Trauma Flashcards
(237 cards)
1
Q
What are the 3 divisions of the trigeminal nerve (CN V) and what areas do they supply?
A
V1 (ophthalmic): upper third of face including eye and nose; V2 (maxillary): midface including infraorbital nerve; V3 (mandibular): lower third of face
2
Q
Which nerve innervates the muscles of facial expression?
A
Facial nerve (CN VII) - lies just inferior to the external auditory canal
3
Q
What bones form the borders of the orbit?
A
Superior: Frontal bone; Lateral wall/floor: Zygoma; Medial floor/anteromedial wall: Maxilla; Medial wall: Lacrimal and ethmoid bones (most delicate)
4
Q
What is required for a true LeFort fracture?
A
Must involve the pterygoid plate and conform to a specific pattern
5
Q
Describe LeFort I fracture pattern
A
Transverse fracture through maxilla above tooth roots (can be unilateral or bilateral)
6
Q
Describe LeFort II fracture pattern
A
Bilateral pyramidal-shaped fracture extending to nasal bridge, maxilla, lacrimal bones, orbital floor and rim
7
Q
Describe LeFort III fracture pattern
A
Craniofacial disjunction - involves nasal bridge, extends through medial orbital walls (ethmoids), orbital floor (maxilla), and lateral orbital wall breaking zygomatic arch
8
Q
How do you clinically detect LeFort fractures?
A
Grasp upper incisors and pull medially: LeFort I = alveolar ridge movement; LeFort II = midface movement; LeFort III = entire face movement
9
Q
What is the tongue blade test and its sensitivity/specificity?
A
Insert tongue blade between molars, patient bites down while clinician twists. If blade snaps = unlikely mandibular fracture. Sensitivity 96-97%, Specificity 64-68%
10
Q
What are the 3 Ellis classification types for dental fractures?
A
Class I: enamel only (not painful, outpatient dentist); Class II: dentin exposed (painful, cover with calcium hydroxide/aluminum foil); Class III: pulp exposed (very painful, urgent dentist within 48hrs)
11
Q
What is the approach to suspected aspirated teeth?
A
1) Thorough oropharynx search; 2) AP/Lateral CXR if not found; 3) Bronchus/esophagus = bronchoscopy/endoscopy; 4) Below diaphragm = no retrieval needed
12
Q
Name 3 techniques for anterior TMJ dislocation reduction
A
1) Syringe method (5-10cc syringe between molars); 2) Intraoral (thumbs on mandible ridge, downward pressure); 3) Extraoral (mandibular angle manipulation)
13
Q
What are 4 indications for Panorex X-rays?
A
1) First TMJ dislocation; 2) Isolated mandibular fractures; 3) Dental fractures; 4) Alveolar ridge fractures
14
Q
At what ages do sinuses become aerated? (Ethmoid, Sphenoid, Frontal, Maxillary)
A
Ethmoid/Mastoid: birth; Sphenoid/Remainder mastoid: 3 years; Frontal: 6 years; Maxillary: 10 years
15
Q
What is the association between facial injuries and brain/C-spine injuries?
A
Recent studies show INCREASED risk of brain injury with facial fractures (contrary to old teaching). C-spine risk may actually be REDUCED. Mechanism of injury is most important factor
16
Q
Which facial lacerations require prophylactic antibiotics?
A
1) Bite wounds; 2) Devascularized wounds; 3) Through buccal mucosa; 4) Involving ear/nose cartilage; 5) Extensive contamination
17
Q
What solutions can preserve avulsed teeth?
A
1) Saliva; 2) Pasteurized milk; 3) Normal saline; 4) Hank’s Balanced Salt Solution
18
Q
What are the 4 parts of the male urethra?
A
1) Pendulous; 2) Bulbous; 3) Membranous; 4) Prostatic (anterior = 1-2, posterior = 3-4, divided by urogenital diaphragm)
19
Q
What causes anterior urethral injuries (5 mechanisms)?
A
1) Straddle injuries; 2) Falls; 3) Gunshot wounds; 4) Self instrumentation; 5) Amputation
20
Q
What causes posterior urethral injuries?
A
Pelvic fractures involving ischiopubic rami (straddle fractures, Malgaigne fractures)
21
Q
What are 4 indications for retrograde urethrogram before Foley?
A
1) History of urethral trauma; 2) Scrotal/penile hematoma; 3) Blood at urinary meatus; 4) High-risk pelvic fracture
22
Q
Describe retrograde urethrogram technique
A
1) Pre-injection KUB; 2) 60mL syringe with contrast; 3) Inject 60mL over 30-60 seconds; 4) X-ray during last 10mL injection
23
Q
How do you interpret RUG results?
A
Normal: contrast enters bladder; Partial injury: extravasation + some bladder contrast; Complete injury: no bladder contrast (needs suprapubic catheter)
24
Q
What are the 3 types of bladder injuries?
A
1) Contusions; 2) Intraperitoneal ruptures; 3) Extraperitoneal ruptures
25
What causes intraperitoneal vs extraperitoneal bladder rupture?
Intraperitoneal: blunt trauma with distended bladder (stretches weak dome); Extraperitoneal: pelvic fractures (shear forces tear anterolateral wall)
26
What are indications for retrograde cystogram?
