A class experiment on ganglion block in human subjects / by W.D.M. Paton and Hannah Steinberg.

  • Paton, William D. M.
Date:
[1956?]
Catalogue details

Licence: In copyright

Credit: A class experiment on ganglion block in human subjects / by W.D.M. Paton and Hannah Steinberg. Source: Wellcome Collection.

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    by one of the demonstrators ; in some of the later experi¬ ments the students themselves, under supervision, made the injections. These observations were continued for six observation periods, giving a total period after administration of the drug of two hours. By this time postural hypotension had in almost every case subsided. Occasionally, after this time, if the student stood still for as long as five or ten minutes he felt a little faint; if this happened he was made to sit down and remain behind until he had completely recovered. As a further safeguard subjects were always asked to arrange beforehand that a colleague could see them home that evening if necessary. They were also asked to fill in the following day a report sheet on their sensations and com¬ ments on the experiment. Pooled Average Results Fig. 3 gives the magnitudes of the average effects of hexa- methonium on the supine and standing blood pressure and the pulse rate, on the body temperature, on the temperature of the skin of the big toe, on salivary secretion, on the near and far points, on the size of the pupil in dim light, and on its reaction to bright light. Although these averages conceal large individual variations presently to be discussed, they serve to provide a fair picture of the predominant effects of the drug and of the time course of action. The most prominent effects are a fall in the blood pressure on standing, together with a considerable increase in standing pulse rate, an increase in the temperature of the big toe, and a fall in body temperature. In addition, there is a distinct reduction in the ability of the eye to accommodate for near vision and to react to light. There is also a detectable acceleration of the heart in a supine position and a small constriction of the pupil under dim illumination. The effect on salivary secretion is small, partly because there was a steady fall in the rate of spontaneous secretion as the experiment pro¬ gressed and the time from the last meal increased. Time of Onset of Effects It is notable that, whereas the fall in standing blood pressure reached its peak something like forty minutes after the injection of the drug, and the rise in skin temperature a peak at about the same time or possibly a little earlier, yet the visual effects had a distinctly greater latency, usually being maximal at about sixty minutes and sometimes per¬ sisting after the cardiovascular effects had ceased. The standing systolic blood had usually returned at the end of 100 to 120 minutes to levels high enough to avoid faintness or any other symptom at the end of the one minute’s stand¬ ing, but might not quite have reached normal levels. The earliest sign of the action of the drug to make its appearance was usually the change in standing pulse rate, which reached a peak approximately twenty minutes after the injection.