The Utility of Ultrasound in Detecting Skull Fractures After Pediatric Blunt Head Trauma Systematic Review and Meta-Analysis

Background: Head trauma is a common reason for evaluation in the emergency department. The evaluation for traumatic brain injury involves computed tomography, exposing children to ionizing radiation. Skull fractures are associated with intracranial bleed. Point-of-care ultrasound (POCUS) can diagnose skull fractures. Objectives: We performed a systematic review/meta-analysis to determine operating characteristics of POCUS skull studies in the diagnosis of fractures in pediatric head trauma patients. Methods: We searched PubMed, EMBASE, and Web of Science for studies of emergency department pediatric head trauma patients. Quality Assessment Tool for Diagnostic Accuracy Studies 2 was used to evaluate risk of bias. Point-of-care ultrasound skull study operating characteristics were calculated and pooled using Meta-DiSc. Results: Six studies of 393 patients were selected with a weighted prevalence of 30.84%. Most studies were at low risk of bias. The pooled sensitivity (91%) and specificity (96%) resulted in pooled positive likelihood ratio (14.4) and negative likelihood ratio (0.14). Using the weighted prevalence of skull fractures across the studies as a pretest probability (31%), a positive skull ultrasound would increase the probability to 87%, whereas a negative test would decrease the probability of a skull fracture to 6%. To achieve a posttest probability of a skull fracture of similar to 2% would require a negative skull ultrasound in a patient with only a pretest probability of similar to 15%. Conclusions: A POCUS skull study significantly increases the probability of skull fracture, whereas a negative study markedly decreases the probability if the pretest probability is very low.