1) Any bladder injury suspicion; 2) Gross hematuria without pelvic fracture; 3) Microhematuria with pelvic fracture
27
What is the management of different bladder injuries?
Contusions: Foley catheter; Extraperitoneal: uncomplicated = observation with Foley, complicated = operative repair; Intraperitoneal: ALL need operative repair
28
What are 3 clinical findings of penile fracture?
1) Slowly progressive penile hematoma; 2) 'Snapping sound' with immediate pain and detumescence; 3) 'Eggplant deformity' (swelling/ecchymosis of shaft)
29
What is the management of penile fracture?
URGENT 24-36 hour surgical repair of tunica albuginea
30
What percentage of penile fractures have associated urethral injury?
10-38% (signs: gross hematuria, blood at meatus, inability to void)
31
What are 6 general indicators of genitourinary trauma?
1) Flank/abdominal/pelvic pain; 2) Urinary retention; 3) Penile/scrotal ecchymosis; 4) Gross hematuria; 5) Blood at urethral meatus; 6) Delayed: HTN, incontinence, sexual dysfunction
32
What are indications for renal imaging in adult trauma?
1) Gross hematuria; 2) Microscopic hematuria WITH shock (SBP <90); 3) History of sudden deceleration (even without hematuria/shock)
33
What are pediatric indications for renal imaging (<16 years)?
1) Gross hematuria; 2) Microhematuria >50 RBCs/hpf; 3) 'Significant' deceleration injuries
34
What are the physiologic trauma team activation criteria?
1) SBP <90; 2) RR <10 or >30; 3) GCS ≤12 or focal neurologic deficit
35
What are anatomic trauma team activation criteria?
1) Amputation proximal to elbow/knee; 2) ≥2 long bone fractures; 3) Flail chest; 4) Tension pneumo/hemothorax; 5) Suspected spinal injury with deficit; 6) Penetrating injury to head/proximally; 7) Unstable pelvis
36
What are mechanistic trauma team activation criteria?
1) Ejection from vehicle; 2) Pedestrian impact >30 km/hr; 3) High-speed MVC/rollover; 4) Fall >20 ft; 5) Severe deceleration; 6) Bike/motorcycle crash >30 km/hr; 7) Burns >10% BSA; 8) Inhalation burns
37
What are commonly missed traumatic injuries?
1) Bleeding scalp wounds; 2) Extremity fractures; 3) Urethral injuries; 4) Posterior injuries (didn't log roll); 5) Penetrating wounds in axillae/buttocks/groin
38
What are indications for ED thoracotomy in blunt trauma?
Signs of life on ED arrival + <10 minutes paramedic CPR
39
What are indications for ED thoracotomy in penetrating trauma?
1) Signs of life in ED then arrest; 2) <10 minutes CPR; 3) Evidence of tamponade with no signs of life
40
What is permissive hypotension and when NOT to use it?
Allow lower BP to avoid clot disruption while maintaining perfusion. DO NOT use in: 1) Head injury; 2) Blunt trauma (controversial)
41
What are the 3 goals of out-of-hospital trauma care?
1) Control deadly bleeding (tourniquets, direct pressure, pelvic binding); 2) Protect airway (needle, cric, intubate); 3) Spinal support
42
What is the threshold for fetal viability?
>24 weeks or >500 grams (estimated by uterine fundus ABOVE umbilicus)
43
What are key cardiovascular changes in pregnancy?
Increased HR, increased cardiac output, 40% increase in blood volume, lower MAP in 1st/2nd trimester
44
What are key respiratory changes in pregnancy?
40% increase in minute ventilation, decreased vital capacity, elevated diaphragm (thoracostomies 1-2 spaces higher)
45
What are key anatomic changes in pregnancy?
Elevated diaphragm, diastasis recti, abdominal contents elevated, bladder displacement, baseline pubic diastasis
46
What is gravid uterus syndrome and management?
Supine hypotensive syndrome - uterus compresses IVC after 20 weeks, decreases CO by 30%. Management: tilt LEFT 15-30 degrees, elevate feet
47
How is fetal distress detected?
1) Abnormal baseline HR (normal 120-160); 2) Decreased variability; 3) Late decelerations (indicate fetal hypoxia)
48
What is placental abruption and its most sensitive sign?
Separation of inelastic placenta from elastic uterus. Most sensitive sign: FETAL DISTRESS. Also: painful vaginal bleeding, cramping, uterine tenderness, frequent contractions
49
What are 2 potential uterine injuries in pregnancy trauma?
1) Premature labor/contractions; 2) Uterine rupture (very rare, severe MVCs with pelvic fractures)
50
What is safe radiation dose in pregnancy?
<5-10 Rads. CT head <50 milirads, CT abdomen ~3 rads, but PELVIC CT can be 3-9 rads
51
What is the approach to pregnant trauma patient (ABCT + UFO)?
A: secure airway (RSI); B: give O2 early; C: avoid vasopressors; T: TILT mother (not D); U: assess Uterus if >24 weeks; F: Fetal tones
52
What additional labs needed in pregnant trauma?
Regular trauma panel + blood type/Rh + βHCG + ABG + DIC tests (PTT, INR, fibrinogen) + Kleihauer-Betke test
53
When do you give RhIG in pregnancy trauma?
