spine and head trauma w

21. Describe the sequence of emergency medical care for a patient with a spinal injury and the steps for performing manual in-line stabilization, including immobilizing a supine patient, a seated patient, and a standing patient. (pp 1755-1767)

Limiting the progression of secondary SCI 2. Treatment a. Perform a primary survey including the ABCDEs. b. Form a treatment plan. c. Perform appropriate treatments. d. During the disability phase, perform a: i. Neurologic exam ii. Complete assessment of the spinal column for deformity, crepitus, step-offs, and point tenderness. e. Place a cervical collar, if indicated, and immobilize the patient. f. If protocols allow selective immobilization, and immobilization is not indicated, then release manual stabilization and continue the assessment based on the patient's condition. g. Spend no more than 10 minutes on the scene. h. Use a slower approach to treatment of spinal injuries for patients who have spinal injury with no life threats. i. Do not ignore life threats to airway, breathing, and circulation by focusing on immobilization and packaging. 3. Spinal splinting best practices a. The spine should be considered one long bone. i. Traditional spinal immobilization uses a cervical collar, a cervical immobilization device, and a long spine board. b. Caveats about traditional methods of spinal immobilization. i. There is no optimal device for spinal immobilization. ii. Vacuum mattresses have been shown to provide effective immobilization with increased patient comfort. iii. Padding behind the occiput, lumbar area, and knees reduces pain and pressure. iv. Adult patients require 0.5 to 2 inches (1.25 to 5 cm) of padding behind the occiput to maintain neutral position of the cervical spine and avoid hyperextension. v. Because of their large occiput, pediatric patients require padding under the torso to maintain neutral position and avoid hyperflexion. vi. Blanket rolls between the legs and along both sides of the body fill voids under the straps, help restrict motion, and increase patient comfort. vii. Cloth tape is ineffective at immobilizing the head or the body. viii. A rigid cervical collar and rigid cervical immobilization device provide the best immobilization of the head. ix. The head, shoulders, and pelvis must be immobilized because these are the weight centers of the body and are subject to the most movement, especially if the patient has to be turned on the backboard. x. Axial movements provide better spinal alignment than do lateral movements. 4. Manual stabilization a. Apply during the primary survey. b. Grasp the patient's head firmly between your hands. i. Extend the fingers and thumbs to avoid extension, flexion, lateral bending, or rotation of the head. ii. Do not exert traction on the patient's head. c. Maintain manual stabilization from the patient's front, rear, or side. i. Stabilization from the rear: thumb placement behind the ears with the fingers spread across the cheeks and jaw ii. Stabilization from the front: causes less patient anxiety because the patient can see who is touching him or her d. Use neutral positioning to allow the most space for the spinal cord. i. May reduce cord hypoxia and excess pressure on the tissues. e. Do not move the patient's head if the patient has: i. Muscle spasms in the neck ii. Increased pain with movement iii. Numbness, tingling, or weakness iv. A compromised airway or ventilation 5. Application of the cervical collar a. A cervical collar is intended to eliminate the axial load of the head by: i. Reducing flexion and extension of the neck ii. Placing the weight of the head on the shoulders iii. Allowing the head to remain in an in-line position b. It does not prevent the patient from turning his or her head sideways. i. Maintain manual stabilization until the patient is fully immobilized. ii. Size the collar appropriately. (a) Follow the manufacturer's instructions. (b) Ensure your hand is parallel to the jaw and measure the distance from the lower jaw to the top of the shoulders. (c) Determine the number of fingers needed to completely fill the space. (d) Transfer that measurement to the adjustable or fixed collar to determine the size of collar you need. (e) Maintain manual in-line stabilization. (f) Wrap the collar around the neck. (g) Secure the collar to the far side of the chin support. (h) Recheck that the patient is in a neutral in-line position. 6. Supine patients a. The patient can be immobilized by securing him or her to a long backboard. i. Use the four-person log roll to move a patient from the ground to a backboard. ii. Another technique is to use a scoop stretcher to lift the patient a few inches off the ground while crew members slide a long backboard under the patient. b. Provide the greatest possible stabilization while immobilizing the patient. i. Try not to have voids between the patient's body and the straps that allow movement ii. Another location that often allows lateral movement is the legs. (a) This is a natural void because of attachment to the pelvis. (b) Place premade blanket rolls on each side of the patient and between the legs. c. If you are using individual straps to secure the patient to the backboard, you must use at least five straps. d. Ensure that the head, torso, and pelvis move as a unit, with your teammates controlling the movement of the body. e. To immobilize a patient on a backboard, refer to Skill Drill 34-1. f. Patients found in a prone position or on their side should be logrolled into the supine position and then immobilized. g. To immobilize a patient on a scoop stretcher, refer to Skill Drill 34-2. 7. Seated patients a. The indications of spinal injury and the severity of associated injuries will dictate your approach to the seated patient. b. If any of the following criteria are met, lower the patient directly onto a backboard using the rapid extrication technique: i. You or the patient is in danger. ii. You must gain immediate access to other patients. iii. The patient has life-threatening injuries that justify rapid extrication. c. Place a cervical collar and manually stabilize the entire spine as you move the patient. d. Seated patients may have no indication for spinal immobilization. i. Have the patient step out of the vehicle (or stand up) and sit on a stretcher beside him or her. ii. If the patient is unable to do so, a backboard can be used for extrication to transfer the patient to the stretcher. iii. Once the patient is on the stretcher, the backboard can be removed. e. If a patient is in cardiac arrest, chest compressions take priority over immobilization. f. Refer to Skill Drill 34-3 to immobilize a seated patient.

1. Differentiate head trauma, head injury, and traumatic brain injury. (p 1713)

. Head trauma: includes both head injuries and traumatic brain injuries (TBIs) i. Head injury: traumatic insult to the head that may result in injury to the soft tissues of the scalp or bony structures of the head and skull, not including the face ii. TBI: impairment of brain function caused by an external force that may involve physical, intellectual, emotional, social, and vocational changes b. SCI: any injury of the spinal cord that disrupts normal spinal cord functions

24. Explain the various circumstances in which the helmet of a patient with a possible head or spinal injury should be left on or removed; include the steps paramedics must take to remove a helmet, including the alternative method for removing a football helmet. (pp 1770-1772)

10. Patients wearing helmets a. Helmets can inhibit full exposure of the patient, hindering efforts at airway management and spinal stabilization. b. The removal of helmets can result in spinal motion. c. Only providers who are familiar with the procedure should attempt helmet removal.

23. Explain how to remove and package a patient with a possible spinal injury from a water incident. (pp 1770-1771)

9. Packaging and removing injured patients from the water a. Assume spinal injury for the following: i. Diving injury ii. Boating injury iii. Watercraft injury iv. Falls from heights c. If respiratory arrest is suspected, ventilation can be done while still in the water. d. In case of cardiac arrest, quickly evaluate the MOI. e. In case of cardiac arrest when a spine injury is not obvious, immediately remove the patient from the water and begin CPR.

