Safety of care
Thoracic aortic dissection: Medico-legal difficulties
An article for physicians by physicians
Originally published March 2007
Failure to diagnose thoracic aortic dissection is not always due to negligence.
Each year CMPA members must respond to allegations of medical negligence related to delays in the diagnosis of thoracic aortic dissection (TAD). The following are examples of two medico-legal closed cases involving experienced clinicians that resulted in different legal outcomes.
Adverse clinical outcomes are an inevitable part of practice even with the best of care. If an adverse outcome results in an allegation of negligence, the courts consider the facts and circumstances of each case. The legal standard of care is not one of perfection, but rather the care that might reasonably have been given by a normal prudent practitioner of similar training in comparable circumstances. The courts rely heavily upon the testimony of other physician medical experts working in the same kind of practice to help establish the applicable standard of care.
A middle-aged athletic male was seen by an emergency physician in an emergency department on a weekend. The patient described an abrupt onset of new symptoms of light-headedness, right chest pain and shoulder pain radiating to the jaw region. These symptoms began during minimal exertion and resolved in about one-and-a-half hours. The patient denied the common cardiac risk factors. Although the patient appeared well overall, there was a significant blood pressure discrepancy noted between the two arms (160/72 left arm, 92/70 right arm), and a cardiac murmur was heard, of which the patient had no prior knowledge. The laboratory results, including cardiac markers, ECG and chest x-ray were normal. As the emergency physician did not reach a diagnosis and was uncomfortable in discharging the patient from hospital, the on-call internist was consulted.
After evaluation, the internist discharged the patient home with the diagnosis still uncertain. Subclavian steal syndrome was considered a possibility. Several non-invasive cardiac investigations were ordered and out-patient follow-up arranged.
Unfortunately, the patient collapsed and died two days later. An acute aortic dissection involving the ascending thoracic aorta, aortic arch and upper descending thoracic aorta was discovered at autopsy. The family brought a lawsuit against both physicians alleging negligence in the care provided.
For this case, the defence asked physicians from emergency and internal medicine to comment on the care provided. These experts were supportive of the emergency physician, as the doctor was unable to identify the problem and so sought out appropriate consultation for assistance. However, sufficient support for the internist could not be obtained from peers in that specialty. Those consulted acknowledged the absence of the classic presentation of TAD of chest pain tearing or ripping in quality. Although the plain chest x-ray was normal in this case, the experts commented that mediastinal widening may or may not be seen as a finding with this investigation in TAD. However, in this case of chest pain, the experts felt the large blood pressure differential between arms and the possibly new murmur required explanation prior to discharge.
On the basis of the lack of expert support, the case was therefore settled and a payment of compensation was made by the CMPA to the family on behalf of the internist.
A middle-aged male smoker presented to an emergency department for evaluation of sudden onset left-sided chest discomfort, which was "like a Charley Horse." The symptoms included a two-hour history of dyspepsia associated with numbness and tingling in the left arm and leg. The blood pressure was recorded as normal in both arms, the cardiovascular and neurological examinations were normal, and repeated ECGs and serial cardiac markers remained negative. As no cardiac cause for the symptoms was detected after eight hours of observation, the patient was discharged home to follow-up with his family physician.
The patient continued to experience intermittent chest pain that he described as worse on inspiration. Three days later, when examined by his family physician, the patient was febrile and a chest x-ray infiltrate suggested left lower lobe pneumonia. He was started on antibiotics.
Three days later, six days after the initial hospital visit, the patient was seen by the family physician again and referred that same day to an internist who saw him in the emergency department. The chest pain continued to be pleuritic in nature. The internist documented a blood pressure that was the same and was within normal limits in each arm, no cardiac murmurs or rubs, and a normal neurological examination. A repeat chest x-ray showed a patchy consolidation in the left lung base. Laboratory work and an ECG remained normal, apart from a mildly elevated WBC. The internist also felt the patient had pneumonia but changed the antibiotics to cover a wider spectrum of organisms.
Unfortunately, two days later the patient collapsed at home and could not be resuscitated. A ruptured dissection of the descending thoracic aorta was found at autopsy. The family brought a lawsuit against all of the physicians alleging negligence in the care provided.
For this case, the defence asked medical experts from emergency, family practice and internal medicine to comment on the care provided. The medical experts were supportive of the documented care provided by the emergency physician, family physician and the internist. Although the plaintiff's (patient's) experts argued TAD frequently presents with atypical chest pain and sometimes neurologic symptoms, the defendant experts believed there was insufficient clinical evidence to suspect the diagnosis. They noted the many unusual features of the case, such as the pleuritic quality of the pain, the presence of signs and symptoms suggesting pneumonia, the normal blood pressures in both arms and the absence of a cardiac murmur. These would understandably make aortic dissection difficult to suspect prior to any further clinical deterioration.
At trial, this case was decided in favour of the defendant physicians.
Thoracic aortic dissection cases
In the last several years, delay in the diagnosis of TAD has continued to cause medico-legal difficulties for members. An initial review indicates the patients were mostly males, ranging in age from 19 to 71 years old. Chest pain accompanied by back pain was a common presentation, but the condition often mimicked other illnesses. Some presented with seemingly unrelated symptoms, for example chest pain with neurological symptoms. Some presented with chest pain that migrated to the abdomen over time. The legal outcomes varied. The CMPA will publish a more complete ansalysis of the medico-legal problems related to thoracic and abdominal aortic conditions in the future.
These cases remind us of the well-recognized difficulties in diagnosing diseases of the aorta.
The bottom line
Medico-legal considerations for thoracic aortic dissection:
- Medical experts have observed the clinical presentation may vary and can mimic many other conditions.
- The clinical assessment, differential diagnosis, investigations, rationale for your treatment plan and follow-up instructions should all be documented.
- The diagnosis may elude even the most experienced and knowledgeable physicians and missing the diagnosis does not necessarily represent negligent medical care.