1 / 70

Nervous System Emergencies

Nervous System Emergencies. Nervous System A & P. Nervous System Basics The body’s control system Exerts control through electrochemical impulses transmitted through nerves Three subdivisions Central nervous system (brain and spinal cord)

orrin
Download Presentation

Nervous System Emergencies

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Nervous System Emergencies

  2. Nervous System A & P • Nervous System Basics • The body’s control system • Exerts control through electrochemical impulses transmitted through nerves • Three subdivisions • Central nervous system (brain and spinal cord) • Peripheral nervous system (cranial, peripheral nerves) • Autonomic nervous system (sympathetic, parasympathetic)

  3. Nervous System A & P • A & P of CNS (brain and spinal cord) • Neuron-nerve cell; fundamental component of the nervous system • Cell body contains nucleus • Dendrites carry nervous impulses to cell body • Axons transmit nerve impulses away from cell body

  4. Nervous System A & P • A & P of CNS (brain and spinal cord) • Transmission of impulses in the nervous system • At rest, neuron is positively charged outside, negatively charged inside • When stimulated, sodium enters cell, potassium rapidly leaves cell • Activity produces positive charge, called action potential, at entry site

  5. Nervous System A & P Overview • A & P of CNS (brain and spinal cord) • Transmission of impulses in the nervous system (cont.) • Action potential transmitted down neuron to meet other neurons at junctions called synapses • Axon releases neurotransmitter (acetylcholine or norepinephrine) that transports impulses across synapse and stimulates connecting nerve

  6. Nervous System A & P Overview • Protective structures of the CNS • Mostly protected by body structures (skull, spinal column) • Also covered by membranes - meninges (pia, arachnoid, dura) • Brain and spinal cord also bathed in cerebrospinal fluid (CSF)

  7. Nervous System A & P Overview • The brain • Cerebrum • Diencephalon • Mesencephalon • Pons • Medulla Oblongata • Cerebellum

  8. Nervous System A & P Overview • Cerebrum • Two hemispheres joined by corpus callosum • Governs all sensory and motor functions • Responsible for language, learning, analysis, memory • Cerebral cortex is outermost layer

  9. Nervous System A & P Overview • Diencephalon • Superiormost portion of brain stem • Contains thalamus, hypothalamus, limbic system • Responsible for involuntary actions • Major role in regulating autonomic nervous system

  10. Nervous System A & P Overview • Mesencephalon • Midbrain-located between mesencephalon and pons • Responsible for motor coordination and eye movement

  11. Nervous System A & P Overview • Pons • Located between midbrain and medulla • Contains connections between the brain and spinal cord

  12. Nervous System A & P Overview • Medulla Oblongata • Located between pons and spinal cord • Marks division between brain and spinal cord • Controls respirations, cardiac function , vasomotor activity

  13. Nervous System A & P Overview • Cerebellum • Located in posterior fossa of cranial cavity • Coordinates fine motor movement, posture, equilibrium, muscle tone

  14. Nervous System A & P Overview • Areas of Specialization • Speech-temporal lobe • Vision-occipital lobe • Personality-frontal lobes • Balance and coordination-cerebellum • Sensory-parietal lobes • Motor-frontal lobes

  15. Nervous System A & P Overview • Vascular supply to brain • Supplied by two systems: carotid system and vertebrobasilar system • Both join at the circle of Willis before entering brain • Interruption of one system will not seriously affect brain perfusion • Venous drainage through venous sinuses and internal jugular veins

  16. Nervous System A & P Overview • Spinal Cord • 17-18 inches long • Leaves the brain through the foramen magnum • Conducts impulses to peripheral nervous system • Conducts sensory impulses to the brain and has reflex arc capability

  17. Nervous System A & P Overview • Spinal Cord (cont.) • Has 31 pairs of nerve fibers • Dorsal roots contain afferent fibers (body to brain) • Ventral roots contain efferent fibers (brain to body) • Nerve fibers innovate corresponding body areas called dermatones

  18. Nervous System A & P Overview • A & P of the peripheral nervous system • Basic information • Consists of cranial and peripheral nerves • Has both voluntary and involuntary components

