Please enable JavaScript.
Coggle requires JavaScript to display documents.
Coma and Head Injury - Coggle Diagram
Coma and Head Injury
ICP
-
Monro-Kellie Doctrine: Idea that once more mass is taken up in the brain, something needs to be pushed out -> CSF
-
-
-
Effects of increased ICP
Herniation (Sub falcine, CEntral, transtentorial, Tosnillar)
-
Medical Management
REsuscitation (ABCs) - Airway oxygenation, resucitate aggressively, manage source of bleeding
Labs: Arterial blood gas, hemoglobin, potassium, glucose, ETOH
-
-
-
-
Respiratory Changes
-
-
Hypoxemia - systemic causes (Inadequate airway management, chest trauma, aspiration)
Circulatory Changes
Hyperdynamic state, increased circulating catecholamines, Tachycardia, Hypertension
Traumatic Brain Injury
-
Subdivisions
-
Closed Head Injury: Skull intact, less capacity for edema, decreasing ICP
Coup-Contrecoup Injury: Contusions that are both at the site of the impact and on the complete opposite side of the brain
Penetrating Injury: Occurs from the impact of a bullet, knife or other sharp objects that forces hair, skin, bone and fragments from the object into the brain
-
Causes
Age Related
Chlildren: Sports related, Falls
15-24: MVC more than 60%, Violence/Assault, Falls - 5%
65 years: Falls - 60.7%, MVC - 15%
Risk Factors
Alcohol often involved, Drugs, ADHD, Family Discord, premorbid personality disturbance, Antisocial behaviour, lack of helmet use
Pathophysiology
Primary vs Second
Primary Injury
Mechanism
External mechanical forces transferred to intracranial contents, direct impact, rapid acceleration of the brain in the skull, blast waves
Includes
Cortical contusion, diffuse axonal injury
Definition
Domage that results directly and immediately as a result of trauam to the brian, seen in intiial minutes/hours after insult
Second Injury
Definition
Damage to brain tissue that takes place after intiial injury, treatable and theoretically preventable
Mechanism
Cascade of biochemical, cellular and molecular
Includes
Secondary brain swelling, axonal injury, inflammation and regeneration
-
Focal vs Diffuse
Focal
Restricted to specific part of brain, sequela related to affected region of brain, much like stroke
Diffuse
Widesperead injury to tissue, may not show on typical imaging
-
Primary Focal Injury
Contusion
Description
Traumatic, or mechanical destruction of small vesssels, bruising, extravasation of whole blood
-
-
-
Vascular
Epidural
Most commonly occurs with a fracture of temporal bone crossing vascular territory of middle meningeal artery/veins
-
-
-
-
-
Secondary Insults
Hypoxia, Ischemia, IC hematomas, Raised ICP, seizures, infection, fluid + electrolyte disturbance
-
Patient Assessment
History
Mechanism of Injuy, level of consciousnesss
Neurological Exam
Consciousness
Glasgow Coma Score
Eye Opening: Spontaneous, to voice, to pain, none
Verbal response: Oriented, confused - sentences, words, sounds, none
Movement: Obeys, localizes, flexion withdrawal, abnormal flexion, extension, none
Brainstem integrity
Pupillary reaction, ocular movement, corneal reflexes, gag/breathing
-
-
-
Consciousness
Definition: Function of ascending reticular activating system and cerebral cortex (RAS - Cell bodies in upper brain stem and project to areas of cerebral cortex)
Visual Impulses, auditory impulses, sensory tracts lead to projections into the cerebral cortex
Lesions that interrupt the integrity of RAS or cortical neurons that receive RAS, disorders of consciousness will result
Disorders
Coma
State of unconsciousness characterized by the ability of paitent to open eyes, follow commands or utter recognizable words
-
-
Vegetative State
State characterized by alternating periods of sleep and wakefullness, no awarenes of self-environment, perceivable evidence, verbal auditory startle, can open eyes
-
Permanent VS: >3 months after non traumatic brain injury, >12 months after TBI
-
Cerebral Autoregulation
Depends on CBF, oxygen partial pressure
Following TBI, normal autoregulatory relationship may be lost, increased ICP decreases CPP