6. Describe cases in which paramedics would use advanced airway techniques to gain definitive airway control in a patient with a head injury versus a spinal cord injury (SCI). (p 1721)

Advanced airway management in patients with head or spine injury 1. Maintain manual stabilization during all airway management procedures. 2. Nasotracheal intubation carries risk and is generally contraindicated. a. When possible, use another method. 3. If the patient will not tolerate advanced airway management, consider pharmacologically assisted intubation. E. Ventilation in the context of head or spine injury 1. Ensure adequate oxygenation and ventilation in any patient with a head injury. a. Do not defer oxygenation if there are signs of hypoxia. b. Administer 100% oxygen via a nonrebreathing mask if the patient is breathing adequately. i. Adequate rate and depth (tidal volume), regular respiratory pattern c. Administer bag-mask ventilation and 100% oxygen for patients with inadequate ventilation. i. Oxygen should flow at a rate of 12 to 15 L/min. ii. Ventilate the patient to maintain the ETCO2 between 35 and 40 mm Hg. (a) If you cannot monitor ETCO2, then a respiratory rate of 10 to 12 breaths/min in the adult patient achieves the target range. iii. Avoid routine hyperventilation. d. The Brain Trauma Foundation (BTF) recommends hyperventilation only if signs of cerebral herniation are present. i. The recommended rates of hyperventilation are: (a) Adult: 20 breaths/min (b) Child: 25 breaths/min (c) Infant (younger than 1 year): 30 breaths/min

13. Discuss diffuse brain injuries, including cerebral concussion and diff use axonal injury, and their corresponding signs and symptoms. (pp 1738-1743)

Affect the entire brain 2. Cerebral concussion a. Caused by rapid acceleration-deceleration forces. c. Forces damage cell membranes of the neurons, which depresses neuronal activity. d. This results in transient dysfunction of the cerebral cortex. i. Signs include: (a) Headache (b) Confusion (c) Disorientation (d) Loss of consciousness (e) Retrograde amnesia: loss of memory relating to events that occurred before injury (f) Anterograde (posttraumatic) amnesia: loss of memory relating to events that occurred after the injury. e. The exact definition of a concussion has been the subject of much debate over the years. f. You probably will treat patients who have experienced a concussion. i. Concussions cause more than 1 million visits to EDs annually. ii. It is estimated that there are 1.6 to 3.8 million sports-related concussions annually. (a) Suspect concussion even with helmet use. g. Athletic venues are a common site of concussions. i. There is no diagnostic test for the presence of concussion. ii. Any time there is a suspicion of a concussion, the player must be removed from play and assessed by a physician. iii. Authorizing an athlete to return to play after a potential concussion is outside the paramedic's scope of practice. (a) Consult medical control. iv. Refer to the steps in concussion action plans developed by the National Federation of State High School Associations (NFHS) in association with the CDC's Heads Up program. h. Assessment and management include the following: i. Complete the primary survey. ii. Address any life-threatening conditions. iii. Secondary assessment is directed at evaluating for the presence of a concussion. iv. If you suspect a concussion, you must complete a thorough evaluation. (a) Assessment will focus primarily on cognition. (b) Patient history is the key component. (c) Ask your patient questions to assess his or her memory and awareness of person, place, time, and situation. (d) With the patient's consent, include people who know the patient during the assessment to verify the patient's answers. (1) Ask athletic trainers to compare the current findings to preseason findings. (2) Ask the patient to remember a series of words or numbers and repeat them later in the call. v. Findings of a concussion may include: (a) Headache, the most common finding (b) Fatigue or fogginess (c) Confusion or altered mental status (d) Inability to recognize people or places (e) Disorientation (f) Dizziness (g) Difficulty concentrating (h) Memory deficits (i) Difficulty maintaining balance (j) Visual disturbances (k) Delayed responses to questions (l) Irritability (m) Changes in behavior (n) Sleep disturbances (o) Sensitivity to light and noise (p) Loss of consciousness (about 10% of patients) (q) Nausea (r) Vomiting vi. Several assessment tools and scales can help identify a possible concussion: (a) The Acute Concussion Evaluation tool from the CDC (b) The Sport Concussion Assessment Tool, for patients 13 years and older (c) The child Sport Concussion Assessment Tool for patients 12 and younger vii. The emergency treatment of a patient with an isolated concussion is as follows: (a) Primarily supportive (b) Patient education, monitoring, and transport to an appropriate facility (c) Mainly physical and mental rest viii. If the patient refuses transport: (a) Obtain informed refusal (b) Your system may require you to contact medical control. (c) Give the patient specific CDC information. 3. Second impact syndrome a. Ask the patient about recent concussions. b. Second impact syndrome is a rare, often fatal result of receiving a second concussion while still recovering from an earlier concussion. c. The brain is vulnerable and autoregulation is disrupted during recovery. d. Minimal force can result in increased cerebral blood flow, brain herniation, and death. i. Death can occur in 2 to 5 minutes after the injury. e. Signs and symptoms include: i. Sudden loss of consciousness after suffering a blow to the head ii. A stunned appearance iii. Loss of eye movements iv. Dilated pupils v. Coma vi. Respiratory failure vii. Cardiac arrest f. The emergency treatment is supportive. g. A second concussion that occurs within 7 to 10 days of a previous concussion necessitates immediate transport to the closest facility with neurosurgical capability. 4. Postconcussion syndrome a. The patient may experience signs and symptoms for 3 to 6 months after the initial concussion. b. This differs from second impact syndrome in that it results from the original concussion, not a second impact. c. It requires that the patient be transported for evaluation by a physician. d. Should be suspected when the patient has at least three of the following signs and symptoms for at least 3 months after a concussion: i. Headache ii. Dizziness iii. Fatigue iv. Irritability v. Insomnia vi. Difficulty concentrating vii. Memory difficulty viii. Intolerance of stress or emotion 5. Diffuse axonal injury a. One of the most common diffuse brain injuries b. Has a high mortality rate c. Most common cause of posttraumatic unconsciousness and the most common cause of a persistent vegetative state after a TBI d. Involves stretching, shearing, tearing of nerve fibers and axonal damage e. Caused by high-speed, rapid acceleration-deceleration forces f. Classified as mild, moderate, or severe g. Assessment and management i. The primary finding is unresponsiveness, often lasting more than 6 hours. ii. Treatment is primarily supportive. iii. Be wary of airway compromise. iv. Perform a primary survey and address any life threats. v. Patients should be transported to the closest facility with in-house neurologists.

