0133427269 Module11 IntracranialRegulation LectureOutline

Module 11 Intracranial Regulation  The Concept of Intracranial Regulation Intracranial regulation ( processes that affect intracranial compensation, adaptive neurologic function Neurologic system regulates, integrates all body functions, muscle movements, senses, mental abilities, emotions Collects sensory input ( processes and interprets input ( causes responses that are manifested as motor or sensory output Normal presentation Divided into two principal parts Central nervous system (CNS) ( consists of brain and spinal cord Peripheral nervous system (PNS) ( consists of cranial nerves and spinal nerves Neuron ( basic cell of nervous system Myelin sheath covers larger, longer nerves ( speeds rate of conduction of nerve impulses White matter of nervous system Physiology review Central nervous system Brain ( largest portion (see Figure 111 REGIONS OF THE BRAIN, p. 688 Protection Meninges ( three connective tissue membranes that cover, protect, nourish CNS Cerebrospinal fluid (CSF) ( primary function to cushion, prevent injury, also nourishes Skull ( protects Cerebrum (see Figure 112 LOBES OF THE CEREBRUM, P. 688) Largest portion of brain Cerebral cortex ( outermost layer, gray matter Responsible for all conscious behavior Frontal lobe ( conscious awareness of sensation, somatosensory stimuli, two-point discrimination Parietal lobe ( conscious awareness of sensation, somatosensory stimuli Occipital lobe ( visual cortex Temporal lobe ( interpreting auditory stimuli, olfactory cortex Diencephalon Thalamus ( gateway to cerebral cortex ( all input processed Hypothalamus ( autonomic control center ( influences activities such as blood pressure (BP), heart rate, force of heart contraction, digestive motility, respiratory rate and depth, perception of pain, pleasure, fear, body temperature, food intake, water balance, sleep cycles Epithalamus ( helps control moods, sleep cycles contains choroid plexus where CSF is formed Cerebellum ( located below cerebrum, behind brainstem Coordinates stimuli from cerebral cortex ( coordinated, smooth skeletal muscle movement Assists with maintaining equilibrium, muscle tone Brainstem ( contains midbrain, pons, medulla oblongata Between cerebrum, spinal cord ( connects pathways between higher and lower structures 10 of 12 pairs of cranial nerves originate in brainstem Influences BP by controlling vasodilation Regulates respiratory rate, depth, rhythm Hiccupping, swallowing, coughing, sneezing Spinal cord ( continuation of medulla oblongata Passes through skill at foramen magnum ( through vertebral column to first lumbar vertebra Protected by meninges, CSF, bony vertebrae Transmit impulses to and from brain ( ascending, descending pathways Reflexes ( stimulus-response activities Fast, predictable, unlearned, innate, involuntary Impulse follows afferent (sensory) nerve fibers ( synapse occurs in spinal cord ( impulse transmitted to efferent (motor) nerve fibers ( additional synapse, stimulation of muscle fibers Peripheral nervous system (PNS) ( 12 pairs of cranial nerves, paired spinal nerves Cranial nerves 12 pairs ( originate in brain, serve parts of head and neck First 2 pairs originate in anterior brain Remaining 10 pairs originate in brainstem Vagus nerve (cranial nerve X) ( only one to serve a muscle, body region below neck Roman numerals Sensory, motor, and mixed See Table 111 CRANIAL NERVES, p. 689 Spinal nerves 31 pairs of nerves, named according to vertebral level of origin See Figure 113 SPINAL NERVES, p. 690 8 pairs of cervical nerves 12 pairs of thoracic nerves 5 pairs of lumbar nerves 5 pairs of sacral nerves Dermatome ( area of skin innervated by cutaneous branch of one spinal nerve All spinal nerves except C1 serve a cutaneous region Genetic and lifespan considerations Infants and children Growth very rapid during fetal period Neonate has several primitive reflexes at birth ( begin to disappear by about 1 month Sucking Stepping Rooting Startle (Moro) Babinski ( normal until around 2 years of age Cry of newborn ( healthillness continuum Strong, lusty versus absent, weak, catlike, shrill Head circumference ( at level of ears across forehead Important to assess childs fine and gross motor skills, language, personal/social skills