Major head trauma Flashcards
The goal of treatment in patients with major head trauma is to prevent secondary injury to the brain, primarily through avoidance of _______ and ______
hypotension, hypoxia
After the initial airway management and resuscitation, the focus is to identify injuries amenable to surgical therapy such as ________, subdural hematoma (SDH) and traumatic hydrocephalus
epidural hematoma (EDH)
After the initial airway management and resuscitation, the focus is to identify injuries amenable to surgical therapy such as epidural hematoma (EDH), _________ and traumatic hydrocephalus
subdural hematoma (SDH)
After the initial airway management and resuscitation, the focus is to identify injuries amenable to surgical therapy such as epidural hematoma (EDH), subdural hematoma (SDH) and ________
traumatic hydrocephalus
Elevation of the head of the bed by ______ (reverse Trendelenburg position) helps to decrease intracranial pressure (ICP) and improves oxygenation.
20 degrees
________ is utilized as a means to reduce ICP only in the scenario of impending herniation and death; it causes cerebral vasoconstriction and exacerbates brain ischemia
Hyperventilation
_______ injury is closely associated with major head trauma; cervical spine imaging with the initial head CT is indicated
Cervical spine
_______ is an injury that occurs at the time of the insult (e.g. the actual traumatic incident itself).
Primary injury is generally considered irreversible
Primary injury
Our aim is to prevent ________, which is the ongoing and progressive damage that occurs to brain tissue after the injury itself.
secondary injury
_______ occurs as a result of many factors, including impaired blood flow, edema, release of excitatory neurotransmitters and neurotoxins.
Secondary injury
______ is the pressure within the skull.
Intracranial pressure
The effects of increased ______ include headache, and possible neurologic dysfunction.
ICP
increasing ICP will force the brain to ________ (slide out of) the skull through the foramen at the bottom of the skull.
herniate
________ is the difference between mean arterial pressure (MAP) and intracranial pressure (ICP).
Cerebral perfusion pressure (CPP)
Cerebral perfusion pressure (CPP)
can be calculated using the following equation:
CPP = MAP - ICP
In the injured brain, cerebral autoregulation is impaired, so changes in ______are felt more directly by the brain
MAP
If the CPP falls too _____, ischemia and infarction of uninjured brain can occur.
LOW
The management of ________ in patients with major brain injury reflects the delicate balance between MAP, CPP and ICP.
blood pressure
CPP cannot be measured directly in the ED but when ICP is increasing, we know that ______ must rise to provide sufficient CPP
MAP
Major Head Trauma
The reasons for intubation include:
- Not maintaining airway, oxygenation or ventilation
- Rapidly progressive deterioration
- Unable to obtain needed neuroimaging due to agitation (these patients require sedation and then usually intubation for airway protection)
- Need for surgery
Prior to intubation, think of rapidly reversible reasons for a decreased mental status.
- Administer glucose in hypoglycemia
* Administer naloxone in cases of opiate intoxication/overdose
___________ position of 20 degrees during and after RSI helps with preoxygenation and prevents rises in ICP by utilizing gravity and by promoting venous drainage.
A Reverse Trendelenburg
RSI medications
Ketamine and etomidate are both good choices for sedation.
Succinylcholine and rocuronium are both acceptable choices for paralytic.
________ has more contraindications but a shorter duration of action.
Succinylcholine
_______is the most powerful determinant of cerebral blood flow.
PaCO2
______ PaCO2 causes vasoconstriction which can cause cerebral ischemia.
Low
_____ PaCO2 can cause hyperemia and increase ICP.
High
Ventilator settings, particularly the ________, have a huge effect on PaCO2
respiratory rate
The current recommendation is for normal ventilation to maintain a normal PaCO2 (______ mm Hg).
35-45
_________, once recommended routinely in severe head trauma, is now reserved for cases of impending herniation when no other options to lower ICP are available.The consequence of hyperventilation is brain ischemia
Hyperventilation
The current recommendation is to maintain PaO2 >____mm Hg, but also to avoid hyperoxia.
PaO2 >60 mm Hg
________ (PaO2 higher than the normal range) is thought to be toxic to many organs, especially the brain by mechanisms that are poorly understood.
Hyperoxia
In general, because ICP is significantly elevated in most cases, MAP must be kept above a ______ of 100-110 mm Hg in order to provide sufficient CPP.
systolic
Normal saline is a good choice initially. ______fluids and albumin should be avoided.
Hypotonic
Head CT _______ contrast is the mainstay of imaging in the ED.
without contrast in head trauma
who are you calling to consult?
Consultation is appropriate for patients with major head injury, even in the absence of surgical lesions such as epidural and subdural hematomas
Neurosurgical Consultation
Immediate __________ in patients with intracranial hemorrhage is appropriate.
reversal of anticoagulation
Reverse heparin with ________
protamine
Reverse ______ with prothrombin complex concentrate (PCC) or fresh frozen plasma (FFP) and IV vitamin K
warfarin
Reverse __________ with either idarucizumab (the specific reversal agent for dabigatran, dose is 5 mg IV) or PCC
direct oral anticoagulants (DOACs)
Seizure prophylaxis in head trauma
- Phenytoin and levetiracetam are commonly used, but it is unclear if these are effective.
- Levetiracetam may be a better choice of seizure
______ is used to reduce edema in a patient at risk for brain herniation.
Hyperosmolar therapy
Osmotic diuresis
______ is indicated for patients with clinical signs of progressive deterioration or herniation (decreasing GCS, pupillary changes and paralysis/posturing).
