The USCIS has struggled with this concept; they tend to be skeptical of H-1Bs for nurses. The seminal USCIS Guidance Memo was written in 2002, and has not been updated to account for the fact that many hospitals and facilities now require a Bachelors degree for all of their nurses. This is especially true in certain units and in magnet facilities.
The New York Times says that about 50% of all nurses hold a Bachelors degree. It should not come as a surprise to the USCIS that the Bachelors degree requirement increasingly is becoming the norm. The Johnson Foundation, long on the cutting edge of nursing educational studies, is cited in the Times piece. JF contends that growing that number to 80% is a realistic and worthwhile goal. As the number of Bachelor degreed nurses swells, the H-1B likely will become even a more viable immigration strategy.