Most of you will have heard the maxim "correlation does not imply causation." Just because two variables have a statistical relationship with each other does not mean that one is responsible for the other. For instance, ice cream sales and forest fires are correlated because both occur more often in the summer heat. But there is no causation; you don't light a patch of the Montana brush on fire when you buy a pint of Haagen-Dazs.-Nate Silver, The Signal and the Noise: Why So Many Predictions Fail-but Some Don't
This four-part series discusses the elements required to prevail in a malpractice lawsuit. In order to succeed, a plaintiff must demonstrate duty (discussed in part 1, July), breach (discussed in part 2, September), causation, and harm. Causation is the most complex of the elements, so part 3 has been divided into two parts. In part 3A (November), I discussed actual and proximatecause, the standard of proof, and loss of chance. Here in part 3B, I discuss intervening acts and superseding causes, the common knowledge exception, foreseeability, and nursing implications. In part 4, the last article in this series, I will address harm.
BACKGROUND
In part 3A on causation, I explained that a plaintiff must demonstrate not only that a nurse breached her duty in departing from the standards of practice, but that it was that departure that caused the patient's injury. The standard of proof in a malpractice suit is a "preponderance of the evidence" (rather than "beyond a reasonable doubt," which is the standard of proof in a criminal trial), meaning that it is more likely than not that the nurse's departure from the standard was the cause of the patient's harm. This generally requires the testimony of an expert witness.
CAUSATION
As I discussed in part 3A, to demonstrate that a nurse's action or inaction caused an injury, a plaintiff must demonstrate proximate cause, which refers to the primary cause of a plaintiff's injury, but not necessarily the only cause of that injury. In addition, there must be a natural and continuous sequence, unbroken by any new cause, that produced the injury and without which the injury would not have occurred. That sequence can be broken in some circumstances.
Intervening act and superseding cause. After a nurse breaches her or his duty to a patient by departing from acceptable standards of care, there may be new forces or actions-referred to as intervening acts-that, combined with the nurse's breach, cause an injury to the patient. If the intervening act relieves the nurse of liability, it becomes a superseding cause. To give an oversimplified example, if a nurse neglects to put up a side rail for a fall-risk patient, she or he has departed from the standard of care. If the patient falls, the nurse is liable. If, however, while the side rail is down, another actor deliberately pushes the patient onto the floor, the nurse is no longer liable. The pusher has committed an intervening act that becomes the superseding cause of the patient's harm. A more detailed example is provided by Scott v. Retz (2009).1
Malissa Retz was a nurse who had been diverting narcotics from Indiana University Hospital and injecting herself with meperidine (Demerol). The hospital was managed by Clarian Health Partners, not the university. In a suicide attempt, Retz injected herself with four vials of morphine and disposed of the uncapped needles in the trash. She was escorted to the ED for treatment, and the used, uncapped needles were sent to the ED in a paper bag. The bag containing the contaminated needles was subsequently delivered by a Clarian nurse to security but never placed in a sharps container. George Scott, a Clarian safety and security investigator, was assigned to work on the narcotics investigation and told to pick up a package related to his investigation. When he picked up the paper bag, he was stuck by one of the uncapped needles in the bag.
Scott filed a negligence complaint against Retz and the university. Retz argued that she did not owe a duty (discussed in part 1 of this series) to Scott and that even if she did, his needlestick was not proximately caused by her actions. The university argued that even if Retz breached her duty to Scott, Clarian employees (the nurse and another safety and security investigator) negligently failed to cap or secure the needles and that was a superseding cause of his injury. Both Retz and the university asked the court to dismiss the case against them, and the trial court did so.
On appeal, the appellate court noted that the chain of causation is broken if an independent actor intervenes between the defendant's negligence and the resulting injury. To determine whether the intervening actions are superseding causes, courts look to such factors as whether the intervening action is foreseeable, whether the "instrumentality" of harm (here the bag of uncapped needles) is under complete control of the intervening actor, and whether the intervening actor is in a better position than the original actor to prevent the harm.
In this case, the court found that Clarian (the umbrella organization managing the hospital) acted as an intervening agency between Retz's actions and Scott's injury. Clarian was better positioned to prevent the needlestick than Retz. Clarian employees had custody and control of the contaminated needles, and it was Clarian's actions that exposed Scott to risk. Although Retz improperly disposed of the needles, that was not the proximate cause of Scott's injury. Clarian's intervening actions became a superseding cause, releasing Retz from liability. In the same manner, Clarian's actions were intervening acts with regard to Indiana University, also relieving the university of liability. Dismissal on behalf of Retz and the university was upheld.
Common knowledge exception. Although plaintiffs must generally prove causation through the testimony of an expert witness, an exception can be made when the information a jury needs can be understood by laypeople. When the allegations of departures from the standard of care and causation of harm are within the common knowledge of lay-people, another evidentiary standard, the common knowledge exception can be used. This exception is called res ipsa loquitur, which means "the thing itself speaks," or as we would say, "the thing speaks for itself." Unlike the malpractice elements duty, breach, cause, and harm, res ipsa loquitur is circumstantial evidence and requires a showing of three things:
1. The injury the plaintiff sustained does not ordinarily occur in the absence of negligence.
2. The defendant was in exclusive control of the instrumentality of harm.
3. The plaintiff did not contribute to her or his own injury.
The classic illustration is a case in which a patient complaint alleges that a sponge from surgery has been left inside a patient. In such cases the plaintiff can argue that
1. sponges are not ordinarily left in a body cavity in the absence of negligence.
2. the operating room team was in exclusive control of the sponges.
