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

We investigated a possible effect of doxapram (a respiratory stimulant) on the peripheral chemoreceptors in man (8 control subjects, 11 bronchitics, and 4 emphysematous). In addition, we determined whether infusion of doxapram could augment blunted chemosensitivity to hypoxia or hypercapnia seen in both chronic obstructive pulmonary disease (COPD) patients and normal subjects. Doxapram infusion caused a significant increase in delta VE/delta SaO2 (p less than 0.05), as well as delta Po.1/delta SaO2 (p less than 0.05) in control subjects, although the changes in both delta VE/delta PeAco2 (where, PeAco2 = end-tidal Pco2) and delta Po.1/delta PeAco2 did not attain significant level. Control subjects with low baseline delta Po.1/delta SaO2 showed significantly larger changes in both delta Po.1/delta SaO2 and delta VE/SaO2 during doxapram infusion than the patients with chronic bronchitis (0.02 less than p less than 0.05). We conclude that doxapram increases chemosensitivity to hypoxia and slightly increase chemosensitivity to hypercapnia, indicating its primary action being stimulation of peripheral chemoreceptors, and doxapram stimulates chemoreceptors little in patients with chronic bronchitis, whereas blunted hypoxic response in normal subjects could be increased markedly.
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PMID:Doxapram on blunted respiratory chemosensitivity to hypoxia in hypoxemic, chronic obstructive pulmonary disease. 362 58

The effect of home long-term oxygen therapy has been evaluated in 70 patients (52 men and 18 women) with chronic respiratory insufficiency due to chronic obstructive pulmonary disease. The mean duration of the observation period was 17.5 months, lasting at least 6 months and in a few cases over 40 months. The cumulative death rate was 22.6% in the first 12 months, 36.5% after two years and 40.7% in the third year. Compared to a previous period of 19.5 months there was an obvious reversal in hypoxemia, an increase in physical capacity and a reduction in the hospitalization rate. Patients with marked respiratory failure and with the clinical features of the "blue bloater" type of chronic bronchitis responded better to the home oxygen therapy than a group of "advanced pink puffers" with hypercapnia and high pulmonary arterial pressure. The present results do however confirm the beneficial effects of long-term domiciliary oxygen administration, and should encourage critical use of this new therapeutic regimen according to the indications so far recommended.
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PMID:[Oxygen home therapy in chronic respiratory insufficiency. Report of experience with 70 patients]. 398 85

Factors determining survival have been analysed retrospectively in 157 admissions of 135 patients with an acute exacerbation of chronic bronchitis and emphysema causing hypoxaemia and carbon dioxide retention. All were treated with controlled oxygen therapy. The death-rate increased with the age of the patient, but was not correlated with the age of the patient, but was not correlated with the severity of hypoxaemia on admission, when the patient was breathing air. The death-rate was significantly higher in those patients in whom arterial [H+] rose above 55 nmol/1 (pH = 7.26) during controlled oxygen therapy. The absence of a rise in the arterial PCO2 during controlled oxygen therapy was not necessarily indicative of a good prognosis, since 5 out of 18 patients showing this response subsequently died in that admission. Only 28% of the 111 patients who left hospital alive survived for five years.
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PMID:Respiratory failure revisited: acute exacerbations of chronic bronchitis between 1961-68 and 1970-76. 610 93

A controlled trial of long term domiciliary oxygen therapy has been carried out in three centres in the U.K. The 87 patients, all under 70 years of age, who took part had chronic bronchitis or emphysema with irreversible airways obstruction, severe arterial hypoxaemia, carbon dioxide retention, and a history of congestive heart failure. The patients were randomised to oxygen therapy (treated) or no oxygen (controls). Oxygen was given by nasal prongs for at least 15 h daily, usually at 2 1/min. The two groups were well matched, both clinically and in terms of lung function and other laboratory findings. 19 of the 42 oxygen treated patients died in the five years of survival follow-up compared with 30 out of 45 controls: in the 66 men in this trial the survival advantage of oxygen did not emerge until 500 days had elapsed. Survival for the 12 female controls was surprisingly poor, 8 of them being dead at 3 years. Mortality was not easy to predict, though a summation of arterial carbon dioxide tension and red cell mass was helpful. Neither time spent in hospital because of exacerbations of respiratory failure nor work attendance were affected by oxygen therapy, but these patients were very ill at the start of the trial and many had already retired on grounds of age or ill-health. Physiological measurements suggested that oxygen did not slow the progress of respiratory failure in those who died early. However, in longer term survivors on oxygen, arterial oxygenation did seem to stop deterioration.
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PMID:Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema. Report of the Medical Research Council Working Party. 611 Sep 12

