FEVER. 



405 



a cold bath. The elimination of urea is increased between one-third and two- 

 thirds. In dogs suffering from septic fever Naunyn observed increased elimina- 

 tion of urea even before the temperature rose prefebrile elevation. At times, 

 however, the urea is in part retained during the febrile process and is eliminated 

 in large amount after the termination of the febrile attack epicritical elimination 

 of urea. The uric acid also is increased. At the same time the urinary pigment 

 derived from the hemoglobin may be increased twenty times and the elimination 

 of calcium be increased seven times. The urinary water is diminished (in typhoid 

 fever) and is excreted in greater amount during convalescence. The fact that the 

 combustion-processes in the body of the febrile patient are exceptionally increased 

 if he be placed in a warmer atmosphere appears especially noteworthy. During 

 the febrile process there is also an increase in oxidation-processes under the influ- 

 ence of colder surroundings, but the increase of combustion in warm surroundings 

 is much greater than in cold. 



4. Diminished Heat-dissipation. That in some cases febrile temperature may 

 actually result from diminished heat-dissipation is shown, for instance, by the 

 sudden attacks of fever that occur after catheterization or with the passage of a 

 gall-stone through tire bile-duct. These are brought about solely through reflex 

 irritation of the vasomotor center, which greatly interferes with heat-dissipation 

 in consequence of contraction of the cutaneous vessels. In other forms of fever 

 in man diminished heat-dissipation is only in part a causative factor, as the fol- 

 lowing analysis will show: 



(a) The Stage of Chill, or the Cold Stage. Here the loss of heat through the 

 pale, anemic skin, by conduction, radiation and evaporation of water, is diminished 

 in greatest degree, but also heat-production is from one and one-half to two and 

 one-half times greater. The rise of temperature in the febrile stage, which 

 often is rapid and marked, alone establishes the fact that the diminished heat- 

 dissipation is not the sole cause of the elevation of temperature. (6) In the hot 

 stage loss of heat from the reddened, hyperemic skin is increased, but the in- 

 creased heat-production still preponderates, v. Liebermeister estimates that a 

 temperature-elevation of i, 2 , 3 or 4 C. corresponds with an increase in heat- 

 production of 6 per cent., 12 per cent., 18 per cent., or 24 per cent., respectively. 

 (c) In the sweating- stage heat-dissipation from the reddened, moist skin, and 

 evaporation, are most pronounced, being more than two or three times the normal 

 loss. Under these circumstances he at -production is either increased or normal 

 or subnormal, so that under such conditions the temperature of the body likewise 

 may become subnormal, down to 36 C. In case of fatal collapse the produc- 

 tion has fallen to three-fourths or one-half of the normal, without simultaneous 

 increase in heat-dissipation. 



Plethysmographic examinations of the vessels of the arm in febrile patients 

 have shown, in accordance with the temperature- variations during the febrile 

 process, that the blood-vessels begin to contract before any elevation of tem- 

 perature is evident. With the progress of the contraction the temperature then 

 rises, and both reach their maximum at the same time. The decline in tempera- 

 ture is subsequently preceded by dilatation of the vessels, and with marked dilata- 

 tion of the vessels the temperature again falls to the normal level. 



5. Deranged Heat-regulation. High surrounding temperature may increase 

 that of the febrile patient more than that of a non-febrile individual. The reduc- 

 tion in heat-production that permits normal animals to maintain their normal 

 temperature in warm surroundings is far less during fever. 



Among the accessory phenomena of fever the following are especially note- 

 worthy: Increase in the intensity and number of the heart-beats, and respiration 

 in adults to 40, in children to 60 in the minute. Both are compensatory phenomena 

 of the elevated temperature. There are, further, diminished digestive activity and 

 intestinal movement, derangement of cerebral activity, of the secretions, of muscu- 

 lar activity, interference with elimination, as for instance of water, or of admin- 

 istered potassium iodid, through the urine. Febrile pyrexia is by some con- 

 sidered as having a curative influence on the body, it being reasoned that the 

 body is cleansed and purified by the heat of the fever. In the presence of 

 high fever molecular degeneration of the tissues has often been found. 



With respect to the blood-corpuscles during fever reference may be made to 

 p. 50, i, to the amount of carbon dioxid in the blood on p. 81, to the vascular 

 tension on p. 142, to the saliva on p. 339, to the digestion on p. 341 D. The utiliza- 

 tion of the food throughout the entire tract has not been found interfered with in 

 marked degree. 



In experiments on animals Krehl and Mathes found an increase of 10 per 



