Chapter 5 – Pediatric Trauma




Abstract




Trauma evaluation and management often focuses on protocols, especially in adults. In children, however, special considerations are made based on epidemiology, physiology, and mechanisms of injury on the location affected.





Chapter 5 Pediatric Trauma


Manpreet Singh and Timothy Horeczko


Trauma evaluation and management often focuses on protocols, especially in adults. In children, however, special considerations are made based on epidemiology, physiology, and mechanisms of injury on the location affected.



Epidemiology


Trauma is the leading cause of death of children >1 year old, with unintentional injury accounting for the majority (Figure 5.1).1 Injuries predominantly include MVCs, followed by homicide/suicide and drowning.1 Most pediatric trauma is blunt; penetrating trauma in children accounts for 10–20% of trauma-related deaths. This number is likely to rise in the future.1





Figure 5.1 Ten leading causes of death by age group, United States in 2015


(data source: Nation Vital Statistics System, National Center for Health Statistics, CDC. Produced by: National Center for Injury Prevention and Control, CDC using WISQARSTM)


Anatomy and Physiology


Children demonstrate several anatomic and physiologic differences compared to adults, which must be considered in the evaluation and management of the pediatric trauma patient.



Anatomical Differences



Airway



  • Head: Children have a relatively large head in proportion to the body. When supine, the prominent occiput causes the neck to flex, which may lead to airway obstruction; always place a rolled towel or sheet under the scapulae to help align airway axes.2



  • Tongue: Usually large and may impede entrainment of air or laryngoscopy.2



  • Larynx: Located anterior and superior in position. The laryngoscopist can look from below up into the airway to aid visualization.2



  • Epiglottis: U-shaped, short, and stiff. As a result, a straight (Miller) blade helps to displace the anterior epiglottis for better visualization.2 A curved (Macintosh) blade may be used in school-aged children and up.2



  • Vocal Cords: Unlike adult vocal cords, which have a horizontal slant, pediatric vocal cords slant vertically.2



  • Trachea: Tends to be short, leading to an increased likelihood of right mainstem intubation.2



  • Airway diameter: Funnel-shaped with the narrowest portion at the cricoid ring. Cricoid pressure can cause collapse of the delicate trachea, causing obstruction and poor visualization.2



  • Lung Capacity: Small lung capacity, leading to a short time to desaturation.2



Developing musculoskeletal system



  • Flexible cartilaginous skeleton and open growth plates cause children to suffer more avulsion injuries, rather than fractures (less calcified, less rigid skeleton).2



  • With less calcification and added flexibility, children have greater incidence of abdominal, chest, and spinal cord injuries without fracture.2



Physiological differences



Age-Specific Vitals (Table 5.1)

Traumatic situations make vital sign interpretation difficult. Heart rate may be variably tachycardic in a frightened, screaming child in a traumatic situation, so a proper blood pressure cuff is essential to prevent an artificially low reading.3




  • Vasoconstriction is a compensatory mechanism to hypovolemia, specifically hemorrhagic shock in trauma. Children compensate for a loss of cardiac output by increasing their heart rate. Thus, tachycardia is the first sign of shock in children, while hypotension is an ominous, late finding.



  • Shock Index: Shock index is defined as HR/systolic BP. Though it has been around for some time, it is underutilized. It is most useful as a reference for physicians before the BP drops, especially in the occult shock patient.4,5




    • Shock Index, Pediatric Adjusted (SIPA)4,5




      1. 4–6 years = 1.2



      2. 6–12 years = 1



      3. >12 years = 0.9





Breathing

Pediatric patients are more prone to hypoxia for a variety of reasons.6




  • Extrathoracic Airway Differences:




    • Obligate nasal breathers



    • Smaller oral airway



    • Cephalic larynx



    • Epiglottis larger



    • Enlarged adenoid tissue



    • Congenital abnormalities




  • Intrathoracic Airway Differences:




    • Fewer, smaller alveoli



    • Poor collateral ventilation



    • Smaller intrathoracic airways collapse



    • Cartilaginous support lacking



    • Residual damage from birth leads to decreased pulmonary compliance



    • Chest wall musculature not fully developed



    • Lower functional residual capacity




  • Respiratory Drive Differences:




