34 



Scientific Proceedings (36). 



with a supply of oxygen, the animal is' often able to pass over the 

 first critical stage of anaphylactic shock, and if sufficient lung area 

 is left, the heart not weakened, and the vaso-motor apparatus left 

 intact so as not to incur too low a blood pressure, the animal al- 

 most invariably recovers. The tables which follow will illustrate 

 clearly the relative value of the four methods thus far found most 

 efficient in reducing the death rate of guinea pigs, and the advan- 

 tage of artificial respiration, especially when oxygen is used. 



A large number of drugs have been tried, but thus far no com- 

 bination seems to equal that of oxygen, adrenalin, and chloral-ure- 

 thane just before injecting the serum into the jugular vein. Aside 

 from the greater number of pigs saved by this method it is of in- 

 terest to note the difference in time intervening between the 

 moment of injecting the serum, and that of death. In almost 

 every case artificial respiration with oxygen prolongs the life ot 

 the animal. Next in efficiency is the administration of atropin or 

 still better oxygen and then atropin. It is well to observe that 

 certain pigs die, in spite of the best treatment, even though one 

 third or more collapsible lung area be left after the injection ; the 

 blood pressure of such animals if recorded will eventually be found 

 to be very low and it gradually gets lower and lower until the 

 animal finally dies. The cause of this seems to be primarily 

 cardiac in origin, the heart beats being greatly diminished in rate 

 and force. There is also some evidence of vaso-dilation and of 

 venous congestion. These are in brief the points which our pres- 

 ent experiments indicate and it is left for a subsequent paper to 

 treat more in detail the effects of various factors influencing 

 anaphylactic shock. 



In conclusion it may be said that in the light of the experi- 

 ments thus far performed the cause of sudden death from serum 

 anaphylaxis is due to asphyxia. The asphyxia is peripheral in 

 origin, and in all probability Auer and Lewis are correct in 

 attributing the asphyxia to tetanic contraction of the muscles of the 

 bronchiolae and alveolar ducts, thereby not admitting of further 

 ventilation of the alveolae. This condition of inspiratory immo- 

 bilization may be greatly allayed and even abolished by certain 

 drugs. Thus far with very sensitive pigs it has been possible to 

 save with atropin sulphate about 28 per cent., with injections of 

 chloralhydrate plus urethane and adrenalin, 41 per cent., by ad- 