Very few therapeutic measures of proven effectiveness are available for the management of chronic bronchitis with chronic respiratory failure. Long-term oxygen therapy undoubtedly improves functional and vital prognoses in patients with severe hypoxaemia (55 less than or equal to PaO2 less than or equal to 60 mmHg) or chronic post-hypoxia cor pulmonale, but its indications are limited by its cost and by numerous practical problems. Owing to its mode of action and pharmacological effects, almitrine bismesylate corrects the main physiopathological disorders underlying hypoxaemia and its complications in chronic bronchitis. Improvement in arterial and tissue oxygen supply and decrease in hypercapnia result from the specific and original action of the drug on the distribution of alveolar ventilation-perfusion ratios--an action that has been clearly demonstrated by the inert gas method and by radioisotopic techniques. Such a mode of action differentiates almitrine bismesilate from long-term oxygen therapy which has similar effects, at least qualitatively, on tissue oxygenation. The lack of undesirable effects on central nervous system, pulmonary circulation and respiratory mechanics confirms the originality and safety of a drug which unquestionably constitutes a novel and major contribution to the long-term treatment of chronic bronchitis with hypoxaemia.
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PMID:[Originality of the mode of action of almitrine dimesylate]. 614 36

In view of their own effects and haemodynamic repercussions, abnormalities in blood gas values are increasingly recognized as being of major significance for the prognosis of chronic obstructive respiratory diseases. Controlled trials of low flow rate oxygen therapy have demonstrated that correcting hypoxaemia in such cases significantly improved the vital prognosis. Almitrine bismesylate administered in single or multiple daily doses in short-medium-or long term treatment to patients with chronic bronchitis and hypoxaemia has proved capable of increasing PaO2 and, when hypercapnia is present, decreasing PaCO2. In responsive patients, a 1.5 mg/kg dose brings about a 5 mmHg change in PaO2 values and, when applicable, PaCO2 values. Several studies with a 1 year follow-up have shown that almitrine bismesylate represents a breakthrough in the management of respiratory failure consecutive to chronic obstructive respiratory disease. Only long-term controlled trials will demonstrate whether this drug can really improve the vital prognosis and even alter the natural course of the disease.
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PMID:[Should arterial gas values be improved in patients with chronic bronchitic respiratory insufficiency? Value of almitrine dimesylate]. 614 37

When administered orally, in the usual doses, to chronic bronchitis patients with hypoxaemia and hypercapnia, almitrine bismesylate corrects blood gas disturbances without producing significant changes in haemodynamic and spirometric values. This effect betrays a specific action on the alveolar ventilation/perfusion imbalance responsible for hypoxaemia. The original mode of action of the drug and its clinical and biological effectiveness demonstrated in long-term treatment, as well as its safety, offer new hopes for the management of chronic bronchitis. The possibility of acting on hypoxaemia conveniently and at an early stage should be expected to delay the development of cor pulmonale, but this remains hypothetical and needs to be confirmed, in spite of strong physiopathological bases, by strictly controlled therapeutic trials. It cannot be definitely stated, at this stage, that almitrine will entirely replace continuous low flow rate oxygen therapy, yet it is already certain that the indications for the latter ought to be re-evaluated for physiopathological, practical and financial reasons.
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PMID:[Almitrine dimesylate: deductions and therapeutic prospects]. 614 39

