1) there is an increase in AP but not in T diameters such that the rib cage adopts a more circular shape; (2) at a given absolute lung volume, AP diameters are smaller in patients with COPD than in normal subjects in the upper but not in the lower portion of the rib cage. These differences in rib cage dimensions may have implications regarding respiratory muscle length and function in patients with COPD.
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PMID:Rib cage dimensions in hyperinflated patients with severe chronic obstructive pulmonary disease. 881 Jun 22

The development of positive pressure ventilation delivered through a nasal or face mask has greatly expanded the use of non-invasive ventilation in patients with chronic respiratory insufficiency, particularly during sleep. Disorders ranging from neurologic and neuromuscular, such as polio and muscular dystrophy, central alveolar hypoventilation, thoracic cage disorders such as kyphoscoliosis, and pulmonary disorders such as COPD, particularly of the blue-bloater type. The relative hypoventilation that is common to each condition is due to varying combinations of an inadequate respiratory drive and an increase in the work of breathing. Previous studies have shown sustained reversal of awake hypercapnia in patients with alveolar hypoventilation syndrome using nocturnal NIPPV. We analysed 10 consecutive patients with chronic respiratory insufficiency due to diverse aetiologies over a period of time using long-term domiciliary nocturnal NIPPV. Awake hypercapnia and hypoxaemia improved in nine patients over time and deteriorated in one patient. There was no significant change in pulmonary function apart from one patient with progressive muscular dystrophy who deteriorated. A considerable reduction in the need for subsequent hospital admission was noted in the group as a whole following institution of NIPPV. We conclude that nocturnal NIPPV improves awake gas exchange in patients with chronic respiratory failure.
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PMID:Nocturnal nasal intermittent positive pressure ventilation (NIPPV) therapy for chronic respiratory failure: long-term effects. 1059 22

Expiratory muscle recruitment is common in stable COPD patients. However, physiological significance of expiratory muscle recruitment in COPD remains unclear. The purpose of this study was to assess the effect of expiratory muscle contraction on force generating ability of the diaphragm in COPD patients breathing at rest. The force generating ability of the diaphragm was evaluated from its pressure swing (Pdi) for a given diaphragm electrical activity (Edi), where Edi was normalized as % of its maximal value [Pdi/(Edi/Edimax)]. Phasic expiratory muscle contraction was measured as the total expiratory rise in gastric pressure (Pgaexp.rise). Nineteen patients with severe COPD, participated in the study but only 10 exhibited phasic rise in Pga during expiration with a mean Pgaexp.rise of 1.91 +/- 0.89 cmH2O. Patients were divided into passive expiration (PE) and active expiration (AE) groups. There was no significant difference in lung function and breathing pattern parameters between the two groups. Pdi/(Edi/Edimax) was 0.63 +/- 0.07 and 0.54 +/- 0.07 cm cmH2O/% in PE and AE groups, respectively, and was not significantly different between each other. Compared with PE group, AE group not only recruited expiratory muscles, but also preferentially recruited inspiratory rib cage muscles and derecruited the diaphragm. In conclusion phasic contraction of expiratory muscles at rest in COPD patients do not improve the force-generating ability of the diaphragm.
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PMID:[Role of expiratory muscles in COPD patients]. 1270 80

Health-related quality of life (HRQL) is defined as a psychological construct describing the subjectively experienced health status based on different components of health including physical state, psychological well-being, social relations and functional capacities. Assessment of HRQL has become steadily more essential in order to evaluate the costs and benefits of modern treatment modalities in patients with chronic and incurable diseases. This is particularly true for patients with home mechanical ventilation (HMV) and severe objective limitations in daily living. Modern instruments such as the Severe Respiratory Insufficiency (SRI) Questionnaire have been specifically designed for clinical trials which aim at assessing the effects of HMV on HRQL in these patients. Recent work has shown that mental health in clinically stable patients following establishment of HMV can be normal despite substantial physical handicaps. Further, HRQL has been shown to be predominantly influenced by the underlying disease. Accordingly, there is increasing evidence that HMV provides beneficial effects on HRQL in patients with neuromuscular and thoracic rib cage diseases, but in contrast, this remains still controversial in patients with COPD. Here, prospective controlled trials using modern specific instruments for HRQL assessment are required in the future to reliably evaluate the effects of HMV on HRQL in patients with COPD.
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PMID:[Quality of life in patients with home mechanical ventilation]. 1700 89

Dyspnea, a symptom limiting exercise capacity in patients with COPD, is associated with central perception of an overall increase in central respiratory motor output directed preferentially to the rib cage muscles. On the other hand, disparity between respiratory motor output, mechanical and ventilatory response of the system is also thought to play an important role on the increased perception of exercise in these patients. Both inspiratory and expiratory muscles and operational lung volumes are important contributors to exercise dyspnea. However, the potential link between dyspnea, abnormal mechanics of breathing and impaired exercise performance via the circulation rather than a malfunctioning ventilatory pump per se should not be disregarded. Change in arterial blood gas content may affect dyspnea via direct or indirect effects. An increase in carbon dioxide arterial tension seems to be the most important stimulus overriding all other inputs from dyspnea in hypercapnic COPD patients. Hypoxia may act indirectly by increasing ventilation and indirectly independent of changes in ventilation. A greater treatment effect is often achieved after the addition of pulmonary rehabilitation with pharmacological treatment.
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PMID:Exercise dyspnea in patients with COPD. 1826 17


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