Hyperosmolar therapy
Mannitol
Mannitol
dose
Dose is 0.25 g/kg to 1.0 g/kg
Mannitol
Requires close monitoring for ______and ______
hypotension and urine output
__________ may be used in patients with concomitant hypotension (e.g. in a bleeding, multiply injured patient with signs of herniation).
Hypertonic saline
Most commonly from a direct blow to the head, with a skull fracture and injury to the middle meningeal artery, resulting in brisk bleeding into the epidural space (between the skull and the dura mater)
Epidural hematoma (EDH)
The CT appearance is of a white lens-shaped lesion on the convexity of the skull, confined by the suture lines, but sometimes crossing the midline.
Epidural hematoma (EDH)
The classic presentation is an initial loss of consciousness (e.g., the initial impact and primary brain injury) followed by a lucid period and then a secondary neurological deterioration. However, only 20% of patients have this classic story.
Epidural hematoma (EDH)
Epidural hematoma (EDH)
management:
- Emergent neurosurgical consultation
* surgical evacuation.
Most commonly from a sudden deceleration injury, resulting in tearing of the bridging veins on the convexity of the brain.this is much more likely in older patients and those with cerebral atrophy
Subdural hematoma (SDH)
Subdural hematoma (SDH)
Because the bleeding is more commonly ______, it may ooze slowly. Patients may not become symptomatic until days or even weeks after the initial injury.
venous
The CT appearance is of a white crescent-shaped lesion on the convexity of the skull which does not cross the midline but rather invaginates into the brain alongside the falx and on top of the tentorium.
Subdural hematoma (SDH)
Over time, the white lesion representing acute blood turns isodense with the brain tissue (typically around 2 weeks post injury) as the clot breaks down; thereafter, the lesions turn darker and closer to the appearance of CSF.
Subdural hematoma (SDH)
Presentations vary widely and may include:
- headache
- focal findings
- progressive decline in level of consciousness
- coma
- seizures.
Subdural hematoma (SDH)
Subdural hematoma (SDH)
Management involves
- emergent neurosurgical consultation
* surgical evacuation
results in shearing of blood vessels in the subarachnoid space.
Traumatic SAH
In contrast to SAH resulting from the rupture of an aneurysm (spontaneous SAH), which causes a central collection of blood in the basal cisterns,_________tends to occur on the periphery of the brain in the cerebral sulci.
traumatic SAH
Large traumatic SAH may dissect into the ventricles, causing __________
hydrocephalus.
_________ are collections of blood within the brain parenchyma, typically along the base of the brain as it slides along the irregular contour of the skull base during deceleration injury.
Cerebral contusions
These appear as white lesions with surrounding edema (darker appearance).
Cerebral contusions
Unlike EDH and SDH, these lesions are often not amenable to surgical evacuation.
Cerebral contusions
Cerebral contusions/hematomas
management:
Serial CT imaging is critical to monitor the progression of these lesions.
is a primary brain injury caused by the shearing of axons in the deep white matter at the instant of the traumatic deceleration.
Diffuse axonal injury (DAI)
The typical clinical picture is of a comatose patient with no or minimal signs of injury on the initial CT. MR will detect the extent of injur
Diffuse axonal injury (DAI)
These injuries are devastating and can progress to massive swelling and herniation within hours or days after injury.
Diffuse axonal injury (DAI)
Diffuse axonal injury (DAI)
treatment:
Treatment is supportive.
All of the patterns of injury described above result in an increase in intracranial volume; thus all have the potential to result in a herniation syndrome (literally the brain sliding out of its compartments and out of the skull).
Herniation syndromes
The uncus (shoulder) of the temporal lobe gets pushed into the midbrain (brainstem) under the edge of the tentorium.
Uncal (transtentorial) herniation
Clinically manifests as deepening coma, pupillary dilation (usually ipsilateral to the lesion) and hemiparesis or posturing (usually contralateral to the lesion).
Uncal (transtentorial) herniation
- The tonsils of the cerebellum slide through the foramen magnum pressing against the medulla.
- May result in sudden death.
Cerebellar tonsillar herniation
_______ is fatal. When it is suspected either on the basis of a changing clinical exam or on imaging it requires immediate emergent neurosurgical consultation and steps to reduce ICP including hyperventilation
Herniation
Herniation is fatal. When it is suspected either on the basis of a changing clinical exam or on imaging it requires immediate emergent neurosurgical consultation and steps to reduce ICP including ________
hyperventilation
______ and ________tools are used to clear the c-spine without films; these are not applicable in patients with major head injury who have alteration of their mental status (see Minor head injury chapter next month for further discussion).
The NEXUS and Canadian c-spine
_____ is appropriate in patients with any signs or symptoms of spinal cord injury (paralysis, weakness, sensory changes, incontinence or decreased rectal tone); spinal injury may be present in these patients even in the absence of CT findings.
MR
If any of the above are met the c-spine cannot be cleared clinically
- Focal neurologic deficit
- Midline spinal tenderness
- Altered level of consciousness
- Intoxication
- Distracting Injury
NEXUS C-Spine
Age ≥65
Extremity paresthesias
Dangerous mechanism:
Fall from ≥3 ft or 5 stairs
Axial load injury
High speed MVC/rollover/ejection
Bicycle collision
Motorized recreational vehicle
Canadian C-Spine