12. Discuss the pathophysiology of intracranial pressure and posturing that can appear with brain injury. (pp 1736-1739)

An increase in ICP can be caused by accumulation of blood within the skull or swelling of the brain. 2. Increased ICP squeezes the brain against bony prominences within the cranium. 3. Cerebral perfusion pressure (CPP) = Difference between mean arterial pressure (MAP) and ICP. a. CPP = MAP - ICP 4. The MAP is the diastolic blood pressure plus one-third of the pulse pressure . a. MAP = DBP + ⅓ PP 5. The normal ICP is 5 to 15 mm Hg, and the normal MAP is 85 to 95 mm Hg. a. These pressures produce a normal CPP of 70 to 90 mm Hg. 6. Any increase in ICP above 20 mm Hg decreases CPP and cerebral blood flow. 7. The body responds to a decrease in CPP by increasing MAP (autoregulation). 8. The brain can autoregulate and ensures adequate CBF when the CPP is between 60 and 160 mm Hg. a. The minimum CPP required to perfuse the brain is 60 mm Hg in an adult. b. A CPP of less than 60 mm Hg leads to cerebral ischemia. c. CPPs of greater than 160 mm Hg produce hypertensive encephalopathy. 9. In response to an expanding intracranial mass, the body reduces ICP by expelling CSF and venous blood from the cranial vault. b. This mechanism keeps the ICP within normal limits in the early stages. 10. When the ICP begins to rise and the CPP begins to drop, the body attempts to maintain CPP by increasing the MAP. a. Indicated by increasing blood pressure b. Widening pulse pressure 11. Other factors interfere with CPP: a. Excess carbon dioxide in the blood b. Hypotension c. Swelling or bleeding 12. Treatment should focus on maintaining CPP (and cerebral blood flow) while mitigating ICP. C. Herniation 1. The brain is forced from the cranial vault, through either the foramen magnum or the tentorium. 2. Lateral herniation syndrome (uncal herniation syndrome) is the most common form of herniation. a. A portion of the temporal lobe (the uncus) is displaced laterally. b. Moves downward through the tentorium incisura. c. Compresses the midbrain and posterior cerebral artery. 3. Signs of herniation include: a. Ipsilateral pupil dilation b. Contralateral motor dysfunction 4. Central herniation syndrome occurs when the brain tissue shifts downward, ultimately compressing the brainstem from above. 5. Tonsillar herniation occurs when part of the cerebellum is forced through the foramen magnum, compressing the brainstem. 6. Brainstem compression destroys the respiratory center, induces apnea, decreases perfusion to the rest of the brain, and ultimately causes death. 7. Early signs and symptoms of increased ICP include: a. Vomiting (often without nausea) b. Headache c. Altered level of consciousness d. Seizures 8. Later signs of increased ICP include: a. Hypertension b. Widening pulse pressure c. Bradycardia d. Changes in respirations (Cushing triad) i. Cheyne-Stokes respirations ii. Central neurogenic respirations e. Unequal and nonreactive pupils f. Coma g. Posturing i. Decorticate (flexor): flexion of the arms and extension of the legs ii. Decerebrate (extensor): extension of the arms and legs

18. Discuss various cord syndromes and the signs and symptoms, including anterior cord syndrome, central cord syndrome, posterior cord syndrome, cauda equina syndrome, and Brown-Séquard syndrome. (p 1751)

Anterior cord syndrome i. Result of displacement of bony fragments into the anterior portion of the spinal cord (a) Often due to flexion injuries or fractures ii. Paralysis below the level of insult with loss of sensation to pain and temperature. d. Central cord syndrome i. Hyperextension injuries to the cervical area present with hemorrhage or edema. ii. Often occurs in conjunction with tears to the anterior longitudinal ligament. iii. Frequently seen in older patients who already have significant degree of cervical spondylosis and stenosis due to arthritis. iv. Greater loss of function in the upper extremities than in the lower extremities. v. Many patients regain all motor function. e. Posterior cord syndrome i. Associated with extension injuries ii. Relatively rare syndrome iii. Produces dysfunction of the dorsal columns iv. Presents as decreased sensation to: (a) Light touch (c) Proprioception (d) Vibration v. Good overall prognosis with therapy and rehabilitation f. Cauda equina syndrome i. Compression of a bundle of nerve roots located at the end of the spinal cord ii. Causes include: (a) Swelling after impact (b) Penetrating objects (c) Bone fragments (d) Expanding hematoma within the spinal column in the lumbar region iii. Can produce the following symptoms: (a) Low back pain (b) Myalgia, paresthesia, or myasthenia in one or both legs (c) Loss of sensation in legs, buttocks, inner thighs, back of legs, or feet (d) Acute bladder/bowel dysfunction g. Brown-Séquard syndrome i. Typically occurs after penetrating trauma ii. Appears with functional hemisection of the cord and complete damage to all spinal tracts on the involved side iii. Nontraumatic causes: disk herniation, spinal cord tumors, and spinal epidural hematomas

27. Discuss nontraumatic spinal conditions, including causes of low back pain and conditions requiring prehospital treatment. (pp 1774-1775)

Back pain 1. This is a common presenting complaint. 2. Susceptibility to injury or degenerative disease may occur due to the weight an upright posture bears on the lumbar spine. 3. Spinal tumors can also be a cause of pain. 4. Risks for developing low back pain include: a. Occupations that require repetitive lifting b. Exposure to vibrations from vehicles or industrial machinery c. Comorbid diseases such as osteoporosis 5. When evaluating: a. Consider disease processes that can result in debilitating lesions. b. Keep anatomy and neurophysiology of the spine and spinal cord in mind. c. Pay attention to the patient's medications. 6. Pain may result from strain or sprain of muscles and supporting structures without significant injury to the nerves. 7. Older adult patients with a history of osteoporosis are at high risk for spontaneous compression fractures of the spine. a. These stable fractures are not associated with SCI. 8. Tumors in the spine can cause pathologic spine fractures, with extension of bone fragments or the tumor itself into the spinal canal, causing SCI. 9. Your assessment should include: a. Examination of the ABCDEs b. History, including SAMPLE history c. Evaluation of pain levels 10. Any patient with a suspected nontraumatic spinal disorder should undergo a neurologic and function examination before movement. i. Adapt transport modalities when transporting patients with scoliosis or kyphosis. 11. Degenerative disk disease is common in patients older than 50 years. a. Over time, the disk will lose height and some of its shock-absorbing effect. b. Disk herniation may occur in patients with preexisting disk degeneration. i. Typically affects men between ages 30 and 50 years ii. May result from poor lifting technique iii. Most commonly occurs at L4 to L5 and L5 to S1 iv. Patients present with pain, tenderness, and a limited range of motion. 12. Definitive diagnosis may require multiple modalities of radiographic imaging. 13. Prehospital management is directed at decreasing pain or discomfort. B. Spinal stenosis 1. A narrowing of the spinal canal that can occur at single or multiple levels, causing compression of exiting nerve roots. 2. Pain radiates from the back into the legs or arms. a. Aggravated by prolonged standing and extension b. Relieved by rest and spinal flexion 3. Place the patient in a comfortable position if transport is required.

