Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 4-month-old baby girl, after a period of apparent good health, began to have aphonia, dyspnea, difficulties with swallowing, cyanosis, apnea, and hypopnea during sleep that resulted in admission to an intensive care unit for intubation and mechanical ventilation. At the age of 9 months she was admitted to our hospital with a possible diagnosis of central hypoventilation syndrome. A polysomnographic study showed apnea and hypopnea (apnea + hypopnea index = 47.1), hypercapnia (mean end-tidal PCO2 89 +/- 15.0 mmHg), and arterial desaturation (mean SaO2 91 +/- 1.7%; lowest SaO2 < 50%; 68% of total sleep time at SaO2 below 93%); the study also showed an absent ventilatory response to CO2, absent cardiac responses to apnea during sleep, and right ventricular hypertrophy. Nocturnal nasal bi-level positive airway pressure (BIPAP), applied initially at 6 cmH2O and gradually increased to 16 cmH2O, caused the sleep-related abnormal respiratory events to disappear. End-tidal PCO2 decreased to 39 mmHg, and SaO2 increased to 94%. After 6 months of nocturnal BiPAP ventricular right hypertrophy reversed and arrested growth and hypotonia normalized. The child has tolerated and has remained on BiPAP support up to her current age of 3 years and continues to use this form of ventilatory assistance without difficulties.
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PMID:Bi-level positive airway pressure (BiPAP) ventilation in an infant with central hypoventilation syndrome. 926 57

5 cases with obesity-hypoventilaion syndrome were reported. The clinical manifestations were obesity, palpitation, dyspnea, lethargy, cyanosis, distention of cervical vein, edema, enlargement of liver and hypertension. All of them were initially diagnosed as chronic bronchitis or heart diseases. Pulmonary function test showed restrictive ventilative defect and hypercapnia with hypoxemia. Mouth oclusion pressure at 0.1 second was higher than the normal value. The response to CO2 was decreased. Hypertrophy of right heart was shown in ECG and X-ray film improvement in symptoms and blood gases analyses were found to be associated with body weight decrease in a follow up period of one year.
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PMID:[Obesity-hypoventilation syndrome]. 927 46

The conscious entrainment of respiratory rhythm to exercise rhythm (ENT) has been hypothesized to alleviate breathing discomfort and reduce the oxygen (O2) cost of ventilation with a resulting decrease in total O2 uptake (VO2) during rhythmic exercise. This hypothesis has been tested in the study reported here. Eight female subjects performed cycle exercise at 50 rpm under two work load conditions of 40% and 60% of maximal VO2. During a 30-min exercise period at each work load, each subject was asked to breathe under two conditions for 15 min each: (1) spontaneously (non-ENT run), and (2) deliberately entraining the breathing rhythm to the cycling rhythm at preferred coupling ratios of the two rhythms (ENT run). In the ENT run, most subjects chose a ratio of 1:2. In each run, pulmonary ventilation (VE), total VO2 and the breathlessness sensation (BS) were measured at 4-5 min. BS was assessed according to a Borg category scale. The remaining 10 min of each 15-min run were allotted for measurement of the O2 cost of ventilation (delta VO2/delta VE), assessed by a hypercapnia-induced hyperventilation method in which the VO2 of the respiratory muscles (VO2RM) was calculated by multiplying delta VO2/delta VE by the prevailing VE. On average, there were no significant differences in any of the variables, VO2, delta VO2/delta VE, VO2RM and BS, between the non-ENT and ENT runs performed at any work load. However, there were wide variations among the subjects in the differences (delta) between the two runs, and significant correlations were found between delta VO2 vs delta VE, delta VO2 vs delta VO2RM, and delta BS vs delta VO2RM of individual subjects. These results indicate that reductions of the total VO2 and BS with ENT could occur in subjects in whom the VO2RM decreased during ENT.
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PMID:Sensation of breathlessness and respiratory oxygen cost during cycle exercise with and without conscious entrainment of the breathing rhythm. 928 99

