What Is an Extradural Hematoma?

Rarely, it refers to those who develop hematoma more than 3 weeks after the injury. It is generally believed that the onset of calcification in the hematoma can be used as a basis for the diagnosis of chronic hematoma.

Duan Wanru	(Resident)	Department of Neurosurgery, Xuanwu Hospital, Capital Medical University
Zhao Ruilin	(Deputy Chief Physician)	Department of Neurosurgery, Xuanwu Hospital, Capital Medical University

An epidural hematoma is a hematoma located between the skull's inner plate and the dura mater. It occurs on the convex surface of the hemisphere and accounts for about 30% of traumatic intracranial hematomas. . The formation of epidural hematomas is closely related to skull injury. Fractures or transient deformation of the skull, tearing of the dural arteries or sinuses located in the sulcus cause bleeding or fractures of the platelets. 90% of epidural hematomas and skull Related to linear fractures.

Western Medicine Name

Epidural hematoma

Affiliated Department

Surgery-Neurosurgery

Disease site

head

Contagious

Non-contagious

Classification of epidural hematomas

Epidural hematoma

Rarely, it refers to those who develop hematoma more than 3 weeks after the injury. It is generally believed that the onset of calcification in the hematoma can be used as a basis for the diagnosis of chronic hematoma.

Subacute epidural hematoma

Epidural hematoma with clinical symptoms and signs appeared within 3 days to 3 weeks after trauma.

Epidural hematoma

It develops within 3 hours to 3 days after trauma.

Epidural hematoma extraacute hematoma

Intracranial hematoma occurred within 3 hours after injury.

The cause and mechanism of epidural hematoma

Epidural hematoma is mainly acute, accounting for about 86%, and sometimes complicated with other types of hematoma. Most of the heads are directly hit by external forces, resulting in skull deformation or fracture at the point of force, and injury to blood vessels. Hematomas generally occur at and near the point of force, so it can be passed through the meningeal blood vessels and sinuses according to the fracture line. Determine the location of the hematoma. Damage to the epidural hematoma caused by damage to the middle meningeal artery accounted for 3/4, followed by damage to the sinuses, plate veins, etc. leading to hematoma. Bleeding accumulates at the point where the dura mater is separated from the skull's inner plate, and the dura mater is further separated as the hematoma increases.

Epidural hematomas are most common in the frontotemporal and parietal temporal regions. This is related to the fact that the temporal region contains the meningeal arteries and veins and is easily torn by fractures. The rapid development of epidural hematomas, most of which are caused by arterial injury, hematomas increase rapidly, can cause cerebral hernias within a few hours, threatening patients' lives. If the bleeding originates from a vein, such as a dural vein, a platelet vein, or a sinus, the disease progresses more slowly and can be of subacute or chronic course.

Acute epidural hematomas are less common in the occipital region, where the dura mater and occipital bone are lightly attached and often venous bleeding. According to research, hematoma requires at least 35g of force to peel the dura from the skull. But sometimes, because the fracture line crosses the superior sagittal sinus or transverse sinus, it can also cause a huge epidural hematoma riding on the sinus. The continuous expansion of this kind of hematoma is mostly caused by the separation of the dura mater and the inner bone plate. Caused by rebleeding, rather than continued bleeding caused by venous pressure alone.

The size of the hematoma is closely related to the severity of the disease. However, the relationship between bleeding rate and clinical manifestations cannot be ignored. Often small and acute hematomas show early symptoms of cerebral compression, while hematomas with slow bleeding begin to show increased intracranial pressure within days or even weeks. Acute hematomas located on the convex surface of the hemisphere often push the brain tissues inward and downward, so that the hippocampus and hook-back of the medial temporal lobe protrude below the cerebellar notch edge, compressing the brain feet, the oculomotor nerve, the posterior cerebral artery, and affecting the pontine veins. And the return of the superior petrosal sinus is called the cerebellum notch hernia. Epidural hematomas, which last for a long time, usually become organic in 6-9 days. They grow into the fibroblasts from the dura mater and are covered with a thin layer of granulation and adhere to the dura mater and the skull. Small hematomas can be fully mechanized, and large hematomas can become cystic and store brown bloody fluids.

