Medical experts seeking to stem the Ebola epidemic are sharply divided over whether most patients in West Africa should, or can, be given intravenous hydration, a therapy that is standard in developed countries. Some argue that more aggressive treatment with IV fluids is medically possible and a moral obligation. But others counsel caution, saying that pushing too hard would put overworked doctors and nurses in danger and that the treatment, if given carelessly, could even kill patients.

The debate comes at a crucial time in the outbreak. New infections are flattening out in most places, better-equipped field hospitals are opening, and more trained professionals are arriving, opening up the possibility of saving many lives in Africa, rather than a few patients flown to intensive care units thousands of miles away.

The World Health Organization sees intravenous rehydration, along with constant measuring of blood chemistry, as the main reason that almost all Ebola patients treated in American and European hospitals have survived, while about 70 percent of those treated in West Africa have died.

Every hospital there should have “early, liberal use of intravenous fluid and electrolyte replacement,” said Dr. Robert A. Fowler, a Canadian critical care specialist who leads a W.H.O. Ebola team. Anything less, he said, is “not medically justified and will result in continued high case-fatality rates.”