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Query: UMLS:C0002871 (anemia)
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IN ADDITION TO THE RESULTS BROUGHT OUT IN THE SEPARATE SECTIONS I WISH TO DIRECT ESPECIAL ATTENTION TO THE FOLLOWING CONCLUSIONS: (1) In ten cases of Cheyne-Stokes respiration observed clinically, the alternate periods of respiratory activity and apnoea were associated with Traube-Hering waves of blood pressure. These cases may be separated into two groups characterized by the relation of the respiratory changes to the changes of blood pressure. In one group the period of respiratory activity was associated with a rise of blood pressure, the period of apnoea with a fall; in the other group, the reverse relations existed. The former group included two cases of Cheyne-Stokes respiration occurring with increased intracranial tension; the latter contained eight cases with cardiac and arterial disease. (2) By means of cerebral compression, periodic respirations may be produced experimentally, and the relation of the blood pressure changes to the respiratory variations are the same as in the clinical cases with increased intracranial tension, namely, a rise of pressure with each group of respirations and a fall with each period of apnoea. In the experiments, during each respiratory group, the blood pressure rises above the line of intracranial tension and with each period of apnoea it falls below this line. With the disappearance of this relation, the periodicity of the respirations likewise disappears. It is probable that the same relation between the blood pressure and intracranial pressure exists when Cheyne-Stokes respiration occurs clinically in association with increased intracranial tension. (3) Disappearance of the periodic respiratory activity in the clinical cases of both groups is accompanied by disappearance of the waves of blood pressure. (4) The waves of blood pressure cannot be regarded as a mechanical effect of the periodic respiratory activity; on the contrary the latter must be due to the changes of blood pressure, or both phenomena may be referable to a common cause. (5) Cheyne-Stokes respiration in states of increased intracranial tension, with blood pressure waves rising and falling above and below the line of intracranial tension, is due to periodic activity of the respiratory, vasomotor, and cardio-inhibitory centres, the underlying cause of which is an alternate anaemia and blood supply to the medullary centres. The vasomotor centre, as the result of periodic increase and decrease of the stimulus, shows periodic variations in its activity. It is stimulated to greater activity during the periods of anaemia, and partially relaxes with each period of blood supply. During the periods of anaemia, the respiratory centre loses its irritability for the acting stimulus, and is therefore apnoeic. It is finally stimulated to activity, either as a result of an increase in its irritability from a preceding rise of blood pressure, or from a great increase in the respiratory stimulus. The cardio-inhibitory centre is stimulated by the periods of anaemia. This stimulation causes slowing of the pulse, which passes off to a considerable extent with the following period of blood supply. (6) Cheyne-Stokes respiration has heretofore been regarded as always the manifestation of the same conditions and capable of the same explanation; the results of this work, on the contrary, show that two distinct groups of cases may be recognized, depending upon the relation of the blood pressure changes to the periodic respiratory activity.(19) (7) The medullary centres show great differences in their susceptibility to anaemia. The respiratory centre is very susceptible to a much reduced blood supply; its irritability is rapidly reduced or lost upon the occurrence of marked or complete anaemia, and is rapidly regained when the blood supply is renewed if the anaemia has not been maintained too long. The effect of a considerable anaemia upon this centre is entirely different from that of a normal or somewhat reduced supply of blood which is more venous than normal, that is, contains more carbon dioxide and less oxygen, such as occurs with ordinary asphyxia. The vasomotor and cardio-inhibitory centres are not nearly so susceptible to anaemia. The former centre may, and frequently does, respond when in a condition of complete anaemia. (8) I am able to confirm, as a result of my experiments upon cerebral compression, in all essential details the conclusions of Cushing, and the general law formulated by him, namely that "an increase of intracranial tension occasions a rise of blood pressure which tends to find a level slightly above that of the pressure exerted against the medulla."
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PMID:CLINICAL AND EXPERIMENTAL OBSERVATIONS UPON CHEYNE-STOKES RESPIRATION. 1986 60

THE RESULTS OF THIS STUDY OF THE CHANGES IN THE BLOOD AFTER SPLENECTOMY AND OF THE EFFECT OF THE ADMINISTRATION OF HEMOLYTIC SERUM ALLOW THE FOLLOWING TENTATIVE CONCLUSIONS: 1. The failure of a hemolytic serum to cause jaundice is due in some way to the anemia which frequently follows splenectomy. Animals, whether splenectomized or not, which have a low blood count and low hemoglobin content do not readily develop jaundice after administration of a hemolytic serum. On the other hand, in animals with a normal blood picture such a serum readily causes, during early periods after splenectomy, a well marked jaundice. 2. The difficulty of producing hemoglobinemia and jaundice in animals splenectomized one month or more, is due, as shown by blood count, the use of hypotonic salt solution test, and by the search for the presence of hemoglobin in the serum and urine, to an increase in the resistance of the red cells. The results of detailed serologic tests upon this point will be presented later. 3. It is possible that spontaneous jaundice occurring at long periods after splenectomy is an accompaniment of the complete regeneration of the blood. The study of the blood in animals splenectomized for long periods, seven to ten months, indicates that spontaneous jaundice occurs only when the animal has recovered from the initial period of anemia and has a high red cell count and high hemoglobin content. 4. As to the mechanism responsible for the anemia following splenectomy and for the increased resistance of the red cells, we can at present offer no explanation.
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PMID:THE RELATION OF THE SPLEEN TO BLOOD DESTRUCTION AND REGENERATION AND TO HEMOLYTIC JAUNDICE : III. THE CHANGES IN THE BLOOD FOLLOWING SPLENECTOMY AND THEIR RELATION TO THE PRODUCTION OF HEMOLYTIC JAUNDICE. 1986 10


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