Pathophysiology of epidural hematoma

Epidural hematomas occur in the epidural space. The hematoma begins with fresh blood and blood clots. After a few days, the blood clot liquefies and is gradually absorbed. A thin layer of granulation tissue is formed around it, and a granulation envelope is formed in about one month. It contains the liquefied blood clot, mixed with soft clots. Some Mechanized into solids.

Patients with typical epidural hematomas have intermediate awake periods. Intermediate awake period refers to the coma at the time of the injury, and the consciousness improves after a few minutes or hours, or even fully awake, and then coma again. This is caused by the formation of epidural hematoma and brain compression. However, it should be noted that not all patients with epidural hematomas have intermediate awakening periods, because changes in consciousness depend on the degree of primary brain injury, the rate of hematoma formation and the presence of other intracranial injuries.

Clinical manifestations of epidural hematoma

Typical acute epidural hematomas are common in young men with linear skull fractures, with the frontal-temporal and parietal-temporal segments being the most common. The clinical manifestations of epidural hematomas may vary due to differences in bleeding rate, hematoma location, and age, but from the clinical characteristics, there are still certain laws and commonalities, that is, coma-sober-then coma. Taking the acute epidural hematoma as an example, it is summarized as follows:

Epidural hematoma unconsciousness

Due to the varying degrees of primary brain injury, there are three different situations in which patients' consciousness changes:

Primary brain injury is minor. There is no primary coma after injury. After the formation of intracranial hematoma, progressive intracranial pressure and disturbance of consciousness begin to appear. Such patients are easy to miss diagnosis.

The primary brain injury is slightly severe. After the injury, he was comatose for a while, then became fully awake or consciously improved, but soon fell into a coma again. Such patients have typical cases of "intermediate awake period", which is easy to diagnose, but Less than 1/3 of these patients are clinical.

(3) The primary brain injury is severe, the coma persists after the injury, and there is a progressive deepening. The signs of intracranial hematoma are often masked by the primary brain contusion or brainstem injury, which is more likely to be misdiagnosed.

Increased intracranial pressure in epidural hematoma

With the increase of intracranial pressure, patients often have headaches, vomiting, agitation, and the typical changes of the four curves, namely Cushing's response, with compensatory features such as increased blood pressure, increased pulse pressure difference, increased body temperature, heart rate, and slow breathing. In response, when failure occurs, blood pressure drops, pulses are weak, and breathing is suppressed. If the intracranial pressure continues to increase, it can cause a cerebral hernia with serious consequences.

Signs of the epidural hematoma nervous system

A simple epidural hematoma has fewer signs of neurological damage in the early stage. Only when the hematoma compresses the brain functional area, there are corresponding positive signs. If the patient immediately develops symptoms and signs such as facial paralysis, hemiplegia, or aphasia, he should Blame it for primary brain injury. When the hematoma keeps increasing and causes the temporomandibular hernia, the patient will not only deepen the conscious disorder, the vital signs will be disordered, but also the typical signs such as dilated pupils on the ipsilateral side and hemiplegia on the opposite side will occur. Occasionally, due to the rapid development of hematomas, the early brainstem is distorted, displaced, and embedded on the contralateral cerebellum notch margin, which causes atypical signs: i.e., dilated pupil on the contralateral side, hemiplegia on the contralateral side; ipsilateral pupil dilation Large, ipsilateral hemiplegia; or contralateral pupil dilated, ipsilateral hemiplegia.

Diagnosis and differential diagnosis of epidural hematoma

Diagnosis of epidural hematoma

The early diagnosis of acute epidural hematoma should be judged before the signs of hernia of the temporal lobe, not after the coma deepens and the pupil dilated, so clinical observation is very important. In addition to the scalp contusion, the localized swelling of the scalp is common, and bleeding occurs from the fracture line to the subperiosteal line, or from the ruptured periosteum to the cap fascia to form a subcapsular hematoma. Patients with increased headache and vomiting, restlessness, increased blood pressure, increased pulse pressure difference, and / or new signs should be suspected of intracranial hematoma, and given the necessary imaging examination in time, including plain X-ray skull, A Ultrasound, cerebral angiography or CT scan.