Benchmarks, milestones ( identify delays The older adult Aging process ( subtle, slow, steady decrease in neurologic function Impulse transmission decreases Reaction to stimuli decreases Reflexes diminished Coordination not as strong Senses not as acute Muscle mass decreases ( moves, reacts more slowly Alterations ( occur as result of illness, injury Patterns of manifestations ( helps determine extent of cerebral dysfunction, improvement/deterioration of function Usually follows predictable progression (except direct damage to brainstem, reticular activating system RAS) Higher function to primitive functions Altered level of consciousness (LOC), behavior changes ( early manifestations See Table 112 PROGRESSION OF DETERIORATING BRAIN FUNCTION, p. 691 See CONCEPTS RELATED TO INTRACRANIAL REGULATION, p. 692 Alterations in level of consciousness Consciousness ( condition in which person is aware of self, environment, able to respond appropriately to stimuli Arousal ( alertness, depends on RAS, diffuse system of neurons in thalamus, upper brainstem Cognition ( complex process by which individual learns, stores, retrieves, uses information Depend on normal physiologic functions of/connections between arousal mechanisms of reticular formation, cognitive functions of cerebral hemispheres Conditions that affect RAS of cerebral hemispheres ( interfere with normal LOC Consciousness dynamic state See Table 113 TERMS USED TO DESCRIBE LEVEL OF CONSCIOUSNESS, p. 693 Individuals LOC may be altered by processes that affect arousal functions of brainstem, cognitive functions of cerebral hemispheres, or both Lesions or injuries Metabolic disorders Medications Brain function depends on continuous blood flow ( unimpeded supplies of oxygen, glucose Global ischemia ( bilateral hemispheric lesion Hypoglycemia ( metabolic disorder Localized masses ( hematoma, cerebral edema Disorders affecting level of consciousness Localized or systemic disorders Increased intracranial pressure (IICP) Cerebral infarction Hematoma Intracranial hemorrhage Tumors Infections Injury from excitatory amino acids Demyelinating disorders Any systemic condition that affects delivery of blood, oxygen, glucose, alters cell membranes ( may also alter LOC Other metabolic alterations that affect LOC Fluid and electrolyte imbalance Hyperosmolality Acidbase alterations Accumulated waste from liver, renal failure Drugs IICP ( sustained elevated pressure (10 mmHg or higher) in cranial cavity Affected by routine activities If rises dramatically, sustained periods of time ( significant tissue ischemia, damage may result Cranial vault is fixed size (except infants) ( IICP ( reduce CSF first ( blood perfusion decreases ( diminished oxygenation Seizures ( periods of abnormal electrical discharges in brain that may cause involuntary movement and/or behavior, sensory alterations Disordered, spontaneous discharge of activity during seizure exhausts energy metabolites, produces locally toxic molecules Alters LOC for a time after seizure Outcomes of altered level of consciousness Full recovery with no long-term residual effects Recovery with residual damage More severe consequences such as persistent vegetative state, brain death Persistent vegetative state (irreversible coma) ( permanent condition of complete unawareness of self, environment, loss of all cognitive functions Severe brain trauma, global ischemia Sleepwake cycles, retains ability to chew, swallow, cough ( cannot interact with environment Eyes may wander ( cannot track Locked-in syndrome ( client alert, fully aware of environment, intact cognitive abilities ( unable to communicate through speech, movement because of blocked efferent pathways from brain Motor paralysis affects all voluntary muscles May be able to communicate through eye movements Infarction, hemorrhage of pons disrupts outgoing nerve tracts Disorders of lower motor neurons, muscles may also paralyze motor responses Amyotrophic lateral sclerosis (ALS), myasthenia gravis Brain death ( irreversible cessation of all brain function, including brainstem Generally recognized criteria Unresponsive coma, absent motor, reflex movements No spontaneous respiration ( apnea Pupils fixed, dilated Absent ocular responses to heat, turning, caloric stimulation Flat EEG, no cerebral blood circulation