SURGICAL SHOCK 33 



2. Transfusing warni saline saturated and bubbling 

 with C0.2 into a vein. 



3. Allowing the animal to breathe in and out of a 

 bag containing air or, better, oxygen. 



The saline is saturated by shaking it in a flask 

 through which carbon dioxide has been bubbled from 

 a cylinder or Kipp's apparatus ; it is then warmed. 

 The delivery tube from the CO.^ cylinder may be 

 introduced into the abdominal cavity, and the gas 

 bubbled through the fluid. 



We may sum up the sequence, then, as follows : — 



1. Hyperpnoea, that is, excessive breathing due to 

 painful or nociceptive impulses. 



2. Leading to acapnia, that is, reduction of carbon 

 dioxide in the blood. In abdominal operations 

 carbon dioxide is exhaled from the intestines, giving 

 rise to a further reduction. 



3. Acapnia causes failure of the veno-pressor 

 mechanism, that is, loss of tone and consequent 

 dilatation of the veins. According to the author, 

 venous tone is controlled by the CO.^ in the blood. 



4. Venous anoxhcBmia, tissue asphyxia, acidosis. — 

 0\\dng to the reduction of CO., in the blood, the 

 respiratory centre is not roused to activity, and the 

 oxygen in the blood is therefore not renewed, so 

 that the tissues suffer from deprivation of oxygen, 

 and acid products enter the blood. 



5. Acute oligceniia. — Henderson considers that loss 

 of carbon dioxide leads in some obscure way to 

 rapid escape of the plasma from the circulatory 

 blood out into the tissues. 



6. Death, usually from tissue asphyxia, or from 



3 



