In Medical Malpractice Overview, medical expert witness Eugene DeBlasio writes on actionable malpractice:
State laws govern the viability of causes of action for medical malpractice. The laws vary in terms of time limits to bring suit, qualifications of “expert” witnesses, cognizable theories of liability, and proper party defendants/proper party plaintiffs. Notwithstanding these differences, there are common requisites for all cases.
First and foremost, a physician must owe a duty to patients before his or her competency in performing that duty can be judged. In U. S. JURISPRUDENCE, a person has no affirmative duty to assist injured individuals, -in the absence of a special relationship with them (such as doctor-patient, attorney-client, guardian-ward, etc.) A doctor dining in a restaurant has no duty to come forward and assist injured others if they suffer a heart attacks while dining in the same restaurant. If the doctor merely continues with his meal and does nothing to help, the ailing others would not have an action for malpractice against him, notwithstanding their harm. However, once a doctor voluntarily decides to assist others or come to their aid, he or she becomes liable for any injury that results from any negligence during that assistance.
Once the requisite doctor-patient relationship is established, the doctor owes to the patient the duty to render care and treatment with that degree of skill, care, and diligence as possessed by or expected of a reasonably competent physician under the same or similar circumstances. The “circumstances” include the area of medicine in which the physician practices, the customary or accepted practices of other physicians in the area (the “locality rule”), the level of equipment and facilities available at the time and in that locality, and the exigent circumstances, if any, surrounding the treatment or medical service rendered. The requisite degree of skill and expertise under the circumstances is established by “expert testimony” from other practicing physicians who share the same or similar skill, training, certification, and experience as the allegedly negligent physician.