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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    to be made on more than 70 students, without any mis¬ hap. The development of the experimental procedure has also prompted us to devise some methods for measuring autonomic function which may be of use to others. Methods Systemic Blood Pressure.—This was measured, using the conventional cuff, by auscultation at the elbow, combined with palpation of the radial pulse when difficulty was found in hearing the sounds in the brachial artery. The blood pressure was taken in the supine position and then standing. To estimate the standing blood pressure sixty seconds, timed with a stop-clock, was allowed to elapse after the subject had got to his feet, and the systolic and diastolic pressures were recorded as near as possible to this time. Where pos¬ tural hypotension made it impossible to obtain a reading, the subject was made to lie down despite the absence of a reading. Under these circumstances it was usually possible to state that the blood pressure was at least below a certain level. Pulse Ra’e.—This was measured in the supine position and in the standing position at the same time as the blood pressure was measured, the observations being made by a second observer. Skin Temperature.—This was measured using a thermo¬ couple and galvanometer, with a reference junction in ice. It was usual to place a thermocouple on the plantar surface of the right big toe, marking the region with a spot of ink so that the same place could be used each time. The thermo¬ couple unit used was that devised by Professor F. R. Winton ; it consisted of a copper-constantan junctipn mounted on a coil of two wires enclosed in a glass tube of 8 mm. internal diameter. When the end of the tube was applied to the skin the thermocouple was held lightly in contact with the skin and shielded by the surrounding tube from draughts. The reading was taken when a steady value was obtained after about thirty to sixty seconds. The body temperature was also recorded, using a clinical thermometer under the subject’s tongue and taking the reading after three minutes. These measurements were not made systematically during the first year, since it was not then appreciated how great a fall in body temperature could occur under the conditions of the experiments. The room temperature was also recorded. Salivary Secretion.—As a rough measure of the salivary secretion by the subject the following procedure was used. While in the supine position he was instructed to swallow any saliva already in his mouth. He was then fed eight half¬ circles of filter paper (12.5 cm. in diameter), one at a time, which had been impregnated with 2.5% citric acid. The subject moved these about gently in his mouth so as to