present on angiography Persistence of these manifestations for 30 minutes1 hour, for 6 hours after onset of coma and apnea Apnea ( apnea test Prognosis Varies according to etiology, age, general medical condition Poor for clients who lack pupillary reaction reflex eye movements 6 hours after onset of coma See ALTERATIONS AND THERAPIES Intracranial Regulation, p. 695 Prevalence Traumatic brain injury (TBI) is becoming more prominent Adolescents and older adults are most vulnerable Falls continue to be leading cause of TBI See Box 11-2 CONCUSSION, p. 696 Case Study Part 1 ( Joshua Thompson is an active 13-year-old who was riding his bike with friends when he fell Prevention Neurologic damage usually occurs after a traumatic event Helmets should be used when bicycling, skateboarding, skating Sports-specific helmets and equipment important for contact sports Older adults ( teach fall prevention Assessment During health screening, focus on complaint, part of total health assessment If LOC altered ( rely on family for information See Table 114 GLASGOW COMA SCALE FOR ASSESSMENT OF COMA IN INFANTS, CHILDREN, AND ADULTS, p. 697 Developmental considerations in infants, children, older adults See LIFESPAN CONSIDERATIONS Assessing the Neurologic System, p. 707 See ASSESSMENT INTERVIEW Neurologic Assessment, pp. 697 See NEUROLOGIC ASSESSMENT, pp. 697-705 See Table 115 ASSESSMENT OF CRANIAL NERVES IN THE UNCONSCIOUS CLIENT, p. 706 Diagnostic tests Several tests may be useful in conjunction with history, physical examination Client preparation, education Tests may include CT scan of head, with/without contrast Magnetic resonance imaging (MRI) X-rays Echoencephalogram EEG Ultrasonography of the brain Brain echogram Cerebral angiography Positron emission tomography (PET) Nerve conduction studies Myelogram Thermography Oculoplethysmography Serum electrolytes Intracranial pressure (ICP) monitoring Therapeutic drug levels Antidiuretic hormone levels CSF assessment Serum glucose Serum protein Case Study Part 2 ( Joshuas mother stops by the pharmacy and picks up the prescriptions Interventions and therapies Focus of management ( identify underlying cause, preserve function, prevent deterioration Airway management IV fluid Treatment protocols to reduce IICP, control seizures Independent interventions Assessing LOC Monitoring fluid intake, output Reducing environmental stimuli Positioning client Taking precautions for seizures, including padding side rails Monitoring ICP Assessing pupils for response to light Using hyperventilation to reduce ICP Measuring vital signs Administering IV fluids Fluid management IV catheter inserted ( fluid balance maintained using isotonic, slightly hypertonic solutions Underlying fluid, electrolyte imbalance corrected Client who is hyponatremic, low serum osmolality ( furosemide (Lasix) ( promote water excretion Collaborative interventions Support ( airway, respiratory maintenance Mechanical if hypoventilation, apnea present Monitor arterial blood gases ( cautious hyperventilation to reduce PaCO2 ( promote cerebral vasoconstriction to reduce cerebral edema Nutrition ( long-term alterations in LOC ( measures to maintain nutritional status initiated Enteral Parenteral Pharmacologic therapy Seizures Antiepileptic drugs (AEDs) ( reduce, control most seizure activity Goal ( protect client from harm, reduce prevent seizure activity without impairing cognitive function, producing undesirable side effects May need to try several medications Status epilepticus ( requires immediate intervention to preserve life Establish, maintain airway Solution of 50 dextrose IV ( prevent hypoglycemia Diazepam, lorazepam ( IV, repeat in 10 minutes Phenytoin IV ( longer-term control Phenobarbital Increased intracranial pressure Diuretics Osmotic diuretics Loop diuretics (Lasix), ethacrynic acid (Edecrin) Sedation, paralysis ( chemical restraints to control restlessness, agitation ( movements increase BP, ICP, cerebral metabolism Antipyretics with/without hypothermia blanket Anticonvulsants GI prophylaxis ( IV H2 inhibitors IV fluids ( maintain fluid/electrolyte balance, vascular volume Vasoactive medication ( if BP unstable Total parenteral nutrition (TPN) if enteral feeding not possible Review The Concept of Intracranial Regulation Relate Link the