1. Pediatric Critical Care Medicine Children’s Healthcare of Atlanta
TRAUMA IN THE PICU
Pediatric Critical Care Medicine
Emory University
Children’s Healthcare of Atlanta

2. Epidemiology #1 cause of death in > 1yr old
Exceeds all other deaths combined
20,000/yr of children & teenagers
65% of all death <19 yrs old – unintentional injury
1 death from trauma  40 hospitalized  1,120 treated in ER
Most pediatric trauma are blunt injury (vs penetrating in adults)
More vulnerable to major abdominal injury from minor forces
More immature musculoskeletal system
Intra-abdominal organs are proportionally larger & closer together  predisposed to multiple organ injury

3. Epidemiology MVC – leading cause of death
½ are unrestrained
2/3 riding with drunk drivers
Pedestrian – leading cause of death in 5-9 yrs old
Bicycle injury increases with age – most common is head trauma

4. Physiologic Differences
Larger head  greater inertia, movement & transfer of energy to the head & brain
Less soft tissue & muscle greater energy transfer to internal organs
Difference in center of gravity
Infant – above umbilicus
1 yr – at the umbilicus
Adults – pubic symphysis
Jack knife effect with 2 points restraint  spinal and intestinal injury in forward collision

5. Resuscitation Causes of early death in injury
Airway compromise
Hypovolemic shock
CNS injury
ATLS : steps in trauma eval
Primary survey
Adjuncts to primary survey
Secondary survey
Adjunct to secondary survey (investigations)
Definitive managementss

6. Resuscitation – Primary Survey
A- Large head/occiput, large oropharyngeal soft tissue, short trachea  frequent Right stem intubation
<12 yr: needle cricothyroidotomy because cricoid cartilage is the major support structure of airway
Surgical tracheostomy <12 yr
B – Pneumothorax, tension pneumothorax, hemothorax
C – Normal physiologic status up to 30% loss of total blood vol; traumatic cardiac arrest or penetrating with witnessed arrest  poor outcome
D – Disability: CNS injury
E – Exposure: prevent further heat loss

7. Resuscitation – Secondary Survey
Similar steps as primary survey

8. Resuscitation – Investigations
Plain X-rays
Lateral C-spine: screen but not adequate in diagnosis
Supine chest: pulmonary of mediastinal injuries, not good in diagnosing small pneumothoraces
Pelvic: major pelvic disruption
Ultra sound
FAST: focused abdominal sonography for trauma, not very reliable in children as in adults
CT:
Chest abd. pelvis as indicated by injury

9. Trauma In PICU Child abuse & neglect Head injury Spinal cord injury
Thoracic injury
Abdominal injury

10. Child Abuse & Neglect
Abuse head trauma: most common in PICU causing more long term morbidity
Neck is weaker with larger head  larger CSF volume (move around), larger water contents  increase in deformability
More rotational : tear bridging veins (SDH) & axons (DAI)
Neurons and axons – less protected due to less myelination
Skeletal injury: posterior rib fractures, metaphyseal fracture, spinous process fractures

11. Child Abuse & Neglect
Abdominal trauma: 2nd leading cause of fatal injury, 40%-50% death rates
Compression: crush solid viscera against anterior spine  burst injuries to solid viscera & perforation of hollow viscera
Deceleration forces  shear injuries at the site of fixed, ligamentous attachment with tear & hematoma formation
Thermal burns
Uniformed thickness – closely replicate the objects
Abuse scald burns – immersion pattern with circumferential & uniform depth, well defined edges, spares body creases

12. Severe Traumatic Brain Injury
Statistic230/100,000
deaths/yr; 10-15% are severe with GCS<8 deaths or permanent brain damage
0-4 yr: worse outcome probably secondary to non-accidental trauma
5-15 yr: favorable outcome compared to adults
Goals: to prevent secondary injury
Optimize substrate delivery & cerebral metabolism
Prevent herniation
Target specific mechanisms involved in the evolution of secondary injuries

13. TBI - Pathophysiology Primary – direct disruption of brain parenchyma
Secondary – cascade of biochemicals, cellular amd molecular events
Ischemia/excitotoxicity, energy failure  cell deaths
Secondary cerebral swelling
Axonal injury

14. TBI – Secondary Injury Post-traumatic ischemia
Extra cerebral insults – hypotension/hypoxemia
Early hypoperfusion are common” CBF <20ml/kg/min associated with poor outcome
CBF recovered usually after 24 hrs
Delayed in normalization of CBF does not associated with poor outcome

