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Biomedical subjects

M Rudolf

Publications and source records attributed to M Rudolf.

13 recordsLinked to original sources
PubMed1979

Changes in arterial blood gases during and after a period of oxygen breathing in patients with chronic hypercapnic respiratory failure and in patients with asthma.

1. Ten patients with chronic hypercapnic respiratory failure (group 1) and eight patients with asthma (group 2) breathed pure O2 from an MC mask for 60 min. Blood gases were measured during this period and for the subsequent 45 min. 2. In mine of ten patients in group 1 and in all eight patients in group 2 arterial O2 tension (Pa,O2) fell to values lower than had been obtained before O2 was given. 3. These undershoots in Pa,O2 are unrelated to changing CO2 stores or to hypoventilation, and are more likely due to persistence of altered ventilation-perfusion ratios associated with O2 breathing. 4. Magnitude of the undershoots is usually small, and periods of less than 15 min of O2 are unlikely to be harmful.

Adolescent↗
PubMed1978

Depression of central respiratory drive by nitrazepam.

In a group of patients with chronic bronchitis, repeated night sedation with 10 mg nitrazepam produced a fall in central respiratory drive and a steady rise in arterial carbon dioxide tension. The changes produced over a five-day period were not clinically important, except in two patients who were already hypercapnic before receiving nitrazepam. The use of this drug in patients with carbon dioxide retention should be avoided.

Aged↗
PubMed1978

Central airways obstruction in carcinoma of the bronchus treated by radiotherapy: a study of pulmonary function.

A battery of lung function tests was performed on 28 patients with carcinoma of the bronchus, before radiotherapy, six weeks later, and at three months. Twenty-five had evidence of ariways obstruction, though only five had a forced expiratory ratio of less than 50%. Nine were shown to have obstruction to a main or lobar bronchus, while 11 definitely did not, but the only significant difference in lung function between groups was in the residual volume calculated from single breath helium dilution. Eight of ten cases of squamous cell carcinoma were central, and seven of these obstructive. Of seven cases with undifferentiated cells only two were central (p less than 0.05) and one obstructive. Breathlessness on presentation was significantly more common in patients with central tumours (6/12) than those with peripheral lesions (1/8), and all six breathless patients with central tumours claimed that this symptom improved after radiotherapy. Radiotherapy may have a palliative effect for breathlessness in patients with central airways obstruction due to tumour.

Aged↗
PubMed1978

Bromhexine in severe asthma.

Fourteen patients with acute severe asthma necessitating hospital admission were all treated with a standard therapeutic regimen, and in addition received either bromhexine or placebo (initially intravenously and subsequently orally) double-blind. We were unable to show any significant improvement in the rate of recovery of the bromhexine-treated group, in terms of either arterial blood gases or change in peak expiratory flow rates.

Acute Disease↗
PubMed1978

Breathlessness.

Explore the source record for details and available documents.

Dyspnea↗
PubMed1977

Hypercapnia during oxygen therapy in acute exacerbations of chronic respiratory failure. Hypothesis revisited.

A modification is proposed to the well-known hypothesis which explains the development of progressive carbon-dioxide retention in patients with acute exacerbations of chronic respiratory failure when they are given supplementary oxygen to breathe. It is suggested that, in these patients, increased production of lactic acid by the brain, due to profound hypoxia, leads to a central hypoxic drive to breathing which is absent in remission when the arterial oxygen tension is higher. Evidence from the literature in support of this modification is sought by comparing the respiratory response to oxygen of patients in an acute exacerbation of respiratory failure with the response of patients in a chronic stable state. Three patients are described in whom the response to oxygen during an acute infective episode was very different from their response when in remission.

Acute Disease↗
PubMed1977

The effect of isoprenaline on plasma renin activity in man: a dose-response curve.

Four normal subjects on a free sodium intake received intravenous isoprenaline in doses of 2, 4, 8 and 16 microgram over 2 min. Three of the subjects received a second infusion of 8 microgram. The rate of renin release indexed by changes in plasma renin activity increased in all subjects at each dose level. The mean peak levels of plasma renin were 9%, 29% and 77% above the mean control levels at doses of 2, 4 and 8 microgram respectively. The response of 16 microgram was no different from that seen with 8 microgram. The renin response obtained at 8 microgram was highly reproducible such that the coefficient of variation for duplicate estimations of plasma renin (twelve duplicates) ranged from 1.7 to 4%.

Dose-Response Relationship, Drug↗
PubMed1976

80% of patients with intrinsic asthma are homozygous for HLA W6. Is intrinsic asthma a recessive disease?

Of 26 patients with intrinsic asthma, 21 (81%) were homozygous for the histocompatibility antigen HLA-W6. Also, half the patients had complement defects, in particular low levels of C2. This is the first indication of a strong genetic component in intrinsic asthma, apart from that already known from family studies. These findings suggest that intrinsic asthma may be a recessive disease.

Asthma↗
PubMed1976

Effect of nitrazepam and flurazepam on the ventilatory response to carbon dioxide.

Ventilatory response to CO2 was measured before and after two different benzodiazepine hypnotics in both chronic bronchitics and patients without chest disease. Flurazepam, but not nitrazepam, produced a significant decrease in CO2 sensitivity, although there was no significant change in FEV1 or mixed venous PCO2. This is the first unequivocal evidence of central depression of respiration by a benzodiazepine and may be the mechanism by which benzodiazepines cause deterioration in patients with respiratory failure.

Adolescent↗