Platelet activation in nocturnal asthma

Platelet activation may be a factor in the bronchial hyperresponsiveness that characterises asthma. As hyperresponsiveness is increased at night, changes in platelet activation over 24 hours were related to the diurnal changes in peak expiratory flow and plasma catecholamine concentrations in five subjects with asthma and five normal subjects. The effect of muscarinic receptor blockade with intravenous atropine at 0400 hours on these measurements was also studied. Platelet activation, assessed as the ration of beta thromboglobulin to platelet factor 4, was highest when the peak expiratory flow rate was at its lowest in the asthmatic subjects. There was no correlation between platelet activation and plasma catecholamine concentrations. Intravenous atropine did not alter the ratio of beta thromboglobulin to platelet factor 4, suggesting that parasympathetic activity is not the cause of the increased platelet activation at night.

Prescribing of nebulized bronchodilators--can we change bad habits?

The accuracy of prescriptions for bronchodilator drugs was monitored before and after an educational circular to the medical staff of five medical wards. The circular contained model prescriptions for beta-agonists alone and combined with ipratropium bromide. There was a significant improvement overall in the accuracy of prescribing.