The effect of ephedrine on experimental shock and hemorrhage.

Abstract

In our previous report, 1 , 2 it was shown that ephedrine, an alkaloid isolated from Ma Huang, possesses sympathomimetic actions. Its outstanding feature is its circulatory stimulation by acting on both the cardiac accelerator ganglia and endings. The rise in blood pressure and pulse rate lasts for more than 15 minutes, and sometimes indefinitely.

The purpose of the present paper is to report the influence of ephedrine in hemorrhage and in shock induced by different methods. All the results were obtained from dogs. Histamine in the dosage of 2-3 mg. per kg., or Witte's peptone in dosage of 50 mg. per kg., caused a fall in blood pressure as low as 30-40 mm. hg., but a subsequent intravenous injection of ephedrine always brought it back to the initial level, and maintained it there for more than 3 hours, when the animal was killed. In surgical and traumatic shock, produced by pinching of the liver, exposure and manipulation of intestines, insertion of ice bags into the abdominal cavity, and opening of windows in the operating room, the external temperature being 25° C., the blood pressure in one experiment fell from 150 to 53 mm. hg. within eight minutes, but was immediately raised to 130 by an intravenous injection of ephedrine. Although there was some fall at the end of 3 hours, it was still well above the critical level. In anaphylactic shock, produced according to the method of Simond, 3 the blood pressure was similarly raised by ephedrine. Finally, the low blood pressure in those animals which had been suddenly bled 25 per-cent of their total volume, was quickly elevated by the injection of ephedrine. The beneficial effect in these cases, however, did not last much longer than one hour, on account of much loss of volume.