Extradural Hematoma is also called as Epidural Hematoma. After head injury, blood may collect in the epidural space between the skull and the dura. This can result from a skull fracture that causes a rupture or laceration of the middle meningeal artery, the artery that runs between the dura and the skull inferior to a thin portion of temporal bone. Hemorrhage from this artery causes rapid pressure on the brain. Symptoms are caused by the expanding hematoma. Usually, there is a momentary loss of consciousness at the time of injury, followed by an interval of apparent recovery (Lucid interval).
Although the lucid interval is considered a classic characteristic of an epidural hematoma, no lucid interval has been reported in many patients with this lesion, and thus it should not be considered a critical defining criterion. During the lucid interval, compensation for the expanding hematoma takes place by rapid absorption of CSF and decreased intravascular volume, both of which help maintain a normal ICP. When these mechanisms can no longer compensate, even a small increase in the volume of the blood clot produces a marked elevation in ICP.
Then, often suddenly, signs of compression appear (usually deterioration of consciousness and signs of focal neurologic deficits such as dilation and fixation of a pupil or paralysis of an extremity), and the patient deteriorate rapidly. An epidural hematoma is considered an extreme emergency; marked neurologic deficit or even respiratory arrest can occur within minutes. Treatment consists of making openings through the skull (burr holes) to decrease ICP emergently, remove the clot, and control the bleeding. A craniotomy may be required to remove the clot and control the bleeding.
A drain is usually inserted after creation of burr holes or a craniotomy to prevent reaccumulation of blood. Prognosis of epidural hematoma is good if there is the presence of lucid interval with the client concerned.
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