ALL Rh-negative mothers with abdominal trauma get RhIG within 72 hours: 300 mcg dose (1st trimester: 50 mcg)
54
What are early, variable, and late decelerations?
Early: mirror contractions (benign); Variable: cord compression (concerning); Late: fetal hypoxia (ominous)
55
What are indications for perimortem C-section?
Fetal heart tones present + >24 weeks gestation + maternal arrest. Must start within 4 minutes of arrest
56
Describe perimortem C-section procedure
Ensure CPR ongoing, chlorhex splash, midline vertical incision epigastrium to symphysis, vertical uterine incision, deliver fetus, clamp/cut cord
57
What are 5 anatomic/physiologic differences in pediatric trauma?
1) Widely distributed forces = multiple injuries; 2) Large surface area = heat loss; 3) Higher metabolic requirements; 4) Higher O2 consumption/glucose use; 5) Great capacity to maintain BP despite 25-30% blood loss
58
What are key pediatric airway differences?
Larger tongue (#1 obstruction), larger adenoids, floppy epiglottis, cephalad/anterior larynx, cricoid ring narrowest part, shorter tracheal length
59
What are pediatric fluid therapy doses for hemorrhagic shock?
10-20 mL/kg crystalloid bolus (repeat up to 3 times), then: PRBCs 10 mL/kg, FFP 25 mL/kg, Platelets 10 mL/kg
60
What are 3 ideal IO sites in pediatrics?
1) Proximal medial tibia; 2) Proximal humerus; 3) Anterior distal femur
61
What are 6 indications for laparotomy in pediatrics?
1) Hemodynamic instability despite resuscitation; 2) Free fluid on FAST + instability; 3) Massive intraperitoneal bleeding; 4) Pneumoperitoneum/bladder rupture/grade V renal; 5) Gunshot wound; 6) Evisceration/peritonitis
62
What are signs of increased ICP in infants?
Full fontanel, split sutures, altered consciousness, paradoxical irritability, persistent emesis, setting sun sign
63
What are signs of increased ICP in children?
Headache, stiff neck, photophobia, altered mental status, persistent emesis, cranial nerve involvement, papilledema, hypertension/bradycardia/hypoventilation, posturing
64
What is an impact seizure?
Seizure with immediate return to normal mental status after postictal period, usually NOT associated with parenchymal injury. Seizures >20 minutes from injury suggest TBI
65
What are the 5 layers of the scalp (SCALP)?
S: Skin; C: Connective tissue; A: Aponeurosis; L: Loose connective tissue; P: Periosteum
66
What is the difference between caput succedaneum and cephalohematoma?
Caput: hematoma freely mobile, crosses suture lines; Cephalohematoma: blood UNDER periosteum, does NOT cross suture lines
67
What is a diastatic skull fracture?
Fracture that crosses through/along suture lines with >2mm separation. Risk for leptomeningeal cysts (growing fractures)
68
Describe typical epidural vs subdural hematoma presentation
Epidural: 'lucid interval' then rapid deterioration, due to VENOUS bleeds in kids (delayed symptoms); Subdural: associated with bridging vein rupture, most common <2 years, may be chronic, vague symptoms
69
What is the management of elevated ICP in pediatrics?
Mannitol 0.5 g/kg IV, maintain CPP ≥50, elevate HOB >30°, head midline, avoid hyperthermia, maintain euvolemia
70
What are 10 pediatric vs adult cervical spine differences?
1) Higher fulcrum C2-3; 2) Larger head size; 3) Smaller neck muscles; 4) Increased ligament flexibility; 5) Flatter facet joints; 6) Incomplete ossification; 7) Wedge-shaped vertebral bodies; 8) Epiphyses mimic fractures; 9) Narrow predentoid space; 10) Pseudosubluxation C2-3 in 40%
71
How do you distinguish true vs pseudosubluxation at C2-C3?
Swischuk line: spinolaminar line C1-3. If crosses C2 anterior cortical margin by <2mm (no soft tissue swelling, no fracture) = pseudosubluxation
72
What are 2 ways to choose pediatric chest tube size?
2 × ETT size OR 4 × ETT size
73
What are pediatric-specific injury patterns?
Lap-belt: small bowel injury/hematoma, pancreatitis, Chance fractures; Handlebar: duodenal hematoma, pancreatic transection; Sports: spleen, kidney, intestinal tract
74
What is SCIWORA?
Spinal Cord Injury Without Radiographic Abnormality - found in 25-50% of pediatric spinal injuries due to elastic vertebral column and tenuous blood supply
75
What are the cord syndrome patterns?
Central: extension injury, arm
76
What is commotio cordis?
Sudden impact to anterior chest stopping cardiac function or causing dysrhythmia. May need long-term antiarrhythmics, pacemakers, cardiac support
77
What are pediatric formulas for airway management?
Cuffed ETT: age/4 + 3.5; Uncuffed ETT: age/4 + 4; Tube depth: age/2 + 12; Tube position: ETT size × 3 = cm at teeth
78
What is the most sensitive indicator of significant trauma in children?
Serial examinations - initial hemoglobin unreliable, physical exam difficult, need continuous monitoring
79
When do you perform pelvic X-ray in pediatric trauma?