    • Immature respiratory center



    • Higher metabolic rates




Thermoregulation



  • Children readily lose heat through convection (high body surface area), conduction (wet diaper), and radiation (large, well perfused head).7



  • In addition, a high surface-area-to-mass ratio with thinner skin and less subcutaneous tissue to provide insulation predisposes children to hypothermia, which, in the setting of trauma, may lead to coagulopathy.7




Table 5.1 Age-specific vital signs























































Age Group HR (beats/min) R Leukocyte Count × 103/mm3 SBP
Newborn >180 <100 >50 >19.5 or <5 <65
Infant >180 <90 >34 >17.5 or <5 <100
Toddler >160 NA >29 >16.5 or <5 <100
Preschool >140 NA >22 >15.5 or <6 <94
School age child >130 NA >18 >13.5 or <4.5 <105


Regions



Head



Anatomy

The head is large relative to the body. The occiput is the biggest portion of the head. The open fontanelles (anterior and mastoid) should be evaluated, and clinicians should examine for subgaleal hematomas, which can be a major source of bleeding.




  • Caput succedaneum – Extra-periosteal collection. Crosses suture lines. Result of birth trauma usually.



  • Cephalohematoma – Between skull and periosteum. Does not cross suture lines.



  • Subgaleal hemorrhage/hematoma – Between skull periosteum and scalp galea aponeurosis. Crosses suture lines.



PECARN

The decision to obtain a CT head in a pediatric trauma should be completed with proper risk stratification using validated clinical predictors. The Pediatric Emergency Care Applied Research Network (PECARN) studies provide a set of guidelines to help guide physicians in cases of minor blunt head trauma (Figures 5.2 and 5.3). If a CT head non-contrast is not indicated, observation in the ED or at home is recommended with reassurance, education, and strict return precautions.





Figure 5.2 Blunt head trauma in children <2 years of age


(obtained from Cal ACEP, with permission)




Figure 5.3 Blunt head trauma in children ≥2 years of age


(obtained from Cal ACEP, with permission)


Airway Management

If the patient has any subtle changes in mental status, be proactive. Consider intubating early, as the respiratory center is underdeveloped, and hypoxia is associated with mortality in traumatic brain injury.



Neck


Because C2/C3 acts as a fulcrum in children less than 8 years old, they tend to have a higher pattern of cervical spine injury (CSI).8 For this reason, most pediatric trauma centers include the cervical spine to C3, in an attempt to avoid unnecessary radiation.8 By age 8, the fulcrum of impact is the C5/C6 level, similar to adults.8


C-Spine fractures are usually rare in pediatric patients due to the following differences9:




  • Ligamentous laxity in facet joints



  • Partially cartilaginous endplates (unfused growth plates)



  • Intervertebral discs with higher water content and elasticity



  • Horizontal facets and shallow facet joints



  • Underdeveloped paraspinous muscles


These factors predispose them to more dislocations and ligamentous injuries. Due to this, there may be stretching of cord and nerve roots leading to Spinal Cord Injury Without Radiological Abnormality (SCIWORA) in children >8 years old.9


Clearance of the c-spine is typically done via NEXUS or Canadian C-Spine Rule (CCR) if the patient is reliable, awake, and alert. Keep in mind that 9% of NEXUS patients were <18-year-old, where thirty had a c-spine injury (0.98%) of which none were <2 years old and only four were <9 years old; thus it was not powered for children <9 years old.10 The NEXUS criteria has 100% (87.8%–100%) sensitivity for pediatric patients, but only 19.9% (18.5%–21.3%) specificity.10 Thus, the low specificity may lead to unnecessary imaging. CCR on the other hand excluded patients <16 years old.10 High sensitivity of this rule may also result in false positives, as well as unnecessary imaging.10


A recent case-control study of pediatric patients <16 years old shows the following eight factors associated with cervical spine injury11:




  • AMS



  • Focal neurologic findings



  • Neck pain



  • Torticollis



  • Substantial torso injury



  • Conditions predisposing to CSI



  • Diving



  • High risk MVC


Having 1+ factors was 98% sensitive and 26% specific for CSI.

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Jan 10, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 5 – Pediatric Trauma
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