The Metric System, or properly now its Systèmè Internationale equivalent, is the universal language for all science, engineering, commerce, sports, etc. world-wide, with very few exceptions.
It is inevitable American doctors need use metric units. Medicine has to follow normal scientific practice. The doctors, hospitals and laboratories probably import quite a lot of medicines and equipment so those will be all to metric measures. Doctors, especially specialists, read and some write for, peer-reviewed journals of international value; they discuss medical matters internationally.
It has nothing whatsoever to do with the political hues of any country.
It is really only an accident of history that the founders of the USA stayed with their versions of the Imperial Measures instead of adopting the French-invented metre, litre, gramme, etc - to use their correct, French spellings. Quite literally an accident, too, as a ship carrying metric reference standards to the young USA was wrecked.
The Systèmè Internationale springs from, and still uses, the original metric, but then adds compound units derived so they are all arithmetically coherent. Some do give practical disadvantages, but for most of those alternatives still defined by the formal SI units, are permitted. These include the Bar and the Degree (of angle, not temperature).
It was devised and ratified by the International Standards Organisation, of which the United States of America is a fully paid-up member and possibly among those with the most influence. Yet which remains one of only about three nations still using the old units for everyday purposes.
The last time I heard a NASA control-room officer commentating on the descent of a lander, on the Moon I think, she was reading the altitudes in metres.
So I am afraid that like it or not, your idea that using the m, l, g, Pa, N, V, A, Rad., etc is somehow "Chinese" or somehow "Communist" is totally mistaken.
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The UK has been almost fully metric for some decades now its a few exceptions are primarily the Mile for road and railway distances and speeds... and the Pint for dispensing draught ales and ciders in pubs!