Unless: age >3 AND no injury complaint AND no impaired LOC AND no distracting injury AND no pelvic pain AND no fracture signs AND no pain with hip movement
80
What are signs of compensated shock in children?
Tachycardia and slow capillary refill - warnings that child is about to crash (can maintain BP despite 25-30% blood loss)
81
What is the 'tongue blade test' for pediatric airway?
Due to larger tongue being #1 cause of obstruction, need better head positioning +/- OPA/NPA
82
Why place thoracostomies 1-2 spaces higher in pregnancy?
Elevated diaphragm leads to more rapid tension pneumothorax development
83
What is the most common cause of unrecognized fatal injury in children?
Abdominal injury - most often associated with MVCs
84
What makes pediatric ribs different and what does this mean?
More compliant/cartilaginous - can compress internal organs without showing fractures. Rib fractures usually indicate massive trauma or abuse
85
What is the significance of 'handlebar injuries' in pediatrics?
Typically cause duodenal hematoma and pancreatic transection/trauma from bike accidents
86
What are the classic 'lap-belt injury' triad?
1) Small bowel injury/hematoma; 2) Pancreatitis; 3) Chance fractures (need to consider with MVCs and seatbelt use)
87
How do you manage traumatic diaphragmatic hernia?
Insert NG tube to decompress stomach, avoid BVM, intubation and surgery required
88
What is the most common site of urethral injuries?
Membranous urethra (posterior) with pelvic fractures and Bulbous urethra (anterior) from straddle injuries
89
What is the best test for maternal and fetal assessment in pregnancy trauma?
Ultrasound - >85% sensitive, >98% specific; 80% sensitive and 100% specific for detecting MAJOR abdominal injury in pregnant patients
90
When should you defer RUG in trauma?
When pelvic CT and angiography anticipated - contrast will obscure imaging and interfere with angiographic hemorrhage control
91
What is the classic teaching about digital rectal exam and urethral injury?
'High-riding prostate is insensitive for urethral injury' - DRE still useful in tertiary survey for tone, bones, blood
92
What are the contraindications to ED thoracotomy?
Blunt trauma: no signs of life on scene AND in ED, CPR >10 minutes; Penetrating: >10 minutes CPR with no signs of life on arrival
93
What is the most important principle in pregnant trauma management?
Mother is ALWAYS first priority - 'do what is best for the mother first'
94
What are the three phases of fetal development regarding radiation sensitivity?
Most sensitive in first trimester; fetal damage rare with <5-10 Rads (equivalent to ~2 CT abdomens)
95
What percentage of trauma deaths are due to kidney trauma?
<0.1% - people rarely die from renal injuries unless kidney is 'pulverized'
96
What is the significance of microhematuria in trauma?
NOT a reliable indicator of significant pathology - make sure it's not rhabdomyolysis causing myoglobinuria
97
What are the delayed signs of genitourinary trauma?
Renovascular hypertension, incontinence, sexual dysfunction
98
What is the management approach for female external genitalia trauma?
Proximal urethral injuries need immediate surgical exploration; distal injuries can be treated with Foley; assess for associated vaginal, urethral, bladder, rectal injury
99
What is the classic mechanism for ureteric injury?
80% are iatrogenic from abdominal/pelvic surgery; trauma cases are rare - GSWs most common traumatic mechanism
100
What are the signs of ureteric injury?
NO reliable acute symptoms/signs; gross/microscopic hematuria absent in 25%. Delayed: fever, nausea/vomiting, hematuria, flank pain, palpable mass (urinoma)
101
What is the treatment approach for ureteric injury?
Operative repair required to prevent persistent urinomas, sepsis, renal failure
102
What is the grading system for renal injuries?
Grade 1: contusion, subcapsular hematoma; Grade 2: <1cm laceration; Grade 3: >1cm laceration; Grade 4: collecting system involved; Grade 5: shattered kidney or vascular avulsion
103
When do you need surgery for renal injuries?
Grade 1: 0% need surgery; Grade 5: 85-93% need surgery. Main renal artery injury >2-6 hours may need nephrectomy
104
What is the most reliable clinical exam finding for mandibular fracture?
Inability to bite down and break a tongue blade with 96-97% sensitivity
105
What is the most important imaging study for suspected facial fractures?
Directed facial CT scanning - best imaging technique for obvious injuries
106
What makes pediatric cervical spine injuries different from adults?
C-spine features approach adult patterns around age 8-10; higher fulcrum at C2-3 leads to higher cervical injuries
107
What is the significance of pseudosubluxation in children?
Seen in 40% of children 8-12 years at C2-3; normal variant due to ligamentous laxity
108
What are the key differences in pediatric shock presentation?
Cool distal extremities, decreased peripheral vs central pulse quality, delayed capillary refill, altered sensorium - can maintain BP until sudden decompensation
109
What is the most important factor in managing pediatric trauma patients?
Serial examinations are essential - single assessments unreliable due to difficulty obtaining history and examining children
110
What makes facial trauma psychologically significant?
Face is central to ability to breathe, eat, communicate - injuries can have serious psychological and psychosocial consequences including unemployment, PTSD, anxiety
111
What has changed about facial trauma epidemiology?
Increasing proportion from interpersonal violence - careful history required, consider abuse in every patient
112
What is the key teaching about shock from facial trauma?
