2. Lesson 8 Central Nervous System Trauma: Injuries to the Brain and Spinal Cord
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15. Anatomy: Skull and Brain Skull Periosteum Dura mater } One functional layer Arachnoid membrane Pia mater Vessels in subarachnoid space Epidural space Subdural space Subarachnoid space
38. Immobilization Algorithm: Blunt Trauma Altered level of consciousness (GCS less than 15) No Yes IMMOBILIZE Rapid transport Spinal pain or tenderness? or Neurological deficit or complaint? or Anatomic deformity of spine? No Yes IMMOBILIZE Rapid transport Concerning mechanism of injury?
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Editor's Notes
Instructor Notes: Generate discussion using the questions below: What are your primary concerns regarding the patient at this point? What possible injuries could exist?
Instructor Notes: Generate discussion using the questions on the slide and information below: This is a critical patient due to the mechanism of injury, compromised airway, impaired ventilations, and neurological deficit. Needed interventions: Airway management with inline manual spinal stabilization, ventilatory support, supplemental oxygen, maintaining body temperature, rapid extrication
Instructor Notes: Airway management may be difficult due to combativeness, trismus, facial injuries, the need for inline spinal stabilization Adjuncts and options for airway management include the following: jaw thrust, suction, basic adjuncts, dual lumen (nonvisualized) airways, laryngeal mask airway, endotracheal intubation, cricothyrotomy Intubation is indicated when: the airway can’t be protected (blood, secretions, emesis), GCS of 8 or less,
Instructor Notes: The best airway is the one that allows the patient to be ventilated with the fewest complications.
Instructor Notes: Proper brain oxygenation relies on an adequate number of circulating red blood cells and an adequate blood pressure, as well as adequate ventilation and oxygenation. Control external hemorrhage; be alert to indications of internal hemorrhage. Hypotension in the trauma patient is hypovolemic until proven otherwise.
Instructor Notes: Critical thinking question: “What are the reasons our patient’s mental status may be altered?” “How are these causes managed?” An early check of the pupils will provide a baseline indication of traumatic brain injury.
Instructor Notes: Indications: Threat to life identified in primary survey External threat to patient or rescuers Rapid extrication should not be used unless there is an indication for it.
Instructor Notes: The skull is composed of numerous bones. Epidural space is a potential space between dura mater and the skull. Dura mater is a heavy protective covering along the skull. Subdural space is a potential space between the dura mater and arachnoid. Arachnoid is a spiderweb-like layer of meninges. Subarachnoid space is an area filled with cerebrospinal fluid (CSF). Pia mater is a meningeal layer adherent to the brain.
Instructor Notes: The cerebrum is divided into symmetrical right and left hemispheres. Each hemisphere is further divided into lobes. The brainstem is responsible for vital functions, such as respiration and some control over the heart, and contains part of the reticular activating system, which is responsible for consciousness. The cerebellum is responsible for coordination and balance.
Instructor Notes: Primary and Secondary Causes of Brain Injury: Primary injury occurs at the time of impact. It is a direct injury to the brain. Secondary injury occurs after the primary injury, due to systemic and/or intracranial causes. Secondary injury can worsen the patient’s outcome, but the prehospital care provider can make a difference in secondary brain injury. Systemic causes: hypoxia, increased or decreased carbon dioxide, anemia, hypotension, increased/decreased blood glucose Intracranial causes: seizures, cerebral edema, hematoma, intracranial hypertension
Instructor Notes: Simple linear fracture — cannot be seen in the field, requires skull x-rays or CT scan for detection. Basilar fracture — fracture to the skull base. May be associated with CSF leakage of the nose (CSF rhinorrhea) or ears (CFS otorrhea). Periorbital ecchymosis (“raccoon’s eyes”) and Battle’s sign take hours to develop. Their absence does not rule out basilar skull fracture. Depressed — deformity seen or noted on palpation. Open skull fracture — CSF and hemorrhage are usually present; brain matter may extrude from the opening.
