A 22-year-old man was walking past a construction site when a brick fell off the scaffold and struck him in the head. Witnesses noted that the patient was unconscious immediately after the incident and did not regain consciousness for approximately 10 minutes. The paramedics placed the patient in cervical spine precautions and brought him to the emergency department. During the primary survey at the emergency department, the patient has apparently normal air exchange, a respiratory rate of 18 breaths/min, blood pressure of 138/78 mm Hg, and a pulse of 80 beats/min. The patient does not open his eyes in response to voice commands but has eye opening in response to painful stimuli. He withdraws from painful stimuli. His only verbal responses are incomprehensible sounds. The secondary survey demonstrates a 3-cm scalp laceration and a contusion over the right temporal region. The right pupil is dilated 6 mm and sluggishly reactive to light; the left pupil is 4 mm in diameter and reacts normally to light. No blood is visualized behind the tympanic membranes. The results from an examination of the truncal region and extremities are within normal limits.
What is the most likely diagnosis?
What should be your next step?
ANSWERS TO CASE 12: Closed Head Injury
Summary: A 22-year-old man has an injury mechanism and presentation indicating an isolated severe closed head injury. He has an initial Glasgow Coma Scale (GCS) aggregate score of 8 (Table 12–1).
Table 12–1 • GLASGOW COMA SCALEa
• Most likely diagnosis: Severe closed head injury with possible mass effect.
• Next step: Immediate endotracheal intubation to control ventilation and oxygenation.
1. Be able to calculate and know the significance of the GCS score.
2. Learn the causes and preventive measures for secondary brain injury.
3. Learn the emergent management for patients with intracranial mass lesions.
This patient may have an epidural hematoma, subdural hematoma, intraparenchymal injury, subarachnoid hemorrhage, diffuse axonal injury, or any combination of these injuries. The anatomic classification of the injury is not important in the initial treatment of this patient. For a patient with a severe head injury, the most important management principle is avoidance of secondary brain injury. Due to the loss of cerebral autoregulation, the injured brain is much more susceptible to hypoxia and hypotension; in brain injury patients with both hypoxia and hypotension, mortality is approximately 75%, and hypotension alone doubles the mortality risk compared to that for normotensive patients with a severe head injury. Definitive airway management by endotracheal intubation is vital in the initial treatment of this patient.
This patient also has evidence of increased intracranial pressure (ICP) with localizing signs, unequal pupils, and hemiparesis. The Monro-Kellie doctrine governs ICP and expanding mass lesions. This equation states that the volume of blood, brain, and cerebrospinal fluid within the nonexpansile cranium must remain constant for ICP to remain constant. If an additional substance, such as an expanding hematoma, is added, the ICP will increase unless a compensatory amount of blood, brain, or cerebrospinal fluid is removed. Once the patient has been intubated and appropriately resuscitated with crystalloids and blood, the emergent treatment of a patient with localizing signs includes controlled hyperventilation and administration of mannitol. Controlled hyperventilation (Paco2 35-40 mmHg) causes cerebral vasoconstriction, reducing the volume of blood in the cranium and allowing room for the intracranial mass lesion. It must be used cautiously, however, because prolonged use can cause cerebral ischemia secondary to reduced blood flow. Intravenous mannitol, at a dose of 0.5 to 1 g/kg, is also used to decrease the volume of blood in the brain and to decrease brain volume related to edema. Mannitol should not be used unless the patient is adequately resuscitated because it can aggravate hypovolemia and cause uncompensated shock.
Up until recently, there had been ongoing debate regarding the utility of early hypothermia induction as a protective strategy for patients with severe traumatic brain injuries (TBIs). The findings from the recently published multicenter randomized controlled trial demonstrated that hypothermia was of no benefits in patients with severe brain injuries.
APPROACH TO: Closed Head Injury
EPIDURAL HEMATOMA: The collection of blood outside the dura but beneath the skull, most often in the temporal region (middle meningeal artery laceration). These hematomas are uncommon, occurring in 0.5% of all head injuries and 9% of severe head injuries, and they have a better prognosis than other types of cerebral hematomas. They appear classically biconvex or lens shaped on a CT scan.