Shock from facial trauma is RARE and results only from obvious external bleeding - don't let facial injuries distract from other causes of shock
113
What is the most important airway consideration in facial trauma?
Assertive airway management indicated - surgical management (cricothyroidotomy) may be required, especially with gunshot wounds
114
What imaging delay is acceptable in facial trauma?
Definitive treatment may be delayed if necessary to allow other serious injuries to be addressed first
115
What are the three components of the Denis 3-column spinal model?
Anterior: vertebral bodies and intervertebral disks with annulus fibrosis and anterior longitudinal ligament; Middle: posterior annulus, posterior vertebral wall, posterior longitudinal ligament, spinal cord; Posterior: spinous processes, nuchal ligament, interspinous and supraspinous ligaments
116
List 8 unstable C-spine injuries
Jefferson fracture, Odontoid fracture, Atlanto-occipital dislocation, Neural arch fracture, Wedge fracture, Bilateral facet dislocation, Spinal subluxation, Teardrop fracture
117
What is a flexion teardrop fracture and is it stable?
Flexion forces cause anterior displacement of small wedge fragment. Highly unstable - usually involves anterior and posterior ligament disruption
118
What is a Jefferson fracture?
Compression fracture of C1 where the atlas bursts open. Diagnosed when C1 lateral masses are >7mm from odontoid peg on open mouth view. Extremely unstable
119
What is a Hangman's fracture?
Traumatic spondylolysis of both pedicles of C2 from forced extension. Technically unstable but often without cord damage due to large neural canal diameter
120
What are the normal predental space measurements?
Maximum 3mm in adults, 5mm in children. Widening suggests atlantoaxial dislocation
121
What is the 6/2 rule for soft tissue spaces on C-spine X-ray?
6mm at C2, 22mm at C6. At C3-C4 it's 5mm. In children: 6mm at C2, 14mm at C6. Increases suggest prevertebral swelling and hemorrhage
122
What is the Line of Swischuk?
Line drawn from anterior aspect of posterior arch of C1 to C3. If distance >2mm suggests fracture in children (helps distinguish pathologic subluxation from normal pseudosubluxation)
123
What are the Canadian C-Spine Rule high-risk criteria?
GCS <15 at 2 hours, suspected open/depressed skull fracture, any sign of basal skull fracture, vomiting ≥2 episodes, age ≥65 years
124
What are the Canadian C-Spine Rule low-risk criteria?
Simple rear-end MVC, sitting position in ED, ambulatory at any time, delayed onset neck pain, absence of midline c-spine tenderness
125
What are the three types of incomplete spinal cord lesions?
Central cord syndrome (ligamentum flavum buckling), Anterior cord syndrome (hyperflexion/disk protrusion), Brown-Sequard syndrome (hemisection)
126
Describe central cord syndrome
Buckling of ligamentum flavum in degenerative arthritis with hyperextension. Affects central grey matter. Relative sparing of legs, 50% become ambulatory
127
Describe anterior cord syndrome
Hyperflexion or bone/disk protrusion into canal. Paresthesias and hyperalgesia with preservation of posterior column (position, touch, vibratory). Fast neurosurgical consult needed
128
Describe Brown-Sequard syndrome
Hemisection of spinal cord from penetrating trauma. Ipsilateral loss of position/vibration/motor, contralateral loss of pain/temperature. Most become ambulatory
129
What is Wallenberg syndrome?
Lateral medullary syndrome from PICA circulation loss. Swallowing difficulty, slurred speech, ataxia, facial pain, vertigo, nystagmus, Horner's syndrome
130
What are the features of Horner's syndrome?
Miosis, ptosis, anhydrosis from damage to ipsilateral sympathetic cervical chain
131
What are 6 causes of Horner's syndrome?
MS, encephalitis, tumors, lateral medullary syndrome, thyroid masses/removal, trauma to base of neck, Pancoast tumor, thoracic aneurysm, sympathectomy
132
What are features of cauda equina syndrome?
Bladder/bowel dysfunction, saddle paresthesias, diminished rectal tone, lower extremity weakness
133
What is spinal shock?
Clinical syndrome of temporary loss of neurologic function and autonomic tone below lesion. Lasts 24 hours to 2 weeks, heralded by return of bulbocavernosus reflex
134
What are features of sacral sparing?
Perianal sensation, rectal motor function, great toe flexor activity
135
What are the ASIA classification grades?
A: Complete (no motor/sensory); B: Incomplete (sensory preserved); C: Incomplete (motor preserved, muscle grade <3); D: Incomplete (motor preserved, muscle grade ≥3); E: Normal
136
What C-spine injuries require CT angiography?
C1-C3 fractures, any vertebral body fracture, transverse foramen fracture, facet subluxation/dislocation, ligamentous injury
137
Are steroids indicated for C-spine injuries?
Highly controversial. Cochrane review says yes, most other sources say no. Common dose: 30mg/kg IV methylprednisolone then 5.4mg/kg/hr infusion
138
What is neurogenic shock vs spinal shock?
Neurogenic hypotension: loss of vasomotor tone and lack of reflex tachycardia from autonomic disruption. Spinal shock: temporary loss of neurologic function below lesion
139
What is the risk of cervical injury in Down's syndrome and RA?