15. TBI – Secondary Injury Excitotoxicity
Glutamate & excitatory amino acid  neuronal damage
1st phase: Na dependent neuronal swelling
2nd: Ca dependent degeneration  DNA damage  DNA repair  Deplete ATP  metabolic failure & necrotic cell deaths
CSF glutamate increases 5 folds in TBI in adults; increase of glutamate correlates with poor outcome
Tx with anti-exitatory MK-801 (NMDA antagonist); other txs- magnesium, glycine site antagonists, hypothermia, pentobarb
NMDA antagonists may induce apoptotic neurodegeneration in children

16. TBI – Secondary Injury
Cerebral swelling: initial min to hrs of post-traumatic hypoperfusion & hypermetabolism  metabolic depression (CMRO2 decreases by 1/3 of normal)
Edema
Vasogenic & BBB disruption
Cellular swelling: astrocytes swelling – uptake of glutamate

17. TBI – ICP Monitoring Parenchymal fiberoptic & microtransducer system
Subarachnoid, subdural, epidural- less reliable
Ventricular- best monitoring with benefit of draining CSF
Keep ICP <20
Keep CPP 40-60
40-50: infants
50-60: Children:
>60: adolescents
lidocaine: decrease catechol surge with direct laryngoscopy

18. TBI – Advanced Monitors
Stable Xenon CT CBF – monitor regional CBF
Stable Xenon technique
Transcranial doppler: measured velocity rather than flow, mainly MCA distribution
Jugular venous saturation: keep >50%, lower assoc. with mortality
NIRS- near infrared spectroscopy: trace the oxidative state of cytochrome, more on trends
PO2 microelectrode implantation to frontal parenchyma: also provide sign metabolic information: glutamate, lactic acid, glucose, ATP
PET: positron emission tomography

19. TBI – ICH Management CSF drain Osmolar therapy Mannitol:
Rapid dec. ICP by dec. viscocity  dec. bl vessel diameter. Depend on intact viscosity autoregulation. Transient (75 min)
Osmotic: (onset 15-30min; duration 1-6 hrs): water moves from parenchyma to circulation; work in intact BBB. May accummulate & worsen cerebral edema
Excreted unchanged in urine: may precipitate ATN & renal failure in dehydrated states. OK to use up to osmo of 365

20. TBI – ICH Management Osmolar therapy
Hypertonic saline: same benefits as mannitol
Other benefits: restoration of cell resting membrane potential, stimulation of atrial natriuretic epptide release; inhibition of inflamation; enhance cardiac performance
Side effects: extrapontine myelinosis: demyelination of thalamus, basal ganglia & cerebellum; SAH (tearing of bridging veins due to rapid shrinkage); renal failure; rebound ICU
Sedation, analgesia, NMB
Anticonvulsion: seizures cause inc. cerebral metabolic demands and release of excitatory amino acids
Head position
30 degree: dec. ICP & mean carotid pressure with no change in CPP & CBF

21. TBI – ICH Management – 2nd tier
Barbiturates: dec. ICP via dec. CMR & CBV; direct neuroprotective effects by inhibiting free radical-mediated lipid peroxidation of membraned
Hypervent:dec. post-injury hyperemia & brain acidosis, restore CBF autoregulation
Prolonged hypervent: dec. brain interstitial bicarb buffering capacity, gradual dec. local vasoconstrictor effects
Hypothermia: 33 C
Hyperthermia exacerbates neuronal deaths
Decompression craniectomy
Lumbar CSF drainage
Controlled arterial hypertension

22. Acute Spinal Cord Injury
High cervical injury
C1-3 : infants/toddlers – MVC, trauma
C4-7 : Adolescents/adults – sport, MVC
Initial injury inc. in inflammatory cells & fibroblasts in cord tissue  cellular necrosis
Release of lysosomal enzyme  traumatic paralysis
“Spinal Shock”: high T or C injuries  absence of sympathetic tone  hypotension, bradycardia & hypothermia

23. Acute Spinal Cord Injury
Treatment
ABC
Methylprednisolone 30mg/kg bolus then 5.4 mg/kg/hr for 23 hrs; need to start bolus within 8 hrs of injury
Careful fluid management with pressors to improve vasodilatation
Osomotic diuretic to dec. secondary edema; low molecular weight of dextran to improve microcirculation
Hyperbaric oxygen therapy
Spinal cord cooling: need to be done within 4 hrs to 10 C
How long
How to deliver
What fluid
Technical difficulty

24. Acute Spinal Cord Injury
Sequelae
Respiratory failure: C3-5 innervation of diaphragm; CN IX innvervation to accessory muscle
UTI: neurogenic bladder, avoid overdistention and large volume residual, inc. risk of infection
Urolithiasis: immobility and hypercalcemia
Acute hypercalcemia due to immobility causing vomiting, polydipsia, polyuria, anorexia, nausea, malaise, listlessness

