HEAD INJURIES Flashcards
TBI contributes significantly to the death of approximately ______ of all trauma victims.
half
The brain is surrounded by how much csf?
150ml
Brain tissue, blood, and CSF exert a pressure within the brain, which isreferred to as
intracranial pressure (ICP)
Hemorrhage or edema that leads to herniation of the brain will compress what CN, Leading to pupillary dilation?
Cranial nerve III (oculomotor)
What pressure is used to characterize pressure driving blood into the brain
Mean arterial pressure (MAP)
How do you calc MAP?
(systole +diastole x2/3) or diastole + 1/3 pulse pressure
What is the amount of pressure it takes to push blood through cerebral circulation. To maintain oxygen, glucose delivery
Cerebral perfusion pressure (CPP)
CPP is calculated how?
MAP-ICP
Normal CPP =
70-80mmhg
Historically _____ has been use to lower ICP
hyperventilation
What type of injury?
(a)Direct trauma to the brain
(b)Contusion, hemorrhages, lacerations or direct mechanical injury
(c) Neural tissue does not regenerate well therefore low expectation of recovery of the tissue associated
Primary brain injury
Types of secondary injury include:
1) Mass effect – elevated ICP (can lead to herniation)
2) Hypoxia (inadequate delivery of O2)
3) Hypotension
2 biggest predictors of poor outcome in head trauma are
-Amount of time spent with ICP > 20mmHg
-Time spent with systolic BP < 90mmHg
Cushing’s triad refers to
elevated systolic BP, bradycardia and
abnormal respirations (Cheyne-stokes)
Once life threatening injuries have been managed if time permits or during transport perform _____
secondary assessment
single most important observation for TBI during secondary survey
Constant/continuous observation of mental status
Depressed vs non depressed skull fractures.
______ can often be palpated and may require surgical intervention
Depressed
________ - suspect if CSF drainage or delayed (several hours) findings of periorbital ecchymosis or battle signs are seen
Basilar skull fracture
Trauma to the eye and orbit must be considered with facial trauma evaluate for:
(a) Hyphema
(b) Open globe
What type of eye injury?
signs include tear drop pupil, sub conjunctival hemorrhage, decrease in vision
Open globe
_________ is a head injury from a hit, blow, or jolt to the heat that:
(a) Briefly knock you out (loss of consciousness), OR
(b) May affect your ability to remember information before, during, or after the event (post traumatic amnesia), OR
(c) Makes you feel dazed, like you had your bell rung (alteration of consciousness)
Concussion
also known as a mild traumatic brain injury
What issue?
(a) Bleeding between skull and Dura Mater
(b) 1-2% of TBI patients
(c) Usually low velocity blow to temporal bone
(d) Pathognomonic history is patient has head trauma with a brief LOC, regains consciousness (lucid interval), then experiences rapid decline in consciousness
(e) Due to the location of the bleed the patient have a great recovery if rapid surgical intervention is performed
(f) Watch for dilated, sluggish non-reactive pupil
Epidural hematoma
What issue?
(a) Account for 30% of severe brain injuries
—1)MVC, falls
(b) Generally results from venous bleed
(c) Bridging veins are torn during blow to the head
(d) Blood collects between Dura and Arachnoid membrane
(e) Typically results from relatively rapid accumulation of blood in the subdural space and rapid onset of mass effect
Subdural hematomas
(a) Bleeding that occurs between arachnoid membrane
(b) Many vessels located in this space
(c) Commonly associated with ruptured cerebral aneurysm and onset of worst headache of life. However, post traumatic is the most common cause. Symptoms include:
-1) Severe HA
-2) Nausea & vomiting
-3) Dizziness
-4) May have meningeal signs
-5) Seizures
(d)Does not cause mass effect due to location therefore surgical intervention is not common
Subarachnoid Hemorrhage (SAH)