SUBDURAL HEMATOMA: The collection of blood between the brain surface and the dura, commonly as a result of the tearing of bridging veins. They are much more common than epidural hematomas, and their prognosis is worse than that for epidural hematomas because of coexisting brain injury.
CONCUSSION: Transient loss of consciousness associated with no CT scan abnormalities.
MILD HEAD INJURY: GCS of 13 to 15.
MODERATE HEAD INJURY: GCS of 9 to 12.
SEVERE HEAD INJURY: GCS of 8 or less.
COMA: Severe head injury generally with a GCS of 8 or less.
BURR HOLE: A hole drilled through the skull, usually on the side of the larger pupil to decompress an intracranial mass lesion. The procedure should only be performed by a physician with adequate training by neurosurgeons, and the procedure should only be done as a lifesaving maneuver when timely transfer to a neurosurgeon is not possible.
As in any trauma patient, airway, breathing, and circulation (ABCs) concerns should be addressed first. The goals include avoidance of hypoxia and hypotension that can exacerbate head injury, and stabilization of associated spine, chest, abdomen, pelvic, and extremity injuries. A neurologic assessment should then be performed and include a pupillary examination and calculation of the GCS. Clinically, the patient with suspected TBI can be classified into mild(GCS 13-15), moderate (9-12), or severe (<9) brain injury groups based on patient’s best GCS. The pupillary examination determines pupil size and reactivity to light. Dilation of a pupil with a sluggish response to light is an early sign of temporal lobe herniation. The third nerve becomes compressed against the tentorium with herniation of the temporal lobe. Ninety percent of the time this herniation and pupillary abnormality occur on the same side of the intracranial lesion. This can direct the placement of emergency burr holes should they become necessary. The GCS evaluates eye opening, motor response, and verbal response. The best motor response is a better indicator of prognosis than the worst response. The trend observed in a patient’s examination is much more important than a single examination. The diagnostic test of choice for all patients with a head injury is CT imaging. The Advanced Trauma Life Support (ATLS) guidelines recommend the liberal use of brain CT in the management of patients with suspected brain injuries. The New Orleans and Canadian Clinical Decision Rules have been published to help guide clinicians in deciding when brain CT should be obtained. The New Orleans Criteria is applicable for patients with , and the guideline recommends CT for all patients with headache, vomiting, age greater than 60, with drug or alcohol intoxication, with persistent antegrade amnesia, and with evidence of traumatic soft tissue or bony injuries above the clavicle. The Canadian CT Head Rule is applicable for patients older than 16 years of age with suspected brain injuries and GCS of 13 to 15, and this rule recommends brain CT for all patients with GCS less than 15 after 2 hours of injuries, patients with suspected open or depressed skull fractures, patients with signs of basilar skull fracture, patients with more than two episodes of vomiting, patients older than 65, patients with retrograde amnesia for longer than 30 minutes, and patients with high-risk injury mechanisms. Brain CT scan should not be obtained at a facility that is not able to treat the head-injured patient definitively if it will delay transfer to a qualified neurosurgeon or trauma surgeon.
Neurobehavioral Sequelae of Traumatic Brain Injury
Many patients with TBIs experience neurobehavioral sequelae (NBS), where it is estimated that 30% to 80% of patients with mild to moderate TBI experience NBS for up to 3 months after the initial injuries. The NBS could manifest as cognitive dysfunction, depression, dizziness, lack of concentration, fatigue, memory difficulties, irritability, and insomnia. Persistence of NBS beyond 3 months is reported in up to 15% of patients with mild TBI; therefore, to optimize patient outcomes following TBI, it is important to provide the patients and their families with short- or long-term rehabilitation and support to help the victims and their families cope with potential social and occupational difficulties.
12.1 A 46-year-old intoxicated man was driving down the highway in the wrong direction when his vehicle struck a pickup truck head-on. He presents with pulse rate of 130 beats/min, blood pressure of 90/62 mm Hg, and respiratory rate of 30 breaths/min. His pupils are 5 mm and are equally round and reactive bilaterally, he does not open his eyes to painful stimulus, he moans with painful stimulus, and he withdraws from painful stimulus. His oxygen saturation with oxygen by face mask is 86%. In addition to the possibility of closed head injury, what other factor most likely is a contributing factor for his low GCS?