3. the patient did not contribute to the sponge being left in her or his body.
In this situation, negligence could be inferred by the jury.
Jones v. Harrisburg Polyclinic Hospital (1981) provides an example of the use of res ipsa loquitur.2 Mary Belle Jones underwent surgery consisting of three different procedures, each requiring a different position: a dilation and curettage was performed in a modified lithotomy position, a laparoscopy was performed in Trendelenburg position, and a laparotomy was performed in the supine position. Her arm was placed on a board throughout all three positions. Postoperatively, Jones experienced intense neck, left shoulder, and left arm pain. She was diagnosed with suprascapular nerve palsy resulting from malpositioning of her arm during position changes. Jones filed a malpractice suit against one of the surgeons, the nurse anesthetist, and the clinic, applying res ipsa loquitur. The jury returned a verdict against all defendants for $56,000. On appeal, the appellate court found that Jones had not satisfied the requirements for applying res ipsa loquitur and that the trial court should not have permitted the jury to reach a verdict on that basis. The court sent the case back to be tried again.
Jones appealed to the Supreme Court of Pennsylvania. The court considered whether res ipsa loquitur could be used in medical malpractice cases and, if so, whether the evidence had been sufficient to support the jury verdict. It noted that expert medical testimony is necessary when laymen cannot draw an inference or conclusion of negligence without it. When common knowledge can establish that events would not have occurred without negligence, such medical testimony is not required and the jury can draw such an inference of negligence. The jury verdict was upheld.
An unsuccessful use of res ipsa loquitur is demonstrated in Schulze v. United States (2019).3 John Schulze reported suicidal thoughts to an NP, who referred him for inpatient treatment at a Veterans Affairs hospital. He was discharged from the hospital the same day and died of a self-inflicted gunshot wound two days later. His wife brought a wrongful death lawsuit, alleging negligence in releasing Schulze rather than admitting him to the hospital. The hospital asked the court to dismiss the case and the court noted that for res ipsa loquitur to apply, the plaintiff would need to establish an injury, that the injury was proximately caused by an instrumentality solely within the control of the defendant or defendants, and that the injury does not ordinarily occur under the circumstances absent negligence on the part of the defendant.3
The court did not find that Schulze had presented evidence meeting these requirements. She did not show that her husband was under the hospital's exclusive control at the time of his death or that the instrumentality of his death was within the control of the hospital. She also did not establish that such an injury does not ordinarily occur in the absence of negligence. She had not presented evidence that patients do not commit suicide after discharge in the absence of negligence. Without providing this foundation, negligence could not be inferred. The motion to dismiss the case was granted.
Foreseeability. The res ipsa loquitur cases discussed above also illustrate the concept of foreseeability, that one should predict the consequences of departing from standards of practice (the possibility of harm). The foreseeability test in a nursing negligence case is whether the nurse could anticipate the risk of harm that any nurse of ordinary skill, care, and diligence would foresee under similar circumstances. Foreseeability in a negligence claim against a nurse does not mean that the precise injury sustained by the patient was predictable. This is illustrated in a Connecticut case from 1980.4
A psychiatric patient identified as "C" was locked in a seclusion room the day after she presented to a hospital with psychosis, "continuing bizarre behavior, hallucinations, irrationality, lack of contact with reality, and agitation." She had been in the seclusion room undergoing treatment for more than a week when her condition worsened. According to court records, she "sustained a grand mal seizure and thereafter continued to display disorientation, confusion, agitation, and at times hostility." A psychiatrist ordered antipsychotic medication.
However, the nurses did not note the order until the next day. They then discovered that the medication was unavailable, yet they did not notify the psychiatrist so that another medication could be ordered, and C was without antipsychotic medication for three days. The nurses also did not notify the psychiatrist during those three days that C was becoming increasingly agitated and hallucinating. The morning of the fourth day, C attempted to leave the unit and told staff that she was hearing voices instructing her to harm herself. She was returned to seclusion and remained there without being assessed or treated. Four hours later, she was found with her head wedged between the side rail and the mattress. She was unconscious and without vital signs. C suffered brain damage that left her in a permanent semicomatose state.
C's estate brought a lawsuit alleging that it was negligent to leave C in a steel bed in a seclusion room without constant observation. The hospital asked the trial court to instruct the jury that it had had no reason to foresee a "bizarre or unusual occurrence," which the court refused to do. The jury returned a verdict of $3.6 million. The hospital appealed, but the appellate court explained that particular injuries do not need to be foreseen, only the general harm that can occur. "[It] is not extraordinary that a psychotic patient who is delusional and whose view of space and distance is distorted might wedge herself between a mattress and a side rail in an attempt either to hurt herself or to extricate herself from an apparent place of confinement."4 In other words, the estate did not need to prove that the hospital would foresee C's injury in the exact way that it occurred. The hospital only needed to anticipate that she could harm herself if left unattended in a seclusion room with a steel-framed bed. The jury verdict was upheld.
IMPLICATIONS FOR NURSES
Nurses can reduce their liability by adhering to professional standards and documenting their observations and communications. It is important that usual and customary practice include the following:
* Involve management when you have concerns about improper orders.
* Engage the chain of command and pursue concerns to resolution, documenting precisely which people are notified and precisely at what times.
* Charting by exception-charting only things that vary from the norm-also known as variance charting, does not provide sufficient evidence of compliance with the standards of care. Observations must be recorded to justify clinical decisions-and to provide an adequate defense, should you need one.
* Adhere to organizational policies and procedures with the understanding that a failure to do so creates foreseeable harm to patients.
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