Proportional assist ventilation (PAV) has recently been proposed as a mode of synchronized partial ventilatory support. This study evaluates the short-term effects of nasal PAV on arterial blood gases in stable patients with chronic hypercapnia. Forty two patients (30 with chronic obstructive pulmonary disease (COPD) and 12 with restrictive chest wall disease (RCWD) due to kyphoscoliosis) underwent a 1 h run of nasal PAV. Randomly, two levels of assistance were performed: 1) PAV was set at a level corresponding to volume assist (VA) and flow assist (FA) at 80% of the individual values of elastance (Ers) and resistance (Rrs) obtained with the "runaway" method; and 2) VA and FA were set at a value corresponding to the difference between the patients' individual Ers and Rrs and normal values of Ers and Rrs. Arterial blood gases and dyspnoea (by visual analogue scale (VAS)) were evaluated in all patients during unsupported ventilation and 60 min of PAV. PAV was well tolerated and resulted in significant improvement in arterial oxygen tension (Pa,O2), arterial carbon dioxide tension (Pa,CO2) (6.8+/-0.8 to 7.4+/-1.4 and 7.2/-0.9 to 6.8+/-0.9 kPa, respectively) and VAS (29+/-23 to 20+/-18%). The effects of PAV were not different in the two groups of diseases nor in the two groups of settings. Different settings of nasal proportional assist ventilation are well tolerated and may improve gas exchange and dyspnoea in patients with stable hypercapnic respiratory insufficiency.
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PMID:Short-term effects of nasal proportional assist ventilation in patients with chronic hypercapnic respiratory insufficiency. 949 69

This study investigated the impact of deep diaphragmatic breathing (DB) on blood gases, breathing pattern, pulmonary mechanics and dyspnoea in severe hypercapnic chronic obstructive pulmonary disease (COPD) patients recovering from an acute exacerbation. Transcutaneous partial pressure of carbon dioxide (Ptc,CO2) and oxygen (Ptc,O2) and arterial oxygen saturation (Sa,O2), were continuously monitored in 25 COPD patients with chronic hypercapnia, during natural breathing and DB. In eight of these patients, breathing pattern and minute ventilation (V'E) were also assessed by means of a respiratory inductance plethysmography. In five tracheostomized patients, breathing pattern and mechanics were assessed by means of a pneumotachograph/pressure transducer connected to an oesophageal balloon. Subjective rating of dyspnoea was performed by means of a visual analogue scale. In comparison to natural breathing deep DB was associated with a significant increase in Ptc,O2 and a significant decrease in Ptc,CO2, with a significant increase in tidal volume and a significant reduction in respiratory rate resulting in increased V'E. During DB, dyspnoea worsened significantly and inspiratory muscle effort increased, as demonstrated by an increase in oesophageal pressure swings, pressure-time product and work of breathing. We conclude that in severe chronic obstructive pulmonary disease patients with chronic hypercapnia, deep diaphragmatic breathing is associated with improvement of blood gases at the expense of a greater inspiratory muscle loading.
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PMID:Acute effects of deep diaphragmatic breathing in COPD patients with chronic respiratory insufficiency. 955 46

Vibratory stimulation applied to the chest wall during inspiration reduces the intensity of breathlessness, whereas the same stimulation during expiration has no effect or may increase breathlessness. The purpose of the present study was to determine whether vibration reduced the intensity of breathlessness during progressive hypercapnia with and without the addition of an external resistive load. A second objective was to see whether the mouth occlusion pressure at 0.2 s (P0.2) was reduced by the vibratory stimulation. Hypercapnic ventilatory response was conducted in 10 healthy male volunteers with simultaneous measurement of visual analog scale, P0.2, and minute ventilation. Hypercapnic ventilatory response was performed and randomly combined with or without vibratory stimulation (100 Hz) as well as with or without inspiratory load. With inspiratory load, in-phase vibration did not cause any significant changes in the slopes of P0.2 and minute ventilation to CO2, whereas the slope of visual analog scale to CO2 significantly decreased from 0.47 +/- 0.15 to 0.34 +/- 0.11 (SE) cm/Torr (P < 0.05). We conclude that in-phase vibration could decrease the slope of breathlessness elicited by inspiratory load combined with hypercapnia without changing motor output.
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PMID:Effects of chest wall vibration on breathlessness during hypercapnic ventilatory response. 957 89

Validity of the hypothesis for the role of the respiratory muscles in deterioration of physical work capacity following long-term hypokinesia was tested. Experiments were performed with participation of 8 female subjects aged from 27 to 36 years in the 120-day head-down bed rest. Physical performance and functional status of the respiratory muscles have been determined during incremental loading on bicycle ergometer with normal respiration and breathing against additional external resistance. Functional deficit of the respiratory muscles due to long-term bed rest was shown not to allow adequate ventilation and gas exchange at submaximal loads. This resulted in dyspnea, hypoventilation-induced decrease in oxygen consumption and carbon dioxide release, hypercapnia, and lowered threshold of anaerobic metabolism which, in parallel with the deconditioning of the cardiovascular system and the skeletal anti-g musculature, were responsible for degradation of aerobic physical work capacity.
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PMID:[Functional status of respiratory muscles and physical endurance among women under prolonged hypokinesia]. 960 10