14. Discuss focal brain injuries, including cerebral contusion and the various types of intracranial hemorrhage, and signs and symptoms of each. (pp 1742-1746)

Cerebral contusion 1. Brain tissue is bruised and damaged in a local area. 2. Greater neurologic deficits are observed than with concussion. 3. The frontal lobe is most commonly affected. 4. Swelling of the brain leads to increased ICP. C. Intracranial hemorrhage 1. Epidural hematoma a. Accumulation of blood between skull and dura mater b. Happens in 0.5% to 1% of all head injuries c. Always results from a blow to the head d. Ordinarily an immediate loss of consciousness, a brief lucid interval, and another loss of consciousness. e. High survivability with early treatment and surgery i. If the patient loses consciousness because of increased ICP, the likelihood of mortality increases significantly. f. Signs and symptoms in the conscious patient: i. Limited to those of an associated concussion and any soft-tissue damage or crepitus to the area of impact g. Signs and symptoms as ICP increases: i. Ipsilateral pupil dilation ii. Contralateral motor dysfunction iii. Nausea and vomiting iv. Seizures v. Urinary incontinence vi. Visual disturbances vii. Posturing viii. Cushing triad (late)

7. Describe the circumstances in which paramedics should establish intravenous access in a patient with a head or spine injury, including the importance of judicious fluid administration. (pp 1722-1723)

Circulation a. In the absence of a pulse, immediately initiate CPR. b. Control major bleeding with direct pressure, gauze, hemostatic agents, or pressure dressings. i. Do not apply excessive pressure to scalp lacerations in which an underlying fracture is suspected. c. Examine skin color, temperature, and moisture. i. Patients with significant sensory loss may take on the surrounding environmental temperature. ii. Patients with neurogenic shock will have skin that is warm, dry, and flushed. d. Volume resuscitation might be necessary if there is an absent or diminished pulse. i. Establish at least one 18-gauge IV line with normal saline or lactated Ringer solution. ii. Do not administer dextrose-containing solutions because they may worsen cerebral edema. (a) The only indication for administering glucose is confirmed hypoglycemia iii. Restrict your use of IV fluids for patients with a severe closed head injury. (a) If hypotension develops, infuse fluids as needed to maintain a systolic blood pressure of at least 90 mm Hg. e. Patients in pure neurogenic shock may need vagolytic drugs and vasopressors. i. Consider transcutaneous pacing for refractory symptomatic bradycardia. f. Use a cardiac monitor with every critically injured patient.

11. Explain the difference between a primary (direct) injury and a secondary (indirect) injury, giving examples of mechanisms of injury (MOIs) that could cause each injury. (p 1736)

Classified into: a. Primary brain injury i. Injury to the brain and its associated structures ii. Results instantaneously from impact to head b. Secondary brain injury i. Consequence of primary injury ii. Includes: (a) Cerebral edema (b) Intracranial hemorrhage (c) Increased ICP (d) Cerebral ischemia and hypoxia (e) Hypoglycemia (f) Hypotension (g) Infection iii. Can last anywhere from a few minutes to several days following the initial injury 2. MVC the most common cause of brain injury a. Coupe-contrecoup: Front-and-rear type of injury i. The passenger's head hits the windshield on impact, and the brain continues to move forward until it strikes the inside of the skull. (a) Results in compression injury (or bruising) to the anterior portion of the brain and stretching or tearing of the posterior portion ii. The head falls back against the headrest and/or seat, and the brain slams into the rear of the skull. iii. The same type of injury may occur on opposite sides of the brain in a lateral crash. b. The injured brain starts to swell because of dilated cerebral vessels and an increase in cerebral fluid.

26. Discuss possible complications of SCI, including autonomic dysreflexia, requiring prehospital management. (p 1773)

Complications of spinal cord injury 1. A cause of high morbidity and mortality. 2. Potential for aspiration or respiratory arrest, especially with high cervical injuries. 3. Loss of intercostal muscles impairs coughing and deep breathing. 4. Deep vein thrombosis and pulmonary embolism are late complications. 5. Autonomic dysreflexia (also called autonomic hyperreflexia) is a late complication. a. Potentially life-threatening b. Most commonly occurs with injuries above T4 to T6 c. Results from loss of parasympathetic stimulation d. A massive, uninhibited, uncompensated cardiovascular response i. Cool, pale extremities ii. Systolic blood pressures of greater than 200 mm Hg iii. Diastolic blood pressures of 130 mm Hg or greater iv. Vagal compensation e. Common causes: i. Skin lesions ii. Constrictive clothing iii. Sharp objects compressing the skin f. Prehospital management i. Focuses on supporting the vital systems ii. May be necessary to reduce blood pressure with vasodilators

9. Discuss patient assessment and management of scalp lacerations. (p 1733)

Consider the mechanism. a. Inspect for missing tissue, impaled objects, or residual contaminants. b. Evaluate for signs of continued bleeding, and reevaluate often. 2. In isolated lacerations, stop the bleeding. a. Apply direct pressure for minor to moderate lacerations. b. Pressure dressings and hemostatic agents may be required for significant lacerations. c. If time and other injuries do not prevent it, a quick cleansing rinse can reduce the incidence of infection. 3. Do not explore the injury. a. This may disrupt a clot formation and restart bleeding.

15. Describe management of head and brain injuries, including thermal management, treatment of associated injuries, and pharmacologic therapy. (pp 1746-1747)

Consideration of factors such as the severity of the injury and the patient's level of consciousness 1. Treatment priorities must be based on the conditions that will kill the patient first. 2. Check breathing pattern and rate. 3. Watch closely for signs of increasing ICP. 4. Ensure time on the scene does not exceed 10 minutes. 5. Maintain an open airway and ensure the patient's breathing is adequate. a. Administer oxygen and provide suction as necessary. b. Avoid hypoxia, hypocapnia, and hypercapnia. c. Use strategies (described earlier) for airway management and ventilatory support. d. En route, establish vascular access by starting an IV of normal saline or lactated Ringer solution. i. Infuse fluid at a rate that will prevent hypotension and preserve CPP. e. Assess serum glucose level and administer glucose or glucagon if it is indicated. f. Elevate the head of the stretcher or backboard to about a 15° to 30° angle if possible. g. Treat seizures if present. h. Consider sedation or chemical restraint if necessary. B. Thermal management 1. Do not allow the patient to develop hyperpyrexia. a. Can worsen the condition of the brain 2. Do not cover a patient with blankets if ambient temperature is 70°F (21°C) or higher. C. Pharmacologic therapy 1. Usually not indicated for brain-injured patients. 2. May be ordered if transport will be prolonged. a. Mannitol (Osmitrol) b. Furosemide (Lasix) 3. Seizures must be terminated as soon as possible. a. Benzodiazepines should be used. 4. No neuroprotective agents are currently administered in a prehospital setting.

