You've gotta be very careful with this. There is not categorical "duty to rescue" but when it comes to medical practitioners the courts are often willing to impose one with even very slightly justifying factors. I don't believe that failing to carry out a duty to rescue can result in criminal charges but it can definitely make you liable in civil court.
http://www.mauriceblackburn.com.au/media/373165/article by gw and alw _ medical practitioner and the duty to rescue_.pdf (this is an Aussie link but as far as I know common law countries have similar approaches to this concept)
"A factor that was relevant in the decision to impose a duty to assist on the doctor, and which is also of
significance in itself in terms ofa doctor's legal obligations, is the fact that the Act regulating medical
professionals imposes an obligation on doctors to assist. Section 36(1 )(1) of the Medical Practice Act 1992
(NSW) states that unsatisfactory professional conduct includes "(r)efusing or failing, without reasonable cause,
to attend (within a reasonable time after being requested to do so) on a person for the purpose of rendering
professional services in the capacity of a registered medical practitioner in any case where the practitioner has
reasonable cause to believe that the person is in need of urgent attention by a registered medical practitioner,
unless the practitioner has taken all reasonable steps to ensure that another registered medical practitioner
attends instead within a reasonable time."
I realize this isn't exactly what you were responding to before, but hopefully this illustrates that the question of whether or not medical practitioners have a duty to rescue is actually separate from the ongoing debate about healthcare reform and healthcare as a right vs. privilege.