Children are not small adults Children are Not Small Adults Anatomic considerations Pliable bony & cartilagenous structures - Significant thoracic inj

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1 PEDIATRIC CHEST TRAUMA Children are not small adults Role of imaging Spectrum of injury

2 Children are not small adults Children are Not Small Adults Anatomic considerations Pliable bony & cartilagenous structures - Significant thoracic injury w/out bony injury Greater vessel elasticity - Aortic & great vessel injury rare

3 Children are Not Small Adults Physiologic considerations Smaller blood vessels & enhanced vasoconstriction - Bleeding often stops spontaneously Smaller circulating blood volume - Greater physiologic derangement w/ injury Children are Not Small Adults Physiologic considerations Presence & severity of chest injury strongly impacts outcome Lower mean trauma score Increased mortality Sivit. Radiology 1989;171:815

4 Children are Not Small Adults Anatomic considerations Smaller size - Smaller FOV & decreased contrast volume IV contrast cc/kg; max 120 cc - inj vol/60 sec Increased sensitivity to radiation - Use low tube current & breast shielding Role of imaging

5 Radiography Thoracic Trauma Identify life- threatening injury Assess gas- exchange capability Localize tubes & catheters Radiography - Limitations Underestimates or misses > 1/3 injuries Lacks specificity for mediastinal injury Imprecise localization of thoracotomy tubes

6 Initial supine exam Repeat erect exam

7 CT Improved injury detection & quantification Greater specificity for mediastinal bleed Precise localization of thoracostomy tubes CT - Limitations Lacks specificity for tracheal & main bronchial injury Lacks specificity for esophageal injury

8 Spectrum of injury Chest wall injury May have significant intra-thoracic thoracic injury w/out bony injury Displaced rib fractures may result in injury Infant rib fractures specific for abuse Multiple fractures marker for severe injury

9 Rib fractures in Child Abuse Squeezing force during shaking Involve posterior & lateral arcs Frequently multiple and bilateral

10 Multiple rib fractures Multiple fractures result from great deal of kinetic energy associated with severe injury Associated with increased morbidity & mortality Garcia. J Trauma 1990;30:695

11 Parenchymal injury Spectrum of injury Direct compression Contrecoup compression Shearing forces Laceration by fractured ribs Contusion Alveolar & interstitial hemorrhage & edema Focal or multifocal opacities Posterior > anterior Subpleural sparing

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13 Laceration Torn alveoli or bronchioles Parenchymal air cavities May be surrounded by hemmorhage Favorable outcome w/ medical mgmt

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15 Initial exam F/U 3 days later 15

16 Initial exam +3d +10d Thoracic air leak 1 O alveolar or small airway rupture Uncommonly tracheal, bronchial or esophageal

17 Pneumomediastinum Erect PA film more sensitive than AP view Lateral displacement of mediastinal pleura Continous diaphragm sign Thymus sail sign +/- Associated pneumothorax Pneumomediastinum Lateral displacement mediastinal pleura

18 Pneumomediastinum Air outlining thymus Continuous diaphragm Air in pleural space Pneumothorax Id visceral pleural line Erect PA most sensitive Lateral decubitus, expiratory or cross- table lateral for small collections

19 Pneumothorax Increased thoracic lucency Pneumothorax Hemidiaphragm sharpness Deep costophrenic sulcus

20 Tension pneumothorax Uncommon Most often with mechanical ventilation Lifethreatening Large size Mediastinal shift Uncommon Pneumopericardium Direct communication from pneumothorax Air partially or completely surrounds heart Pericardium sharply outlined by air

21 Tracheal-bronchial Injury Cervical trachea Typically direct blow to anterior neck Laceration usually longitudinal & posterior at junction of cartilagenous & membranous trachea Thoracic trachea Injury usually within 2 cm of carina Often single transverse laceration

22 Tracheal-bronchial Injury Non-specific findings Large pneumothorax or pneumomediastinum Large amounts of subcutaneous air in neck Tracheal-bronchial injury Specific findings Abnl ETT position or configuration Tracheal wall defect Fallen lung sign

23 Esophageal injury Uncommon o injury Most occur in cervical or upper thoracic Imaging findings non-specific including left pneumothorax, pneumomediastinum, subcutaneous air, left pleural effusion Esophageal Injury

24 Esophageal injury Esophagram primary means of detection Non-ionic contrast best choice L > R May be occult Diaphragm injury Elevated diaphragm Indistinct diaphragm Pleural fluid Herniated abdominal viscera CT collar sign

25 Thoracic trauma Children are not small adults Increased bony pliability Greater vessel elasticity Smaller circulating blood volume Smaller patient size

26 Thoracic trauma Imaging & injury 1 o assessment w/ radiography Enhanced quantification w/ CT Rib fractures injury severity marker Contusion/laceration injury spectrum PEDIATRIC CHEST TRAUMA