20. Discuss the evolution of spinal care. (pp 1753-1755)

Immobilization a. This is one of the most common procedures used EMS. b. Preventive immobilization of all trauma patients became routine. 2. Evaluation for each patient a. Indications for immobilization b. Benefits of immobilization c. Risks of immobilization 3. Potential negative consequences of using cervical collars and backboards a. The debate continues. b. Determine what tools are necessary for proper patient care per local protocol. 4. Studies a. Providers can use certain criteria to identify patients who do not need immobilization. b. Patients who may not require immobilization include: i. Ambulatory trauma patients ii. Patients with penetrating trauma but no neurologic deficit iii. Patients with a complete SCI (cord already damaged) c. Complications associated with immobilizing patients with penetrating trauma include the following: i. Immobilization takes time, often causing delays on scene. ii. Immobilization takes multiple people, increasing the likelihood that other procedures may be ignored. iii. Immobilization can complicate and thereby delay airway management and other procedures within the primary survey. 5. Potential negatives of using a backboard a. Hyperextension of the cervical spine can result in neurologic deficit. b. Patients immobilized for a prolonged time often develop pain in the occipital, sacral, and lumbar areas. c. Other complications include: i. Ulcers and pressure sores ii. Increased risk of aspiration iii. Respiratory compromise iv. Raised ICP due to improperly fitted cervical collars v. Difficult airway management 6. Guidelines and position statements a. 2002: American Association of Neurological Surgeons and the Congress of Neurological Surgeons published their Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injuries and recommended full immobilization. b. 2013: The authors of the previous guidelines revised their position and recommended the use of selective immobilization criteria. c. 2013: The National Association of EMS Physicians issued a new statement that affected the immobilization of patients in the prehospital setting. 7. Application to current paramedic practice a. Views on spinal immobilization may be based on historical approaches to treatment, opinion, interpretation of data, or myriad other factors. b. Always follow your local protocols when providing any treatment, and this also applies to immobilization. c. Three common approaches to immobilization: i. All trauma patients are immobilized based on mechanism. ii. Patients with an identified mechanism are evaluated for the presence of spinal injury and either fully immobilized or not immobilized, based on selective immobilization criteria. iii. Patients with a mechanism are evaluated for the presence of spinal injury based on selective criteria and are either fully immobilized, placed in a cervical collar only and secured to the stretcher without a backboard, or not immobilized.

16. Discuss MOIs that may damage the cervical, thoracic, or lumbar spine, including flexion, rotation with flexion, vertical compression, and hyperextension. (pp 1747-1750)

Mechanism of spinal injury 1. Sufficiency of force to cause injury to the spinal column or cord a. Anytime you suspect spinal injury, you should assess whether spinal immobilization is necessary. b. Acute spinal injuries are classified according to the associated mechanism, location, and stability of the injury. 2. Medical history a. Patient's age i. A newborn cannot control his or her head and has an underdeveloped spinal column, large head, and cannot communicate pain. ii. An older adult may have osteoporosis or osteoarthritis and is predisposed to vertebral fracture. iii. A patient with decreased bone density is also at higher risk of a spinal column injury. b. Factors associated with decreased bone density i. Alcohol abuse ii. Asian or Caucasian race iii. Cigarette smoking iv. Diabetes, liver disease, kidney disease v. Family history of osteoporosis vi. History of fractures vii. Inactive lifestyle viii. Use of steroids, barbiturates, anticonvulsants, or thyroid replacement hormones 3. Common locations a. Most SCIs occur in the area of the cervical spine. b. The next most common area is the lumbar region. 4. Flexion injuries a. Result from forward movement of the head. i. Typically result of rapid deceleration or direct blow to the occiput b. At C1 to C2 level, forces can produce an unstable dislocation with or without a fracture. i. Dislocation can be complete or partial. c. Farther down the spinal column, forces can result in an anterior wedge fracture. i. Fracture can be stable or unstable. d. Hyperflexion injuries of greater force can result in teardrop fractures. i. Avulsion fractures of the anterior-inferior border of the vertebral body ii. Raise concern for possible SCI and qualify as unstable fractures iii. Can also result in a potentially unstable dislocation e. Strong forces can result in the anterior displacement of facet joints. f. Patients can experience lateral bending. i. Similar to flexion-extension injury, but from left to right rather than from front to back 5. Rotation with flexion a. The only area of the spine that allows for significant rotation is C1 to C2. i. Injuries are considered unstable due to high cervical location and scant support. b. Often result from high acceleration forces. c. In the thoracolumbar spine, forces typically cause fracture rather than dislocation. 6. Vertical compression a. Transmitted through vertical bodies b. Results from a direct blow to the crown or rapid deceleration from a fall through the feet, legs, and pelvis c. Forces can cause: i. Burst or compression fractures ii. Herniation of disks iii. Compression on the spinal cord and nerve roots iv. Fragmentation into the canal d. Primary SCI when fragments of bone become embedded in the cord 7. Distraction a. Opposite of compression forces b. Results when parts of the body are pulled in opposite directions c. Most classic distraction injury: a hangman's fracture i. Lateral force causes bending and fractures at the C1 to C2 region, which quickly tears the spinal cord. d. Mixed mechanisms with some sort of rotational, flexion, or extension forces usually occur together 8. Hyperextension a. Results in fractures and ligamentous injury of variable stability b. Stable with head and neck in flexion c. Unstable in extension due to no structural support

17. Differentiate primary SCI and secondary SCI, including complete versus incomplete cord injury. (pp 1750-1751)

Primary spinal cord injury a. Occurs at moment of impact b. Penetrating trauma i. Results in transection of neural elements and complete injuries c. Blunt trauma i. Results in compression of portions of the spinal cord or an incomplete dislocation of the vertebral body d. Spinal cord concussion i. Characterized by a temporary dysfunction that lasts from 24 to 48 hours ii. Considered an incomplete injury iii. May be due to a short-duration shock or pressure wave within the cord e. Spinal cord contusions i. Caused by fracture, dislocation, or direct trauma ii. Associated with edema, tissue damage, and vascular leakage f. Cord laceration i. Caused when a projectile or bone enters the spinal canal ii. Likely to result in hemorrhage into the cord tissue, swelling, and disruption of some portion of the cord 2. Secondary spinal cord injury a. Occurs when multiple factors create a progression of the primary SCI i. Minimize further injury through stabilization, neutral alignment, and spinal immobilization. ii. Minimize heat loss and maintain oxygenation and perfusion. 3. Effects of spinal cord injuries a. Spinal cord compression i. Can result from outside or internal pressure on the spinal cord ii. Primary cord compression: appears with a crushed vertebra or intervertebral disk iii. Secondary cord compression: occurs when soft tissues around the cord swell after an injury and compress the cord within the spinal column b. All SCIs either complete or incomplete i. Complete spinal cord injury (a) Complete disruption of all tracts of the spinal cord (b) Permanent loss of all cord-mediated functions (c) No sensation, pain, or movement below the injury (1) Injury high in the cervical spine results in quadriplegia. (2) Injury high in the thoracic area results in paraplegia. ii. Incomplete spinal cord injury (a) Some degree of cord-mediated function is retained.

