“…The cerebral oxygen uptake and the cerebral perfusion are reduced roughly in proportion to the reduction in total body oxygen uptake, cardiac output, pulse rate, and myocardial and renal blood flow. These values all decrease to about 50 per cent of the normal levels at a temperature of 28OC (134,222,263,296 This correlation was first noted by Kety, who stated: 'CIn all of our studies we have been impressed with the close correlation between the level of consciousness and the rate of oxygen consumption by the brain. In patients who are comatose for whatever reason, cerebral oxygen consumption falls to a value of less than 2.0 cc per I oo gm per minute, while in those who are semistuperous or confused, the value lies between 2.5 and 3.0" (156).…”