  19. Nervous System A & P Overview • A & P of the peripheral nervous system • Categories of the peripheral nerves • Somatic motor-carry impulses to skeletal muscles • Visceral sensory-transmit sensations from visceral organs (e.g., full bladder need to defecate, etc.) • Somatic sensory-transmit sensations of touch, pressure, pain, temperature, position • Visceral motor-supply nerves to visceral glands and organs

  20. Nervous System A & P Overview • Autonomic nervous system • Responsible for unconscious control of body functions • Made up of two antagonistic, but normally balanced parts • Sympathetic nervous system controls stress response • Parasympathetic nervous system controls custodial (vegetative) functions

  21. Assessment of the Neurological System • Primary Assessment • First check for responsiveness • Place emphasis on airway maintenance and cervical spine stabilization • With unconscious patients assume cervical spinal injury • Use modified jaw thrust maneuvers • Remain alert for possibility of respiratory arrest

  22. Assessment of the Nervous System • Secondary Assessment • History • Determine trauma vs medical etiology • If trauma • When did incident occur • Mechanism of injury • Any loss of consciousness • Chief complaint • Complicating factors

  23. Assessment of the Nervous System • Secondary Assessment (cont.) • History (cont.) • If nontrauma • Chief complaint • History of present illness • Pertinent underlying medical problems (cardiac disease, hypertension, diabetes, seizures) • Environmental clues (medications, Medic-alert ID, alcohol or drug bottles)

  24. Assessment of the Nervous System • Head to toe survey • Pupils • Check eye movement and pupil reaction • Early indicators of increasing ICP • Cardinal positions of gaze • Fixed, midsize pupils-midbrain • Pinpoint pupils, barely reactive-pons • Unilateral fixed and dilated pupil-third nerve • Fixed or asymmetric pupils-structural lesions • Nonreative pupils-toxic/metabolic states

  25. Assessment of the Nervous System • Head to toe survey (cont.) • Pupils (cont.) • Extraocular movements • Disconjugate gaze-structural brainstem lesion • Doll’s eyes-brainstem dysfunction

  26. Assessment of the Nervous System • Head to toe survey (cont.) • Respiratory derangements common with CNS illness or injury • Cheyne Stokes respiration-period of apnea followed by increasing depth and frequency of respirations • Central neurogenic hyperventilation-rapid, deep, noisy respirations; lesion in CNS • Ataxic respirations-ineffective thoracic muscular coordination due to CNS damage

  27. Assessment of the Nervous System • Head to toe survey (cont.) • Respiratory derangements common with CNS illness or injury (cont.) • Apneustic respirations-prolonged inspiration unrelieved by expiration attempts; damage to upper pons • Diaphragmatic breathing-caused by intercostal muscle dysfunction

  28. Assessment of the Nervous System • Spinal Evaluation-document loss of motor function or sensation • Evaluate for pain and tenderness • Observe for bruises • Observe for deformity • Check for motor, sensory and position in each extremity and bilateral grip strength • Determine response to pain • Note any incontinence

  29. Assessment of the Nervous System • Vital signs that characterize CNS injury • Increased blood pressure • Decreased pulse • Decreased respirations • Increased temperature

  30. Assessment of the Nervous System • Neurological Evaluation - provides baseline neurological findings for later comparison/contrast • Determine level of consciousness • AVPU during primary survey • Note sensation and motor function in extremities • Asymmetry-structural lesions • Abnormal posturing • Flaccid paralysis-spinal cord injury

  31. Assessment of the Nervous System • Glascow Coma Scale • Evaluates coma patient with CNS injury by monitoring • Eye openings • Verbal response • Motor response

  32. Nervous System Emergencies • Altered mental status-hallmark of CNS illness or injury • Basic mechanisms that can produce altered mental status • Structural lesions • Toxic-metabolic states

  33. Nervous System Emergencies • Common causes of altered mental status • Structural • Trauma • Brain tumor • Epilepsy • Intracranial hemorrhage • Other space-occupying lesions

  34. Nervous System Emergencies • Common causes of altered mental status • Metabolic • Anoxia • Hypoglycemia • Diabetic ketoacidosis • Hepatic failure • Renal failure • Thiamine deficiency

