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Biomedical subjects

G M Cochrane

Publications and source records attributed to G M Cochrane.

At least 91 records · Page 5Linked to original sources
PubMed1983

The effect of posture on the sympathoadrenal response to theophylline infusion.

We studied the effect of posture on the sympathoadrenal response to intravenous theophylline in six normal subjects. On three separate occasions they received an intravenous infusion of either theophylline (6 mg/kg) while supine, theophylline (6 mg/kg) while standing or saline as placebo while standing. With the subjects standing theophylline caused tremor, a peak heart rate of 99 +/- 6 beats/min, and an elevation of plasma cyclic AMP from 9.3 +/- 0.7 to 15.1 +/- 1.7 nmol/1 (mean +/- s.e. mean). There was a small, but significant, elevation of plasma adrenaline, noradrenaline and glucose. The elevation in plasma catecholamines was insufficient to explain either the sympathomimetic effects of theophylline or the rise in plasma cyclic AMP. Theophylline had little or no effect with the subjects supine. The mean peak theophylline concentration following infusion was significantly higher with the subjects upright than when supine (18.3 c.f. 12.4 mg/l, P less than 0.025). However, adequate plasma levels of theophylline were obtained in all subjects when lying or supine. Analysis of individual data suggests that differences in plasma levels of theophylline are unlikely to account for the increased effects seen on standing. The mechanism of action of theophylline cannot be explained by increased secretion of catecholamines alone. Theophylline appears to amplify the increased sympathetic activity associated with standing and this is probably by phosphodiesterase inhibition.

Adrenal Glands↗
PubMed1983

Aids in the home.

Explore the source record for details and available documents.

Persons with Disabilities↗
PubMed1982

Intravenous naloxone in acute respiratory failure.

A 58-year-old man presented with acute on chronic respiratory failure. In the acute stage of his illness an infusion of the opiate antagonist naloxone caused an improvement in oxygen saturation as measured by ear oximetry from 74% to 85%, while a saline infusion resulted in a return of oxygen saturation to the original value. When he had recovered from the acute episode the same dose of naloxone had no effect on oxygen saturation. These findings suggest that in acute respiratory failure there may be overproduction of, or increased sensitivity to, endorphins.

Acute Disease↗
PubMed1982

The rate of rise of alveolar carbon dioxide pressure during expiration in man.

1. The purpose of the study was to see whether the rate of rise of alveolar PCO2 (PA, CO2) in expiration was directly proportional to the rate of pulmonary elimination of CO2 (VCO2) in man in the steady state. 2. Alveolar ventilation at rest and during exercise in man was calculated from the difference between total ventilation and dead space ventilation, and from the ratio of the rate of pulmonary CO2 elimination to the mean expired alveolar CO2 (total) fraction. The results were indistinguishable. In agreement with other workers' findings alveolar ventilation changed in direct proportion to the rate of carbon dioxide elimination, confirming the isocapnia of exercise ventilation in man. 3. The rate of rise of expiratory alveolar PCO2 in individual breaths has been obtained by two methods. In the first, a pattern of respiration with constant expiratory flow in each breath brought expiratory alveolar profiles to the outermost end of the airway. In the second method, the early part of the alveolar PCO2 during normal expiration was calculated from airway PCO2 and expired volume. 4. The data obtained with both methods show that, in the steady state, expiratory alveolar PCO2 rises at a rate which is directly proportional to the rate of CO2 production.

Carbon Dioxide↗
PubMed1982

Plasma concentrations of lignocaine during fibreoptic bronchoscopy.

Peak plasma concentrations of lignocaine were recorded in 41 patients receiving topically applied lignocaine for fiberoptic bronchoscopy. Adequate anaesthesia was achieved in all patients with an average dose per unit weight of 9.3 +/- 0.5 mg/kg (SEM) giving a mean peak plasma concentration of 2.9 +/- 0.5 mg/l-1 (SEM) (+/- SEM 0.5). The plasma concentration exceeded toxic levels of 5.0 mg/l-1 in only two patients, and no complications were observed. Peak concentrations were influenced only by dose per unit weight administered and not by factors considered likely to influence mucosal absorption from the bronchial tree, such as sputum production, airflow obstruction, or cigarette smoking. A major proportion of the total dose of lignocaine was required to anaesthetise the nose, pharynx, and larynx, only a small proportion being needed for the bronchial tree. Lignocaine gel (2% w/v) was preferred by patients, and in a study of 10 volunteers, produced lower plasma concentrations when used as a topical anaesthetic than did lignocaine aerosol (10% w/v) or lignocaine solution (4% w/v).

