A patient may assume only risks that arise from appropriate care. For example, any operation done under general anesthesia carries a small risk of anoxic brain damage. Assume that a patient consents to general anesthesia, including acknowledging the risk of brain damage. The anesthesiologist then negligently overdoses the patient with an anesthetic agent, fails to monitor the patient, and discovers the mistake only after the patient is brain injured. The patient’s informed consent to the risks of anesthesia would not prevent the patient from suing for the negligent administration of anesthesia.

The law does not allow a provider to force a patient to assume the risks of negligent medical care because of the involuntary nature of medical care. A person providing a necessary service has a duty to provide that service in a proper manner. This policy is intended to preserve the quality of necessary services. Conversely, it does not apply to services that the consumer may freely reject. For example, in most states, a skydiving service can successfully require that a customer waive the right to sue for all risks, including those from negligent acts of the service. This is accepted because skydiving is a purely voluntary activity.