Skull fractures
Skull fractures: Excerpt from Handbook of Diseases
Skull fractures may be simple (closed) or compound (open) and may or may not 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.
CLINICAL TIP: Because possible damage to the brain is the first concern, rather than the fracture itself, a skull fracture is considered a neurosurgical condition.
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 a cranial vault fracture; a basilar fracture is at the base of the skull and involves the cribriform plate and the frontal sinuses. Because of the danger of grave cranial complications and meningitis, basilar fractures are usually far more serious than vault fractures.
Causes
Like concussions and cerebral contusions or lacerations, skull fractures invariably result from a traumatic blow to the head. Motor vehicle accidents, bad falls, and severe beatings (especially in children) top the list of causes.
Signs and symptoms
Skull fractures are often 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.
Bleeding can occasionally 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 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 response.
If the patient with a skull fracture remains conscious, he’s apt to complain of a persistent, localized headache. A skull fracture also may result in cerebral edema, which may cause compression of the reticular activating system, cutting off the normal flow of impulses to the brain and resulting in possible respiratory distress. The patient may experience an altered 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, decreased pulse and respiratory rates, and progressive unresponsiveness.
Sphenoidal fractures may also damage the optic nerve, causing blindness. Temporal fractures may cause unilateral deafness or facial paralysis.
Symptoms reflect the severity and extent of the head injury. 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.
A vault fracture commonly produces soft-tissue swelling near the fracture, making it hard to detect without a computed tomography (CT) scan.
A basilar fracture often produces 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. 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 seizure disorders (epilepsy), 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. Every suspected skull injury calls for a thorough history of the trauma and a CT scan to attempt to locate the fracture. (Keep in mind that vault fractures often 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, the draining nasal or ear fluid should be tested for CSF. The tape will turn blue if CSF is present; it won’t change in the presence of blood alone. However, the tape will also turn blue if the patient is hyperglycemic.
The patient’s bedsheets may show the halo sign — a blood-tinged spot surrounded by a lighter ring — from leakage of CSF.
Brain damage can be assessed through a CT scan and magnetic resonance imaging, which disclose intra-cranial hemorrhage from ruptured blood vessels and swelling. Expanding lesions contraindicate lumbar puncture.
Treatment
Effective treatment depends on the type and severity of the fracture.
Linear fractures
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 and debridement of any wounds after injection of a local anesthetic.
If the patient with a skull fracture hasn’t lost consciousness, he should be observed in the emergency room for at least 4 hours. After this observation period, if vital signs are stable and if the neurosurgeon concurs, the patient can be discharged. At this time, the patient should be given an instruction sheet to follow for 24 to 48 hours of observation at home.
Vault and basilar fractures
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, thereby reducing 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, basilar and vault fractures often require dexamethasone I.V. or I.M. to reduce cerebral edema and minimize brain tissue damage.
Special considerations
❑ Establish and maintain a patent airway; nasal airways are contraindicated in patients with possible basilar skull fractures. Intubation may be necessary.
❑ Suction the patient through the mouth, not the nose, to prevent the introduction of bacteria in case a CSF leak is present.
❑ Be sure to obtain a complete history of the trauma from the patient, his family, any eyewitnesses, and ambulance personnel.
❑ Ask whether the patient lost consciousness and, if so, for how long. The patient will need further diagnostic tests, including a complete neurologic examination, a 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 bed 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 secretions can drain properly. Elevate the head of the bed 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 stem from 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.
CLINICAL TIP: Don’t give the patient narcotics 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. If the patient requires a gastric tube, choose an orogastric tube if you suspect a basilar skull fracture.
When a skull fracture requires surgery:
❑ 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 baseline laboratory studies, such as a complete blood count, serum electrolyte studies, and urinalysis.
❑ After surgery, monitor vital signs and neurologic status frequently (usually every 5 minutes until the patient is stable, and then every 15 minutes for 1 hour), watching for 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 patency of the indwelling urinary catheter. Take special care with fluid intake. Hypotonic fluids (even dextrose 5% in water) can increase cerebral edema. Their use should be restricted; give them only as needed.
❑ 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:
❑ 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 with sterile gauze. The patient may need suturing.
❑ 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 relieve the patient’s headache with acetaminophen. 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 weakness develops 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: Handbook of Diseases
- Author(s): Springhouse
- Year of Publication: 2003
- Copyright Details: Handbook of Diseases, Copyright © 2003 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: Handbook of Diseases
Authors: Springhouse
Publisher: Lippincott Williams & Wilkins
Copyright: 2003
ISBN: 1-58255-266-5
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