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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In experiments on 105 white rats using histological, histochemical, and morphometric methods the state of the lungs following daily "rises" in a pressure chamber to the "hight" of 5000--9000 m at verious time intervals--from 1 day to 9 weeks was studied. In 18 animals "ascents" were preceded by sinistral pulmonectomy. In parallel, the heart was investigated by the method of separate weighing. At initial stages changes in the lungs were characterized predominantly by impairment of the blood- and lymphocirculation. Subsequently, disorders of the microcirculation were observed to diminish and compensatory-hypertrophic changes in the lung tissue and vessels were noted. As the effect of hypoxia continued, sclerotic processes appeared, and extensive focal emphysema developed. These changes were manifested in a greater degree and appeared sooner with an increase in the extent of rarification of the atmosphere. Possibilities for adaptation to hypoxia in animals with the one lung were considerably lower as compared with normal ones. Hypercapnia produced an effect similar to that of hypoxia, making its influence on the structural elements of the lungs graver. Prolonged hypoxia led to hypertrophy of the right ventricle of the heart; the main factor in development of which the authors considered the elevation of the tonus and subsequent structural rearrangement of small vessels in the form of myoelastosis and myoelastofibrosis of the walls with narrowing of the lumen.
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PMID:[Changes in the lungs and the mass of the right ventricle of the heart in chronic hypoxia (experimental-morphological study)]. 12 41

A group of 6 males with severe alpha1-antitrypsin deficiency, underwent clinical and pulmonary function evaluation. Findings were compared to those in a group of males with different degrees of airflow obstruction, comparable ages and tobacco consumption, but with normal serum levels of alpha1-antitrypsin. The deficient group was characterized by: (1) a relatively early appearance of symptoms; (2) disturbed lung scans, mostly in the basal zones; (3) radiological evidence, in most cases, of pulmonary emphysema with, in particular, bullae in the lower lung zones; (4) hypoxemia without hypercapnia and a decreased TCO/VA, and (5) a more or less severe reduction of maximal expiratory flows largely, but not exclusively due to a decrease in lung elastic recoil. Clinical and functional parameters did not permit a clear distinction between the deficient and non-deficient groups.
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PMID:[Pulmonary function and clinical pattern in homozygous (PiZ) alpha1-antitrypsin deficiency (author's transl)]. 31 18

A homogeneous sample of 14 patients with advanced chronic bronchitis and emphysema complicated by secondary polycythaemia and pulmonary hypertension was examined. Eight patients who were receiving long-term oxygen therapy (LTO2) for 15-20 h in the 24 h day showed a significantly faster, that is more normal, frequency of the dominant EEG activity and a higher level of arterial oxygenation when breathing air than six similar patients not receiving LTO2. Acute administration of oxygen (2 1/min) for 15 min did not change the EEG pattern in either group of patients. The frequency of the dominant EEG activity in all 14 patients showed a significant positive correlation with the arterial oxygen saturation and negative correlation with the level of polycythaemia. Occurrence of intermixed EEG show activity theta and delta was positively correlated both with hypoxaemia and hypercapnia. The results suggest that the LTO2 in patients with chronic ventilatory failure has a beneficial effect on cerebral function as measured by EEG.
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PMID:The effects of long-term oxygen therapy on the EEG in patients with chronic stable ventilatory failure. 49 89

Studies of percutaneous transtracheal ventilation with intermittent jets of oxygen under high pressure have demonstrated a tendency toward carbon dioxide retention and poor alveolar washout. A modification of the percutaneous transtracheal ventilation fevice to include an expiratory phase improves pulmonary gas exchange and minimizes the possibility of CO2 retention. The most common complication is subcutaneous emphysema caused by incorrect catheter placement. Although endotracheal intubation is unquestionably the treatment of choice, percutaneous transtracheal ventilation does offer a viable alternative when intubation cannot be rapidly accomplished.
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PMID:A modified, simple device for the emergency administration of percutaneous transtracheal ventilation. 62 19

Respiratory drive (deltaP 0.1/deltaPCO2) and ventilatory response (deltaVE/deltaPCO2) to CO2 has been estimated in 20 normal subjects and 28 patients with chronic obstructive pulmonary disease (COPD). In patients with COPD, drive and ventilatory response to CO2 were diminished, but no statistical correlation with FEV1, MBC, TLC, FRC, RV/TLC was found. A statistically negative correlation was found between blood bicarbonate and drive or ventilatory response to CO2. Patients with emphysema and normal PaCO2 demonstrated normal deltaP 0.1/deltaPCO2. In contrast, patients with chronic bronchitis with the same pulmonary function abnormalities and hypercapnia had significant diminution of the deltaP 0.1/deltaPCO2. Therefore, we feel that pulmonary function abnormalities alone cannot explain the deltaP 0.1/deltaPCO2 decrease; in most cases there sould coexist a diminished respiratory sensitivity.
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PMID:Respiratory drive in patients with chronic obstructive pulmonary disease. 67 65

