At hospitals in Florida patients are asked to remove the wristbands or cover them with white tape.
Tampa Bay's St Petersburg Times reported that Lisa Johnson, vice president of patient services for Morton Plant Mease Health Care, said:
"It could be confusing, particularly in the situation of a code or a cardiac arrest where people have to think very quickly.
"We wouldn't want to mistake a Lance Armstrong bracelet and not resuscitate someone we're supposed to."
Up to 28 million of the Nike-supported bands have now been sold by the Lance Armstrong foundation.