25. Thoracic Injury 2:1 male to female 92%: blunt trauma
48% pulmonary contussion
39% Pneumo/hemothoraces
30% rib fractures
33% in pediatric trauma fatality
Airway obstruction
Tension pneumothoraces
Massive hemothoraces
Cardiac tamponade

26. Thoracic Injury Rib fractures Pulmonary contussion
> 3 rib fx: reliable indication of intrathoracic or other organ involvements
Scapular or post rib fx – not associated with great vessels injury
Thoracic spine fx – inc. suspicion of great vessel injury
Pulmonary contussion
Absence of external signs: chest wall abrasion, tachypnea, abn. BS
Tx: fluid management, pulm. Toilet & respiratory support; corticosteroid is harmful

27. Thoracic Injury Pneumo/hemothorax
Large bore in hemothorax to avoid fibrothorax & lung entrapment
CT: can cause exanguinating hemorrhage (intercostal, hilar or mediastinal vessel injuries)
Severe tracheobronchial disruption: high energy impact injuries, sub Q emphysema, dyspnea, sternal tenderness, hemoptysis. X-Ray: sub Q emphysema, pneumo-mediastinum, pneumothorax, air surrounding bronchus, abn. Appearance of ETT, collapsed of lung toward chest wall
Cardiac injury: 3%, most died at the scene
Myocardial contusion: act as MI or SVT & VT; min clinical significance, symptoms usually 12 hours post injury
Valvular dysfunction: papillary or chordae ruptures;
Cardiac rupture, pericarcial effusion, cardiac arrhythmias

28. Thoracic Injury Aortic & great vessels injuries Others
Traumatic aortic disruption: mid scapular back pain, UE hypertension, dec. femoral pulses bilaterally, inc. CT output
X-Ray: widened mediastinum, deviation of NG or CVL, blurring of aortic knob, abn. paraspinous stripe, right tracheal deviation, upward shift of Left stem main bronchus
Others
Diaphragmatic ruptures: L>R
Esophageal rupture
Lung cysts

29. Abdominal Trauma 83% blunt trauma
Solid organ injury: liver, spleen, kidneys
1- Spleen: extends below costal margin
grade I-IV, mainly observation
Surgical indication
Persistent hypotension or evidence of continuous hemorrhage
>50% blood volume replacement
Other life threatening associated intra-abdominal injury
I & II healed after 4 months
III-IV: healed after 6-11 months

30. Abdominal Trauma
2- Liver: also extends below the costal margin; associated with highest mortality
May require surgical correction of injuries to the hepatic vein or vena cava  associated with high mortality
3- Duodenum:
Mostly hematoma, some with disruption of lumen
Observation with TPN, bowel rest, resolution 2-4 weeks
4- Pancreas:
- Operative repair depending on anatomy of injury & integrity of the main pancreatic duct
- Upper abdominal pain, inc. amylase, edema of gland, fluid in the lesser sac
- Fracture of pancreas when crossing over vertebral colume

31. Abdominal Trauma 6-Small bowel:
Disruption, mesenteric avulsion, wall contussion
More at fixation points: proximal jejunum at ligament of Treitz, terminal Ileum
7- Renal trauma:
- Flank tenderness, mass or ecchymosis
- Hematuria
- Hematoma, laceration or vasular injury
- Isolated urinary extravasation: not an emergent surg. Expl.
- Need Abx
- Renal pedicle injuries are rare
- Ureteral injury – surgical repair

32. Abdominal Trauma 7- Blunt abdominal aortic injury:
- Occur in high energy injury
- Most common at inferior mesenteric artery or at the level of the kidneys
- Major abdominal venous injuries are usually fatal

33. Abdominal Trauma 8- Bladder injury: mostly intra-abdominal
- Burst injury
- Rupture with pelvic fracture
- Cystography: extra-peritoneal bladder rupture  fluid extending superiorly and anteriorly to the level of umbilicus & by fluid in the retrorectal presacral space
- Tx: depends on the location of injury:
- extraperitoneal managed with catheter drainage alone; - penetrating or bladder neck injury or with vaginal/rectal injury required surgical repair

34. Abdominal Trauma 8- Bladder injury: mostly intra-abdominal
- Burst injury
- Rupture with pelvic fracture
- Cystography: extra-peritoneal bladder rupture  fluid extending superiorly and anteriorly to the level of umbilicus & by fluid in the retrorectal presacral space
- Tx: depends on the location of injury:
- extraperitoneal managed with catheter drainage alone; - penetrating or bladder neck injury or with vaginal/rectal injury required surgical repair

35. Abdominal Trauma 11- Pelvic fracture:
- Single fracture of pubic ramus: rarely clinical significance
- Multiple fractures: associated with significant intra-abdominal injuries
- Sites of silent hemorrhage