In 83 patients with severe, largely irreversible bronchial obstruction (FEV1/VC less than 40% and FEV1 after orciprenaline inhalation less than 120% of the control value) and radiologie evidence of AD-emphysema, arterial PCO2 and PO2 were measured at rest in supine position and on the bicycle ergometer during a steady-state exercice of 5 min. Alveolar hypoventilation (PCO2 greater than 45 mm Hg) was most often observed in the cases with FEV1 less than 1.01 (in 22 patients [27%] at rest and in 26 patients [31%] during exercise). However, there was no significant correlation of the PCO2 increase with the degree of bronchial obstruction. In all patients there was a marked inhomogeneity of the alveolar ventilation or the alveolar-capillary O2 transfer in relation to alveolar blood perfusion. Indeed, the alveolar-arterial PO2 difference was increased (40 mm Hg at rest and 45 mm Hg during exercise). The additional increase of this gradient during exercise was due to an unequal distribution of alveolar O2 diffusing capacities in connection with the alveolar blood flow (preceding measurements of the N2 gradient between alveolar air and arterial blood revealed a mean fall from 18 at rest to 8 mm Hg during exercise). The observed deterioration of hypoxemia during exercise (without additional hypercapnia) is to a great extent related to the degree of bronchial obstruction measured by simple spirometry. Thus, measurements of PCO2 and PO2 at rest and during exercise appear to be a helpful adjuvant to routine spirometry in the diagnosis of subclinical emphysema.
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PMID:[Arterial CO2- and O2 partial pressure at rest and during exertion in pulmonary emphysema]. 89 50

To determine whether personality is related to dyspnea sensation, 19 healthy males and 17 male patients with pulmonary emphysema were tested for modified visual analog scale (VAS) during hypoxic and hypercapnic interventions. Personality was tested by both Yatabe-Guillford test and manifest anxiety scale. VAS score correlated positively with anxiety score during hypercapnia and inspiratory resistive loading under hypercapnia in healthy subjects. In patients, anxiety score correlated positively with VAS scores during hypoxia, hypercapnia, and resistive loading under hypercapnia. Scores for nervousness and cyclic tendency correlated with VAS scores during hypoxia and hypercapnia in patients. These results indicate close relation between anxiety and dyspnea in healthy as well as emphysematous subjects. In emphysema, nervousness and cyclic tendency are the additional determinants for dyspnea.
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PMID:[Relation between dyspnea and personality in patients with pulmonary emphysema and healthy subjects]. 140 68

Alveolar hypoventilation due to the chronic obstruction of the airway such as pulmonary emphysema, or severe restrictive dysfunction due to sequela of pulmonary tuberculosis causes chronic hypercapnia (chronic respiratory acidosis). Ninety-five percentile of significance band of chronic and acute hypercapnia of both experimental and clinical setting is introduced in the graphic display of the acid-base balance. On acute exacerbation of these disorders, examination of arterial blood gas in series are usually plotted along the significance band of hypercapnia. With clinical improvement, the plot will gradually drop down to the chronic stable area of the band. Although cases with metabolic disorders complicate the interpretation, evaluation of the acid-base status using the graphic display will be of help at bedside assessment.
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PMID:[Graphic evaluation of the significance band for hypercapnia in pulmonary disorders]. 143 7

The Medical Research Council and the Nocturnal Oxygen Therapy Trial studies clearly demonstrated that long-term oxygen therapy (LTOT) for more than 15 h/day improved mortality and morbidity in a well-defined group of patients with chronic obstructive pulmonary disease. There are no similar randomised control studies in patients with other hypoxaemic lung diseases such as pulmonary fibrosis and pneumoconiosis. The prescription of oxygen for other restrictive lung disorders is complicated by hypoventilation requiring mechanical support as well as oxygen and should be restricted to special centres. The clearest indications for LTOT are for patients with cor pulmonale, hypoxic chronic bronchitis and emphysema, and in terminally ill patients who require palliation. Before LTOT is considered, the patient must be clinically stable and on appropriate optimum therapy such as antibiotics, bronchodilators, physiotherapy and having stopped smoking tobacco. Many patients first present for LTOT with profound hypoxaemia and hypercapnia during an infective, often oedematous exacerbation of their lung disease. Assessments should occur during convalescence when the patient is clinically stable. They should be shown to have a PaO2 less than 7.3 kPa and/or a PaCO2 greater than 6 kPa on two occasions at least 3 weeks apart. FEV1 should be less than 1.5 litres, and there should be a less than 15% improvement in FEV1 after bronchodilators. All patients should be assessed by an experienced chest physician. Patients with a PaO2 between 7.3 and 8 kPa who have polycythaemia, right heart failure or pulmonary hypertension may gain benefit from LTOT but this is still to be clearly proven.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Indications for long-term oxygen therapy. 151 74

Patients with cardiopulmonary insufficiency undergoing laparoscopic surgery with carbon dioxide (CO2) pneumoperitoneum may retain CO2 resulting in clinically significant respiratory acidosis. A canine model of pulmonary emphysema induced by papain inhalation was utilized to evaluate the respiratory effects of both CO2 and helium pneumoperitoneum. Prior to papain inhalation and 5 and 8 weeks after initial treatment under general anesthesia, mechanical ventilation was adjusted to maintain the end-tidal CO2 (ETCO2) at 40 mm Hg during baseline and pneumoperitoneum physiologic monitoring periods. Utilizing an analysis of variance, hemodynamic and respiratory physiologic parameters were compared. In this canine model, all dogs demonstrated consistent hypercarbia during CO2 pneumoperitoneum prior to papain treatments, but CO2 retention was significantly increased in the emphysematous state. The occurrence of hypercarbia during CO2 pneumoperitoneum may be underestimated by ETCO2 monitoring as was revealed by an increased PaCO2 (arterial carbon dioxide pressure)-ETCO2 gradient with an increasing time interval between papain exposure and period of physiologic monitoring. Irrespective of the pulmonary condition of the dog, helium pneumoperitoneum did not produce any hypercarbic or acidic changes when compared with the concomitant baseline period of dogs prior to the induction of pneumoperitoneum, thus suggesting that helium pneumoperitoneum may be a reasonable alternative in patients at risk for CO2 retention.
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PMID:Hypercarbia during carbon dioxide pneumoperitoneum. 173 68


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