COPD is an extremely common, chronic disorder characterized by a reduction in airflow after the administration of an inhaled bronchodilator as measured by the FEV1. The diagnosis is suspected in patients with a history of several decades of cigarette smoking who present with nonspecific respiratory symptoms. The diagnosis is established by simple forced expiratory spirometry. Baseline evaluation usually includes a chest radiograph and some assessment of functional capacity, either by history or with some form of exercise testing. In patients whose initial FEV1 is more severely reduced or who have significant dyspnea, an arterial blood gas is indicated at baseline. Dyspnea, hypoxemia, or hypercarbia that is out of proportion to the measured FEV1, at either presentation or follow-up, should prompt a thorough evaluation for complicating conditions. There are important roles in health care delivery and chronic disease management strategies for RCPs, primary care providers, and specialty trained pulmonary physicians. The need for repeated, extensive, or expensive testing will be largely driven by patients symptoms but disease monitoring with periodic assessments of dyspnea, functional capacity, and spirometry can be performed without great expense.
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PMID:Diagnosing and monitoring the clinical course of chronic obstructive pulmonary disease. 977 Feb 58

The successful management of outpatients with COPD requires a multifaceted approach that includes prophylactic, palliative, and life-extending therapies. All patients should undergo smoking cessation, avoid potentially harmful environments, and receive influenza and pneumococcal vaccines at recommended intervals. Although medical therapy may yield only marginal benefits in patients with minimal airway responsiveness, even small improvements may translate into significant functional benefits and will be greatly appreciated. Therefore, every effort should be expended to optimize the patient's medical regimen and to ascertain that methods of delivery (such as use of spacers) are as recommended. Physical therapy measures may be useful in patients with copious sputum production, and pursed-lip and diaphragmatic breathing exercises may reduce dyspnea and lend a sense of control to patients with severe flow limitation. Oxygen therapy is the only modality demonstrated to improve survival in patients with severe COPD and may give symptomatic relief to some patients. Its use, however, is restricted to patients meeting guidelines for hypoxemia, and although dyspneic patients not meeting these guidelines may desire oxygen, insurers will decline coverage for them. Newer modalities, such as noninvasive ventilation, may improve gas exchange and quality of life in some patients with hypercapnia and nocturnal oxygen desaturations, but subgroups of COPD patients who benefit have not been well-defined, and pending further investigation, guidelines for use should be considered tentative. Patients should be encouraged to enter a comprehensive rehabilitation program, but if one is unavailable or the patient declines, a rehabilitation approach should be applied. Practitioners should attempt to educate patients at each visit, offering advice not only on medications, but also on regular exercise, good nutrition, and ways of coping psychologically with chronic illness. By taking such a comprehensive and caring approach, and being available to assist with problems and crises, the practitioner can help to enhance the quality and length of the COPD patient's life.
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PMID:Outpatient management. 977 Feb 59

Breathlessness arises from increased medullary respiratory center activity projecting to the forebrain (respiratory corollary discharge hypothesis). Subjects with congenital central hypoventilation syndrome (CCHS) lack the normal hyperpnea and breathlessness during hypercapnia. The corollary discharge hypothesis predicts that if CCHS subjects have normal hyperpnea during exercise, they will experience normal breathlessness during exercise. To test this, we studied four CCHS subjects and six matched controls during an exhausting constant-load cycling test requiring substantial anaerobiosis. CCHS subjects rated significantly less breathlessness at the end of the test than controls, but ventilation (index of respiratory corollary discharge) was also somewhat lower in CCHS (not significant). In both groups, breathlessness increased disproportionately more than ventilation towards the end of exercise. These data failed to disprove the corollary discharge hypothesis of breathlessness, but do suggest that the relationship between ventilation and breathlessness is non-linear and/or that projections of chemoreceptor afferents to the forebrain (presumed lacking in CCHS) is one source of breathlessness in normals.
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PMID:Respiratory sensations during heavy exercise in subjects without respiratory chemosensitivity. 985 52


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