List three factors leading to a missed diagnosis of aortic dissection
List key pitfalls in the management of acute aortic dissection
A 78-year-old woman with a past medical history of hypertension was in good health until she experienced acute onset of confusion, which resolved after a few minutes. Then she had two episodes of black and "tarry" foul-smelling diarrhea (i.e., melena, usually indicative of gastrointestinal bleeding). She was concerned about the symptoms so presented to the hospital. On presentation, she had no abdominal pain, chest pain, shortness of breath, or focal weakness in her arms or legs. Her physical examination was notable for tachycardia. Her mental status examination was normal. Laboratory tests showed mild anemia and new acute renal insufficiency. Chest radiograph revealed some right hilar fullness but was otherwise negative, and electrocardiogram showed sinus tachycardia.
A 78-year-old woman with a past medical history of hypertension was in good health until she experienced acute onset of confusion, which resolved after a few minutes. Then she had two episodes of black and "tarry" foul-smelling diarrhea (i.e., melena, usually indicative of gastrointestinal bleeding). She was concerned about the symptoms so presented to the hospital. On presentation, she had no abdominal pain, chest pain, shortness of breath, or focal weakness in her arms or legs. Her physical examination was notable for tachycardia. Her mental status examination was normal. Laboratory tests showed mild anemia and new acute renal insufficiency. Chest radiograph revealed some right hilar fullness but was otherwise negative, and electrocardiogram showed sinus tachycardia.
The patient was diagnosed with a transient ischemic attack and possible gastrointestinal bleeding and admitted to a telemetry unit for monitoring and ongoing testing. She generally did well with no further confusion and resolving diarrhea. She did have a persistent sinus tachycardia.
The patient was diagnosed with a transient ischemic attack and possible gastrointestinal bleeding and admitted to a telemetry unit for monitoring and ongoing testing. She generally did well with no further confusion and resolving diarrhea. She did have a persistent sinus tachycardia.
On the morning of hospital day 2, she was found unconscious by the nursing staff and found to be in cardiac arrest. Her cardiac rhythm was pulseless electrical activity. Despite maximal resuscitation efforts, the patient could not be resuscitated and died.
Autopsy revealed the cause of death to be an acute aortic dissection (tear in the aorta) extending from the ascending aorta to the renal arteries, along with an acute hemothorax (blood in the chest cavity). The dissection was probably present on admission and the tear in the aorta had impaired blood flow leading to all of her symptoms, including the transient ischemic attack, the gastrointestinal bleeding, and the renal failure. The dissection likely worsened while the patient was hospitalized, and its rupture into her chest cavity was the terminal event.
Autopsy revealed the cause of death to be an acute aortic dissection (tear in the aorta) extending from the ascending aorta to the renal arteries, along with an acute hemothorax (blood in the chest cavity). The dissection was probably present on admission and the tear in the aorta had impaired blood flow leading to all of her symptoms, including the transient ischemic attack, the gastrointestinal bleeding, and the renal failure. The dissection likely worsened while the patient was hospitalized, and its rupture into her chest cavity was the terminal event.
Aortic dissections are classified by the area of aortic involvement
Type A: involving the ascending aorta
Type B: all other dissections
Acute aortic dissection is rare
Acute aortic dissection is rare
The true incidence is hard to define because aortic dissections can be instantly fatal in the pre-hospital setting; death is often attributed to other causes
The incidence of acute aortic dissection is higher in men and older adults
If undiagnosed and untreated, acute aortic dissection can have a very high mortality
If undiagnosed and untreated, acute aortic dissection can have a very high mortality
For untreated type A dissection, mortality is estimated to be 1%−2% per hour for the first 48 hours, with a 50% mortality by day 3
Common presentations of acute dissection can include the following:
Common presentations of acute dissection can include the following:
Chest pain (90%)
Sudden, severe, sharp, stabbing, or tearing chest pain (40%−50%)
Pain radiating to the back (47%−64%)
Chest pain with a widened mediastinum on chest radiograph (60%)
Pulse deficits or differences in blood pressure between the arms (19%−34% for type A)
Chest pain with new aortic regurgitation (32%−76%)
Less common presentations for dissection include:
Less common presentations for dissection include:
Pain that radiates to the abdomen and lower extremities (17%)
Ischemic complications such as renal infarction (14%), mesenteric ischemia (5%), spinal cord ischemia (3%)
Inferior myocardial infarction (1%−7%)
Ear nose and throat complications due to mass effect of proximal/aortic arch dissection such as trachea (dyspnea, stridor), esophagus (dysphagia), recurrent laryngeal nerve (hoarseness), sympathetic chain (Horner syndrome)
The classic physical examination findings for acute aortic dissection (e.g., diastolic murmur, blood pressure differential between arms, focal neurologic deficit) are seen in fewer than half of all patients with acute aortic dissection
The classic physical examination findings for acute aortic dissection (e.g., diastolic murmur, blood pressure differential between arms, focal neurologic deficit) are seen in fewer than half of all patients with acute aortic dissection
