Dissent wasn't silenced, just (mostly) disregarded. In Transactions of the American Medical Association, 1 (1848), the Committee on Surgery of The American Medical Association warned that use of anaesthesia could provoke "convulsions more or less severe and protracted, prolonged stupor, high cerebral excitement, alarming and long continued depression of vital powers, and asphyxia. As secondary effects, bronchitis, pneumonia, and inflammation of the brain." Pennsylvania Hospital initially prohibited the use of anaesthesia by it's doctors, "it being considered by the judicious surgeons in this institution as a remedy of doubtful safety"; but the ban was revoked in 1853. Critically, the sceptics were ill-organised. They lacked any unifying ideology. Opponents of the new painless surgery were powerless to stem the revolution. The need to rationalise surgical agony had passed.
In December 1846 anaesthetics were administered in London. By January they were used in Paris and other European capitals. In June they were adopted in Australia and soon in every country in the world. When "safe, sustainable and complete" technologies to eliminate emotional pain are discovered, they will quite possibly propagate at least as fast. Unfortunately, current agents tend to be "partial, occasional and dangerous". No "ideal pleasure drug" or super-soma yet exists. Sceptics claim that the existence of such wonderdrugs is forever impossible.
Ether Inhaler (1867)
Refs and Further Reading
Anaesthesia and Anaesthetics