They are *very* British and maybe don't travel that well. Although they started out as gentle satires on British institutions (the army, the NHS...), the humour became increasingly dominated by sexual innuendo and this and their excellent repertory cast of famous comedians is what they became famous for (think Benny Hill humour).
That said, Nurse was apparently a surprise hit in the US in its day. It's pretty untypical, though, being an early example before the repertory company had been built (Sid James, Kenneth Williams, Hattie Jacques, Barbara Windsor and many others were all regulars) and the sex jokes had taken hold. Try one of the better of the Sixties or Seventies entries for a more accurate picture, e.g., Cleo, Screaming, Up the Khyber...