What Is 'Res Ipsa Loquitur' In a Medical Malpractice Case?

The "res ipsa loquitur" rule often comes up in medical negligence cases where the patient was harmed while sedated.

By , J.D., University of San Francisco School of Law
Updated by Charles Crain, Attorney (UC Berkeley School of Law)

In many injury-related cases, the injured person's testimony about what happened is powerful evidence of the defendant's legal responsibility. Think, for example, about a plaintiff who testifies convincingly about a defendant running a red light and causing an accident.

But what happens if the injured person has no direct evidence of how the injury occurred? This situation comes up often in medical malpractice cases, because an unconscious or sedated patient is almost always at a loss when it comes to describing what happened. In cases like these, injured parties may be able to use a legal principle called res ipsa loquitur (Latin for "the thing speaks for itself") to help them make their case.

In this article we'll explain what res ipsa loquitur is and when it can be used to help prove medical malpractice.

Why Is Res Ipsa Loquitur Important?

Res ipsa louitur is a legal principle that, in some medical malpractice cases, allows a jury to presume that a health care provider was negligent, instead of requiring the injured party to establish negligence. It then falls on the provider to disprove any wrongdoing.

This can be a huge help to plaintiffs seeking to prove medical malpractice, because proving negligence is a key component of any successful personal injury case. "Negligence" is the legal term for when someone is more careless than they should be in a particular situation. In medical malpractice cases, judges and juries decide if a health care provider was negligent by comparing the treatment they gave a patient to the applicable "medical standard of care."

When Does Res Ipsa Loquitur Apply to a Medical Malpractice Case?

In a medical malpractice case, res ipsa loquitur will usually apply if the injured patient proves that:

  • the harm ordinarily wouldn't have happened unless someone was negligent
  • the harm occurred while the injured party was under the care and control of the health care provider, and
  • the injured patient didn't contribute to the harm.

Let's take a closer look at each of these three elements.

The Harm Ordinarily Would Not Have Happened Unless Someone Was Negligent

Proving this element of res ipsa loquitur can be straightforward or complex, depending on what kind of medical error led to the medical malpractice case.

In egregious cases, jurors will generally have no trouble finding that the harm would not have happened without negligence, and res ipsa loquitur typically applies. Doctors leaving surgical instruments in the body, or operating on the wrong limb, are clear examples of this kind of obviously negligent conduct.

However, in cases involving more complex facts, common knowledge may not be enough to determine whether the harm ordinarily wouldn't have happened. For example, what if a patient alleges that a doctor misused surgical instruments, or caused avoidable injury to surrounding organs during surgery? Evaluation of claims like this could require knowledge and understanding of complex issues like:

  • the patient's overall health condition before the procedure
  • how the procedure ordinarily works, and
  • why the doctor took certain actions.

Often, the injured party will call on expert witnesses to assist jurors in understanding these issues. The majority of states permit this kind of expert testimony to help jurors acquire the knowledge they need to infer negligence. In some states, though, the courts have ruled that, if the matter at issue is not within common knowledge, res ipsa loquitur is inapplicable. Instead, the injured party must prove that the relevant medical standard of care was breached, as in any other medical malpractice case.

These differences between state laws are one example of the importance of understanding your own state's rules for medical malpractice cases, and of working with an attorney who understands the relevant laws.

The Harm Occurred While the Injured Party Was Under the Care and Control of the Health Care Provider

To satisfy the second element of res ipsa loquitur, the injured party must prove that the injury was caused by an agency or instrumentality within the exclusive control of the health care provider. Essentially, the defendants in a medical malpractice lawsuit must have had enough control over the situation that their negligence, as opposed to some other factor, is the only reasonably likely cause of the plaintiff's injuries.

In cases involving surgical errors, proof of exclusive control is seldom an issue—by its nature a surgical procedure involves physically separating a patient from everyone except the health care providers performing the operation.

But it can still sometimes be difficult to determine whether a patient was specifically under the control of a hospital or of particular doctors. A hospital or other health care facility is almost always legally responsible for the actions of any doctor it employs. But it's common for doctors to be independent contractors who work at a hospital but not for the hospital. In that situation it's more complicated for a medical malpractice plaintiff to prove that the hospital is legally responsible for the doctors' actions.

In the same vein, it isn't always clear which individual doctors (or other health care providers) were in control at the time of a patient's injury. Multiple health care providers are often involved in caring for a patient, and there is typically a team of surgeons, nurses, anesthesiologists, and surgical technologists present in the surgical room.

Courts generally apply res ipsa loquitur against all individuals with concurrent control over what's going on in the operating room. But some courts have denied application of res ipsa loquitur where the injured party failed to demonstrate that the defendant—and not another health care provider—had exclusive control of the injury-causing "agency or instrumentality."

For instance, a patient suffered injuries because one doctor inserted drains as part of a surgical procedure and a second doctor later failed to remove the drains properly. The court refused to apply res ipsa loquitur against the physician who inserted the drains, concluding that there was no reason to believe that her role in the patient's surgeries had led to his injuries.

The Injured Party Did Not Contribute to the Harm

Generally, in surgery or other medical procedures, the injured patient bears no fault by virtue of the circumstances. But there are often multiple possible causes of an injury, some of which could be the result of the injured person's own actions and decisions. In cases like these, courts have generally held that negligence on the part of the health care provider need not be the only explanation for the patient's harm in order for res ipsa loquitur to apply. It just has to be the most probable explanation.

For instance, consider a case where the plaintiff was in a serious car accident and suffered injuries including a broken jaw. He underwent surgery under general anesthesia to repair his jaw, and soon after suffered seizures and was diagnosed with severe brain damage. Should that plaintiff have been entitled to a res ipsa loquitur instruction relating to the brain damage? Or should res ipsa loquitur not apply because of the possibility the brain damage was caused by the car accident?

In that case, an appeals court examined the facts and concluded that res ipsa loquitur should apply. Even though there was a possibility that the brain damage occurred during the accident, the most likely cause was negligence on the part of the hospital and medical personnel who treated the defendant's injured jaw.

Learn More About Making a Malpractice Claim

If you've suffered an injury as a result of medical treatment, it's important to understand how to file a medical malpractice lawsuit and to know the time limits for filing your case. As we've discussed in this article, proving medical malpractice generally involves expert testimony about medical issues, along with other evidence gathered during the discovery process. That means it's important, if you think you might have a claim, to seek out an attorney who has experience handling medical malpractice cases.

Make the Most of Your Claim
Get the compensation you deserve.
We've helped 175 clients find attorneys today.
There was a problem with the submission. Please refresh the page and try again
Full Name is required
Email is required
Please enter a valid Email
Phone Number is required
Please enter a valid Phone Number
Zip Code is required
Please add a valid Zip Code
Please enter a valid Case Description
Description is required

How It Works

  1. Briefly tell us about your case
  2. Provide your contact information
  3. Choose attorneys to contact you