Altered Cerebral Function & Increased Intracranial Pressure

1. Altered Cerebral Function & Increased Intracranial Pressure RNSG 2432 Enhanced Concepts of Adult Health Fall 2011 Lisa Randall, RN, MSN, ACNS-BC

2. Objectives • Define and discuss altered cerebral function and increased ICP • Analyze etiology and pathophysiology of altered cerebral function • Discuss/illustrate signs and symptoms, diagnostics, and treatment • Formulate nursing diagnoses that address physical, psychosocial, and learning needs • Prioritize and evaluate nursing interventions

4. Definitions • Cerebral function • Mental status • Speech • Eyes • Cranial nerves • Motor • Sensory • Reflexes

5. Definitions • Obtundation • << A/A • Clouding • Stupor • Deep sleeplike state • Vigorous stimulation • Coma • Unresponsiveness • PVS • MCS • Consciousness • Arousal • Awareness • Lethargy • < alertness • < awareness • < thought process

6. Comatose State • Unarousability • Absence of sleep/wake cycles • Inability to interact with the environment • GCS =/< 8

7. Persistent Vegetative State • Intermittent wakefulness • Sleep-wake cycles • No awareness of self or environment http://youtu.be/Pl1IPTpHUHs

8. Minimally Conscious State • Altered consciousness • Evidence of self or environmental awareness is demonstrated

9. Anatomy http://www.youtube.com/watch?feature=player_detailpage&v=HVGlfcP3ATI

10. Pathophysiology • Reticular Activating System (RAS) • Reticular Formation • Gray cells within brainstem extends into thalamus • Wakefulness • Arousal • Alertness

12. EtiologyAltered Cerebral Dysfunction • Lesion/injury to the RAS or cerebral cortex • Metabolic disorders • Anoxic injury • Drugs • Seizures

13. Assessment • LOC • Health history • drugs/head injury/metabolic • Physical exam • Vital signs • Temperature • Cushing’s reflex/triad • Neuro Vital Signs • LOC, Pupils, Strength/Movement, Sensation • Glasgow coma scale • NIH Stroke Scale

14. Cushing Triad • Edema • Increased intracranial pressure • Increased systolic BP • Widening pulse pressure • Normal = 40 mmHg • Decreased pulse rate • Irregular respirations

15. GLASGOW COMA SCALE

16. GLASGOW COMA SCALE Range of possible scores = 3-15 A score of 13 to 14 indicates mild deficit. A score between 9 and 12 points to moderate deficit, and a score of 8 or less indicates severe coma.

17. Decorticate posturing- abnormal flexion Decerebrate posturing- abnormal extension

18. Assessment • Mental status • General appearance/behavior • State of conciousness • Mood and affect • Thought content • Intellectual capacity

20. Cranial Nerves

21. Assessment of arousal/cognition Vision & Pupillary light reflex Sensory: CN II - Optic • Visual acuity Motor: CN III - Oculomotor • PERRL • Direct/consensual • EOMs (CN IV/VI) http://www.youtube.com/watch?v=cuZXz92hd8g&feature=relate

23. Assessment Arosual/cognition EOM’S & Brain stem function • Eye movement • CN III,IV,VI • Oculocephalic reflex • Doll’s eyes • Sensory CN VIII • Motor CN III,IV,VI • Dolls eyes • (+) opposite direction • intact brain stem • (-) no movement

24. Cranial Nerve Assessment • Glossopharyngeal (IX) • Gag/swallow • Vagus (X) • Gag/Swallow • Spinal Accessory (XI) • Shoulder shrug • Hypoglossal (XII) • TML • Trigeminal (V) • Corneal reflex • Sensory • mastication • Facial (VII) • Expression • Taste • Acoustic (VIII)

25. Motor • Ability to move, strength, and symmetry • Grips, arm strength, & drift • Planter flexion, dorsiflexion, & leg strength • Coordination • Finger to nose, heel up and down shin • Planter Reflex- Babinski testing • Meningeal signs- Brudzinski & Kernig’s sign

26. Planter Reflex and Babinski testing • Babinski's reflex • (+) great toe flexes and the other toes fan out • Abnormal after the age of 2.

27. Meningeal signs- Brudzinski, nuchal rigidity Hips and knees flex when the neck is flexed

28. Meningitis signs- Kernig’s sign Stiffness of the hamstrings causes an inability to straighten the leg when the hip is flexed to 90 degrees.