Atlantoaxial instability leading to subluxation/dislocation due to ligamentous laxity in both conditions
140
What are the 6 therapeutic interventions for post-arrest brain?
Avoid hypotension (MAP >65), avoid hypertension (diastolic <120), avoid hypoxia/hyperoxia, avoid hyper/hypocarbia, maintain euthermia, maintain euglycemia, consider therapeutic hypothermia, treat seizures aggressively
141
What are 5 techniques for initiating therapeutic hypothermia?
Cold saline infusion, misting and fans, ice packs in groin/axilla, cooling blankets, internal cooling (bladder irrigation, chest tubes, ECMO)
142
What are 4 mechanisms of therapeutic hypothermia benefit?
Decreases metabolic demand, decreases free radical formation, decreases inflammatory cytokine production, prevents programmed neuronal cell death
143
What is the relationship between PCO2 and cerebral blood flow?
Direct relationship - high PCO2 causes vasodilation and higher ICP. Goal PCO2 30-35mmHg for hyperventilation in herniation (only for acute signs of increased ICP)
144
What is the relationship between PO2 and cerebral blood flow?
Inverse relationship - low PO2 causes vasodilation. Goal PaO2 80-120 (18% higher mortality when PaO2 >300 for long periods)
145
What is cerebral perfusion pressure?
CPP = MAP - ICP. Goal is to maintain MAP and reduce ICP. CPP is the pressure gradient across the brain
146
What are indications for ICP monitoring?
Severe head injury (GCS <9), moderate head injury (GCS 9-12) who cannot be monitored with serial neurological exams
147
What is the Canadian CT Head Rule high-risk criteria?
GCS <15 at 2 hours, suspected open/depressed skull fracture, any sign of basal skull fracture, vomiting ≥2 episodes, age ≥65
148
What is the Canadian CT Head Rule medium-risk criteria?
Amnesia before impact ≥30 minutes, dangerous mechanism
149
What is the New Orleans CT Head Rule criteria?
Headache, vomiting, age >60, drug/alcohol intoxication, persistent anterograde amnesia, visible trauma above clavicles, seizure
150
Which CT head rule is more specific?
Canadian CT Head Rule (36.3% vs 10.2% specificity for traumatic intracranial lesions)
151
What is a concussion?
Complicated minor TBI leading to short-lived distortion of axons. Hypermetabolic state persists for weeks. Only functional PET shows damage
152
What is second impact syndrome?
When athlete sustains second concussion before complete recovery from previous concussion. Causes rapid, sometimes fatal decline due to cerebral edema
153
What are the return to play guidelines for concussion?
Stepwise approach, only advance if asymptomatic. Generally return to play one week AFTER totally asymptomatic during training and exercise
154
What are the GCS categories for TBI severity?
Severe: GCS <8, Moderate: GCS 9-13, Mild: GCS 14-15
155
What are indications for seizure prophylaxis in TBI?
Depressed skull fracture, paralyzed/intubated patient, any seizure, penetrating brain injury, any brain bleed (epidural, SDH, ICH)
156
What are indications for antibiotics in TBI?
Penetrating head injury, depressed skull fracture, complicated scalp lacerations. NOT for simple otorrhea/rhinorrhea
157
What are 7 clinical features of basal skull fracture?
Blood in ear canal, hemotympanum, rhinorrhea, otorrhea, Battle's sign, raccoon's eyes, cranial nerve deficits
158
What are 3 signs of cerebral edema on CT?
Sulcal effacement, loss of grey-white differentiation, compression of ventricles
159
What are 5 differences between SDH and EDH on CT?
SDH: crescentic, crosses suture lines, layers, bridging vein damage; EDH: lens-shaped, single bone space, middle meningeal artery damage
160
What is the Monroe-Kellie doctrine?
Sum of brain volume, CSF, and blood must remain constant. Increases in one leads to decreases in others. CSF moves out first
161
What is Cushing's reflex?
Hypertension, bradycardia, fluctuating respiratory effort - specific to increased ICP but only occurs 30% of the time
162
What is Kernohan's notch syndrome?
False localizing motor findings due to contralateral cerebral peduncle compression by tentorium. Left SDH causing left (not right) hemiparesis
163
What are the 5 herniation syndromes?
Uncal herniation, central transtentorial herniation, upward transtentorial herniation, cerebellar-tonsillar herniation, subfalcine herniation
164
Describe uncal herniation presentation
Anisocoria, ptosis, impaired EOMs, sluggish pupil ipsilaterally. Contralateral hemiparesis and positive Babinski. Progression to decerebrate posturing
165
What are 3 types of occlusive vascular injuries?
Transection (pulsatile bleeding, vessels retract), thrombosis (intraluminal clot from stasis or scarring), reversible arterial spasm (especially in children)
166
What are 4 types of non-occlusive vascular injuries?
Intimal flap/dissection, compartment syndrome, AV fistula, pseudoaneurysm
167
What are the hard signs of vascular injury (HARD)?
Expanding pulsatile Hematoma, Arterial pulsatile bleeding, bRuit/thRill, Diminished/absent Distal pulse
168
What are soft signs of vascular injury?
Diminished pulse compared to other side, isolated peripheral nerve injury, history of severe hemorrhage, unexplained hypotension, large non-pulsatile hematoma
169
What are warm vs cold ischemia times?
