Before the issue of "standard of care" arises in a medical negligence cause, it must first be determined whether a relationship existed between the doctor and patient that triggered the duty for the doctor to exercise professional judgment and care. The existence or nonexistence of this duty is a preliminary question of law. St. John v. Pope, 901 S.W.2d 420, 424 (Tex. 1995); Bird v. W.C.W., 868 S.W.2d 767, 769 (Tex. 1994) (holding that the existence of duty of health professional is question of law); accord Salas v. Gamboa, 760 S.W.2d 838, 840 (Tex. App.--San Antonio 1988, no writ) (holding that before reaching question of standard of care, court must decide the question of law, whether the defendant owes a duty). When that relationship does not exist, Texas law is clear that the physician cannot be liable for professional negligence because he has no duty to exercise professional care. See: St. John, 901 S.W.2d at 423 (holding that on-call emergency room physician could not be sued for malpractice due to lack of physician-patient relationship where physician called by emergency room staff gave his opinion that patient should be transferred to another facility); Almaguer v. Jenkins, 9 S.W.3d 835, 836-837, 1999 (Tex. App.--San Antonio, November 30, 1999, no pet. h.) (holding that physician owes no duty to examinee because no professional relationship exists when physician merely examines person for worker's compensation report); Ortiz v. Shah, 905 S.W.2d 609, 611 (Tex. App.--Houston [14th Dist.] 1995, writ denied) (holding that on-call emergency room surgeon who did not arrive at hospital before patient died from gunshot wound could not be sued for medical malpractice because no physician-patient relationship was established); Wilson v. Winsett, 828 S.W.2d 231, 232 (Tex. App.--Amarillo 1992, writ denied) (holding physician who examined applicant for social security benefits and discovered mass but failed to disclose its existence to examinee not liable for medical negligence because no physician-patient relationship); Fought v. Solce, 821 S.W.2d 218, (Tex. App.--Houston. [1st Dist.] 1991, writ denied) (holding that no physician-patient relationship existed between on-call orthopedic specialist who was twice consulted while patient was in emergency room and refused to come in and treat patient); Salas, 760 S.W.2d at 840 (holding no physician-patient relationship when plaintiff alleged that he took his baby into doctor's office when baby was turning blue and doctor refused to treat, though evidence controverted that doctor knew of emergency). In other words, "the duty to treat the patient with proper professional skill flows from the consensual relationship between the patient and physician, and only when that relationship exists can there be a breach of a duty resulting in medical malpractice." St. John, 901 S.W.2d at 423.