Concepts Ready Go to Companion Skills Manual Refer Go to Nursing Student Resources Reflect Case Study Part 3 ( The surgeon has placed a drain, and Joshua now has a Glasgow Coma Scale rating of 15 Exemplar 11.1 Increased Intracranial Pressure Overview IICP ( sustained, elevated pressure (15 mm Hg or higher in adults) in intracranial cavity Transient increases with normal activities not harmful Sustained IICP can result in significant tissue ischemia Pathophysiology and etiology Adult cranial cavity rigid, filled to capacity with noncompressible elements Brain, CSF, blood ( dynamic equilibrium Monro-Kellie hypothesis Normal ICP 515 mmHg with client lying with head elevated 30 OR 60180 cm H2O client lying in lateral recumbent position Cerebral blood flow, perfusion ( brain needs constant supply of oxygen, glucose Interruption of cerebral blood flow ( ischemia, disruption of cerebral metabolism Pressure, chemical auto regulation ( compensatory mechanisms Cerebral arterioles change diameter to maintain cerebral blood flow when ICP increases Stretch receptors in small blood vessels of brain cause smooth muscle of arterioles to contract Increased arterial pressure stimulates these receptors ( vasoconstriction Decreased arterial pressure decreases stimulation of these receptors ( vasodilation Buildup of metabolic byproducts may cause vasoconstriction, vasodilation CO2 increases ( cerebral vasodilation IICP may result from increase in intracranial contents ( lesions, hydrocephalus, cerebral edema, excess CSF, intracranial hemorrhage Relationship between volume of intracranial components and intracranial pressure known as compliance Intracranial hypertension ( sustained state of IICP, can be life threatening Autoregulatory mechanisms ( limited ability to maintain cerebral blood flow Etiology Commonly results from head trauma ( different causes throughout life span Infants, young children ( falls, abuse Preschool, school age ( accidents Adolescents, young adults ( motor vehicle accidents, addiction behavior, trauma from violence Older adults ( falls Abnormal cellular growth ( benign, malignant tumors Risk factors Increase risk of trauma ( (risk of cerebral trauma Medications that alter balance, perception, reflex responses Weakness resulting from lack of muscle strength, poor nutrition, illness Lifestyle choices such as drug, alcohol use, violent behavior, contact sports without proper protective equipment Premature infant at risk for IICP as result of intracranial hemorrhage secondary to fragile cranial blood vessels Prevention Teach prevention of trauma Caution adolescents to avoid recreational drug and alcohol use Handle premature infants carefully Clinical manifestations With loss of regulation ICP continues to rise, cerebral perfusion falls ( tissue ischemia Changes in cortical function earliest manifestations of IICP Behavior, personality changes Memory, judgment impaired Speech pattern may be noted Client LOC decreases Lifespan considerations Early signs of IICP in children ( headache, nausea, vomiting, dizziness or vertigo, downward deviation of the eyes, slight change in LOC, restlessness Early signs of IICP in infants ( symptoms for children (above) plus irritability, bulging fontanels, increased head circumference, high-pitched shrill cry, sensitivity to touch and sound Late signs ( decreased LOC, Cushing triad, increased systolic blood pressure, widened pulse pressure, bradycardia, irregular respirations, fixed and dilated pupils See CLINICAL MANIFESTATIONS AND THERAPIES IICP, p. 711 Collaboration Identify, treat underlying cause ( control ICP to prevent herniation syndrome Medical emergencydiagnosis made on basis of observation, neurologic assessment Diagnostic tests CT scan, MRI general initial test Lumbar puncture NOT performed when IICP suspected ( release of pressure could cause cerebral herniation Surgery Removal of tumor Resection of infracted, necrotic tissue to reduce brain mass Drainage catheter, shunt may be inserted via burr hole to drain excess CSF Pharmacologic therapy See MEDICATIONS IICP, p. 712 Diuretics (osmotic diuretics) commonly used to reduce ICP Loop diuretics may be prescribed Sedation, paralysis used as chemical restraints Antipyretics Anticonvulsants GI prophylaxis IV fluids Vasoactive medications TPN