Warm ischemia (room temperature): 6 hours until complete damage, 10% irreversible at 10 hours, 90% irreversible at 12 hours. Cold ischemia: up to 24 hours tolerated
170
How do you calculate arterial pressure index (API)?
API = systolic pressure of injured extremity ÷ brachial systolic pressure in uninjured upper extremity
171
What is an abnormal API result?
API <0.9 indicates possible vascular injury requiring further evaluation (CTA). API >0.9 unlikely to have vascular injury
172
What are limitations of API?
Both limbs injured, too much soft tissue injury, intimal flap with partial flow, good collateral flow, arteries with no palpable pulses, shotgun wounds, will NOT find venous injuries
173
What vessel is most commonly injured in upper extremity?
Brachial artery
174
What vessel is most commonly injured in lower extremity?
Femoral artery
175
What are 5 late complications of vascular injury?
Delayed thrombosis, intermittent claudication, chronic pain, edema, aneurysm/pseudoaneurysm formation
176
What are 4 causes of pulse deficit other than vascular injury?
Congenitally absent vessel, vasospasm, shock/low BP, PVD, provider error
177
What are the 3 approaches for knee dislocation vascular evaluation?
1) Routine arteriography on every case 2) CTA on selected cases with unclear injury 3) Physical exam and API - if both normal, done
178
What are the upper extremity arterial branches?
Axillary → brachial → profunda/superior ulnar collateral/inferior ulnar collateral → radial/ulnar → common interosseous/anterior interosseous → digital arteries
179
What are the lower extremity arterial branches?
External iliac → femoral → profunda femoris → popliteal → posterior tibial/anterior tibial/peroneal → dorsalis pedis/arcuate
180
What are the secondary systemic insults in head injury?
Hypotension (SBP <90), hypoxia (PaO2 <60), anemia, hyperpyrexia (>38.5°C), hypercarbia, coagulopathy, seizures
181
What is the difference between primary and secondary brain injury?
Primary: mechanical damage at time of trauma (lacerations, hemorrhages). Secondary: intracellular derangements from depolarization and ionic shifts - target of all current therapies
182
What are the 3 methods to decrease ICP?
Hyperventilation, osmotic and diuretic agents, CSF drainage
183
What are the components of cerebral blood flow equation?
CBF = CPP/CVR (Cerebral Perfusion Pressure ÷ Cerebral Vascular Resistance)
184
What is the target temperature for therapeutic hypothermia?
2015 AHA guidelines: 32-36°C for 24 hours with prognostication at 72 hours post-arrest or post-cooling
185
What medications are used for shivering prevention during hypothermia?
Paralytic agents, sedation, fentanyl
186
What is the NNT for good neurological outcome with therapeutic hypothermia?
7 (reported in Rosen's)
187
What temperature management study changed practice?
Nielsen et al. TTM study (2013): No difference between 33°C vs 36°C, but both had active temperature monitoring/regulation
188
What are the inclusion criteria for Canadian CT Head Rule?
GCS 13-15 within 24 hours of blunt head trauma with witnessed LOC, amnesia, or disorientation. Age ≥16
189
What are the exclusion criteria for Canadian CT Head Rule?
Age <16, minimal trauma with no LOC/amnesia/disorientation, anticoagulation, penetrating trauma, seizure disorder
190
What is post-concussive syndrome?
Affects cognitive, psychomotor, behavioral performance. Headache, sensory sensitivity, memory/concentration problems, sleep/mood changes. 50% chance of 6-month symptoms if early dizziness/headache/nausea
191
When is re-injury risk highest after concussion?
First 10 days due to deficits in balance, reflexes, speed, information processing
192
What are the ABCs of lateral C-spine films?
Alignment (3 lines: anterior/posterior vertebral bodies, spinolaminal), Bony abnormalities, Cartilage space, Soft tissue spaces
193
What is pseudosubluxation in children?
Normal hypermobile spine appearance at C2/C3. Line of Swischuk helps differentiate: >2mm distance suggests actual fracture
194
What are the high-risk factors for proximity wounds?
Age >60, anticoagulated patients, VP shunts (all head injury rules exclude these populations - low threshold to scan)
195
What are the low-risk factors for mild TBI discharge?
Accurate history with trivial mechanism, asymptomatic/mild headache, no vomiting, no other injuries, normal pupils, intact orientation/memory, initial GCS 15, <24 hours since injury
196
What is the difference between vasogenic and cytotoxic edema?
Vasogenic: BBB endothelial junction failure → transvascular leakage. Cytotoxic: intracellular process from membrane pump failure due to ischemia/hypoxia
197
What are the Denver criteria for high-risk vertebral signs?
Cervical spine fracture, unexplained neurological deficit, basilar cranial fracture into carotid canal, Le Fort II/III fracture, cervical hematoma, Horner syndrome, cervical bruit, ischemic stroke, head injury with GCS <6, hanging with anoxic injury
198
What is the goal systolic BP in TBI management?
Keep systolic BP >90 mmHg to avoid 'popping the clot'
199
What is the goal PCO2 for hyperventilation in TBI?
30-35 mmHg. Causes vasoconstriction with onset in 30 seconds, peaks at 8 minutes. Should NOT be used routinely - only for acute signs of increased ICP
200
What is the dose of mannitol for TBI?
