"Key medical objections to infant anesthesia - that it was (a) unnecessary and (b) dangerous - were resolved by the brilliant research of Kanwal Anand and colleagues at Oxford from 1985 to 1987. Making precise measurements of infant reactions to surgery, they proved that the babies experienced pain, needed and tolerated anesthesia well, and had probably been dying of metabolic and endocrine shock following unanesthetized operations."
Source: http://www.nocirc.org/symposia/second/chamberlain.html