The effects on ventilation, gas exchange and pulmonary haemodynamics of 1 h infusion of 0.5 mg X kg-1 almitrine (Vectarion) were studied in 14 patients with chronic bronchitis, with clear hypoxemia (PaO2 less than 65 mmHg) and hypercapnia (PaCO2 greater than or equal to 45 mmHg). The separate effects of the almitrine solvent and/or the solution were studied in six similar chronic bronchitics. In this latter group, blood gases and haemodynamic values were not significantly altered. In subjects treated with almitrine, PaO2 raised from 51.9 +/- 6.6 (control: T0) to 61.9 +/- 9.9 mmHg at the 60th min (t60) of infusion (p less than 0.001); PaCO2 decreased from 52.8 +/- 6.3 (t0) to 45.7 +/- 5.2 mmHg at t60 (p less than 0.001). The effects on blood gases were still marked 10 min after infusion (t70). The significant increase in PaO2 was faster (10th min) than that of PaCO2 (20th min). The mean pulmonary artery pressure (Ppa) rose appreciably, from 27.8 +/- 11.3 at t0 to 35.5 +/- 12.5 mmHg at t60 (p less than 0.001). This rise was significant from the 10th min (p less than 0.005) and was related to that of pulmonary vascular resistance since on average cardiac output and pulmonary wedge pressure did not change. Ppa came back to its initial value at t70. Thus pulmonary vasoactive effects were at the same time early and transitory. They seemed due to an arterial vasoconstriction (role of chemoreceptors?), which could also explain the perfusion redistribution to the best ventilated areas and the improvement of VA/Q inequalities.
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PMID:[Pulmonary hemodynamic effects of intravenous almitrine in patients with chronic bronchitis and respiratory insufficiency]. 615 73

From 1967 to 1972 12 patients were operated on for emphysematous bullae in the Liverpool regional cardiothoracic centre. The patient with the poorest lung function died in the immediate postoperative period but the remainder survived for more than five years. All but one of the survivors showed evidence of benefit three to six months after surgery and all those not retired returned to full-time employment for at least five years. Nine patients were reviewed 5-10 years after surgery. These all reported a gradual return of dyspnoea, which was matched by a falling one-second forced expiratory volume (FEV1) (mean fall 82 ml a year); but five were still maintaining some of their postoperative improvement. When mean preoperative lung function values were compared with the values obtained 5-10 years later there was still a significant improvement in forced vital capacity; but FEV1, residual volume, transfer coefficient, and arterial oxygen and carbon dioxide tensions were unchanged. Chest radiographs showed no new bullae or (except in one case) any increase in size of pre-existing bullae. We conclude that the removal of large emphysematous bullae did not hasten the progress of the underlying emphysema and that in most patients some benefit lasted for more than five years after the operation. Patients treated by lobectomy fared at least as well as those treated by bullectomy alone. It may be relevant to the relatively good progress of patients in this series that only three had suffered from chronic bronchitis before operation or smoked after operation, all but two had bullae occupying half or more of one hemithorax, and none had hypercapnia.
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PMID:Surgical treatment of emphysematous bullae: late outcome. 640 36

Changes in blood gas tensions occurring when 100% oxygen or air was used as the driving gas for nebulised salbutamol were studied in 23 patients with severe airways obstruction. The patients fell into three groups: nine had chronic bronchitis and emphysema with carbon dioxide retention, seven had emphysema and chronic bronchitis without carbon dioxide retention, and seven had severe asthma (no carbon dioxide retention). When oxygen was used as the driving gas patients who retained carbon dioxide showed a mean rise of 1.03 kPa (7.7 mm Hg) in their pressure of carbon dioxide (Pco2) after 15 minutes (p less than 0.001) but the Pco2 returned to baseline values within 20 minutes of stopping the nebuliser. The other two groups showed no rise in Pco2 with oxygen. When air was used as the driving gas none of the groups became significantly more hypoxic. Although it is safe to use oxygen as the driving gas for nebulisers in patients with obstructive airways disease with normal Pco2, caution should be exercised in those who already have carbon dioxide retention.
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PMID:Oxygen as a driving gas for nebulisers: safe or dangerous? 641 92


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