TCRN Review - Head and Neck (Neurological
Trauma and Maxillofacial and Neck Trauma)
(29 questions on exam)
What are the three main constituents in
... [Show More] the brain? - CSF, Brain Tissue (mostly water), Blood
The brain makes up approximately _____% of the volume of the skull and is _____% water. -
80%
75%
CSF makes up about _____% of the volume of the skull. - 10%
There is approximately _____ mL of CSF. - 125-150 mL
Blood makes up about _____% of the volume of the skull and _____% of the blood is venous. -
10%
80%
The pressure of water, CSF and blood against the skull is known as _____. - ICP - Intracranial
pressure
What are the normal ICPs for children and adults? - Child - 0-5 mmHg
Adult - 5-12 mmHg
ICP pressures above _____ mmHg in any age group is considered elevated. - 20 mmHg
ICP pressures above 20 mmHg do what? - Compromise blood flow into the skull and contribute
to cerebral hypoxia and hypoglycemia.
What can happen if ICP pressures climb too high? - The brain may be forced out of the skull
through any opening (such as skull fractures, tentorial plate or foramen magnum).
ICP above _____ mmHg is severe and life-threatening. - 40 mmHg
ICP between _____ and _____ mmHg is termed "moderate intracranial hypertension". - 20 and
40 mmHg
ICP above 20 mmHg is abnormally high and is known as _____. - Early increased ICP
What should resting ICP be? - Less than 10 mmHg
When ICP increases, pressure is exerted downwards on brain tissue, affecting the cerebral
cortices _____ and _____. - Reticular Activating System (RAS) and Cranial Nerves
List 6 things caused by pressure on the RAS (Reticular Activating System). - 1. Progressive
restlessness
2. Confusion
3. Disorientation
4. Lethargy or combativeness
5. Changes in speech
6. Loss of judgement
List 4 motor functions caused by increased ICP. - 1. Monoplegia
2. Hemiplegia
3. Over-pronation or supination of the wrists
4. Pronator drift
List 5 eye changes caused by increased ICP. - Diplopia
Blurred Vision
Visual field defects (loss of sight in part of one visual field)
Conjugate deviation of eyes or gaze palsies
Oval pupils with hippus
Increased ICP causes _____ losses. - Sensory
List 3 things caused by pressure on the hypothalamus. - Nuchal rigidity
Temperature changes
Vomiting (usually without nausea)
Describe how to test for pronator drift. - Ask the patient to hold both arms straight forward
with the palms up for at least 30 seconds. Have the patient close his or her eyes. Monitor for
unilateral downward drift of one hand (known as pronator drift).
Describe "conjugate deviation of the eyes". - Both eyes move in the same direction.
What is a gaze palsy? - Inability to move both eyes in one direction.
What is a hippus? - Pupil rapidly dilates and constricts when stimulated with light so it looks as
though it is jiggling up and down.
List 6 late signs of increased ICP. - 1. Further reduction in LOC and responsiveness
2. Wide fluctuations in core body temperature
3. Seizures
4. Pressure on the brainstem
5. Pupillary changes
6. Flexor/extensor posturing
What two things are caused by pressure on the brainstem? - Cushing's Triad
Decreased or absent brainstem reflexes
What is Cushing's Triad? - Systolic hypertension with a widened pulse pressure
Bradypnea or irregular respirations
Bradycardia
What are some examples of absent brainstem reflexes? - Cough, gag, corneal, Doll's eye, cold
calorics
What 2 types of pupillary changes are caused by pressure on the brainstem? - Unilateral or
bilateral dilation
Decreased reactivity to light
What are the 7 indications of brainstem herniation? - GCS decreases by 2 or more points
BP and ICP significantly increase
Heart rate drops by 30-40 BPM
Respiratory pattern changes
Unilateral or bilateral dilation of the pupils
Pupils fail to react to light
Posturing
What are the indications for ICP monitoring? - Salvageable patients with severe injury
GCS score of 3-8 after resuscitation
Abnormal findings on the CT scan (hematomas, contusions, swelling, herniation, compressed
basal cisterns)
What are the contraindications to ICP monitoring? - Wake patient
Coagulopathies
What are the risk factors with ICP monitoring? (2) - Infection (8% of patients)
Hemorrhage (2-10% of patients)
What are the risk factors for infection related to ICP monitoring? - Concurrent systemic
infections
Longer duration of monitoring (highest risk factor after 10 days of use)
Presence of intraventricular hemorrhage or subarachnoid hemorrhage
Open skull fracture
Trauma
Cerebrospinal fluid leakage at the site
What are the signs of infection associated with ICP monitoring? - Headache (if patient has
headache from the injury, look for changes in the headache)
Neck stiffness
Fever
AMS
New-onset seizures
Which patients are most likely to have hemorrhage related to ICP monitoring? - More likely in
patients who develop coagulopathies
Discuss hemorrhages related to ICP monitoring? - Most hemorrhages are small (less than 15
mL) and clinically insignificant. Clinically significant hemorrhage occurs in 1% of cases.
What two things are perfusion to cerebral tissue dependent upon? - An adequate MAP that is
able to propel blood from the body into the skull
A normal ICP
Describe the relationship between MAP and ICP. - ICP acts against MAP to reduce blood flow
from the body into the skull.
How do you determine CPP? - CPP = MAP-ICP
What is the average CPP (cerebral perfusion pressure)? - 80-100 mmHg
A CPP above _____ mmHg is ideal. - 70
A CPP above _____ mmHg is required for consciousness. - 60
A CPP less than _____ mmHg causes critical reduction in brain tissue oxygenation. - 50
A CPP below _____ mmHg reduces cerebral blood flow to 25% of normal - 40
A CPP below _____ mmHg equates to irreversible brain ischemia - 30
If the MAP is lower than the CPP, the patient is _____. - Dead
What is the first step in performing a neurological assessment? - Determine LOC
What is the LOC of a patient who responds immediately to minimal external stimuli? - Alert
What is the LOC of a patient in a state of drowsiness or inactivity, in which the patient needs
increased stimulus to be awakened, but is still easily arousable. - Lethargic
What is the LOC of a patient who is very drowsy when not stimulated, follows simple
commands when stimulated, a duller indifference to external stimuli still exists, and response is
minimally obtained? - Obtunded [Show Less]