Skull fractures
Skull fractures: Excerpt from Professional Guide to Diseases (Eighth Edition)
Because of possible brain damage, a skull fracture is considered a neurosurgical condition. Skull fractures may be classified as simple (closed) or compound (open) and may displace bone fragments. Skull fractures are further described as linear, comminuted, or depressed. A linear fracture is a common hairline break, without displacement of structures; a comminuted fracture splinters or crushes the bone into several fragments; a depressed fracture pushes the bone toward the brain.
In children, the skull’s thinness and elasticity allow a depression without a fracture. (A linear fracture across a suture line increases the possibility of epidural hematoma.) Skull fractures are also classified according to location, such as cranial vault fracture and basilar fractures. Because of the danger of grave cranial complications and meningitis, basilar fractures are usually far more serious than cranial vault fractures.
Causes and incidence
Skull fractures invariably result from a traumatic blow to the head. Motor vehicle accidents, bad falls, sports injuries, and physical assaults top the list of causes. The brain can be directly affected by damage to the nervous system and by bleeding.
Closed head injuries occur in 200 out of every 100,000 patients. Severe head trauma carries a 30% mortality rate.
Signs and symptoms
Many skull fractures are accompanied by scalp wounds — abrasions, contusions, lacerations, or avulsions. If the scalp has been lacerated or torn away, bleeding may be profuse because the scalp contains many blood vessels. Occasionally, bleeding may be heavy enough to induce hypovolemic shock. The patient may also be in shock from other injuries or from medullary failure in severe head injuries.
Linear fractures that are associated only with concussion don’t produce loss of consciousness. They require evaluation, but not definitive treatment. A fracture that results in a cerebral contusion or laceration, however, may cause the classic signs of brain injury: agitation and irritability, loss of consciousness, changes in respiratory pattern (labored respirations), abnormal deep tendon reflexes, and altered pupillary and motor responses.
If the patient with a skull fracture remains conscious, he is apt to complain of a persistent, localized headache. A skull fracture may also result in cerebral edema, which may cause compression of the reticular activating system. This cuts off the normal flow of impulses to the brain and results in possible respiratory distress. The patient may experience alterations in level of consciousness (LOC), progressing to unconsciousness or even death.
When jagged bone fragments pierce the dura mater or the cerebral cortex, skull fractures may cause subdural, epidural, or intracerebral hemorrhage or hematoma. With the resulting space-occupying lesions, clinical findings may include hemiparesis, unequal pupils, dizziness, seizures, projectile vomiting, progressive unresponsiveness, and decreased pulse and respiratory rates. Sphenoidal fractures may also damage the optic nerve, causing blindness, whereas temporal fractures may cause unilateral deafness or facial paralysis. Symptoms reflect the head injury’s severity and extent. However, some elderly patients may have cortical brain atrophy, with more space for brain swelling under the cranium, and consequently may not show signs of increased intracranial pressure (ICP) until it’s very high.
Vault fractures commonly produce soft-tissue swelling near the fracture, making it difficult to detect without a computed tomography (CT) scan.
Basilar fractures commonly produce a hemorrhage from the nose, pharynx, or ears; blood under the periorbital skin (raccoon eyes) and under the conjunctiva; and Battle’s sign (supramastoid ecchymosis), sometimes with bleeding behind the eardrum (hemotympanum). This type of fracture may also cause cerebrospinal fluid (CSF) or even brain tissue to leak from the nose or ears.
Depending on the extent of brain damage, the patient with a skull fracture may suffer residual effects, such as seizures, hydrocephalus, and organic brain syndrome. Children may develop headaches, giddiness, easy fatigability, neuroses, and behavior disorders.
Diagnosis
Suspect brain injury in all patients with a skull fracture until clinical evaluation proves otherwise. Consequently, you’ll need to obtain a thorough injury history and magnetic resonance imaging (MRI) or a CT scan (to locate the fracture) for every suspected skull injury. (Keep in mind that many vault fractures aren’t visible or palpable.)
A fracture also requires a neurologic examination to check cerebral function (mental status and orientation to time, place, and person), LOC, pupillary response, motor function, and deep tendon reflexes.
Using reagent strips, test the draining nasal or ear fluid for CSF. The tape will turn blue in the presence of CSF but will remain the same in the presence of blood alone. However, the tape will also turn blue if the patient is hyperglycemic. Also check the patient’s bedsheets for the halo sign — a blood-tinged spot surrounded by a lighter ring — from leakage of CSF.
Brain damage can be assessed by a CT scan and MRI, which reveal intracranial hemorrhage from ruptured blood vessels and swelling. Expanding lesions contraindicate a lumbar puncture.
