UBP Book 1, Case 1 (Trauma/Critical Care-Head Injury) Flashcards
What is the GCS?
A scoring system based on eye opening, best motor response, and best
verbal response that has a strong correlation with severity of head injury and patient
outcome.
Little things that can be helpful when describing how you will intubate the patient:
place the patient in 30° reverse-trendelenburg to
improve respiratory mechanics, facilitate intubation, and reduce the risk of passive
regurgitation (make sure that this positioning is hemodynamically tolerated)
How can you tell if someone is cleared from c-spine?
The
criteria for C-spine clearance include: 1) the absence of cervical pain or tenderness, 2)
the absence ofparesthesias or neurologic deficits, 3) normal mental status, 4) no
distracting pain, 5) >4 years of age. If the above criteria are not met, then a cross-
table lateral film showing C1 through Ti, an open mouth odontoid view, and an
anterior/posterior view are required. Even with an appropriate radiographic
examination, 7% of fractures are missed
What’s so bad about a basilar skull fracture-why wouldn’t you want to nasally intubate when people have one? What signs do they have?
Given the presence of periorbital ecchymosis and hemotympanum, it
would be inappropriate to perform a blind nasal intubation as these findings suggest a
possible basilar skull fracture. With this type of fracture, there is a risk of advancing
the ETT into the brain when attempting a blind nasal intubation.
When considering vital signs in these types of patients-remember:
Catecholamines are released with head injury!
If they ask if the patient needs fluid resuscitation, what can you say?
Mention that they could be (unless you know they’re not), and that you would have to perform a thorough physical exam with special attention to
urine output (if a Foley catheter is in place), mucous membranes, cap refill, and blood
loss, recognizing that there could be hidden blood loss in the blah, blah, blah
How do you feel about D5LR hanging in a brain injury patient?
I do have a problem with the D5LR since hyperglycemia may augment
ischemic brain injury. For this reason, glucose-containing solutions are usually avoided in patients with brain injury.
So, in patients with elevated BP and head trauma-are you treating the hypertension?
without ICP monitoring it is very difficult to know whether his increase in blood
pressure is in response to an acute increase in intracranial pressure (i.e. reflex
response in order to maintain cerebral perfusion), or simply the result of pain,
hypoxia, hypercarbia, anemia, or hypovolemia. Therefore, I would first: (1) take
steps to reduce his intracranial pressure, (2) consult a neurosurgeon for potential ICP
monitoring, and (3) ensure adequate analgesia, intravascular volume replacement, and
ventilation. Ifl determined that treatment of his blood pressure was indicated, I
would carefully reduce his blood pressure by titrating a short acting agent (i.e.
esmolol), with the goal of bringing his blood pressure to a safer level without
compromising cerebral perfusion. I would not attempt to normalize his blood pressure
since higher than normal blood pressures may be necessary to provide adequate
cerebral perfusion in the presence of his elevated ICP (CPP =MAP - ICP).
Cerebral perfusion pressure formula:
MAP-ICP (or CVP-whichever is higher)
Autoregulation in the setting of head trauma: What numbers are the range? Can it be affected by trauma?
it is quite possible that this
regulatory mechanism is abolished in the presence of head trauma, making cerebral
blood flow pressure dependent. In the absence of chronic hypertension, intact
cerebral autoregulation maintains cerebral blood flow at a constant rate with mean
arterial pressure ranging from 60- 150 mmHg.
What is normal CPP? What’s ideal in a patient with head injury?
Normal CPP is around 80-100 mmHg. In a patient with head injury
the optimum CPP is unknown. While earlier studies suggested improved outcomes
with a CPP of70-80 mmHg, there is more recent evidence showing that CPP > 70
mmHg may increase the incidence of ARDS. Additionally, some studies indicate that
cerebral ischemia may occur in the head injury patient with CPP below 50-60 mmHg.
Therefore, it would seem reasonable to try to maintain a CPP of 60-70 mmHg
Do you always require ICP monitoring?
It’ll be case specific, but I would definitely discuss the possibility with the surgeon.
Again-things you can do to decrease ICP without a drain:
There are several actions I can take to decrease ICP including: (1)
making sure there is no venous obstruction, particularly in this patient with a c-collar
in place; (2) elevating the patient’s head 15-30 degrees (ifhemodynamically
tolerated) to increase venous drainage; (3) administering mannitol, which reduces ICP
by osmotically shifting fluid from the brain compartment to the _intravascular
compartment, decreasing production of CSF (this affect is seen with hypertonic
fluids), and inducing reflex cerebral vasoconstriction secondary to decreased blood
viscosity (keep in mind that this drug may potentially worsen cerebral edema if the
BBB is not intact, and/or result in the expansion of an intracranial hematoma as
surrounding brain tissue shrinks with osmotic diuresis); ( 4) administering furosemide,
recognizing that in the presence ofhypovolemia, this diuretic could lead to
hypotension and worsening cerebral ischemia; and
So, would you ever hyperventilate a patient with head trauma? What is the
problem with hyperventilation? How long do its effects last?
I would consider hyperventilation to a C02 of25-30 mmHg if other
methods to reduce ICP were unsuccessful and I thought the elevated ICP was severe
enough to place the patient at risk for brain stem herniation. However, there is a risk of exacerbating cerebral ischemia by inducing cerebral
vasoconstriction in a patient with lower than normal cerebral blood flow following
head trauma. I would also keep in mind that the effects of hyperventilation are
temporary (24-48 hours) because HC03 levels in the CSF adjust to compensate for
the change in PaC02.
The patient’s temperature is 33 degrees. Does this concern you?
Yes-poor wound healing, coagulopathy, cardiac dysrhythmias