8. Discuss specific assessments used with a patient with possible SCI, including a neurologic exam. (pp 1724-1725, 1727-1732)

Reevaluate the patient's mental status and response to stimuli. 2. Check for presence of a pulse. 3. Evaluate motor and sensory function in each extremity. 4. Observe the back to assess for penetrating trauma. 5. Palpate the patient's spinal column for: a. Deformity b. Step-offs c. Point tenderness d. Crepitus 6. Use the information to determine whether the patient needs spinal immobilization. 7. With head trauma and TBI, the pupils can reveal valuable information about the patient and his or her condition. a. Consider performing a quick baseline assessment during the disability portion of your primary survey. 8. Remove any clothing that would obstruct your secondary assessment. a. Cover the patient with a blanket as needed to maintain normal body temperature. b. In cold environments, move the patient to a warmer environment as quickly as possible without further compromising the spine. H. Level of consciousness 1. When you suspect head injury: a. Perform a baseline neurologic assessment using AVPU. b. Obtain a GCS score. 2. A change in the level of consciousness is the single most important sign that you can detect when you assess the severity of brain injury. a. Level of consciousness usually indicates extent of brain dysfunction. Neurologic exam a. Intended to establish a baseline for later comparison and to determine whether to immobilize the patient. b. Determine the level of consciousness. c. Myotomes are regions in the body where motor components of spinal nerves supply specific tissues and muscles. i. Ask the patient to: ii. Flex (C5) and extend (C7) both elbows and then wrists (C6). iii. Abduct and adduct his or her fingers against resistance (T1). (a) As an alternative, ask the patient to curl the fingers while applying resistance (C8). iv. Bend and extend the knees. v. Plantar flex the feet and ankles (S1 to S2). vi. Dorsiflex the toes to gravity and against resistance (L5). vii. Motor integrity in an unresponsive patient can be assessed via response to painful stimulus. d. Dermatomes are regions in the body where sensory components of spinal nerves supply specific areas of the body surface. i. Test general loss of sensation. ii. Ask about abnormal sensations. (a) Pins and needles (b) Electric shock (c) Hyperacute pain to touch (hyperesthesia) e. Assess sensory integrity bilaterally from the feet up. i. Identify the lowest level of normal sensation. ii. Assess the patient's perception of light touch, temperature, and position (proprioception). f. Reflexes can provide valuable information about sensory input. i. In significant SCIs, reflexes are usually absent but return several hours or weeks later. ii. If reflexes are intact, preservation of motor and sensory activities is likely. iii. A positive Babinski reflex occurs if the toes move upward in response to stimulation on the sole of the foot.

25. Describe prehospital pharmacologic treatment of patients with SCI. (pp 1772-1773)

Short-acting, reversible sedatives are commonly recommended for acute agitated patients. 2. Pain medication may be necessary. 3. Corticosteroids were historically used in the acute phase of SCI. a. Many recent protocols avoid their use. b. Many organizations recommend against steroid use in the management of acute spinal injury.

10. Discuss types of skull fractures, including linear, depressed, basilar, and open skull fractures. (pp 1734-1735)

Significance related to: a. Type of fracture b. Amount of force applied c. Area of head that sustained the blow 2. Potential complications: a. Intracranial hemorrhage b. Cerebral damage c. Cranial nerve damage 3. Four types of skull fractures: a. Linear skull fractures (nondisplaced skull fractures) i. Account for the majority of all skull fractures ii. Most occur in the temporal-parietal region of the skull iii. No gross physical signs b. Depressed skull fractures i. Result from high-energy direct trauma to a small surface area of the head with a blunt object. ii. The frontal and parietal regions are most susceptible because the bones are relatively thin. iii. Patients often present with neurologic signs. iv. Have the greatest association with patient death. c. Basilar skull fractures i. Associated with high-energy trauma but usually occur following diffuse impact to the head. ii. Can be difficult to diagnose with radiography d. Open skull fractures i. Result of severe force ii. Often associated with trauma to multiple body systems iii. Exposure of brain tissue iv. High mortality rate 4. Assessment and management of skull fractures a. Use the pads of your fingers to apply pressure over the entire skull. i. Note any swelling, edema, deformity, depressions, or crepitus. b. Basilar skull fracture signs include: i. CSF drainage from ears or nose ii. Raccoon eyes iii. Battle sign (a) May not appear up to 24 hours after injury c. Identify and treat any life threats found in the primary survey. d. Provide manual in-line stabilization of the cervical spine. e. Provide supportive care for linear skull fractures. i. Lightly cover exposed brain tissue with sterile dressing (sterile saline). ii. For CSF leakage, apply loose sterile dressings, but do not stop flow. iii. Impaled objects should be stabilized and protected.

19. Discuss the signs and symptoms of neurogenic shock and spinal shock. (pp 1751-1752)

Spinal shock i. Temporary local neurologic condition that occurs immediately after spinal trauma ii. Swelling and edema within 30 minutes iii. Present with variable degrees of acute spinal injury (a) Flaccid paralysis (b) Flaccid sphincters (c) Absent reflexes iv. Impaired sensory function below the injury v. Usually subsides in hours to weeks i. Neurogenic shock i. Results from temporary loss of autonomic function at the level of injury ii. Hemodynamic and systemic effects: (a) Hypotension (b) Hypovolemia and sensitivity to sudden position changes (c) Decreased stroke volume and cardiac output (d) Bradycardia (e) Hypothermia and absence of sweating (f) Loss of bladder control, priapism, and/or paralytic ileus with hypoactive bowel sounds

5. Discuss mechanisms of head and spine injury that paramedics should consider when assessing a patient. (pp 1720-1721)

The following high-risk MOIs strongly suggest spinal injury and indicate full spinal motion restriction should be applied: a. High-velocity crash (greater than 40 mph) with severe vehicle damage b. Unrestrained occupant of moderate- to high-speed MVC c. Vehicular damage with compartmental intrusion (12 inches) into patient's seating space d. Fall of an adult from a height greater than 20 feet e. Fall of a child from a height greater than 10 feet f. Penetrating trauma near the spine g. Ejection from a moving vehicle h. Motorcycle crash of greater than 20 mph i. Auto-pedestrian or auto-bicycle crash of greater than 20 mph j. Death of occupant in the same passenger compartment k. Rollover crash (unrestrained) 4. MOIs with uncertain or low risks for spine injury include: a. Moderate- to low-velocity MVC (less than 40 mph) b. Patient involved in MVC with isolated injury without positive assessment findings for SCI. c. Isolated minor head injury without positive mechanism for spine injury d. Syncopal event in which patient was already seated or supine e. Syncopal event in which patient was assisted to supine position by bystander

22. Discuss when and how to perform rapid extrication. (pp 1766-1770)

The process of manually stabilizing and moving a patient from a sitting position onto an immobilization device without the use of a vest-type immobilization device. b. Use rapid extrication in the following situations the: i. Vehicle or scene is unsafe. ii. Patient cannot be properly assessed before being removed from the vehicle. iii. Patient needs immediate intervention. iv. Patient's condition requires immediate transport. v. Patient blocks your access to another seriously injured patient. c. Do not use the rapid extrication technique if the injuries are not urgent. d. Rapid extrication requires a team of three experienced providers.

