Week 7 Lecture notes - Intracranial Regulation: concept overview PDF

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Goes over the concept and gives a brief overview of exemplars, risk factors, nursing interventions and possible treatment...

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INTRACRANIAL REGULATION: CONCEPT OVERVIEW Intracranial Regulation: The Brain ! ! ! ! ! ! ! ! ! Definition of the Concept: • Intracranial ◦ Within the bone structure that encloses the brain • Regulation ◦ Maintenance of balance to promote an environment conducive to optimal brain function • Increased intracranial pressure ◦ Pathological condition or trauma causes pressure within the cranial vault to increase ! ! !

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! Anatomy/physiology considerations: • Cranial vault ◦ Brain tissue ◦ Blood ◦ Cerebrospinal fluid • Monro-Kellie doctrine ◦ Pressure vs compliance ◦ Intracranial pressure • Blood-brain barrier • Meninges ◦ Dura mater ◦ Arachnoid mater ‣ subarachnoid space ◦ Pia mater • Autoregulation • Hyperventilation ! ! ! • Impairment and dysfunction associated with intracranial regulation: ◦ Impaired perfusion ◦ Compromised neurotransmission ◦ Glucose regulation ◦ Pathological states • Consequences of impaired intracranial regulation: ◦ Cerebral edema ◦ Increased intracranial pressure ◦ Brain tumors • Individual risk factors for impaired intracranial regulation: ◦ Age ◦ HTN ◦ DM ◦ Smoking ◦ Obesity ◦ CV Disease Clinical Manifestations/Assessment: • History ◦ Paresthesia and paralysis ◦ Loss of Consciousness, dizziness, fainting ◦ Headache ◦ Change in Memory ◦ Change in sensation ◦ Impaired chewing/swallowing ◦ Muscle weakness ◦ Bowel incontinence ◦ Vomiting (projectile) • Blood glucose level • VS changes ◦ Cushing's triad ◦ Change in body temperature • LOC ◦ Glasgow Coma Scale ◦ Mental status exam • Cranial Nerve Exam • Invasive monitoring ◦ Intracranial Pressure (ICP) ◦ Cerebral Perfusion Pressure (CPP) monitoring ◦ Cerebral oxygenation (PbtO2) • Respiratory Pattern • Musculoskeletal changes ◦ Hemiparesis/hemiplegia

◦ Posturing ◦ NIH Stroke Scale ! Posturing: A. Decorticate response. Flexion of arms, wrists, and fingers with adduction in upper extremities. Extension, internal rotation, and plantar flexion in lower extremities. B. Decerebrate response. All four extremities in rigid extension, with hyperpronation of forearms and plantar flexion of feet. C. Decorticate response on right side of body and decerebrate response on left side of body D. Opisthotonic posturing

Cranial Nerve Exam • CN I • CN II • CN III • CN III, IV, VI ◦ Occulocephalic reflex ‣ The occulocephalic reflex (doll's eyes) requires the head to be turned side to side; a normal response is that the eyes move in the direction opposite the direction the head is turned ‣ Absence of doll's eyes (i.e., eyes stay midline or fall to the direction that the head is being turned toward) indicates brainstem injury • CN V, VII ◦ Corneal reflex • CN VII, IX, X • CN VIII • CN IX, X ◦ Gag reflex • CN XI • CN X, XII! ! ! ! ! ! ! !

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! Cranial Nerve Mnemonic ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Abnormal Respiratory Patterns of Coma ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Diagnostics • Imaging studies ◦ CT Scan, MRI and/or PET scan ◦ Cerebral angiography and X-ray • Electroencephalogram • Brain Biopsy • Lumbar puncture • Serum chemistry, hematology, coagulopathy studies Clinical Management • Pharmacotherapy ◦ Osmotic diuretics ◦ Sedatives ◦ Analgesics ◦ Antiepileptics ◦ Glucocorticoids ◦ Antipyretics ◦ Antihypertensives ◦ Antiparkinsonian agents ◦ Cholinesterase inhibitors • Surgical interventions ◦ DEcompressive craniectomy ◦ Craniotomy ◦ Placement of shunts Nursing Management • Patient positioning • Activity management • Airway management • Hyperventilation • Bowel management • Nutrition management • Patient and family education • Rehabilitation Interrelated Concepts ! ! ! ! ! !

