Plaintiff Minnie Mohr consulted defendant Dr. Williams, an ear specialist, for hearing problems. After examination, Dr. Williams advised surgery on Mohr's right ear and obtained her consent to that operation. Mohr entered a hospital and was placed under general anesthesia for the right-ear procedure. Once she was anesthetized, Dr. Williams conducted a more thorough examination and concluded that Mohr's left ear was in worse condition and that surgery on the left, rather than the right, was indicated. Without awakening Mohr or obtaining her express consent, he proceeded to operate on the left ear, not the right. There was evidence that the left-ear condition warranted timely attention, but also evidence that there was no immediate, life- or limb-threatening emergency requiring instant intervention. Mohr later experienced adverse effects and sued Dr. Williams for assault and battery based on the unauthorized surgery. At trial, the jury found for Mohr. On appeal, Dr. Williams argued that his good faith, skill, and the medical necessity of the left-ear operation justified his conduct, and that the jury should have been instructed on an emergency/necessity defense.
Does a physician commit a battery by performing, without the patient's express consent, a different surgical procedure than the one authorized while the patient is under anesthesia, when no true emergency prevents obtaining consent?
A medical procedure performed without the patient's consent constitutes a battery unless circumstances amounting to an emergency make it necessary to act immediately to preserve the patient's life or health and obtaining consent is impracticable. Consent must be to the particular operation performed; good faith, due care, and the operation's potential benefit do not excuse the lack of consent. The emergency (necessity) exception applies only where delay to obtain consent would involve serious risk.
Yes. Absent a genuine emergency preventing the obtaining of consent, a physician who performs a materially different operation than the one authorized commits a battery. The court reversed and ordered a new trial because the jury instructions did not adequately submit the emergency/necessity defense, but it affirmed the governing principle that unauthorized surgery is unlawful unless justified by true necessity.
The court grounded its analysis in the fundamental right to bodily integrity, a core tenet of tort law that requires consent to physical contact. In the medical context, patient consent must be specific to the operation performed; agreeing to surgery on one part of the body does not imply consent to a different procedure discovered desirable after anesthesia. The court rejected the notion that a physician's good intentions, skill, or the prospective benefit of the operation can substitute for consent, because doing so would erode personal autonomy and enable paternalistic overreach. At the same time, the court recognized a limited emergency exception rooted in the doctrine of necessity: when a patient is unconscious or otherwise incapable of consenting and immediate action is required to avert serious harm, the law implies consent to necessary treatment. That exception is narrow; it applies only where delaying to obtain consent would pose substantial danger. The record contained conflicting evidence on whether Mohr's left-ear condition required immediate intervention. Because the trial court's instructions effectively removed the emergency justification from the jury's consideration, the Minnesota Supreme Court ordered a new trial to allow the jury to evaluate whether an emergency existed. Nevertheless, the court made clear that, in the absence of such an emergency, performing a different operation than the one consented to constitutes battery.
Mohr v. Williams is a cornerstone case in medical battery and the doctrine of informed consent. It teaches that consent is operation-specific and sets the template for the emergency exception that later cases and statutes adopt. For law students, the case illustrates the intersection of intentional tort principles (battery), patient autonomy, and policy-based defenses (necessity). It also highlights the importance of precise jury instructions where defenses like emergency may apply, and it foreshadows the later evolution from bare consent to informed-consent requirements.
Mohr v. Williams crystallizes the rule that patient consent is a prerequisite to medical intervention and that the scope of consent is limited to the procedure authorized. The court's recognition of a narrow emergency exception balances respect for autonomy with the practical need for physicians to act swiftly when lives or health are immediately at stake.