Aortic dissection is a condition of the aorta (the largest artery of the body), where there is a tear in the vessel wall and flowing blood enters between the layers of the aortic wall and dissects the layers apart. Aortic dissection is an extremely serious medical emergency.

The aorta is made up of three layers (as are all arteries): a tunica intima (mainly endothelial cells), a middle layer called the tunica media (that consists of smooth muscle and elastic tissue), and an outer layer, the tunica adventitia composed of connective tissue.

In an aortic dissection, blood penetrates the intima, and enters the aortic media. The high pressure rips the layers of the media apart, allowing more blood to enter. This can propagate along the length of the aorta for a variable distance, dissecting either towards or away from the heart or both. The initial tear is usually within 10cm of the aortic valve.

The risk in aortic dissection is that the aorta may rupture, leading to massive blood loss resulting in death. Actor John Ritter died in 2003 from this complication of aortic dissection.

Table of contents

1 Causes 2 Diagnosis 3 First Aid 4 Field Care (for EMTs) 5 Clinical Treatment

Causes

Aortic dissection is uncommon and associated with hypertension (high blood pressure) and connective tissue disorders. It can also be the result of chest trauma.

Diagnosis

The pain has been described as excruciating, often migrating with the path of tearing and has been known to have been mistaken for the pain of a myocardial infarction (heart attack). Patients have described feeling the ripping of the aortic wall. A pulse may be absent (sometimes just on one side). In contrast to patients suffering a heart attack, patients suffering an aortic dissection tend not to have diaphoresis (profuse sweating).

In diagnosing an aortic dissection, initial tests should be done to exclude a myocardial infarction. An ECG and cardiac enzymes should be done as initial screening tests.

Echocardiography may be of use and chest CT scans are of use in diagnosing an aortic dissection.

First Aid

It is unlikely that a first-aider will recognize this condition. Call for help and arrange for immediate transport to advanced medical care. In wilderness first aid, immediate evacuation is imperative, by MEDEVAC to an advanced medical facility if available.

Field Care (for EMTs)

Transport immediately to a facility capable of emergency cardiac surgery such as a trauma center, not a community hospital without a surgical service. "Load and go". Provide oxygen therapy and supportive care.

Clinical Treatment