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Ventilation of the Lung during Chloroform Narcosis. 

 By G. A. Buckmaster and J. A. Gardner. 



(Communicated by Dr. A. D. Waller, F.R.S. Received August 19, — 

 Read November 16, 1911. 



(From the Physiological Laboratory, South Kensington, University of London.) 



In the report of the Chloroform Committee of the British Medical 

 Association for 1910, the view is expressed that during chloroform narcosis 

 the blood retains unimpaired up to the time of death its normal capacity of 

 absorbing oxygen, and that if the amount of this gas diminishes in the blood, 

 the decrease is solely due to the slowing of the respiration. This opinion is 

 based on experiments made by J. Tissot. These indicate that when the 

 respiration stops in an asphyxia induced by long anaesthetisation, 100 c.c. 

 of the arterial blood of the dog may contain as little as 0'78 c.c. and 

 2 - 83 c.c. of oxygen, although samples taken at intervals during anaesthesia 

 show only a slight fall in oxygen content, so long as the ventilation of the 

 lung remained normal. In our experiments on the composition of the blood- 

 gases during chloroform anaesthesia,* examination of the tracings of the 

 respiratory movements during continuous inhalation of chloroform gave no 

 indication that the progressive diminution in the amount of oxy-haemoglobin 

 as anaesthesia continued could be attributed to any slowing of the respiration, 

 and none of our tracings showed any marked alteration in the frequency or 

 amplitude of the respiratory movements. We were, therefore, unable to 

 agree with the views expressed by Tissot. All our tracings were taken by 

 means of a tambour applied to the chest wall in the usual way. Observa- 

 tions on the respiratory movements made by other observers were, as far as 

 we can gather, made in a similar manner. It is obvious that such records 

 afford no information which will enable an opinion to be formed with regard 

 to the lung ventilation which is capable of precise interpretation. In order 

 to ascertain more definitely whether the diminution in the amount of oxy- 

 hemoglobin in chloroform narcosis was due to changes in the type or depth 

 of respiration, or whether it was due to the direct interference by the 

 chloroform with the function of transporting oxygen which the red corpuscles 

 possess, we determined to investigate the pulmonary ventilation during 

 anaesthesia by means of a plethysmograph. 



* ' Journ. Physiol.,' Nov. 9, 1910, vol. 41, p. 246. 

 VOL. LXXX1V. — B. 