B. Polysubstance abuse
C. History of seizure disorder
D. Alcohol intoxication
E. Chronic syphilis infection
12.2 A short time after arrival to the ED, the patient described in Question 12.1 underwent intubation, mechanical ventilation, and placement of bilateral chest tubes for bilateral pneumothoraces. After an additional infusion of 1000 mL of lactated Ringer solution, the patient’s blood pressure improves to 120/80 mm Hg and heart rate is decreased to 100 beats/min. With painful stimuli, the patient does not open his eyes but withdraws to painful stimulation. A CT scan of the brain demonstrates bilateral frontal contusions, subarachnoid hemorrhage, and diffuse brain edema bilaterally. Which of the following are the most appropriate next steps?
A. Craniectomy for the evacuation of subarachnoid hemorrhage.
B. Mechanical ventilation, IV fluids, and placement of ICP monitor.
C. Place bilateral burr holes in the ED.
D. Administer IV corticosteroids and mannitol at 1-g/kg dose.
E. Administer mannitol.
12.3 An 18-year-old skier who was not wearing a helmet runs into a tree during a downhill run. He is brought to the emergency department where he is noted to be screaming random words and phrases, localizing to pain, and opening his eyes to his name. Following your initial evaluation, you contact the neurosurgeon for consultation. How would you classify the severity of his closed head injury?
E. Unable to evaluate
12.4 An 18-year-old man presents with the injury mechanism described in Question 12.3, with normal blood pressure, does not open eyes to painful stimuli, has abnormal flexion of the upper extremities with pain, and moans with painful stimuli. Which of the following is the most appropriate next step?
A. CT scan.
B. 2000-mL IV fluid bolus.
C. IV mannitol.
D. Contact the neurosurgeon.
E. Endotracheal intubation.
12.1 A. This patient has a GCS of 7 (E1, V2, M4). Low GCS can be contributed by alcohol intoxication and polysubstance abuse; however, given the reported oxygen saturation of 91%, the degree of mild hypoxia is unlikely to be a factor responsible for his low GCS. Because hypoxia and hypotension are potentially correctable contributors to secondary brain injuries, these factors should be identified and addressed early during the initial management. Chronic neurosyphilis infection usually causes balance issues or sometimes the Argyll Robertson papillary reflex. A history of a seizure disorder will not typically affect level of consciousness, except in the immediate postictal state.
12.2 B. The patient now has a GCS of 6T (E1, V1T, M4). His hypotension and hypoxia have been improved with his initial management. At this time he is found to have frontal contusions, cerebral swelling, and subarachnoid hemorrhage. Although the brain CT findings are causes for alarm, these findings are not amendable to operative treatment; midline shift and focal hemorrhage would be possible indications for surgical decompression. Optimizing the patient’s condition providing best supportive care to prevent secondary brain injury is the most effective treatment at this time for his brain injury. The placement of an ICP monitoring device would be helpful in this case to help detect intracranial hypertension and direct management. Mannitol administration is not indicated at this time because there is no clear evidence of intracranial hypertension. The use of steroids is not indicated for the management of TBIs.
12.3 B. Moderate closed head injury with GCS of 11 (E3, V3, M5). Given this level of brain injury, intubation and mechanical ventilation are not mandatory. However, all precautions should be taken to avoid hypotension, hypoxia, and hypercapnia. Early brain CT scan and continued monitoring of neurological status are needed in this patient.
12.4 E. This patient has an initial GCS of 6 (E1, V2, M3), which places him in the category of severe brain injury. Early intubation to optimize oxygenation and ventilation is critical in the prevention of secondary brain injury. While CT scans and neurosurgical consultations are important aspects of this patient’s care, airway management takes precedence over these other measures. Mannitol is not indicated during the primary survey in this patient.
Prevention of secondary brain injury begins with optimizing the patient’s oxygenation, ventilation, and brain perfusion, particularly correcting hypoxemia, hypoventilation, and hypotension.
The initial GCS determined at the emergency department and the patient’s age are the most important indicators of outcome in head-injured patients.
Pupillary reflex and the GCS (eye opening, motor response, and verbal response) are the cornerstones of initial neurologic assessment.
The side with the dilated pupil is usually the side on which the intracranial mass is located.
NBS may occur following even mild brain trauma; therefore it is important to provide follow-up, assessment, and rehabilitation for these patients.
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