This is a theory of liability that basically states “the thing speaks for itself”. This doctrine is applied in medical malpractice usually in cases where the injury is in a location of the body distinct from the proposed procedure or operation. The classic case is Ybarra v. Spangard, 25 Cal.2d 486, 154 P.2d 687 (1944), here the plaintiff underwent an appendectomy but awoke from surgery with pain in his arm. The court applied Res Ipsa Loquitur to the facts, finding (in part), “the defendant had control at one time or another the of…instrumentalities which might have harmed the patient…”
Three conditions must be met for application of this doctrine: The accident must be the kind that does not ordinarily occur in the absence of someone’s negligence; it must be caused by an agency or instrumentality within the exclusive control of the defendant; and it must not have been due to any voluntary action or contribution on the part of the plaintiff. Dobbs, The Law of Torts Sect 249 (2000).
Some courts have resisted use of this doctrine because of concern that healthcare providers would be in constant fear of liability from rare bad outcomes. In Siverson v. Weber, 57 Cal2d 834, 22 Cal.Rptr 337 P.2d 97 (1962) the court acknowledged this doctrine would place an undue burden on the medical profession and limit the use of innovations even if due care is exercised.
Some states allow a jury to infer negligence vis-à-vis Res Ipsa, others treat the doctrine as a presumption that a defendant must rebut. Appropriate review of recent caselaw is prudent for defense against this type of allegation.