In Tuer v. McDonald, 347 Md. 507, 701 A.2d 1101 (1997), Tuer, a patient awaiting coronary bypass surgery, began to suffer chest pains. His surgery was rescheduled and he was given Heparin, "an anti-coagulant, to help stablize the angina." Id. at 509. On the day of the operation, the Heparin was discontinued a few hours before the surgery was to begin, in accordance with hospital protocol and at his surgeon's direction, "to allow the drug to metabolize so that Mr. Tuer would not have an anticoagulant in his blood when the surgery commenced." Id. at 510. Unfortunately, Tuer's surgery was then delayed another three to four hours. During that delay, Tuer developed arrhythmia and shortness of breath and then went into cardiac arrest. Despite efforts to save him, Tuer died the next day. Id. Following his death, the hospital "changed the protocol with respect to discontinuing Heparin for patients with unstable angina." Instead of discontinuing Heparin several hours before surgery, the new protocol required that Heparin be given such patients until they are taken into the operating room. Id. at 510-11. In the medical malpractice action that followed, Tuer's surgeon testified that he considered restarting the Heparin after surgery was postponed, but then rejected the idea as too dangerous. To impeach that testimony, the plaintiffs, Tuer's family, sought to introduce evidence of the change in the protocol to show that it was both feasible and safe to restart the Heparin once the surgery was delayed. Denying their request, the circuit court excluded the evidence as a subsequent remedial measure. Id. at 513-14. On appeal, there was no dispute as to whether the protocol change was a subsequent remedial measure. Id. at 511. The parties disagreed as to whether it was admissible for impeachment purposes. Affirming the circuit court's ruling, the Court of Appeals held that the change in protocol was not admissible to impeach the doctor's testimony as to the safety of restarting Heparin. Tuer, 347 Md. 507 at 531. The Court explained that the doctor "was not asserting . . . in any absolute sense, that restarting the Heparin would have been unsafe but only that, given the complications that could have arisen . . . there was a relative safety risk that, at the time, he and the hospital believed was not was worth taking." Id. at 529. The change in protocol, the Court stated, only suggested that the doctor "and his colleagues reevaluated the relative risks in light of what happened to Mr. Tuer and decided that the safer course was to continue Heparin." Id. at 532. "That kind of reevaluation," the Court asserted, "is precisely what the exclusionary provision of the Rule was designed to encourage." Id. The Court of Appeals concluded in Tuer that the nature of the purported contradiction did not warrant impeachment by introducing evidence of the defendants' remedial measure.