Polytrauma Flashcards
(30 cards)
What is the “Golden Hour” in polytrauma management?
The hour after a major trauma in which emergency treatment needs to be initiated for there to be likelihood of a successful outcome for the patient. The patient must be stabilized before even moving them.
TAOD
traumatic atlanto-occipital
dislocation
What are the alternative names for TAOD?
- Occipital-cervical dislocation
- Cranio-cervical dislocation
- Craniocervical dissociation
- Internal decapitation
Why is TAOD 3x more common in children than adults?
Due to children’s:
- Disproportionately larger head-to-body ratio
- Flatter shape of the occipital condyles
- More flexible and weaker ligaments
What percentage of deaths does TAOD cause in motor trauma accidents (MTA)?
- 8-35% of MTA deaths
- 10% of fatal cervical spine injuries
- Up to 31% of immediate deaths in MTA injuries
What is the mechanism of injury for TAOD?
A combination of forces:
- Hyperextension +/- lateral flexion
- Hyperflexion or hyperextension with distraction
How do TAOD injuries differ between children and adults?
Children: Related to ligamentous injuries
Adults: More connected to bony injuries
What should align on a midline sagittal CT section to rule out TAOD?
The anterior foramen magnum should line up with the dens
A line projected downward from the dorsum sellae along the clivus to the basion should point to the dens
Criteria to confirm TAOD
- Power Ratio <1mm
- Wholly’s DBI <12mm
- SUN <2.5mm
- BAI (Basion-Axis Interval) <12mm
- CCI (Occipital-Condyle C1 Interval) <4-4.3mm
- Clivus line Tangent to dens, if dens >2mm off line = craniocervical instability
All six measurements check different aspects of skull-spine stability:
Power Ratio = anterior-posterior position
Wholey’s DBI = C1-C2 relationship
SUN = posterior alignment
BAI = vertical distance/ligament integrity
CCI = direct separation gap
Clivus Line = skull base-spine alignment
What is the Power Ratio and its normal values?
Ratio of line from Basion to spinolaminar line of C1 / Opisthion to posterior cortex of C1 anterior arch
Normal range: 0.6 to 1.0 (mean = 0.8)
Abnormal: >1.0 implies anterior cranio-cervical dislocation
What is Wholey’s DBI and its normal value?
The midpoint of anterior margin of foramen magnum (Basion) should line up with the tip of C2. Normal space is <12mm.
What is the SUN ratio and its normal value?
The C1-C2/C2-3 articular mass interval with normal ratio being <2.5.
What is the Harris Basion-Axis Interval (BAI) normal value?
Must be <12mm.
BAI = bottom of the skull to tip of C2
What is the Occipital-condyle - C1 interval (CCI) and its normal values?
Must be >4.3mm (or 4.0mm)
The CCI is very symmetrical in children but not in adults
4.0mm is a mean of 8 equidistant measurements
Greatest separation of occipital and C1 articular mass measured perpendicular to the mass: <2.5mm
Sum of left and right CCI when normal: <5mm
What is Clivus Line
Clivus Line (Wackenheim’s Line)
What: Line drawn along back edge of clivus (skull base slope)
Normal: Should be tangent to or just touch tip of C2 dens
Abnormal: Dens projects >2mm above or below line
Danger: Basilar invagination or craniocervical instability
Why is CCI particularly important in pediatric diagnosis?
American Association of Neurological Surgeons recommends CCI in pediatric patients to diagnose TAOD due to 100% sensitivity and specificity.
What are the three types of TAOD dislocations?
Type 1: Base of skull moves anteriorly (forward) relative to the dens
Type 2: Skull moves superiorly (upwards) relative to cervical spine
Type 3: Skull moves posteriorly (backwards) relative to cervical spine
Note: Multiple classifications may exist in a single patient
What is the sensitivity of lateral cervical spine in detecting TAOD?
Low sensitivity (10-76%) in detecting atlanto-occipital dislocation.
What is the easiest line to assess on lateral c-spine for TAOD?
The line drawn down the clivus of the sphenoid needs to point toward the top of the dens. This only gauges anterior shift of occipital condyles relative to C1.
What are the current recommendations for cervical spine imaging?
Spinal Cord Society: MDCT with reformatted images should be the initial examination
Cervical spine radiographs only used if CT is not available or unaffordable
AANS: If lateral cervical spine shows prevertebral soft tissue swelling, maintain high level of suspicion
What are the three main categories of traumatic head injury?
- Primary Intraaxial Injury
- Primary Extraaxial Injury
- Secondary CNS Injury
What are the types of primary intraaxial injuries?
These are direct brain injuries that happen right when trauma occurs - essentially damage inside the brain tissue itself.
Three Main Types:
1. Contusions (Brain Bruises)
Like bruises on your skin, but in the brain
Small bleeding spots (petechiae) on the brain’s surface
The deeper white matter usually stays intact
Can happen on the opposite side from where you hit your head (called “contrecoup”)
- Hematomas (Blood Clots)
Larger, well-defined collections of blood inside brain tissue
More organized than contusions
- Shearing Injuries
Happen when your head spins or stops suddenly (like in car accidents)
The brain tissue gets twisted and torn
Usually affects deeper brain areas like the frontal and temporal lobes, and sometimes the brainstem
Creates tiny bleeding spots called microbleeds
What are the types of primary extraaxial injuries?
These are bleeding injuries that occur in the spaces around the brain, not inside the brain tissue itself.
- Subdural hematoma (SDH)
- Extradural/epidural hematoma (EDH)
- Traumatic subarachnoid hemorrhage (SAH)
- Intraventricular hemorrhage
Summarise the primary extraaxial injuries
Four Main Types:
1. Subdural Hematoma (SDH)
Blood between the brain and its outer covering
Usually from torn veins
- Extradural/Epidural Hematoma (EDH)
Blood between the skull and the brain’s outer covering
Usually from torn arteries
- Traumatic Subarachnoid Hemorrhage (SAH)
Blood in the fluid spaces around the brain
- Intraventricular Hemorrhage
Blood in the brain’s fluid-filled cavities
