In Johnson v. Agoncillo, 183 Wis. 2d 143, 148, 515 N.W.2d 508 (Ct. App. 1994), the plaintiffs attempted to hold a family practitioner treating a high-risk obstetrical patient to the standard of an average physician treating such high-risk patients, rather than to the standard of the average family practitioner who treats such patients. See Johnson, 183 Wis. 2d at 150. The Court rejected the plaintiffs' proposed standard, explaining that the family practitioner's decision to treat a high-risk obstetrical patient did not transform the family practitioner into a physician who treats high-risk obstetrical patients. See Johnson, 183 Wis. 2d at 152. The family practitioner remained a family practitioner who treated obstetrical patients and was '"required to use the degree of care, skill, and judgment which is usually exercised in the same or similar circumstances' by the average physician in that class." Id. As an example of the application of this standard, the court observed that a cardiologist who treats a cancer patient is held to the standard of care applicable to a cardiologist, not to the standard of care applicable to an oncologist. See Johnson, 183 Wis. 2d at 151-52.