0.25-1 g/kg. Draws tissue water into vascular space to reduce brain volume. Peak effect in 60 minutes. Reserve for life-saving situations
201
Do steroids help in head injury?
NO - steroids show NO benefit and INCREASED mortality in head injury
202
What are the clinical features of moderate TBI?
GCS 9-13. Change in LOC, progressive headache, post-trauma seizures, vomiting, confusion, somnolence but can still obey commands
203
What percentage of mild TBI patients have abnormal CT?
5-15% may have abnormal CT scan, but <1% need neurosurgery
204
What is the 'talk and deteriorate' patient?
Patient with moderate TBI who deteriorates within 48 hours due to epidural/subdural hematoma - requires close observation
205
What are the features of Battle's sign?
Retroauricular hematoma - sign of basilar skull fracture
206
What are the features of raccoon eyes?
Periorbital ecchymosis - sign of basilar skull fracture
207
What cranial nerve deficits occur with basilar skull fracture?
Facial paralysis, decreased auditory acuity, dizziness, tinnitus, nystagmus
208
What is the mortality rate for severe TBI?
35% mortality rate
209
What percentage of severe TBI patients need neurosurgery?
25% need neurosurgical intervention
210
What factors affect TBI prognosis?
Age, comorbidities, initial motor activity, pupil response, secondary insults (NOT initial GCS or CT findings)
211
What are the complications of DIC in TBI?
Injured brain releases tissue thromboplastin → activates extrinsic clotting → DIC → increased risk of intracranial hemorrhage
212
What cardiac changes occur with TBI?
50% of ICH and 70% of SAH patients develop dysrhythmias. SVT, diffuse T wave changes, prolonged QT, ST changes, U waves from catecholamine surges
213
What is neurogenic pulmonary edema?
Develops minutes to days post-TBI from catecholamine surges, increased hydrostatic forces, and systemic inflammatory reaction
214
What causes meningitis after basilar skull fracture?
Pneumococcus if fever within 3 days. Gram-negative bacteria if fever >3 days. Treat with ceftriaxone and vancomycin
215
When should prophylactic antibiotics be given for basilar skull fracture?
Prophylactic antibiotics in acute setting of CSF leaks are NOT recommended, but they do decrease meningitis incidence (no clear consensus)
216
What is the pathophysiology of brain abscess after TBI?
Post-traumatic fistulae with tracts into sinuses, bone fragments left in cranium, or post-operative complication
217
What are the signs of brain abscess?
Headaches, vomiting, fevers, declining mental status, increased ICP, focal findings, nuchal rigidity, seizures
218
How is brain abscess diagnosed?
Contrast-enhanced CT head. LP is dangerous with signs of increased ICP
219
What bacteria cause brain abscess after TBI?
Gram-negative anaerobes and Staphylococcus aureus
220
What is the treatment for post-traumatic brain abscess?
Surgery unless isolated cerebritis. Antibiotics based on culture
221
What causes cranial osteomyelitis?
Pain, tenderness, erythema at fracture site. May need bone scans for diagnosis. Treat with antibiotics and surgery
222
Should patients with TBI receive VTE prophylaxis?
YES - patients should receive prophylactic LMWH to prevent VTE. They do NOT worsen ICH hematoma expansion
223
What is diffuse axonal injury (DAI)?
Shearing injury from acceleration-deceleration forces. CT insensitive (only detects 19% vs 92% with MRI T2). If visible on CT, degree of damage is much greater
224
What are the CT findings in DAI?
Small hemorrhagic lesions, often multiple. If couple of small lesions visible on CT, much greater damage present
225
What imaging is best for DAI?
MRI with T2-weighted imaging (92% sensitive vs 19% for CT)
226
What is the relationship between intracranial pressure and herniation?
Once 50-100ml of CSF space filled, ICP increases and CPP compromised → vasoparalysis → autoregulation failure → vasodilation → vasogenic edema → increased ICP → cessation of cerebral blood flow
227
What is the significance of a dilated non-reactive pupil?
Compressed oculomotor nerve from uncal herniation
228
What are the respiratory patterns in central herniation?
Sighs, yawns, shallow-irregular breaths, then respiratory arrest
229
What is the lucid interval in epidural hematoma?
Brief period of normal consciousness between initial impact and subsequent deterioration due to expanding hematoma
230
What artery is typically involved in epidural hematoma?
Middle meningeal artery
231
What veins are typically involved in subdural hematoma?
Bridging veins
232
What is the classic CT appearance of epidural hematoma?
Lens-shaped (biconvex) hyperdensity that does not cross suture lines
233
What is the classic CT appearance of subdural hematoma?
Crescentic hyperdensity that crosses suture lines
234
What is the treatment priority in severe TBI?
Prevent secondary brain injury through maintaining adequate oxygenation, perfusion, and preventing increased ICP
235
When should emergency trephination be considered?
When neurosurgeon unavailable and patient develops acute herniation syndrome not responding to hyperventilation and mannitol
236
What is the target oxygen saturation in TBI?
Avoid both hypoxia and hyperoxia. PaO2 goal 80-120 mmHg
237
What is the significance of fever in TBI?
Fever >38.5°C worsens injury by stimulating injured brain tissue metabolism - increases metabolic demand 10% per degree Celsius
