For other uses, see LPN (disambiguation) . A licensed practical nurse (LPN) in much of the United States and most Canadian provinces is a nurse who cares for people who are sick, injured, convalescent, or disabled. LPNs work under the direction of registered nurses or physicians.or other uses, see LPN (disambiguation) . A licensed practical nurse (LPN) in much of the United States and most Canadian provinces is a nurse who cares for people who are sick, injured, convalescent, or disabled. LPNs work under the direction of registered nurses or physicians.