Bedside ultrasonography to identify hip effusions in pediatric patients

Abstract

Study objective: We determine whether pediatric emergency physicians can use bedside ultrasonography to accurately identify hip effusions in pediatric patients.

Methods: This was a prospective study conducted in the emergency department (ED) of an urban tertiary care freestanding pediatric hospital. A convenience sample of children younger than 18 years and who required hip ultrasonography as part of their ED evaluation was enrolled. Pediatric emergency physicians with focused ultrasonographic training performed bedside ultrasonography on patients' symptomatic and contralateral hips and categorized the findings as "effusion" or "no effusion," according to a priori definitions. Physicians rated their confidence for each bedside ultrasonographic result on a scale of 1 (not confident) to 5 (very confident). Bedside ultrasonographic results were compared with the radiology department's ultrasonographic results, which were considered the criterion standard. Standard performance metrics (sensitivity, specificity, and positive and negative predictive values) were calculated.

Results: Three physicians enrolled patients. Twenty-eight patients were enrolled, and 55 hips were studied. In all hips (both symptomatic and contralateral), bedside ultrasonography had a sensitivity of 80% (95% confidence interval [CI] 51% to 95%), a specificity of 98% (95% CI 85% to 99%), a positive predictive value of 92% (95% CI 62% to 99%), and a negative predictive value of 93% (95% CI 79% to 98%). In the 28 symptomatic hips, bedside ultrasonography had a sensitivity of 85% (95% CI 54% to 97%), a specificity of 93% (95% CI 66% to 99%), a positive predictive value of 92% (95% CI 60% to 99%), and negative predictive value of 88% (95% CI 60% to 98%). When physician self-rated confidence was high, the sensitivity of bedside ultrasonography in symptomatic hips was 90% (95% CI 54% to 99%), the specificity was 100% (95% CI 70% to 100%), the positive predictive value was 100% (95% CI 63% to 100%), and the negative predictive value was 92% (95% CI 62% to 99%).

Conclusion: With focused training, pediatric emergency physicians were able to use bedside ultrasonography to identify hip effusions in pediatric ED patients.