2o8 Transactions of the Canadian Institute. [Vol. \'II. 



eleven — more than 50 per cent — were doubtful. Their 17th Conclusion 

 is that, " Imperfect anaesthesia is the cause of a large number of cases 

 of danger under chloroform." 



We have seen that workers differ greatly as to the danger of great 

 falls in blood pressure due to chloroform administration. It seems 

 clear, however, that such falls are at any rate indications that the patient 

 is very deeply under, and if only one could clinically recognize such a 

 fall with ease it would be a valuable danger signal. Duplay and 

 Hallion^ hope before long to describe a method of ascertaining the 

 blood pressure during surgical operations under anaesthetics ; and if 

 they or any one else should succeed, a valuable result will have been 

 attained. 



Occasionally during the administration of chloroform, sudden falls of 

 blood pressure may occur, along with marked slowing of the pulse, 

 evidently of the nature of vagus inhibition of the heart. Such falls were 

 noted by the Glasgow Commission, and were considered to be a cause of 

 sudden death under chloroform.'- The members of this Commission, in 

 discussing the points of agreement between them and the Hyderabad 

 Commission, say that " Both observed peculiarly sudden and unexpected 

 falls of pressure and slowing of the heart. The Commissions differed as 

 to the origin of these. The Hyderabad Commission attribute it to 

 asphyxia ; the Glasgow Commission say not asphyxia, whatever may 

 be the cause.'"^ These falls closely resemble those which we gave early 

 in this work as occurring occasionally in dogs apparently without 

 cause ; no chloroform being administered at the time. When 

 they occur during the administration of chloroform the Hyderabad 

 Commission, as stated, consider them to be asphyxial and of no danger, 

 in fact, the opposite, as tending to prevent the further absorption of the 

 poison. Lieut.-Col. Lawrie* dogmatically states that, " The special 

 effects which the Glasgow Commission attributed to chloroform were 

 produced by accidental asphyxia . . . the slowing of the pulse and 

 circulation through stimulation of the vagus is a safeguard in chloroform 

 poisoning." 



Tracing 22 shows such a fall. Chloroform was started at 7, the dog 

 being already slightly under. He struggled a little. The sudden fall 

 occurred ten seconds later. The chloroform was not removed, and yet 



1 Archives Generales de Medicine, Aug. 1900. 



2 Journal ot Anatomy and Physiology, Vol. XIII., p. 395. 



3 " Remarks on the 2nd Hyderabad Commission," by Drs. McKendrick, Coats and Newman, British 

 Medical Journal, June 14th, 1900. 



4 Lancet, June 21st, 1900. 