For example, data from the IRAD database of 2538 patients found a pulse deficit in one arm or blood pressure differential between arms in only 20% of patients
In this case, the patient had transient neurologic symptoms, which can be seen in 50% of patients
While the absence of chest pain in this patient may seem unusual, it is not — one-third of patients with a dissection do not present with chest pain
Diagnosis of acute aortic dissection is confirmed by advanced imaging such as ultrasound, CT, or MRI
Diagnosis of acute aortic dissection is confirmed by advanced imaging such as ultrasound, CT, or MRI
Conventional chest radiographs show widening of the aorta in 63% of type A dissections, while 11% show no abnormality
The comparable values in type B dissections were 56% and 16%
Due to the limited sensitivity of chest radiographs, especially in type B dissections, a normal chest radiograph should not be used to rule out acute aortic dissection
Due to the limited sensitivity of chest radiographs, especially in type B dissections, a normal chest radiograph should not be used to rule out acute aortic dissection
In this patient, a right hilar fullness was noted. Without access to the actual chest radiograph, it is difficult to comment on how or whether this finding should have influenced the clinicians in this case
Diagnosis of aortic dissection in the emergency department (ED) is missed 16%−38% of the time
Diagnosis of aortic dissection in the emergency department (ED) is missed 16%−38% of the time
One study identified three key factors that appeared to predispose to missing the diagnosis of acute aortic dissection :
Perceived mild disease at presentation
Misdiagnosis as another disease (most often acute coronary syndrome)
Absence of "typical" radiographic findings such as a widened mediastinum or common laboratory findings
Another study examined misdiagnosis of acute aortic dissection in the ED and found that neither age, male sex, nor a history of hypertension were significant risk factors for missed diagnosis
Another study examined misdiagnosis of acute aortic dissection in the ED and found that neither age, male sex, nor a history of hypertension were significant risk factors for missed diagnosis
Instead missed diagnoses were significantly higher in the absence of pulse deficit and the absence of widened mediastinum on chest radiography
Common misdiagnoses include acute coronary syndrome (19%), musculoskeletal pain (20%), pneumonia/pulmonary embolism (20%), pericarditis (12%), and GI pain (9%)
Not only is the diagnosis of acute aortic dissection often missed, but the disease is often mismanaged
A recent review outlined pitfalls in management. Key recommendations were:
Clinicians should not exclude the possibility of acute aortic dissection based solely on the absence of tearing chest pain, pulse or blood pressure differential, or a widened mediastinum on chest radiograph
Thrombolytic therapy (given for presumed stroke) can be fatal in acute aortic dissection. Providers should consider the possibility of acute aortic dissection in patients presenting with acute neurologic deficits
Thrombolytic therapy (given for presumed stroke) can be fatal in acute aortic dissection. Providers should consider the possibility of acute aortic dissection in patients presenting with acute neurologic deficits
Emergency medicine providers should recognize that patients with chest pain and a slightly elevated troponin may not have an acute coronary syndrome but may have an acute aortic dissection
All patients with dissection (type A and B) should have prompt surgical evaluation
More effective education for emergency providers should emphasize pitfalls in the evaluation of chest pain and acute dissection
More effective education for emergency providers should emphasize pitfalls in the evaluation of chest pain and acute dissection
Emergency medicine providers could be trained to do bedside echocardiography to evaluate the aortic root
In this case, as the patient's confusion was transient, TIA was a reasonable initial diagnosis
In this case, as the patient's confusion was transient, TIA was a reasonable initial diagnosis
Yet, absent shock or hypoperfusion, the renal failure likely should not be attributed to the GI bleeding
Presumably, aortic dissection of the proximal aorta involving the cerebral vessels could have caused the symptoms of TIA
Extension of the dissection to the abdomen could lead to mesenteric ischemia and gastrointestinal bleeding
Involvement of the renal arteries could explain the renal failure
Acute aortic dissection is a challenging diagnosis that may not present with the classic sudden onset of tearing or sharp chest pain or pulse deficits but with painless manifestations involving other body systems such as neurological, GI, and renal
Acute aortic dissection is a challenging diagnosis that may not present with the classic sudden onset of tearing or sharp chest pain or pulse deficits but with painless manifestations involving other body systems such as neurological, GI, and renal
Providers should be familiar with common and uncommon presentations of acute aortic dissection and keep an open mind when patients present with multiple seemingly unrelated complaints
Absence of mediastinal widening on chest radiograph does not rule out aortic dissection
Absence of mediastinal widening on chest radiograph does not rule out aortic dissection
Misdiagnosis can occur when patients present with mild illness, when symptoms are suggestive of another disease (e.g., acute coronary syndrome), and when radiographic findings are not typical
Providers should be aware of specific pitfalls in the management of acute aortic dissection