Nonpharmacologic therapy ICP monitoring Facilitates continual assessment of ICP, effects of therapy, nursing interventions Cerebral perfusion pressure difference between mean arterial pressure (MAP), ICP Basic monitoring system Intraventricular catheter, subarachnoid bolt or screw, epidural probe See Figure 1111 TYPES OF ICP MONITORING, p. 712 Intraventricular catheters can drain CSF and measure ICP Subarachnoid device ( subarachnoid space Sensor implanted ( connected to transducer that converts impulses to signal ( recording device translates to a tracing, digital value, graphic recording Transcranial blood flow monitored with transcranial Doppler studies ( measure velocity of blood flow in cerebral vessels Cerebral perfusion pressure ( pressure it takes for heart to provide brain with blood Calculated by subtracting ICP from MAP See Table 116 RISK FACTORS FOR INFECTION WITH INTRACRANIAL PRESSURE MONITORING, p. 713 Mechanical ventilation Clients with IICP often require intubation Important to maintain adequate oxygenation with partial pressure of arterial oxygen at about 100 mmHg, carbon dioxide of about 35 mmHg Other therapies Physical therapy to prevent muscle atrophy Respiratory therapy Spiritual, psychologic counseling Nursing process Assessment Assess, monitor every 15 minutes to 1 hour Include LOC, behavior Motor, sensory functions Pupillary size, reaction to light Vital signs Look for trends, sudden changes in LOC, vital signs Monitor pulse oximetry, arterial blood gases (ABGs) Diagnosis Ineffective Airway Clearance Ineffective Tissue Perfusion Cerebral Ineffective Breathing Pattern Risk for Aspiration Risk for Infection Planning Client will maintain ICP less than 20 mmHg Client will experience no further complications as result of ICP Family members will demonstrate ability to maintain a low-stimuli environment Client will not experience infection as result of ICP monitoring Client will maintain adequate cerebral perfusion to prevent further cellular damage Implementation Performing neurologic assessments Maintain airway patency preoxygenate before suctioning Ensure adequate ventilation Positioning and movingmaintain alignment of head and neck Institute seizure precautions Monitor fluid and electrolytes Monitor ABGs Elevate head of bed to 30, as prescribed Monitor bladder distention, bowel constipation If client alert, assist in moving up in bed Plan nursing care so activities are not clustered together Maintain fluid limitations if prescribed For client with ICP monitoring device Keep dressings over catheter dry, change dressings on prescribed basis Monitor insertion site for leaking CSF, drainage, infection Use strict aseptic technique when in contact with device Evaluation ICP returns to acceptable limits following treatment Clients LOC improves with reduction of ICP Client experiences no infection as the result of ICP monitoring Family describes appropriate outcome expectations related to amount of cellular damage resulting from IICP Review Relate Link the Concepts and Exemplars Ready Go to Companion Skills Manual Refer Go to Nursing Student Resources Reflect Case Study  Exemplar 11.2 Seizure Disorders Overview Abnormal electrical discharges in the brain that may cause involuntary movement, behavior or sensory alterations Epilepsy is a chronic seizure disorder Pathophysiology and etiology Result of abnormal excessive concurrent electrical discharges from cortical neuronal network of cells on surface of brain Triggered by environmental, physical stimuli Acute insults ( most common cause of seizures in children Focal seizures ( caused by abnormal electrical activity in one hemisphere, specific area of cerebral cortex Generalized seizures ( result of diffuse electrical activity that often begins in both hemispheres of brain simultaneously, spreads throughout the cortex into brainstem Etiology Some are idiopathic ( no known cause Genetic factors may lower threshold Some caused by underlying pathology Febrile seizures ( generalized seizures, usually occur in children, as result of rapid temperature rise above 39(C (102(F) Usually seen between 3 months and 5 years of age Often a family history of febrile seizures Risk factors Infants susceptible during first year of age ( decreases with age Other risk factors Small-for-gestational-age