UBP 1.1 (Short Form): Trauma & Critical Care -- Head Injury Flashcards
Secondary Subject: Glasgow Coma Scale / Managing the Trauma Patient / Cervical Spine Clearance / Elevated Intracranial Pressure/Cerebral Autoregulation/Cerebral Perfusion Pressure/Pulmonary Embolism/ARDS/SIADH & Cerebral Salt Wasting Syndrome
What is the Glasgow Coma Scale?
It’s 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.
A score of 8 or less which persists for 6 hours is considered severe injury and is associated with a mortality rate of ~35%.
A score of 9-12 suggests moderate injury.
A score of 13-15 suggests mild injury.
Determine GCS Score by listing out the table
How do you determine the Glascow Coma Scale (GCS) score?
Eye Opening:
- 4 = Spontaneous
- 3 = To Speech
- 2 = To Pain
- 1 = None
Verbal Response:
- 5 = Oriented, Conversing
- 4 = Disoriented, Conversing
- 3 = Inappropriate Speech - mostly words
- 2 = Incomprehensible Sounds
- 1 = None
Motor Response:
- 6 = Follows verbal commands
- 5 = Localizes to pain
- 4 = Withdraws to pain
- 3 = Decorticate flexion
- 2 = Decerebrate extension
- 1 = No response (Flaccid)
What are your treatment goals in this patient?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
- My initial goals are to assess and secure his airway and then achieve hemodynamic stabilization.
- Additionally, I would treat and avoid contributory factors to secondary neurologic injury such as –
- Hypoxia
- Hypercarbia
- Hypotension
- Anemia
- Finally, a full body assessment for injuries would be performed if not done simultaneously.
Would you intubate this patient?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
- Given the potential difficulty of managing his airway due to –
- his super morbid obesity,
- facial injuries,
- C-collar, and
- signs consistent with basilar skull fracture, –
- I would be very concerned that further deterioration of his mental status could place me in the position of managing his airway emergently (i.e., apnea).
- Moreover, this patient with a significant head injury may not tolerate the hypercapnia-induced increases in cerebral blood flow, and subsequent increase in ICP, associated with hypoventilation or apnea.
- Therefore, I would proceed with intubation, despite the presence of spontaneous ventilation, to reduce the risk of –
- aspiration,
- hypoventilation,
- apnea, and
- to forego the necessity of managing his difficult airway under more emergent conditions.
The patient is becoming more combative.
How will you intubate him?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
Since an awake fiberoptic intubation would not likely prove successful (uncooperative, facial/airway trauma), I would:
- ensure the availability of difficult airway equipment;
- have the surgeon at bedside and ready to perform a tracheostomy, if necessary;
- place the patient in 30 degree reverse-Tburg to improve respiratory mechanics, facilitate intubation, and reduce the risk of passive regurgitation (make sure that this positioning is hemodynamically tolerated);
- pre-oxygenate the patient;
- carefully titrate IV ketamine, in an attempt to achieve an adequate plane of anesthesia while maintaining spontaneous respiration;
- ensure manual in-line stabilization;
- remove the front of the cervical collar to allow for the careful application of cricoid pressure (care must be taken to avoid unintentional injury to the cervical spine); and
- perform laryngoscopy for ETT placement.
My primary goal is to safely secure the potentially difficult airway of this uncooperative and super morbidly obese patient who has facial injuries, a C-collar in place, and signs consistent with a basilar skull fracture (which would eliminate nasal intubation as an acceptable alternative).
Therefore, while intubating him I would attempt to AVOID:
- factors that may contribute to increased intracranial pressure, such as –
- hypoxia,
- hypercarbia, and
- sympathetic stimulation;
- hypotension, which may lead to inadequate end-organ perfusion (cerebral perfusion is particularly at risk if his intracranial pressure is elevated);
- cervical spine injury; and
- aspiration of either gastric contents or damaged teeth (increased risk secondary to pain, inadequate fasting period, obesity, diminished mental status, and potential for difficult airway management).
Assuming you are concerned about elevated intracranial pressures, is it advisable to utilize _ketamine_ for induction?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
- Ketamine-induced increases in –
- sympathetic tone,
- cerebral blood flow (may increase 50-60% secondary to cerebral vasodilation), and
-
regional CMRO2 (total CMRO2 is not increased because increases in some areas of the brain are balanced by decreases in other areas)
- are undesirable in this patient with potentially elevated ICP.
- However, my overriding goal when inducing this patient with a potentially difficult airway is –
- to maintain spontaneous respirations throughout induction and intubation.
- Therefore, given the minimal effects of carefully titrated ketamine on ventilatory drive, I would administer this drug for induction, recognizing that the potential detrimental effects on ICP are small in comparison to those associated with hypoxia, hypercarbia, and loss of the airway.
Shouldn’t you use succinylcholine for ETT placement?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
- While succinylcholine would be desirable in optimizing intubating conditions and reducing the risk of aspiration, I would not utilize it in this case due to –
- concerns for difficult airway management and potentially elevated ICP.