CT manifestations: The vast majority (85%) of epidural hematomas have typical CT characteristics: there are biconvex or epidural hematomas with clear high-density shadows below the skull's inner plate, and the CT value is 40HU-100HU; In some hematomas, small circular or irregular low-density areas can be seen. It is believed that fresh blood bleeding (lower density than clot) is still caused by short trauma time, and it is caused by mixing with serum that overflows when the clot shrinks. Hematomas can be semilunar or crescent-shaped; individual hematomas can infiltrate into the extracranial soft tissue through a separate fracture gap; bone windows often show fractures. In addition, hematoma showed a space effect, displacement of the midline structure, compression, deformation and displacement of the diseased lateral ventricle. Vein-derived epidural hematomas have low venous pressure and late formation of hematomas. Hematomas may dissolve during CT scans, showing a slightly higher or lower density area. A small number of patients are asymptomatic when they are injured, and chronic epidural hematomas occur later. At this time, scanning after enhancement can show the enhancement of the envelope of the inner edge of the hematoma, which is helpful for the diagnosis of isodense epidural hematoma.

MRI manifestations: Hematomas occurred mostly in locations directly receiving violence, with local fractures, scalp hematomas, and hematomas were generally limited and did not exceed the boundaries of cranial sutures. The morphological changes of epidural hematoma are similar to CT. Hematomas are biconvex or spindle-shaped, with sharp borders, located between the skull's inner plate and the surface of the brain. The signal strength of the hematoma changes, which is related to the age of the hematoma. In the acute phase, on a T1-weighted image, the hematoma signal is similar to that of the brain parenchyma. Hematomas appear as low signal on T2-weighted images. In the subacute and chronic phases, the T1 and T2 weighted images showed high signals. In addition, due to the hematoma mass effect, the affected side of the cerebral cortex is compressed and distorted, which is the sign of brain gyration. Increasing distance from the skull inner pole, inward migration of blood vessels on the surface of the brain (cortex), etc., suggest signs of extracranial space occupying lesions, leading to a clearer diagnosis.

Differential diagnosis of epidural hematoma

Need to identify the following diseases

1. Subdural hematoma:

The cause of subdural hematoma is similar to that of epidural hematoma. Most of them are caused by trauma caused by fracture or skull rupture after cranial fracture. The part is between the meninges and skull, but the difference is that CT shows a wide range of Moon-shaped high-density shadow can cross the cranial suture.

2. Hemisphere occupying lesions:

Occupying lesions such as intracerebral hematomas, brain tumors, brain abscesses and granulomas are easily confused with chronic epidural hematomas. The main differences were that there was no history of head trauma and more obvious signs of limited neurological deficits. Confirmation also requires CT, MRI, or cerebral angiography.

Subarachnoid hematoma: Subarachnoid hematoma is also a common cause of intracranial occupying, which can be manifested by increased intracranial pressure and disturbance of consciousness. Subarachnoid hematomas can be divided into two categories: traumatic and spontaneous: traumatic can be combined with epidural hemorrhage; spontaneous often with severe, explosive headaches, the cause of which is mostly intracranial vascular malformations or arteries Caused by tumor rupture.

Emergency measures for epidural hematoma

For the emergency rescue of high intracranial pressure and life-threatening acute acute epidural hematoma, drilling and puncture can be used to clear the epidural hematoma, and some liquid hematoma can be discharged by taper holes or drilling. The indication is relatively stable, with a bleeding volume of about 30 to 50 ml, which was clearly positioned by CT examination, and the midline shift was more than 0.5 cm, and no further bleeding occurred. Methods According to the thickest part of the hematoma shown in CT, taper holes or drilled holes, and then insert a suction needle or a broken suction tube with a twisted wire. After draining part of the blood, inject urokinase, or urokinase plus hyaluronidase to dissolve the remaining blood clot, and repeat it several times, leaving the tube to drain for 3 to 6 days until the CT re-examination of the hematoma has been exhausted. The puncture treatment of acute epidural hematoma should closely observe the changes of the condition, and review the CT in time. If the hematoma decreases by less than 1/3 after suction and initial liquefaction or the symptoms are not significantly relieved, the bone flap should be used to remove the hematoma in time.