infants Underlying neurologic conditions Brain tumors, infections Stroke, cerebral palsy Autism, family history, abuse of drugs Prevention Seizure threshold Avoid triggers Maintain good self-care Clinical manifestations Initial manifestation ( tonic phase Unconsciousness, continuous muscular contraction Basal metabolic rate rises, increasing bodys demand for oxygen ( client may become pale, cyanotic May become hypoglycemic Symptoms depend on type and duration Partial (focal), generalized Tonicclonic most common type in children ( alternating repetitive tonicclonic activity Alternating muscular contraction, relaxation Postictal period after seizure ( decreased LOC, client often sleepy, arousable Aura may precede seizure ( early warning May be sensory alteration Odor, taste, vision See CLINICAL MANIFESTATIONS AND THERAPIES Seizure Disorders, p. 717 Collaboration Diagnostic tests CBC, blood chemistry, urine culture, lumbar puncture Serum drug levels EEG CT scan or MRI, angiography Lead level Pharmacologic therapy AEDs (anticonvulsant drugs) ( reduce, control most seizure activity Do not cure Raise seizure threshold or limit spread of abnormal activity in brain Status epilepticus ( continuous seizure that lasts 30 minutes or series of seizures, consciousness is not regained Immediate intervention Airway priority IV 50 dextrose Diazepam or lorazepam IV, repeated in 10 minutes if necessary Phenytoin IV for longer-term control of seizures Phenobarbital See Table 117 MANAGEMENT OF STATUS EPILEPTICUS, p. 719 Clinical therapies for children Febrile seizures not usually treated with anticonvulsant Parental education using antipyretics, light clothing Protect child from injury in case of another seizure Second febrile seizure likely ( rectal diazepam, diazepam gel prescribed for home treatment Generalized seizure 10 minutes ( monitor for electrolytes, glucose, blood gases, increasing fever, abnormal blood pressure Anticonvulsants IV or rectally Longer seizure lasts, harder to control Physician provides seizure action plan for child with history of seizures School Day care Anticonvulsant monotherapy to minimize side effects Add other medications if necessary Serum drug levels Intractable seizures ( continue to recur even with optimal medical management Multiple medications Diet therapy Ketogenic therapy occasionally used for children under 8 ( high fat, low carbohydrate, adequate protein diet Ketosis believed to produce anticonvulsant effects Monitor urine ketones Complications ( constipation hyperlipidemia, kidney stones Seizure free for 2 years ( trial of antiepileptic medication withdrawal Nursing process Assessment History Description of seizure Physical and neurologic examination Monitor Physiologic status LOC Vital signs, signs of hypoxia See Table 118 NURSING ASSESSMENTS BEFORE, DURING, AFTER SEIZURE, p. 720 Family adaptation to seizure disorder Diagnosis Ineffective Breathing Ineffective Airway Clearance Risk for Trauma Chronic Low Self-Esteem Anxiety Ineffective Therapeutic Regimen Management Readiness for Enhanced Family Processes Planning Focus on safety Maintain airway patency Administer medications Provide emotional support Acute, long-term management Implementation Place nothing in clients mouth during seizure Position client on side so secretions can drain Monitor to ensure adequate oxygenation Protect client from self-harm during seizures Pad side rails if in bed Children with frequent seizures ( helmets Medic alert bracelet Administer IV medications cautiously ( monitor respiratory status Give medications for ongoing management of seizures orally Stress need to treat child as normally as possible Refer to support groups if indicated Encourage clients, families to express fears, anxieties Evaluation Client achieves good seizure control Clients self-esteem is enhanced ( participation in well-supervised sports, activities Client maintains patent airway during seizure Clients safety is maintained during seizure activity Appropriate seizure management plan created by client, family in conjunction with healthcare team Review Relate Link the Concepts and Exemplars Ready Go to Companion Skills Manual Refer Go to Nursing Student Resources Reflect Case Study  2015 by Education, Inc. 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