  35. Nervous System Emergencies • Common causes of altered mental status • Drugs • Barbiturates • Narcotics • Hallucinogens • Depressants

  36. Nervous System Emergencies • Common causes of altered mental status • Cardiovascular • Hypertensive encephalopathy • Shock • Anaphylaxis • Dysrhythmias • Cardiac arrest • CVA

  37. Nervous System Emergencies • Common causes of altered mental status • Respiratory • COPD • Toxic gas inhalation • Infectious • Encephalitis • Meningitis

  38. Nervous System Emergencies • Primary Assessment • Special attention to the airway and c-spine • Consider AEIOU TIPS mnemonic • Early intubation

  39. Nervous System Emergencies • Secondary Assessment • History • Length of alteration in mental status • Onset • History of recent head trauma • patient under medical care • Alcohol or drug use • Preceding symptoms or complaints • Any medications • Medic-Alert tags

  40. Nervous System Emergencies • Secondary Assessment (cont.) • Physical exam-should include breathing, response to stimuli, eye response, pupil response, being particularly alert in suspected CNS illness or injury cases • Pupillary reflexes-fixed, dilated, or asymmetric pupils • Extraocular movements-dysconjugate gaze

  41. Nervous System Emergencies • Secondary Assessment (cont.) • Physical exam-should include breathing, response to stimuli, eye response, pupil response, being particularly alert in suspected CNS illness or injury cases • Motor findings-asymmetry, decorticate or decebrate posturing, flaccid paralysis • Respiratory patterns • Vital signs-hypertension, bradycardia, unusual body temperature

  42. Nervous System Emergencies • Management • Immobilization of the cervical spine • Assure patency and adequate breathing • Draw venous blood sample, check blood sugar with glucometer or chem strip • IV 5% D5W at TKO rate; related NS or LR if trauma • Cardiac monitor

  43. Nervous System Emergencies • Drug considerations • 50mL of 50% dextrose (25 grams) IV to correct hypoglycemia • Naloxone 1-2 mg IV to reverse narcotic overdose • Thiamine 100mg IV to correct thiamine deficiency and allow glucose metabolism • Mannitol 25g IV to reduce ICP • Decadron 4-24 mg IV to reduce cerebral edema

  44. Nervous System Emergencies • Management with chronic alcoholism • Many have thiamine deficiency • Wernicke’s syndrome-memory loss, disorientation • Korsakoff’s psychosis-disorientation,m muttering delirium, insomnia, delusions painful extremities, bilateral foot drop, pain on pressure over long nerves • These patients should receive 100 mg Thiamine IV or IM

  45. Nervous System Emergencies • Management with ICP • Hyperventilate patient • Decadron 4-24 mg IV to reduce cerebral edema • Mannitol 25g IV to cause an osmotic diuresis

  46. Nervous System Emergencies • Seizures • Pathophysiology of seizures • Massive electrical discharge of one or more groups of neurons in the brain • Can be general or partial • Generalized seizures-grand mal and petit mal • Partial seizures-simple or complex (psychomotor)

  47. Nervous System Emergencies • Seizures (cont.) • Causes of seizures • Stressors such as hypoxia, sudden elevation in temperature, or hypoglycemia in healthy persons • Structural diseases such as tumors, head trauma, eclampsia, vascular disorders • Idiopathic epilepsy is the most common cause

  48. Nervous System Emergencies • Seizures (cont.) • Types of Seizures • Grand Mal-generalized motor seizure • Produces loss of consciousness from brain hypoxia • Causes uncontrollable tonic/clonic movements of extremities • Disrupts respirations, producing cyanosis • Often lead to frothing, incontinence, mental confusion • Coma or drowsiness follows (postical period)

  49. Nervous System Emergencies • Seizures (cont.) • Grand-mal (progression) • Aura-subjective sensation preceding seizure • May be psychic (déjà vu) • May be sensory (a noise, sight, sound, odor) • Loss of consciousness • Tonic phase-continuous motor tension and contraction of muscles

  50. Nervous System Emergencies • Seizures (cont.) • Grand-mal (progressioncont.) • Hypertonic phase-extreme muscular rigidity, hyperextension of the back • Clonic phase-extreme muscular rigid

More Related