2. Review key points of head and spine anatomy and physiology. (pp 1713-1719)

The scalp 1. Composed of multiple layers. a. Subcutaneous tissue that contains major vessels b. Superficial fascia that is attached to the vessels i. Do not underestimate the blood loss potential from scalp hemorrhage. ii. Do not get distracted from other life-threatening injuries. B. The skull 1. Consists of 28 bones that make up: a. Cranium b. Auditory ossicles c. Face 2. Cranial vault: eight flat, irregular bones a. Generates blood cells (hematopoiesis) b. Protects the brain by directing impacts around it c. Provides a nondistensible container for the brain, CSF, and blood i. A hematoma would increase intracranial pressure (ICP). 3. The floor of the cranial vault: several ridges and depressions that have openings that allow nerves to exit the skull a. Coup-contrecoup injury: the brain impacts two sides of the skull i. Lacerations from skull floor ii. Contusions from contact with frontal and occipital bones 4. The base of the skull a. Consists of parts of the ethmoid, sphenoid, occipital, frontal, and temporal bones b. Divided into the anterior fossa, middle fossa, and posterior fossa i. Basilar skull fracture (a) Can occur in the anterior fossa or the middle fossa (b) Can involve the temporal bone (c) Revealed in the field by the drainage of CSF from the nose or ears C. The brain 1. Contains billions of neurons that serve various vital functions 2. Major regions: a. Cerebrum b. Diencephalon (thalamus and hypothalamus) c. Brainstem (medulla, pons, midbrain) d. Cerebellum 3. Accounts for 2% of body weight a. Most metabolically active and perfusion-sensitive organ in the body b. Completely reliant on a constant source of oxygen and glucose via cerebral blood flow 4. Continually manipulates physiology as needed to guarantee supply is available a. Loss of blood flow for 5 to 10 seconds will result in unconsciousness. 5. The cerebrum a. Largest portion of the brain b. Responsible for higher functions, such as reasoning c. Divided into right and left hemispheres d. Cerebral cortex: largest portion of cerebrum i. Regulates voluntary skeletal movement and the level of awareness. ii. Injury may result in paresthesia, weakness, and paralysis of extremities. e. Each hemisphere is divided into lobes. i. The frontal lobe is important to voluntary motor action and personality traits. (a) Injury could result in seizures or placid reactions (flat affect). (b) It filters the raw emotional impulses from the limbic system. (1) Any injury to the frontal lobe may result in personality changes in the patient ii. The parietal lobe processes information from sensory receptors in the skin and joints. (a) It governs the perception of pain, temperature, and vibration. (b) It is also responsible for proprioception (ability to perceive position and movement of one's body or limbs) (1) Injury to this lobe may prevent patients from calculating 2 + 2 or knowing how many dimes are in a dollar. iii. The occipital lobe processes visual information. (a) A blow to the back of the head causes one to see stars. iv. The temporal lobe controls speech, long-term memory, hearing, taste, and smell. 6. The cerebellum a. Located beneath the cerebral hemispheres in the inferoposterior part of the brain b. Sometimes called "athlete's brain" i. Responsible for maintenance of posture, equilibrium, and coordination (a) Injury can prevent the patient from performing rapid alternating movements. (b) Injury may impair ability to touch the finger to the nose or walk a straight line. 7. The brainstem a. Consists of midbrain, pons, and medulla b. Located at the base of brain c. Connects the spinal cord to the rest of the brain d. Houses many structures crucial to vital functions i. Reticular activating system (a) Responsible for maintenance of consciousness ii. Centers that control heart rate, blood pressure, and respiration (a) Damage can produce cardiovascular derangement, respiratory arrest, or death. D. The meninges 1. Protective layers that surround and enfold the entire CNS. a. Dura mater: strong, fibrous outermost layer i. Covers the entire brain ii. Forms the tentorium (structure that separates the hemispheres from the cerebellum and brainstem) iii. Firmly attached to the internal wall of the skull iv. Splits into two surfaces and forms venous sinuses (a) An injury to the venous sinuses can cause a subdural hematoma b. Arachnoid: delicate, transparent second layer c. Pia mater: thin, translucent, and highly vascular third layer i. Adheres directly to the surface of the brain 2. Between each of the meningeal layers is a potential space in which bleeding can occur. a. Epidural hematoma: occurs between the dura mater and the skull and is usually caused by a rupture of the middle meningeal artery b. Subdural hematoma: occurs between the dura mater and the arachnoid membrane and is usually caused by a rupture of the bridging veins in this space c. Subarachnoid hemorrhage: occurs below the arachnoid membrane E. The spine 1. Consists of 33 vertebrae divided into 5 sections a. Stabilized by ligaments and muscle b. Support and protect neural elements c. Allow for fluid movement and erect stature 2. The vertebral body: bone that supports and stabilizes the body a. Components include: i. Lamina ii. Pedicles iii. Spinous processes 3. Basic characteristics shared by the vertebrae a. Except the atlas and axis (C1 and C2) 4. Separation and cushioning of each vertebra by intervertebral disks a. As the body ages, these disks become thinner. i. Causes height loss associated with aging b. Stress on the vertebral column can cause disks to herniate into the spinal canal. i. May result in injury to the spinal cord or nerve root c. The vertebral column can sustain normal flexion and extension of 60% to 70% without stressing the spinal cord. 5. The spinal cord a. Transmits nerve impulses between the brain and the body b. Located at the base of the brain c. Leaves the skull through the foramen magnum d. Separates into cauda equina (collection of individual nerve roots) at the base of the skull i. Thirty-one pairs of spinal nerves emerge from different segments of the spinal cord. (a) C1 to C7 exit the spinal cord above their respective vertebrae. (b) C8 exits below the C7 vertebra. (c) All other spinal nerves exit the spinal column below the respective vertebrae for which they are named. ii. Spinal nerve groups are named based on source of origin and point of termination. (a) Ascending tracts carry information to the brain. (b) Descending tracts carry information from the brain to the body. 6. Converge into plexuses that enable several spinal nerves to control one area of the body a. One example is the cervical plexus (C1 through C5). i. Phrenic nerve (C3 through C5) also arises from this plexus and contains nerves that supply (or innervate) the diaphragm b. The brachial plexus (C5 through T1) joins nerves controlling the upper extremities. i. The main nerves arising from this plexus are the axillary, median, musculocutaneous, radial, and ulnar. c. The lumbar plexus (L1 through L4) supplies the skin and muscles of the abdominal wall, external genitalia, and part of the lower limbs. d. The sacral plexus (L4 through S4) gives rise to the pudendal and sciatic nerves. i. Supplies the buttocks, perineum, and most of the lower limbs. 7. The sympathetic nervous system a. Mobilizes the body for activity. i. The brain transmits information through the brainstem and the cervical spinal cord. b. The thoracolumbar system provides sympathetic stimulation through alpha and beta receptors. i. Alpha receptor stimulation induces smooth muscle contraction in the blood vessels and bronchioles. ii. Beta receptors respond with relaxation of smooth muscles in the blood vessels and bronchioles. c. Controls sweating, pupil dilation, temperature regulation, and flight or fight responses. d. Loss of sympathetic stimulation can disrupt homeostasis. 8. The parasympathetic nervous system a. Includes fibers arising from cranial and sacral nerves (also called the craniosacral nervous system) b. Carries signals to the organs of the abdomen, heart, lungs, and skin c. Slows heart rate in an attempt to control increasing blood pressure when the sympathetic nerves are stimulated

3. Explain patient assessment for a person with a suspected head or spine injury, including variations that may be required for specific injuries. (pp 1719-1732)

