Ultrasound Accurate for Diagnosing Pneumonia in Children

Laura Putre

March 17, 2015

Pediatricians looking for alternative ways to diagnose childhood pneumonia may have another effective tool at their disposal: the lung ultrasound (LUS). LUS had high specificity and sensitivity in the hands of trained clinicians, according to a meta-analysis published online March 16 in Pediatrics.

Pediatric pneumonia is the number one cause of death by illness in children worldwide. It can be especially difficult to diagnose because symptoms vary according to a child's age and the cause of infection. In addition, some symptoms are not exclusive to childhood pneumonia but can indicate other illnesses as well. Clinicians often use chest radiographs to help diagnosis pneumonia, but it is not always accurate and can be prohibitively expensive for low-resource areas.

Maria A. Pereda, MD, from Johns Hopkins University in Baltimore, Maryland, and colleagues conducted a meta-analysis of previous research on LUS in childhood pneumonia and found that LUSs accurately identified childhood pneumonia 96% of the time (95% confidence interval [CI], 94% - 97%) and led to a correct negative diagnosis 93% of the time (95% CI, 90% - 96%).

"Although the sensitivity and specificity are best in the hands of expert users, our study provides evidence of good diagnostic accuracy even in the hands of nonexperts," the researchers state.

Small Number of Studies

To identify relevant studies, the authors searched recent medical literature and found 15 studies to review and included eight studies, with a total of 765 children, in their analysis. Six studies were in pediatric patients in the general population, and two were in newborns.

Positive and negative likelihood ratios were 15.3 (95% CI, 6.6 - 35.3) and 0.06 (95% CI, 0.03 - 0.11), respectively. The area under the receiver operating characteristic curve was 0.98.

The American Association of Pediatrics recommends using chest radiographs cautiously because of possible adverse effects in children from ionizing radiation and the fact that a negative chest radiograph does not eliminate the possibility of having pneumonia. In addition, in places with limited resources, chest radiographs may be unavailable or difficult to access.

LUS, in contrast, is comparatively inexpensive, safe, and portable, and the technology is relatively easy to learn, thanks in part to recent advances in ultrasound technology.

"Recommendations to train general pediatricians on LUS for the diagnosis of childhood pneumonia may have an important impact in different clinical settings," the researchers state, "especially in resource-poor countries and small primary care clinics where [chest radiographs] may not be commonly available."

The researchers note several study limitations, including that most studies in the analysis had a low number of subjects and that the number of studies analyzed was small. In addition, although the overall rigor of the studies was high, there were distinct differences in the data collected and the ways the studies were conducted. Not all research compared LUS results with clinical diagnoses, for instance.

The authors have disclosed no relevant financial relationships.

Pediatrics. Published online March 16, 2015. Abstract


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