This kind of operation is simple and easy to perform, and is conducive to saving patients' lives quickly. It is used for the emergency rescue of extremely acute epidural hematomas. It can temporarily relieve part of the cranial hypertension and win time. It is often used for pre-hospital or pre-operative emergency treatment. ^[1]

Epidural Hematoma Treatment

Surgical treatment of epidural hematoma

Acute epidural hematoma should, in principle, be operated upon diagnosis, to exclude hematoma to relieve intracranial hypertension, and to give appropriate non-surgical treatment after surgery according to the condition.

Indications for surgery include:

The degree of disturbance of consciousness gradually deepens;

The monitoring pressure of iliac cranial pressure is above 2.7kpa, and it shows a progressive increase;

signs of focal brain damage;

Those who have deteriorated during non-surgical treatment;

Children with epidural hematoma> 20ml above the curtain and> 10ml below the curtain may consider surgery;

There is no obvious disturbance of consciousness or increased intracranial pressure, but the hematoma on CT examination is large (> 30ml above the curtain,> 10ml below the curtain,> 20ml in the temporal area, or the midline shift is> 1cm although the hematoma is not large), the ventricle or brain Those with obvious pressure on the pool;

Miniature epidural hematomas of the transverse sinus sulcus should be actively operated if there are signs of progressive intracranial pressure that exclude other causes;

Contraindications to surgery include:

In addition to routine contraindications to surgery, patients with frequent death and extremely low GCS score of 3 are unresponsive, have dilated pupils, do not have spontaneous breathing or do not rise in blood pressure; foreign perspectives: GCS scores of 75 or older Patients should also be treated non-surgically, because the prognosis is poor whether or not surgery is performed.

Non-surgical treatment of epidural hematoma

Acute epidural hematomas must be treated promptly and reasonably without surgery, whether or not surgery is performed, especially in patients with severe primary brain damage and / or secondary brain damage, and must not be taken lightly. For acute, epidural hematomas with a clear, stable condition and hematoma volume <15ml, symptoms of increased intracranial pressure such as headache, dizziness, and nausea can be manifested, but generally there are no signs of the nervous system, and the presence of hematoma is difficult to determine without CT scans. After diagnosis by CT scan, dehydration, hormones, hemostasis, blood circulation and blood stasis treatment can be used, and the hematoma can be absorbed in about 15 to 45 days. Dynamic CT monitoring during conservative treatment. Puncture treatment is feasible for hematomas exceeding 30ml. In the subacute and chronic periods, hematomas have been partially or completely liquefied, most of the hematomas have been removed, and liquefaction can be completely removed once or twice. hematoma. But the patient's mind, clinical symptoms and dynamic CT scan must be observed dynamically. Once hematoma was found to increase, immediately switch to surgical treatment. ^[2]

Prognosis of epidural hematoma

For those with no other serious complications and minor primary brain injury, timely surgery is performed, and the prognosis is mostly good. The mortality rate is between 5% and 25%, and there are large disparities in different regions or units. The mortality of acute epidural hematoma is directly related to the patient's level of consciousness before surgery. The mortality is higher in patients with acute epidural hematoma who are unconscious. In those patients who were awake before surgery without local neurological impairment, the mortality rate was almost zero. The mortality of patients with subdural hematoma, intracerebral hematoma, and cerebral contusion was four times that of uncomplicated. All suggest a poor prognosis.

In fact, the main cause of death in patients with epidural hematoma is not the hematoma itself. The degree of primary brain injury and the secondary damage to the brain stem caused by the formation of cerebral hernia are the main factors leading to poor prognosis.

In addition, advanced age, poor clinical status, large hematoma volume, delayed operation time, severe midline shift, and persistently high intracranial pressure all suggest poor prognosis.

Epidural hematoma care

Preoperative care of epidural hematoma

Closely observe the changes in the condition, assist in various CT and other examinations, and pay attention to the presence of intermediate awake periods, such as increased headache and vomiting after injury, progressively deeper consciousness, progressively dilated pupils on one side, dull or disappeared light reflection, Contralateral limb paralysis, hematoma formation should be considered, and the doctor should be notified immediately. Those who need surgery should immediately prepare before surgery, such as fasting, shaving, matching blood, etc., prepare rescue items and medicines, keep the room clean, quiet, and suitable for temperature and humidity. Place the patient in an air-conditioned room to prevent The patient has a fever to reduce the oxygen consumption of brain cells.