Treatment
Although occasionally even a simple linear skull fracture can tear an underlying blood vessel or cause a CSF leak, linear fractures generally require only supportive treatment, including mild analgesics such as acetaminophen, and cleaning, debridement, and repair of any wounds after injection of a local anesthetic.
If the patient with a skull fracture hasn’t lost consciousness, observe him in the emergency department for at least 4 hours. Following this observation period, if his vital signs are stable and if the neurosurgeon concurs, you can discharge him. Before discharge, give the patient an instruction sheet to follow for 24 to 48 hours of observation at home.
More severe vault fractures, especially depressed fractures, usually require a craniotomy to elevate or remove fragments that have been driven into the brain and to extract foreign bodies and necrotic tissue. This reduces the risk of infection and further brain damage. Other treatments for severe vault fractures include antibiotic therapy and, in profound hemorrhage, blood transfusions.
Basilar fractures call for immediate prophylactic antibiotics to prevent the onset of meningitis from CSF leaks as well as close observation for secondary hematomas and hemorrhages. Surgery may be necessary. In addition, both basilar and vault fractures commonly require I.V. or I.M. dexamethasone to reduce cerebral edema and minimize brain tissue damage.
Special considerations
❑ Establish and maintain a patent airway; nasal airways are contraindicated in patients who may have a basilar skull fracture. Intubation may be necessary. Suction the patient through the mouth, not the nose, to prevent introducing bacteria if a CSF leak is present.
❑ Be sure to obtain a complete history of the traumatic injury from the patient, family members, any eyewitnesses, and emergency medical services personnel. Ask whether the patient lost consciousness and, if so, for how long.
❑ Assist with diagnostic tests, including a complete neurologic examination, CT scan, and other studies.
❑ Check for abnormal reflexes such as Babinski’s reflex.
❑ Look for CSF draining from the patient’s ears, nose, or mouth. Check pillowcases and linens for CSF leaks and look for a halo sign. If the patient’s nose is draining CSF, wipe it — don’t let him blow it. If an ear is draining, cover it lightly with sterile gauze — don’t pack it.
❑ Position the patient with a head injury so that secretions can drain properly. Elevate the bed’s head 30 degrees if intracerebral injury is suspected.
❑ Cover scalp wounds carefully with a sterile dressing; control any bleeding as necessary.
❑ Take seizure precautions, but don’t restrain the patient. Agitated behavior may be due to hypoxia or increased ICP, so check for these symptoms. Speak in a calm, reassuring voice, and touch the patient gently. Don’t make any sudden, unexpected moves.
❑ Don’t give the patient opioids or sedatives because they may depress respirations, increase carbon dioxide levels, lead to increased ICP, and mask changes in neurologic status. Give acetaminophen or another mild analgesic for pain as ordered.
If a skull fracture requires surgery, proceed as follows:
❑ Obtain consent, as needed, to shave the patient’s head. Explain that you’re performing this procedure to provide a clean area for surgery. Type and crossmatch blood. Obtain orders for baseline laboratory studies, such as a complete blood count, serum electrolyte studies, prothrombin time, partial thromboplastin time, and urinalysis.
❑ After surgery, monitor the patient’s vital signs and neurologic status frequently (usually every 5 minutes until the patient is stable and then every 15 minutes for 1 hour), and report any changes in LOC. Because skull fractures and brain injuries heal slowly, don’t expect dramatic postoperative improvement.
❑ Monitor intake and output frequently, and maintain the patency of the indwelling urinary catheter. Monitor fluid intake carefully. Because hypotonic fluids (such as dextrose 5% in water) can increase cerebral edema, give fluids only as ordered.
❑ If the patient is unconscious, provide parenteral nutrition. (Remember, the patient may regurgitate and aspirate food if you use a nasogastric tube for feedings.)
If the fracture doesn’t require surgery, proceed as follows:
❑ Wear sterile gloves to examine the scalp laceration. With your finger, probe the wound for foreign bodies and a palpable fracture. Gently clean lacerations and the surrounding area; cover them with sterile gauze. Assist with suturing if necessary.
❑ Provide emotional support for the patient and his family. Explain the need for procedures to reduce the risk of brain injury.
❑ Before discharge, instruct the patient’s family to watch closely for changes in mental status, LOC, or respirations and to give the patient acetaminophen for a headache. Tell them to return him to the hospital immediately if his LOC decreases, if his headache persists after several doses of mild analgesics, if he vomits more than once, or if he develops weakness in his arms or legs.
❑ Teach the patient and his family how to care for his scalp wound. Emphasize the need to return for suture removal and follow-up evaluation.
Book Source Details
- Book Title: Professional Guide to Diseases (Eighth Edition)
- Author(s): Springhouse
- Year of Publication: 2005
- Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2005 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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