Administration, Topical↗
PubMed1982

High-dose inhaled terbutaline in the management of chronic severe asthma: comparison of wet nebulisation and tube-spacer delivery.

Eight patients with chronic severe asthma, poorly controlled by conventional doses of inhaled bronchodilator, were treated with high-dose inhaled terbutaline (4 mg four times daily), via either wet nebulisation of terbutaline respirator solution, or by tube-spacer aerosol, using cannisters delivering 1 mg terbutaline per metered dose. All patients improved objectively and subjectively on these higher dosage regimens during both day and night. A trial of high-dose inhaled beta2 sympathomimetic therapy should be considered in any patient with chronic severe asthma who fails to obtain benefit from standard doses of inhaled bronchodilator.

Aerosols↗
PubMed1982

Rheumatoid arthritis: vocational rehabilitation.

The consequences of inflation and accelerating introduction of automation and microprocessors into industry are a shift from unskilled to skilled work, the lessening of opportunities for the unskilled worker, and growing unemployment. If disabled people are competing for employment they must take every opportunity to extend education and acquire skills. Juvenile chronic arthritis presents one set of problems in vocational rehabilitation at the beginning of a working career and adult rheumatoid arthritis another, commonly in those over 45 years old and previously established in work. The prevalence of severe disability in juvenile chronic arthritis is about 1 in 20 000 of the population, females are affected twice as often as males and 1 in 10 has defective vision or blindness due to chronic iridocyclitis. At school, besides education, there must be emphasis on encouraging independence, self-confidence, mobility and determination. A School Leavers' Conference early in the last year at school gives the adolescent the best chance of choosing a career. Rheumatoid arthritis is three times more common in women and increasingly, over the last 40 years, women are working besides home-making. Morning stiffness, fatigue, immobility and pain are the common symptoms of widespread involvement of joints and systemic disturbance. The principal determinant in the success of vocational rehabilitation is personality, and the social and environmental factors are more significant than the degree of disability. The Disablement Resettlement Officer can assure continuity of rehabilitation between the health and employment services: a favourable outcome is work, self-derived income independence and freedom of movement using whatever technical aids are required to achieve this.

Adolescent↗
PubMed1981

Respiratory arterial pH and PCO2 oscillations in patients with chronic obstructive airways disease.

1. Arterial pH oscillations have been monitored in vivo in patients with well defined chronic obstructive bronchitis, asthma and clinical emphysema. 2. The patients with clinical emphysema were shown to differ from those with chronic obstructive bronchitis on the basis of a number of clinical and physiological criteria. 3. Patients with asthma showed least attenuation of their pH oscillations as a group, in contrast to emphysematous patients who showed most attenuation. In patients with clinical emphysema the attenuation was relatively homogeneous. The patients with chronic obstructive bronchitis showed the full range from normal oscillations (zero attenuation) to zero (complete attenuation). 4. The amplitude and approximate rate of change of upslope of the PaCO2 oscillations in vivo were calculated, from measured pH oscillation amplitudes, using buffer slope values in vitro from Siggaard Anderson [(1962, 1963) Scandinavian Journal of Clinical and Laboratory Investigation, 14, 598-604; 15, 211-217], then dividing the PaCO2 amplitude by half the respiratory period. 5. Mean arterial PCO2 in vitro showed a very strong correlation with the downslope of the pH oscillation in vivo (calculated as for PaCO2 upslope) in patients without clinical emphysema. This correlation would be expected to some extent, owing to the logarithmic relationship of PaCO2 oscillations to pH oscillations. However, the mean arterial PCO2 also showed a very strong correlation with the upslope of the calculated PaCO2 oscillations, again excluding patients with clinical emphysema.

Adult↗
PubMed1981

Sleep apnoea in diabetic patients with autonomic neuropathy.

Breathing during sleep was monitored in 8 diabetic patients with objective evidence of autonomic neuropathy and in 8 diabetic patients without neuropathy. Thirty or more periods of apnoea lasting 10 seconds or longer during one night's sleep were demonstrated in 3 of the diabetic patients with autonomic neuropathy. Such apnoeic periods may be related to the high incidence of cardiorespiratory arrests reported in such patients, particularly in association with anaesthesia or pneumonia.

Adult↗
PubMed1981

Effect of inhaled alpha-blocker on airflow obstruction in asthma.

A controlled study of the effect on airflow obstruction of 30 mg of the alpha-blocker thymoxamine given by inhalation is reported in 10 patients with chronic stable asthma. No significant change in peak expiratory flow rate was seen with either thymoxamine or placebo in any patient. Alpha-adrenergic receptors are therefore unlikely to contribute significantly to resting bronchomotor tone in chronic stable asthma.

Adult↗