Postoperative epidural hematoma care

Recumbent position: After returning to the ward, the patient goes to the pillow and lies on his back with his head tilted to one side. After 6 hours, the head of the bed is raised by 15 ° 30 °. The head and neck pillows are ice pillows or ice caps to reduce brain edema and reduce brain cell consumption. Oxygen, reducing bleeding from head wounds. Keep head dressings dry to prevent wound infections.

Illness observation: Regularly observe the signs of consciousness, pupil, blood pressure, breathing, heart rate and vomiting, and record it. Those who are not awake under general anesthesia should be observed every 15-30 minutes. Observe the doctor's orders every 1 to 2 hours after awakening. The changes in consciousness, pupils, BP, P, R, positioning signs, and vomiting can reflect changes in the intracranial condition. After the consciousness, the patient gradually develops a disturbance of consciousness and progressively worsens. Dilated pupils, dull or disappeared light reflection, hemiplegia of the opposite limb, compensatory increase in blood pressure, slowed pulse and respiration, and progressive vomiting, indicating the risk of secondary intracranial hemorrhage or cerebral edema, which should be immediately notified The doctor also actively cooperated with the rescue.

(3) Respiratory tract care: The patient is given oxygen inhalation after returning to the ward, and the flow rate is 2L / min. Surgery is performed under general anesthesia. Patients are susceptible to posterior tongue fall, laryngeal spasm, increased respiratory secretions, weakened coughing and swallowing reflexes, and vomitus aspiration caused by aspiration pneumonia before awakening. The airway is unobstructed, and the secretions from the airway are aspirated in time. Patients with coma have many respiratory secretions, hypoxia and hypercapnia often occur due to hypoventilation, increased PaCO2 in arterial blood, hypoxic acidosis caused by hypoxia, lowering the cerebrospinal fluid pH value, can cause cerebral blood vessels to expand, and hypoxia causes Swelling of brain cells, thereby increasing intracranial pressure and exacerbating the condition, tracheotomy should be performed if necessary. After tracheotomy, the inner cannula should be cleaned and boiled and disinfected 3 to 4 times daily, and respiratory secretions and sputum should be aspirated in time. If the liquid is not easy to be sucked out, you can use chymotrypsin for ultrasonic nebulization inhalation, 2 to 3 times a day, to keep the dressing at the tracheal incision clean and dry, and strictly aseptic operation.

Drain tube care: often keep the head drainage tube unobstructed, and notify the doctor in time if it is found to be unsatisfactory. The drainage bag is flush with the skull. Replace it once a day. Carefully observe and record the color and quantity of the drainage fluid to maintain head drainage. The tube is fixed to prevent it from falling off and twisting.

Nutrition: Give a high-protein, high-calorie, high-vitamin diet, sobriety patients will be liquid for 1 to 2 days after surgery, and no vomiting will gradually change to semi-liquid, general food. Patients with coma and dysphagia should be given nasal feeding 3 to 5 days after operation. Pay attention to food hygiene and prevent diarrhea. Fasting and nasal feeding should take 2 to 3 times daily oral care.

Skin care: Coma and bedridden patients cannot automatically turn over, poor skin resistance, and the skin is susceptible to pressure ulcers caused by moisture and slag epidural blood swelling. Therefore, it is necessary to do skin care for patients, sleep on air mattresses, Keep the sheets flat, clean, and dry, and turn over every 1 to 2 hours. When turning over, the movement should be gentle, avoid dragging, pulling, and pushing, and massage the bone process with 50% safflower alcohol to promote local blood circulation and prevent pressure ulcers. happened.

Functional exercise: Those who have limb hemiplegia or mobility impairment after surgery should keep their limbs in a functional position. After the acute period, massage and massage the patients as soon as possible to help patients move their limbs, promote limb function recovery, prevent foot drooping, limb stiffness and loss. Sexual atrophy.