The scalp 1. Composed of multiple layers. a. Subcutaneous tissue that contains major vessels b. Superficial fascia that is attached to the vessels i. Do not underestimate the blood loss potential from scalp hemorrhage. ii. Do not get distracted from other life-threatening injuries. B. The skull 1. Consists of 28 bones that make up: a. Cranium b. Auditory ossicles c. Face 2. Cranial vault: eight flat, irregular bones a. Generates blood cells (hematopoiesis) b. Protects the brain by directing impacts around it c. Provides a nondistensible container for the brain, CSF, and blood i. A hematoma would increase intracranial pressure (ICP). 3. The floor of the cranial vault: several ridges and depressions that have openings that allow nerves to exit the skull a. Coup-contrecoup injury: the brain impacts two sides of the skull i. Lacerations from skull floor ii. Contusions from contact with frontal and occipital bones 4. The base of the skull a. Consists of parts of the ethmoid, sphenoid, occipital, frontal, and temporal bones b. Divided into the anterior fossa, middle fossa, and posterior fossa i. Basilar skull fracture (a) Can occur in the anterior fossa or the middle fossa (b) Can involve the temporal bone (c) Revealed in the field by the drainage of CSF from the nose or ears C. The brain 1. Contains billions of neurons that serve various vital functions 2. Major regions: a. Cerebrum b. Diencephalon (thalamus and hypothalamus) c. Brainstem (medulla, pons, midbrain) d. Cerebellum 3. Accounts for 2% of body weight a. Most metabolically active and perfusion-sensitive organ in the body b. Completely reliant on a constant source of oxygen and glucose via cerebral blood flow 4. Continually manipulates physiology as needed to guarantee supply is available a. Loss of blood flow for 5 to 10 seconds will result in unconsciousness. 5. The cerebrum a. Largest portion of the brain b. Responsible for higher functions, such as reasoning c. Divided into right and left hemispheres d. Cerebral cortex: largest portion of cerebrum i. Regulates voluntary skeletal movement and the level of awareness. ii. Injury may result in paresthesia, weakness, and paralysis of extremities. e. Each hemisphere is divided into lobes. i. The frontal lobe is important to voluntary motor action and personality traits. (a) Injury could result in seizures or placid reactions (flat affect). (b) It filters the raw emotional impulses from the limbic system. (1) Any injury to the frontal lobe may result in personality changes in the patient ii. The parietal lobe processes information from sensory receptors in the skin and joints. (a) It governs the perception of pain, temperature, and vibration. (b) It is also responsible for proprioception (ability to perceive position and movement of one's body or limbs) (1) Injury to this lobe may prevent patients from calculating 2 + 2 or knowing how many dimes are in a dollar. iii. The occipital lobe processes visual information. (a) A blow to the back of the head causes one to see stars. iv. The temporal lobe controls speech, long-term memory, hearing, taste, and smell. 6. The cerebellum a. Located beneath the cerebral hemispheres in the inferoposterior part of the brain b. Sometimes called "athlete's brain" i. Responsible for maintenance of posture, equilibrium, and coordination (a) Injury can prevent the patient from performing rapid alternating movements. (b) Injury may impair ability to touch the finger to the nose or walk a straight line. 7. The brainstem a. Consists of midbrain, pons, and medulla b. Located at the base of brain c. Connects the spinal cord to the rest of the brain d. Houses many structures crucial to vital functions i. Reticular activating system (a) Responsible for maintenance of consciousness ii. Centers that control heart rate, blood pressure, and respiration (a) Damage can produce cardiovascular derangement, respiratory arrest, or death. D. The meninges 1. Protective layers that surround and enfold the entire CNS. a. Dura mater: strong, fibrous outermost layer i. Covers the entire brain ii. Forms the tentorium (structure that separates the hemispheres from the cerebellum and brainstem) iii. Firmly attached to the internal wall of the skull iv. Splits into two surfaces and forms venous sinuses (a) An injury to the venous sinuses can cause a subdural hematoma b. Arachnoid: delicate, transparent second layer c. Pia mater: thin, translucent, and highly vascular third layer i. Adheres directly to the surface of the brain 2. Between each of the meningeal layers is a potential space in which bleeding can occur. a. Epidural hematoma: occurs between the dura mater and the skull and is usually caused by a rupture of the middle meningeal artery b. Subdural hematoma: occurs between the dura mater and the arachnoid membrane and is usually caused by a rupture of the bridging veins in this space c. Subarachnoid hemorrhage: occurs below the arachnoid membrane E. The spine 1. Consists of 33 vertebrae divided into 5 sections a. Stabilized by ligaments and muscle b. Support and protect neural elements c. Allow for fluid movement and erect stature 2. The vertebral body: bone that supports and stabilizes the body a. Components include: i. Lamina ii. Pedicles iii. Spinous processes 3. Basic characteristics shared by the vertebrae a. Except the atlas and axis (C1 and C2) 4. Separation and cushioning of each vertebra by intervertebral disks a. As the body ages, these disks become thinner. i. Causes height loss associated with aging b. Stress on the vertebral column can cause disks to herniate into the spinal canal. i. May result in injury to the spinal cord or nerve root c. The vertebral column can sustain normal flexion and extension of 60% to 70% without stressing the spinal cord. 5. The spinal cord a. Transmits nerve impulses between the brain and the body b. Located at the base of the brain c. Leaves the skull through the foramen magnum d. Separates into cauda equina (collection of individual nerve roots) at the base of the skull i. Thirty-one pairs of spinal nerves emerge from different segments of the spinal cord. (a) C1 to C7 exit the spinal cord above their respective vertebrae. (b) C8 exits below the C7 vertebra. (c) All other spinal nerves exit the spinal column below the respective vertebrae for which they are named. ii. Spinal nerve groups are named based on source of origin and point of termination. (a) Ascending tracts carry information to the brain. (b) Descending tracts carry information from the brain to the body. 6. Converge into plexuses that enable several spinal nerves to control one area of the body a. One example is the cervical plexus (C1 through C5). i. Phrenic nerve (C3 through C5) also arises from this plexus and contains nerves that supply (or innervate) the diaphragm b. The brachial plexus (C5 through T1) joins nerves controlling the upper extremities. i. The main nerves arising from this plexus are the axillary, median, musculocutaneous, radial, and ulnar. c. The lumbar plexus (L1 through L4) supplies the skin and muscles of the abdominal wall, external genitalia, and part of the lower limbs. d. The sacral plexus (L4 through S4) gives rise to the pudendal and sciatic nerves. i. Supplies the buttocks, perineum, and most of the lower limbs. 7. The sympathetic nervous system a. Mobilizes the body for activity. i. The brain transmits information through the brainstem and the cervical spinal cord. b. The thoracolumbar system provides sympathetic stimulation through alpha and beta receptors. i. Alpha receptor stimulation induces smooth muscle contraction in the blood vessels and bronchioles. ii. Beta receptors respond with relaxation of smooth muscles in the blood vessels and bronchioles. c. Controls sweating, pupil dilation, temperature regulation, and flight or fight responses. d. Loss of sympathetic stimulation can disrupt homeostasis. 8. The parasympathetic nervous system a. Includes fibers arising from cranial and sacral nerves (also called the craniosacral nervous system) b. Carries signals to the organs of the abdomen, heart, lungs, and skin c. Slows heart rate in an attempt to control increasing blood pressure when the sympathetic nerves are stimulated