Please provide us with the full sentence containing "high gods of medicine" along with a sentence or two beforehand and possibly the sentence following. You are allowed to quote up to four sentences from original to provide context for your question.
"As long ago as 1860 it was the proper thing to be born at home. At present, so I am told, the high gods of medicine have decreed that the first cries of the young shall be uttered upon the anaesthetic air of a hospital, preferably a fasshionably one."
It seems to mean simply "the medical authorities". Using the phrase "high gods of medecine" is poking fun at the authorities, implying that their pronouncements have godlike force - or that they think themselves godlike
No, you couldn't use it to mean "modern medecine", unless perhaps you were poking fun at modern medecine too.