Biomedical subjects

M R Partridge

Publications and source records attributed to M R Partridge.

68 records · Page 4Linked to original sources

PubMed1986

Asthma education: more reading or more viewing?

An audit of a hospital asthma clinic has revealed deficiencies in its educational activities. A significant minority of attending patients failed to understand the rationale behind their therapy and would take potentially inappropriate action when symptoms worsen. Many of those taking oral theophylline therapy were shown to be at risk of self-induced toxicity. Watching a videotape about the disease in the waiting room was found to be more popular than leaflets and books as a source of information.

Adolescent↗

PubMed1984

Direct labelling of ipratropium bromide aerosol and its deposition pattern in normal subjects and patients with chronic bronchitis.

A technique for the direct labelling of ipratropium bromide with bromine-77, with reconstitution of the drug in a metered dose inhaler so as to be identical to the commercial product, was used to study drug deposition patterns in seven normal subjects and seven patients with chronic bronchitis (mean FEV1 32% (SD 12.2%) predicted normal). The gamma camera image of the thorax was divided into a middle zone--the mediastinal zone--and the lung itself into a central zone comprising its medial third and a peripheal zone, the lateral two thirds. Measurements after 10 inhalations of labelled ipratropium bromide showed similar results for the two groups of subjects. The total lung dose inhaled was 11.2% of 203 micrograms and 11.7% of 186 micrograms in the normal subjects and the patients respectively. In contrast to the deposition patterns seen in aerosol studies using steady state inhalation methods, there was no difference in deposition pattern--that is, the distribution between the central and the peripheral lung zones--between the normal subjects and the patients with airways obstruction.

Adult↗

PubMed1981

The site of airflow limitation in asthma: the effect of time, acute exacerbations of disease and clinical features.

We have used the helium/oxygen technique to assess the main site of airflow obstruction in patients with asthma. Of 14 out-patients with asthma studied serially (minimum of three observations over 5-12 months) 10 remained either responders or non-responders to helium/oxygen (He/O2) on each occasion tested, despite variations in severity of airflow obstruction. Four out of six patients studied during an acute exacerbation of asthma were initially non-responders to He/O2 but became responders during recovery. The response to He/O2 of these and 15 other patients with asthma was compared with a variety of clinical features. There was a statistically significant decline in flow rate response to He/O2 breathing with increased length of history of asthma, but no differences in smoking history, are, sex or atopic status between the responders and non-responders. This implies a progressive involvement of smaller peripheral airways during the course of the disease. Perhaps more systematic treatment of young asthmatics would prevent this.

Adult↗

PubMed1981

Moment analysis of the flow-time curve after breathing gases of different densities.

In an attempt to improve methods of determining the site of airway narrowing we have tried using a heavier than air gas mixture (SF6/02) in addition to the more widely used lighter than air gas mixture (HE/O2). Response to varying inspired gas density has been assessed by means of change in mean transit time (MTT) as well as by means of change in flow rate at 50% of vital capacity (Vmax50). The possibility that derivatives of second moment analysis of the flow time curve reflect the presence of small airway disease is studied. The reproducibility of response to SF6/O2 breathing was better than that to He/O2 breathing. However there was no correlation between response to these two gas mixtures in either normal subjects or in patients with asthma. The response of MTT to He/O2 breathing correlated with the response to Vmax50 and although no more reproducible, there are theoretical advantages in using MTT as the method of assessment. The derivative of the second moment of the flow-time curve. COV, did not correlate with flow rate response to He/O2 breathing.

Adult↗

PubMed1981

Site of action of ipratropium bromide and clinical and physiological determinants of response in patients with asthma.

