The use of corticosteroids in the treatment of acute asthma.

A study of 23 patients admitted to hospital with severe acute asthma is reported in which plasma cortisol level on admission was significantly correlated with the degree of acidaemia and pulse rate. Patients who had not previously received treatment with corticosteroids responded satisfactorily to repeated daily injections of tetracosactrin depot, the rate of improvement being comparable to that observed in other patients treated with intravenous hydrocortisone hemisuccinate. A prompt and sustained rise in plasma cortisol was also seen following tetracosactrin. The total daily dose of hydrocortisone required to achieve plasma cortisol levels above 100 mug/100 ml was less when given by continuous intravenous infusion compared with intermittent injections, and a regime of 3 mg/kg body weight every six hours by infusion appeared satisfactory. Most patients reported subjective improvement by about four hours after starting treatment but objective evidence did not appear until about six hours from the start. Measurements of FEV1 and FVC proved to be the most reliable indices of the beginning of improvement although pulse rate was the first index to show maximum improvement. Previous maintenance treatment with corticosteroids in patients with asthma did not appear materially to affect the plasma half-life of intravenous hydrocortisone (4 mgm/kg body weight) when compared with healthy subjects or other patients with asthma who had not previously been treated with corticosteroids.