29. Neuro assessment - Sensation • Visual fields • Dull vs. sharp • Sensation same or different with eyes closed • Face • Hands • Arms • Abdomen • Feet • Legs

30. Homonculus

31. Assessment – Respiratory Changes • Brainstem compression • Yawning & sighing • Cheyne-Stokes • Central neurogenic hyperventilation • Apneustic breathing • Cluster breathing • Ataxic respirations

32. Assessment • http://www.youtube.com/embed/CUaEwgfKOEc

33. Question • A patient with an intracranial problem does not open his eyes to any stimulus, has no verbal response except muttering when stimulated, and flexes his arm in response to painful stimuli. The nurse records the patient’s GCS score as • A. 6 • B. 8 • C. 9 • D. 11

34. Question • The nurse recognizes the presence of Cushing’s triad in the patient with • A. increased pulse, irregular respiration, increased BP • B. decreased pulse, irregular respiration, increased pulse pressure • C. Increased pulse, decreased respiration, increased pulse pressure • D. decreased pulse, increased respiration, decreased systolic BP

35. Question • CN III originating in the midbrain is assessed by the nurse for an early indication of pressure on the brainstem by • A. assessing for nystagmus • B. testing the corneal reflex • C. testing pupillary reaction to light • D. testing for oculocephalic (doll’s eyes) reflex

36. Question • An unconscious patient with increased ICP is on ventilatory support. The nurse notifies the healthcare provider when arterial blood gas (ABG) measurement results reveal a • A. pH of 7.43 • B. SaO2 of 94% • C. PaO2 of 50mm Hg • D. PaCO2 of 30mm Hg

37. DiagnosticsR/O and identify cause of LOC • CT • MRI • EEG • Cerebral angiogram • TCD • LP • BG • Electrolytes/Osmolality • ABGs • CBC • Liver function • Kidney function • Toxicology

39. IncreasedIntracranialPressure

40. ICP Concepts • Monro-Kellie hypothesis • 80/10/10 rule • Autoregulation • Cerebral arterioles • MAP (Mean arterial pressure) • Perfusion depends on B/P and chemical (CO2) • Normal MAP is 70 to 100 • < 60 - peripheral organs not perfused • < 50 – brain not perfused • Critical to maintain normal MAP with Increased ICP

41. Compensatory Mechanisms • Vasoconstriction • Decreased CSF • CSF shunting • Increased CSF reabsorption

42. Compliance • Brain’s ability to tolerate an increase in volume without an increase in pressure • Indications of decreased compliance: • Sustained increase in ICP in response to stimuli • Greater increases to non-noxious stimuli

43. Normal Pressure v Compensated v Uncompensated

44. “Rules” of Compensation • A slowly expanding mass is tolerated better that a rapidly expanding mass • Brain tissue is compressible, but functional impairment, possibly irreversible does occur • Location matters

45. Cerebral Perfusion Pressure • Pressure needed for adequate blood flow to brain • CPP = MAP – ICP • Need higher MAP if ICP increased • 70-100 mmHg • <50 mmHg = ischemia • <30 mmHg = death

46. MAP – ICP = CPP Arterial Blood Pressure - Brain & CS Fluid Compression = Actual Cerebral Blood Flow CPP 70 to 100 mmHg Danger of CPP < 50 mmHg MAP 50 to 150 mmHg Autoregulation Edema, CS Fluid, Tumor Increased ICP > 20 mmHg Normal ICP 0 to 15 mmHg Increased MAP needed to perfuse brain

47. Pathophysiology • Changes in contents of cranial vault

48. Causes of Increased ICP • Increased intrathoracicpressure • Coughing • Straining • Suctioning • Peep • Impairment of cerebral venous drainage • Positioning • Mass effect • Tumor • Blood clot • Edema • Increased CBF • Increased blood flow • Increased PaCO2 • Decreased PaO2 • Vasodilators

49. ICP indicators • Changes in LOC • Worsening headache • Cognitive deficits • Pupillary changes • Increasing B/P with widening pulse pressure • Irregular respiratory patterns • Bradycardia • Seizures • Aphasia • Dysconjugate gaze • Hemiparesis or hemiplegia

50. Assessment • Health history- assess brain involvement • PE • Altered cerebral function assessment • Frequency depends on potential IICP • Early sign- change in LOC • 3rd Cranial nerve compression • Papilledema • Projectile vomiting • Vision changes • Seizures • Late sign- Cushing VS changes