It has been suggested that in normal subjects inhaled anticholinergic agents have a preferential dilating effect on large central airways. We therefore studied 21 patients with asthma to see if response to inhaled ipratropium bromide was related to the initial central or peripheral site of major airway narrowing. Fourteen out of 21 patients with asthma increased their Vmax more than 10% after ipratropium but when assessed by air and helium/oxygen (He/O2) flow-volume curves, responders and non-responders to He/O2 breathing were divided equally between those who benefited from the drug, and those who did not. There were no significant differences in percentage improvement in Vmax between initial responders, and initial non-responders to He/O2 breathing. Furthermore the results from air and He/O2 flow-volume curves suggest that, contrary to some previous reports (not in asthmatics), inhaled ipratropium has a generalised action throughout the airways. There were no differences in severity of airflow obstruction, nor in age, sex, smoking history, or atopic status between those who benefited from ipratropium and those who did not. However, those improving after the drug had a significantly longer history of asthma than those who did not.

Adult↗

PubMed1979

Asthma in Asian immigrants.

Adult Asian immigrants to the United Kingdom attending an asthma clinic have been compared with a control group of non-immigrant Caucasian asthmatic patients of similar age distribution. The Asian immigrants had a later age of onset of asthma than their non-immigrant controls. Comparison with studies of asthmatic patients in India suggests that this may be an intrinsic ethnic difference but an effect of migration in early adult life is not excluded. Despite a later age of onset, the frequency of positive skin prick tests to common allergens was similar in the immigrant and control groups and 71% of the Asians had positive reactions to the house dust mite. Most other clinical features, the variability of airways obstruction and the requirements for treatment showed no significant differences between the two groups.

Adolescent↗

PubMed1979

Effect of hyperlipidaemia on pulmonary diffusing capacity for carbon monoxide.

There is conflicting evidence on the effect of hyperlipidaemia on pulmonary diffusing capacity for carbon monoxide (DLCO or TLCO) in man. We have measured the carbon monoxide transfer factor per unit alveolar volume (TLCO/VA or KCO) by the single breath method in 25 patients with hyperlipidaemia, and in three normal subjects before and after infusions of an intravenous fat emulsion, Intralipid. Non-smokers with hyperlipidaemia had normal levels of TLCO/VA, whereas some of the smokers showed a slight reduction. In neither group was there any correlation of TLCO/VA with serum triglyceride or cholesterol concentrations. A reduction in triglyceride concentrations of up to five-fold produced by plasma exchange (three studies in two patients) or by dietary manipulation (one patient) had no significant effect on the levels of TLCO/VA. Intralipid infusion in three normal subjects caused a four- to five-fold increase in serum triglyceride concentration but had no effect on TLCO/VA. We conclude that moderate degrees of hyperlipidaemia have no effect on pulmonary diffusion.

Adult↗

PubMed1979

Effect of an inhaled antihistamine (clemastine) as a bronchodilator and as a maintenance treatment in asthma.

Although intravenous chlorpheniramine can cause bronchodilatation, oral and parenteral antihistamines have not proved useful in treating asthma. Inhaled antihistamines may cause throat irritation, but a recent study of the antihistamine, clemastine, showed it to be an effective bronchodilator without irritant effects. We have extended these studies to determine the site of action of inhaled clemastine and to assess its potential usefulness both as a bronchodilator and as a maintenance treatment. Eleven stable asthmatic patients received inhaled clemastine and placebo and the effect was assessed by serial maximum expiratory flow volume (MEFV) curves breathing air and a helium/oxygen (He/O2) mixture. There was no significant improvement in peak flow rates during air breathing after clemastine and no significant difference between the responses to drug and placebo. Minor but significant changes were seen in some flow measurements on the downslope of the MEFV curve during air and He/O2 breathing, and these are tentatively ascribed to a dilating effect of clemastine on peripheral airways where flow is laminar. Subsequent administration of inhaled isoprenaline showed the patients to be still capable of significant bronchodilatation. The addition of clemastine, from a pressurised aerosol, to the patients' therapeutic regimen for two weeks was no more effective than placebo in controlling airflow obstruction, and did not reduce the need for standard bronchodilators. In our patients clemastine was not a clinically useful bronchodilator either acutely or as a maintenance treatment for asthma.

Adult↗

PubMed1978