Blood-Pressure (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1914 edition. Excerpt: ...vagus control does not check the rise of pressure which is apparently due to CO2 stimulation of the vasomotor centre. The change in the pulse rate, on the other hand, is believed to result from vagus stimulation. The difference in response between an open and a closed pneumothorax, which is only one of degree, has been explained as due to the fact that in the latter, in addition to stimuli which result from pleural irritation, those arising in the bronchial mucous membrane (since respiratory excursions are still present) are superadded. The 1 Observations on the Effect on the Blood-pressure of withdrawal of Fluid from the Thorax and Abdomen, Jour. Amer. Med. Assoc., January 5, 1907, xlviii. 2 Zur Frage d. Kiinstlichen Pneumothorax, Pflilger's Arch., 1910, exxxiv, 31. irritation of the pleura is conducted by the sensory fibers of the vagus to the nucleus and produces increased vagus tone.1 Clinical Data.--Spontaneous pneumothorax may come on suddenly with acute pain and shock, especially if the onset occurs during exercise in apparently healthy individuals. Frequently, however, pneumothorax occurs insidiously2 during the course of tuberculosis. In the former instance a primary fall of bloodpressure is succeeded by a rise to above the normal, which is in part at least the result of anxiety, pain, and asphyxia. In the latter instance blood-pressure changes are neither constant nor marked, especially if only a partial pneumothorax is present. There is considerable reason to believe that the occurrence of pneumothorax in the course of tuberculosis may have beneficial effects. Certainly the artificial production of this condition is often attended with marked symptomatic improvement. Just to what extent this is due to changes in the pulmonary...