Instructor Notes: Epidural — usually associated with temporal/parietal skull fracture; generally caused by arterial bleeding (middle meningeal artery). The classic presentation after injury is brief loss of consciousness, a lucid interval, then unresponsiveness. Subdural — usually the result of venous bleeding. May have a slow progression. Intracerebral, also known as cerebral contusion , may expand over time. All types may lead to intracranial hypertension and brain herniation
Instructor Notes: Hypoxia increases brain cell death and edema. Altered carbon dioxide levels lead to cerebral vasoconstriction or vasodilation, each of which may impair perfusion of the brain. Hypotension and anemia impair oxygen delivery to the brain. The brain is dependent on a constant supply of glucose. Brain cells cannot function without it. Increased glucose is also associated with worse neurological outcome.
Instructor Notes: If the volume within the skull increases, there is little room for expansion. If the brain swells, blood and CSF are forced out of skull, impairing cerebral oxygen delivery. Cerebral perfusion pressure equals mean arterial pressure minus intracranial pressure (ICP cannot be measured in the prehospital setting). Normal ICP is less than 20 mm Hg. If ICP increases (due to cerebral edema or intracranial hematoma) and MAP is unchanged CPP falls- CPP should be at least 60 – 70 mm Hg.
Sedation — Titrate narcotic or benzodiazepines but beware of ventilatory depression. Chemical paralysis — Moderate to long-acting neuromuscular blocking agent (pancuronium, vecuronium). Osmotherapy (mannitol) — Given to decrease increased ICP (0.25 to 1.0 gm/kg). Controlled, mild hyperventilation — ETco 2 , 25 to 30 mm Hg. If ETco 2 is not available, consider ventilation at these rates: adult 20 breaths/min, child 30 breaths/min, infant 35 breaths/min.
Instructor Notes: The patient appears to have sustained a high spinal cord injury. Participants should be concerned with airway, breathing, circulation, and inline manual stabilization of the cervical spine.
Instructor Notes: Additional Information: MVCs — 48% of spinal injuries -Falls — 21% of injuries -Penetrating injuries — 15% of injuries -Sports injuries — 14% of injuries - Others — 2% of injuries
Instructor Notes: Vertebral anatomy: Body Spinous process Vertebral foramen (opening) The spinal cord fills the majority of the vertebral foramen (spinal canal), leaving little room for edema or bone injury.
Instructor Notes: Ligaments and muscles maintain the spine in a normal anatomic position with normal curvatures. Injuries occur when the spinal column is stressed beyond normal movement. Breakdown of spinal injuries: 55% cervical, 15% thoracic, 15% thoracolumbar junction, and 15% in the lumbrosacral regions.
Instructor Notes: Dermatome assessment can help identify injury location. Nipple line — T4 Umbilicus — T10
Instructor Notes: Secondary injuries occur after the initial impact from conditions such as edema, ischemia, or the movement of bony fragments.
Instructor Notes: Considerations for spinal immobilization need to be based on a complete specific assessment of the patient that follows an established algorithm. Neurological deficit includes any patient with a GCS score less than 15.
Instructor Notes: Unstable spinal fractures from penetrating trauma are extremely rare. Life-threatening conditions take priority. Airway compromise or gross hemorrhage should always be the first priorities for any trauma patient. Spinal precautions should be considered whenever possible. Patients who have sustained penetrating trauma without neurological complaints do not need spinal immobilization. If the patient has any neurologic complaint he or she should be fully immobilized
Instructor Notes: Apply padding where needed — Pad behind the head on adults, behind the torso on pediatrics; also may need to pad under lumbar curve and between patient’s legs Do not secure the upper extremities under the chest straps; they should be secured separately.
Instructor Notes: An appropriate receiving facility should have a functioning CT scanner and should have prompt availability of neurosurgeon. Frequent reassessment should be done — includes primary survey, including GCS and pupils. The supine position is preferred to maximize CPP; although elevating the head of patient’s bed may moderately decrease intracranial pressure, it is generally associated with a fall in MAP and CPP.
