Chapter 36: Traumatic Brain Injury

Statistics 80,000 have disability; 50,000 die from head injury Head injury profiles Age 15 to 24 Male Causes Motor vehicle accidents Falls (especially in the young and older populations) Violence

Mechanism of Injury Important information to get from those at the scene Important in determining where the injury is located and the type of neurologic deficits Mechanism of injury Acceleration – moving object hits nonmoving head Deceleration – moving head hits stationary object Coup-contrecoup – damage from rebound effect Rotational – twisting of brain in the skull (See Figure 36-1.)

Question Which of the following predisposes an elderly patient to falls and possible head injury? A. An enlarged cerebrum B. Sinus arrhythmia C. Nocturia D. The use of steroids in the elderly

Answer C. Nocturia Rationale: Nocturia (getting up to void at night) along with decreased visual acuity leads to falls. Cerebral atrophy, not enlargement, leads to more room for the brain to move, and therefore the brain would be subject to trauma against the bony skull. Steroids are not always used in the elderly, and complications are not associated with falls. Atrial fibrillation and flutter can lead to strokes or syncope and falls.

Pathophysiology: Types Primary (due to initial injury) Types Lacerations Skull fracture Basilar skull fracture Concussion Contusion Hematomas SAH (subarachnoid hemorrhage) DAH (diffuse axonal injury) Cerebrovascular injury Secondary (generally due to response to injury) Types Cerebral edema Ischemia Herniation syndromes Coma

Primary Injuries Scalp lacerations Always a bit scary as they tend to bleed a lot Skull fractures Open/compound Linear Closed Depressed Bone fragments may enter the dura

Primary Injuries: Basilar Skull Fracture Classic signs, usually due to CSF leakage from the sinuses or bleeding in unusual areas Otorrhea Postauricular hematoma (Battle’s sign) Rhinorrhea Periocular ecchymosis (“raccoon’s eyes”)

Question Which of the following symptoms indicates a fracture of the middle fossa in a basilar skull fracture? A. Otorrhea B. Rhinorrhea C. Raccoon’s eyes D. Halo sign

Answer A. Otorrhea Rationale: A communicating fracture of the middle fossa in a basilar skull fracture manifests with otorrhea (CSF from the ear) or Battle’s sign (mastoid ecchymosis). A fracture of the anterior fossa or front of the skull usually produces raccoon’s eyes and rhinorrhea (CSF from the nose). The halo sign is a bloodstain surrounded by a yellowish “halo.” The halo sign can happen with any CSF drainage and is not limited to any one area of the brain.

Question In a patient with a head injury, the endotracheal tube should be inserted through the nose. A. True B. False

Answer B. False Rationale: Nothing should be passed into the nose of a patient with head trauma, especially a basilar skull fracture. If a nasogastric or endotracheal tube is nasally inserted, the tube could pass into brain tissue because of the fracture and communication with the CSF.

Primary Brain Injuries Concussion Mild brain trauma causing an alteration in mental status May or may not have a change in LOC Can have memory deficits both before and after the accident May have residual effects that need to be monitored Contusion Focal injury usually due to microtrauma to the vascular system Symptoms depend on depth of injury and amount of tissue contused Mortality can be from cerebral swelling Usually resolves within 24 to 72 hrs

Primary Brain Injuries: Hematomas Hematomas are lesions in the brain caused by traumatic bleeding. Types include: Epidural Subdural Intracerebral Traumatic subdural hemorrhage Diffuse axonal Injury Cerebrovascular Injury (Refer to Figure 36-2.)

Secondary Brain Injury These are due to changes in the brain as a result of trauma. Types include: Cerebral edema Ischemia Herniation syndromes Coma

Secondary Injury: Edema and Ischemia Cerebral edema peaks in 72 hrs Cytotoxic Vasogenic Ischemia – decreased blood flow and possible infarction Major cause of permanent injury and death

Secondary Injury: Herniation Syndromes Caused by the shifting of structures under pressure. Cushing’s triad is a late sign. There are four types: Uncal – supratentorial herniation; ipsilateral “blown pupil”; contralateral weakness Tonsillar – through foramen magnum; respiratory arrest Central (transtentorial) Upward cerebellar The first two are most commonly seen in critical care.

Secondary Injury: Coma Defined as a change in the LOR RAS is disrupted Persistent vegetative state Arousal but no cognitive function Role of the GCS Causes Refer to Box 36-2.

Nursing Assessment of the Brain-Injured Patient LOR is the most sensitive indicator AVPU scale Painful stimuli types Glasgow Coma Scale Tests for cognitive function Alert and oriented x3 Hand grasps and letting go Refer to Figure 36-5.

Eye Changes Extraocular movements PERRLA Oculocephalic Oculovestibular

Nursing Assessment of the Brain-Injured Patient: Brain Stem Responses Corneal reflex Cough/gag

Nursing Assessment of the Brain-Injured Patient: Motor Function Test all of these and record responses on both sides of the body: Localization Withdrawal Decorticate Decerebrate Babinski’s reflex

Nursing Assessment: Respiratory Function Cheyne-Stokes – periods of apnea slowly building in rate/depth till a peak is met (cerebral hemisphere trauma; normal age- related change) Central neurogenic hyperventilation – rapid, regular, sustained and deep (upper midbrain) Apneustic – long pauses with full inspiration/expiration (brain stem) Ataxic – irregular and unpredictable (medulla) Refer to Figure 36-6.

Diagnostic Testing CT MRI Angiography Transcranial Doppler ultrasonography EEG Jugular bulb catheter

Medical Management and Nursing Care Airway Always #1 priority Keep pCO2 35 to 45 mmHg Avoid hyperventilation in first 24 hrs Fluid resuscitation To keep ICP within normal range and BP stable ICP monitoring Positioning

Question A nurse would see increased intracranial pressure during which of the following position changes? A. Logrolling the patient B. Extreme hip flexion C. Keeping the head of the bed at 30 degrees D. Placing sandbags on the side of the head to keep it in alignment

Answer B. Extreme hip flexion Rationale: Logrolling the patient, keeping the HOB at 30 degrees, and sandbagging each side of the head help lowering increased ICP. Extreme hip flexion increases intra-abdominal pressure, which can be transmitted to the cranial vault.

Medical Management and Nursing Care Prevention and treatment of seizures Medications for prophylaxis in early phase only Dilantin (phenytoin) General seizure precautions Temperature maintenance Therapeutic hypothermia doesn’t affect outcomes Monitoring fluids and electrolytes Diuretics Monitoring for SIADH, diabetes insipidus, glucose and salt- wasting syndrome

Medical Management and Nursing Care (cont.) Cardiovascular Monitor for MI and rhythm disturbances Monitor for DIC Use of pulmonary artery catheter Hazards of immobility (DVT, contractures) Pulmonary Aspiration pneumonia ETT management, suctioning, tube feeding management Monitor for ARDS and “flash” pulmonary edema

Medical Management and Nursing Care (cont.) Nutrition Nutrition ASAP Protein-rich formulas Integumentary and musculoskeletal system Contracture prevention Early PT Family support Importance of being honest and truthful Information Active involvement Behavioral changes

Brain Death Examination Normothermic Coma Negative brain stem reflexes Apneic Organ procurement