- My primary reason for avoiding succinylcholine is the risk of inducing apnea in this patient with potentially elevated ICP (hypoxia and/or hypercarbia lead to increased ICP) and several risk factors for difficult airway management (i.e. super morbid obesity, facial fractures, loose teeth, lack of cooperation, and a C-collar).
- Moreover, the transient increase in ICP associated with succinylcholine (possibly secondary to fasciculations) would be undesirable in this patient with apparent head trauma (although this succinylcholine-induced increase in ICP tends to be transient and small in comparison to that which would result from hypoxia or hypercarbia).
The neck radiographs show no apparent injury.
Is this patient’s C-spine clear?
(What is the criteria for C-spine clearance?)
It is impossible to clear this patient’s C-spine given his mental status, which makes it impossible to rule out pain upon palpation of the cervical spine.
Criteria for C-Spine Clearance:
- The absence of cervical pain or tenderness
- The absence of paresthesias or neurologic deficits.
- Normal mental status (& No intoxication - no drugs/etoh)
- > 4 years of age
- No distracting pain
http://www.mdcalc.com/nexus-criteria-for-c-spine-imaging/#how-to-use
If the above criteria are not met, then a cross-table lateral film showing C1 through T1, an open mouth odontoid view, and an anterior/posterior view are required.
Even with an appropriate radiographic examination, 7% of fractures are missed and ligamentous injury is NOT ruled out. (According to UBP)
When the patient is stable enough to tolerate an interruption in resuscitation, a CT scan could be utilized to evaluate the cervical spine.
You are having difficulty placing the endotracheal tube with direct laryngoscopy, and the resident suggests a blind nasal technique. How would you respond?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
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.
(Difficult Airway Algorithm:)
Rather, if laryngoscopy were difficult, I would consider calling for help, releasing cricoid pressure (cricoid pressure may increase the difficulty of laryngoscopy), and attempting intubation with a video laryngoscope (limiting my total attempts to three).
If I remained unsuccessful, I would ventilate as necessary while attempting to establish a more definitive airway via an alternative technique, such as fiberoptic bronchoscope, gum rubber bougie, lighted stylet, or surgical access.
Ok. The patient is intubated. What do you make of his initial vital signs?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
A hyperdynamic circulatory response is NOT unusual following head injury and may result from a surge in epinephrine.
Additionally, pain, hypoxia, hypercarbia, hypovolemia, and/or anemia could be responsible for his tachycardia and hypertension.
In either case, I would attempt to optimize the patient by controlling his pain, replacing fluid losses with blood products or crystalloid as necessary, and ensuring adequate ventilation.
Given my concerns about potentially elevated ICP and decreased cerebral perfusion pressure, I would probably avoid treating his tachycardia and hypertension with a B-blocker or vasodilator.
If treatment of this kind was deemed necessary, I would use a short acting agent like esmolol.
This patient is also mildly hypothermic which may be beneficial in so far as it reduces CMRO2.
Does this patient require fluid resuscitation?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
Possibly.
I would perform a thorough 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 abdominal compartment or secondary to the right femur fracture.
My goals in fluid resuscitation are – to maintain cerebral perfusion pressure by restoring circulating blood volume and avoiding hypotension.
At the same time, I want to reduce the risk of cerebral edema by maintaining serum osmolality and avoiding significant reductions in colloid oncotic pressure.
Are you ok with the D5LR that is currently hanging?
Any concerns with LR?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
I do have a problem with the D5LR since hyperglycemia may augment ischemic brain injury.
For this reason, glucose-containing solutions are usually avoiding in patients with brain injury.
Theoretically, the small amount of free water in lactated Ringer’s solution (100 mL of free water per liter) could result in increased brain edema as compared to an isotonic solution such as normal saline.
Would you lower the patient’s blood pressure if it increased to 205/118 mmHg?
(5’7” 180 kg 22 yo male is brought to trauma suite s/p MVA. He is somnolent, uncooperative, spontaneously breathing, withdraws from painful stimuli (does NOT localize), and is speaking inappropriately. On exam, he has a swollen right leg, ecchymosis into the periorbital tissue, hemotympanum, multiple facial fractures, and multiple loose teeth. There is an 18g IV in his left arm with D5LR hanging. VS: P = 134, R = 24, BP 178/108, O2 sat = 96% on non-rebreathing mask, T = 33 C.)
This blood pressure is very high and must be addressed.
However, 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:
- take steps to reduce his intracranial pressure
- consult a neurosurgeon for potential ICP monitoring, and
- ensure adequate analgesia, intravascular volume replacement, and ventilation.
If I 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).
What is the equation for cerebral perfusion pressure?
MAP - ICP or CVP (whichever is greater)
Isn’t there autoregulation of blood flow to the brain?
What is the range for normal cerebral autoregulation?
While autoregulation may be intact, 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.
