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Biomedical subjects

J W Hadfield

Publications and source records attributed to J W Hadfield.

9 recordsLinked to original sources
PubMed1988

Dose related effects of salbutamol and ipratropium bromide on airway calibre and reactivity in subjects with asthma.

The relationship between change in airway calibre and change in airway reactivity after administration of bronchodilator drugs has been investigated by comparing the effect of increasing doses of inhaled salbutamol and ipratropium bromide on the forced expiratory volume in one second (FEV1), specific airways conductance (sGaw), and the dose of histamine causing a 20% fall in FEV1 (PD20) in six subjects with mild asthma. On each of 10 occasions measurements were made of baseline FEV1, sGaw, and PD20 after 15 minutes' rest, and followed one hour later, when the FEV1 had returned to baseline, by a single nebulised dose of salbutamol (placebo, 5, 30, 200 and 1000 micrograms) or ipratropium (placebo, 5, 30, 200 and 1000 micrograms) given in random order. Measurements of FEV1, sGaw, and PD20 were repeated 15 minutes after salbutamol and 40 minutes after ipratropium. Salbutamol and ipratropium caused a similar dose related increase in FEV1 and sGaw, with a mean increase after the highest doses of 0.76 and 0.69 litres for FEV1 and 1.15 and 0.96 s-1 kPa-1 for sGaw. Salbutamol also caused a dose related increase in PD20 to a maximum of 2.87 (95% confidence interval 2.18-3.55) doubling doses of histamine after the 1000 micrograms dose, but ipratropium bromide caused no significant change in PD20 (maximum increase 0.24 doubling doses, 95% confidence interval -0.73 to 1.22). Thus bronchodilatation after salbutamol was associated with a significantly greater change in airway reactivity than a similar amount of bronchodilatation after ipratropium bromide. This study shows that the relation between change in airway reactivity and bronchodilatation is different for two drugs with different mechanisms of action, suggesting that change in airway calibre is not a major determinant of change in airway reactivity with bronchodilator drugs.

Administration, Inhalation↗
PubMed1986

Is driving gas flow rate clinically important for nebulizer therapy?

Ten patients with stable asthma were studied to see whether the flow rate used to drive a nebulizer was clinically important. Each received 1 mg of salbutamol in 2 ml of physiological saline via a Sandoz 'Lifeline' nebulizer driven by piped oxygen at 8, 6 and 4 litres/min on separate randomly allocated occasions. Although the time for nebulization was significantly longer as flow rate was reduced, there was no significant difference in the bronchodilator response.

Adult↗
PubMed1982

Localised airway narrowing in sarcoidosis.

Four patients developed multiple narrowings or occlusions of bronchi during the early stages of sarcoidosis when the chest radiograph showed no evidence of pulmonary fibrosis. Three of the patients had symptoms of breathlessness and wheezing and all had an obstructive defect of ventilation. Bronchography showed stenoses that were not apparent at bronchoscopy. It is concluded that the possibility of bronchial narrowing should be considered in patients who develop breathlessness or wheezing at any stage of sarcoidosis, and that bronchoscopy should be supplemented by bronchography.

Adult↗
PubMed1981

Ultrasound of the pleura: an assessment of its clinical value.

In a prospective study, A mode ultrasound scanning contributed to the diagnosis and management of 24 of 50 consecutive patients with pleural disease. In 30% of patients it was superior to radiology in clarifying the solid or fluid nature of a pleural opacity, and in 42% of patients it allowed selection of the most appropriate site for the aspiration of pleural fluid. The technique is simple and the apparatus is widely available. We believe that ultrasound is an important practical aid in the diagnosis and management of pleural disease.

Humans↗
PubMed1981

Diagnostic accuracy of cytology and biopsy in primary bronchial carcinoma.

The accuracy of diagnosis in 656 patients with the four common histopathological types of primary lung cancer has been assessed by comparing the cell type diagnosis made on cytological and histological investigation with that determined by examination of the surgically resected or necroscopy specimen. The accuracy of diagnosis achieved by cytological examination of sputum and bronchial aspirate, and by bronchial biopsy histology was over 85%. The least accurate diagnostic procedure was percutaneous needle biopsy (62%). Squamous and small cell tumours were accurately diagnosed by all four investigations but errors were made in the diagnosis of large cell and adenocarcinomas. Nearly half the number of patients (43%) with large cell carcinoma were later reclassified as having squamous carcinoma and of the patients with adenocarcinoma 32% had been predicted to be squamous and 18% large cell carcinoma. We consider such quality control of pretreatment diagnosis mandatory in management of individual patients and before enrollment in clinical trials.

Adenocarcinoma↗
PubMed1980

Rifampicin-induced thrombocytopenia.

Rifampicin occasionally causes thrombocytopenia when given as part of an intermittent regimen. A case is reported of severe thrombocytopenia developing after one dose of rifampicin, following a 4-month gap in daily therapy. The literature on rifampicin-induced thrombocytopenia is reviewed.

Adult↗