Evaluating pediatric patients presenting to the ED with head trauma can be a challenging task for emergency physicians (EPs). Specifically, identifying a nondisplaced skull fracture is not always possible through physical examination alone. 1 However, point-of-care (POC) ultrasound permits rapid identification of skull fractures, which in turn assists the EP to determine if advanced imaging studies such as computed tomography (CT) are necessary.
A previously healthy 10-month-old male infant presented to the ED with his mother for evaluation of rhinorrhea, cough, and fever, the onset of which began 24 hours prior to presentation. The patient’s mother reported that the infant continually tugged at his right ear throughout the previous evening and was increasingly irritable, but not inconsolable.
Initial vital signs at presentation were: blood pressure, 95/54 mm Hg; heart rate, 146 beats/min; respiratory rate, 36 beats/min, and temperature, 101.8 °F. Oxygen saturation was 96% on room air. The physical examination was notable for an alert well-appearing infant who had a tender nonecchymotic scalp hematoma superior to the right pinna, clear tympanic membranes, crusted mucous bilaterally at the nares, nonlabored respirations, and wheezing throughout the lung fields.A POC ultrasound scan performed over the hematoma demonstrated a right nondisplaced parietal skull fracture ( Figure 1 ).
To evaluate for skull fractures using POC ultrasound, the area of localized trauma must first be identified. 2,3 Evidence of trauma includes an area of focal tenderness, abrasion, soft-tissue swelling, and hematoma. 2,3 The presence of any depressed and open cranial injuries are contraindications to ultrasound. In which case, a physician should consult a neurosurgical specialist and obtain a CT scan of the head.
A high-frequency linear probe (5-10 MHz) is used to scan the area of localized trauma; this should be performed in two perpendicular planes using copious gel and light pressure ( Figures 2a-2c ).Skull fracture on ultrasound will appear as a cortical irregularity that is distinguishable from normal skull suture lines. If a cortical disruption is identified, the contralateral side should be scanned to distinguish the fracture from skull suture lines. 2 Suture lines can be distinguished from a nondisplaced fracture because suture lines can be followed back to the associated fontanelle. 3
Closed head trauma is one of the most common pediatric injuries, accounting for roughly 1.4 million ED visits annually in the United States. 5 Four to 12% percent of these minor traumas result in an intracranial injury, 2 and the presence of a skull fracture is associated with a 4- to 20-fold increase in risk of underlying intracranial hemorrhage. 3
Clinical assessment alone is not always reliable in predicting skull fracture and intracranial injury, especially in children younger than 2 years of age. 2,3 Ultrasound is safe, noninvasive, expedient, cost-effective, and well tolerated in the pediatric population for identifying skull fractures, 3 and can obviate the need for skull radiographs 4 or procedural sedation. Moreover, POC ultrasound can serve as an adjunct to the Pediatric Emergency Care Applied Research Network head injury algorithm for head CT use decision rules if the fracture is not palpable on examination.