! INTRACRANIAL REGULATION: TRAUMATIC BRAIN INJURY Head injury: Traumatic brain injury (TBI) • High incidence ◦ TBI are twice as common in males • High potential for poor outcome • Deaths occur at three points in time after injury ◦ Immediately after the injury ◦ Within 2 hours after the injury ◦ 3 week after the injury Scalp Lacerations • External head trauma • Scalp is highly vascular -> profuse bleeding • Major complications – blood loss and infection Skull Fractures • Linear or depressed • Simple, comminuted, or compound • Closed or open • Location determines manifestations • Complications ◦ Infection ◦ Hematoma ◦ Tissue damage Basilar skull fractures: • Linear fracture involving the base of the skull ◦ Manifestations can evolve over the course of several hours, vary with the location and severity of fracture ‣ cranial nerve deficits ‣ Battle's sign ‣ Raccoon eyes • This fracture generally is associated with a tear in the dura and subsequent leakage of CSF Diffuse head injuries vs Focal injuries Concussion • Considered a minor TBI • Brief disruption in LOC • Retrograde amnesia • Headache • Short duration • May result in post concussion syndrome (PCS) ◦ Persistent headache ◦ Lethargy ◦ Personality and behavior changes ◦ Shortened attention span, decreased short-term memory ◦ Changes in intellectual ability Diffuse Axonal Injury • Widespread axonal damage ◦ Occurs primarily around axons in the subcortical white matter of the cerebral hemispheres, basal ganglia, thalamus, and brainstem ◦ the trauma changes the function of the axon, resulting in axon swelling and disconnection • Decreased LOC • Increased ICP • Decortication, decerebration • Global cerebral edema • Approximately 90% of patients with DAI remain in a persistent vegetative state Focal Injury: Lacerations • Tearing of brain tissue • Intercerebral hemorrhage • Subarachnoid hemorrhage

• Intraventricular hemorrhage Concussions • Bruising of brain tissue • Associated with closed head injury • Can cause hemorrhage, infarction, necrosis, edema • Often associated with coup-countercoup injury ◦ Occurs when the brain moves inside the skull due to highenergy or high-impact mechanisms • Can rebleed (blossoming) • Focal and generalized manifestations • Monitor for seizures • Potential for increased hemorrhage in on anticoagulants

Hematomas • Epidural hematoma ◦ Bleeding between the dura and the inner surface of the skull ◦ Neurologic emergency ‣ Usually involves meningeal artery ◦ Initial period of unconsciousness ◦ Brief lucid interval followed by decrease in LOC ◦ Headache, nausea, vomiting, or focal findings ◦ Requires rapid evacuation • Subdural Hematoma ◦ Bleeding between dura mater and arachnoid ◦ Most common source ‣ Veins that drain brain surface into sagittal sinus ‣ Can also be arterial ◦ Acute Subdural Hematoma ‣ Within 24 to 48 hrs of injury ‣ Symptoms related to increased ICP ‣ Decreased LOC, headache ‣ Ipsilateral pupil dilated and fixed if severe ◦ Subacute Subdural Hematoma ‣ Within 2-14 days of the injury ‣ May appear to enlarge over time ◦ Chronic Subdural Hematoma ‣ Weeks or months after injury ‣ More common in older adults • Potentially larger subdural space ‣ Presents as focal symptoms ‣ Increased risk for misdiagnosis • Intracerebral Hematoma ◦ Bleeding within brain tissue ◦ Usually within frontal and temporal lobes ◦ Size and location of hematoma determine patient outcome • Subarachnoid Bleeds ◦ Covered in stroke lecture

Diagnostic studies: CT scan • Best diagnostic test to determine craniocerebral trauma MRI, PET, evoked potential studies Transcranial Doppler studies Cervical spine CT/x-ray Emergency Treatment: Patent airway Stabilize cervical spine Oxygen • Intubate if GCS...