Methods of Raising a Low Arterial Pressure, 



Summary. 



When the arterial pressure is low from loss of blood, it cannot be brought 

 back, except to a certain degree, by the injection of saline solution in volume 

 equal to that of the blood lost. But if the viscosity of such solutions is 

 raised to that of the blood, a return to normal height is possible. 



The effect of saline injections is also much less lasting than that of 

 solutions containing gum or gelatin. The difference in this case is due to the 

 osmotic pressure of the colloids, by which loss of water by the kidneys and to 

 the tissues is prevented. Solutions containing gum do not produce oedema in 

 artificial perfusion of organs. 



When the fall of blood pressure is due to peripheral vaso-dilatation, gum 

 or gelatin solutions, although more effective than pure saline, produce a much 

 less permanent rise than in cases of loss of blood. No signs of heart failure 

 could be detected and the cause of the fall of the raised pressure to its original 

 height- is still obscure. The combination of a small dose of barium chloride, 

 as recommended by Langley, with a moderate amount of gum solution was 

 found to be the most satisfactory method in such cases and no diminution of 

 vaso-motor excitability resulted. 



The view that fall of arterial pressure produces peripheral vaso-constriction 

 by means of nervous channels and that rise of arterial pressure produces 

 vaso-dilatation was confirmed by artificial perfusion of a limb. 



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(2) Scarpa, < Arch, di Fisiol.,' vol. 5, p. 375 (1908). 



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(1906). 



(4) Moore and Roaf, 'Biochem. Journ.,' vol. 2, p. 34 (1907). 



(5) Knowlton, 'Journ. Physiol.,' vol. 43, p. 219 (1911). 



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(7) Starling, 'Journ. Physiol.,' vol. 19, p. 312 (1896). 



(8) Bayliss, ' Roy. Soc. Proc.,' B, vol. 81, p. 269 (1909). 



(9) Fischer and Hogan, ' Kolloidchem. Beihefte,' vol. 3, p. 385 (1912). 



(10) Bayliss, ' Roy. Soc. Proc.,' B, vol. 84, p. 229 (1911). 



(11) Boycott, 'Journ. Path. Bacterid.,' vol. 18, pp. 11 and 498 (1913). 



(12) Downs, ' Amer. Journ. Physiol.,' vol. 40, p. 522 (1916). 



(13) Evans and Ogawa, ' Proc. Physiol. Soc.,' in ' Journ. Physiol.,' vol. 49, p. ix (1915). 



(14) Langley, ' Journ. Physiol.,' vol. 45, p. 239 (1912). 



(15) Johansson and Tigerstedt, ' Skand. Arch. Physiol.,' vol. 1, p. 331 (1889). 



(16) Pilcher and Sollmann, ' Amer. Journ. Physiol.,' vol. 35, pp. 59 and 70 (1914). 



(17) Bogert, Underbill and Mendel, 'Amer. Journ. Physiol.,' vol. 41, pp. 189 and 219 



REFERENCES. 



(1916). 



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