## Facts

- Joseph Roman Ybarra consulted Dr. Tilley for abdominal pain; Tilley diagnosed appendicitis and arranged an appendectomy by Dr. Spangard at a hospital owned/managed by Dr. Swift.
- Ybarra was medicated, taken to the operating room, and placed under anesthesia administered by Dr. Reser; he was unconscious throughout the surgery.
- Before the operation, Ybarra had no prior pain or injury to his right arm or shoulder.
- After awakening, Ybarra experienced sharp pain between his neck and right shoulder, reported it to nurses and to Dr. Tilley, and the condition worsened.
- Ybarra developed inability to rotate or lift his right arm, with paralysis and muscle atrophy around the shoulder.
- A subsequent physician (Dr. Clark) found diminished sensation and muscle atrophy and attributed the condition to trauma from pressure or strain applied between the right shoulder and neck.
- The injury involved a body part not being treated in the appendectomy and occurred while Ybarra was unconscious and under the care of multiple medical personnel.

## Issues

1. Whether res ipsa loquitur permits an inference of negligence when an unconscious patient suffers an unusual injury to an untreated body part during surgery.
2. Whether the doctrine may be applied against multiple medical defendants when the plaintiff cannot identify the specific actor or instrumentality that caused the injury.

## Decision

- The California Supreme Court reversed the judgments of nonsuit for all defendants.
- The court held that res ipsa loquitur applied because the injury was unusual in the setting of an appendectomy and suggested negligent pressure or strain during the period of unconsciousness.
- The court concluded that all defendants who had control over Ybarra’s body or over instrumentalities that might have caused the injury could be required to meet the inference of negligence by explaining their conduct.
- The case was remanded for further proceedings, allowing the claims to proceed to the jury with the res ipsa inference available.

## Legal Principles

- Res ipsa loquitur applies when (1) the accident is of a kind that ordinarily does not occur without negligence, (2) it is caused by an agency or instrumentality within the defendant’s control, and (3) it was not due to the plaintiff’s voluntary action.
- In team-based medical treatment of an unconscious patient, the “control” requirement is satisfied if each defendant had some control over the patient’s body or over potentially injuring instrumentalities during the relevant period.
- When the plaintiff is unable to identify the specific cause because the defendants had superior access to the facts, the inference of negligence may be applied to require those defendants to come forward with an explanation.

## Conclusion

The court permitted an unconscious surgical patient to rely on res ipsa loquitur for an unexplained injury to an untreated body part and required all medical defendants with control during the operative period to explain their conduct, rather than allowing uncertainty about the specific negligent actor to defeat the claim at the nonsuit stage.


Ybarra v. Spangard, 25 Cal. 2d 486, 154 P.2d 687 (Cal. 1944)