If there's a shortage, it's because employers need to pay more, same as every other labor "shortage." Nursing is in demand everywhere, and not everyone has what it takes to do their work. If they could be making more money somewhere else, that's where they'll go.
A couple of years ago, I compared my salary to all my friends in the same field, and found they were all making at least 25% more than me. I asked my work for more money, they said no, so I left. Last I heard they can't find anyone who'll work for so little except fresh grads who can't keep up with the heavy workload nor the high quality demanded by the doctors. And several nurses have told me similar stories.
Just pay.