514 



THE VENOUS OXYGEN CONTENT AND THE ALKALINE 



RESERVE OF THE BLOOD IN PNEUMONIC 



INFLUENZA. 



By H. S. Halcro Wardlaw, D.Sc., Linnean Macleay Fellow 

 of the Society in Physiology. 



(From the Physiological Laboratory of the University of 



Sydney. ) 



The skin of persons suffering from pneumonic influenza often 

 assumes a distinctly bluish or plum-coloured tinge. This colour 

 ation was at first described as a cyanosis, and was attributed to 

 the most likely cause of such a condition : a deficient oxygenation 

 of the blood in the lungs. Such an assumption is the most 

 natural one to make to explain a condition of this kind accom- 

 panying a disease of the respiratory system. It was observed, 

 however, that many of the persons whose skins became coloured 

 in this way did not show any marked signs of respiratory dis- 

 tress . 



The question therefore arose, whether this colouring of the 

 skin really was a cyanosis in the generally accepted sense of 

 the word, that is to say, whether the colour actually was due to 

 an abnormally large proportion of reduced haemoglobin in the 

 blood. An excess of haemoglobin would be the result of de- 

 ficient oxygenation of the blood, and under ordinary conditions 

 of acidity, would lead to marked dyspnoea. 



To explain the absence of obvious respiratory distress in the 

 case of the " cyanosis" accompanying pneumonic influenza seve- 

 ral hypotheses have been put forward. It has been suggested 

 that the nerve centre governing respiration may be poisoned; 

 that its sensitiveness may thus De dulled, and that the accumula- 

 tion of products due to insufficient oxidation may no longer 

 produce its customary response in increased ventilation of the 

 lungs . 



Another suggestion is that the colouring matter of the blood 

 may itself be altered somehow. It may no longer be capable of 

 taking up its normal amount of oxygen in the lungs, and a 



