Lung ultrasound for the diagnosis of pneumonia in children: a meta-analysis

Abstract

Background and objective: Pneumonia is the leading cause of death of children. Diagnostic tools include chest radiography, but guidelines do not currently recommend the use of lung ultrasound (LUS) as a diagnostic method. We conducted a meta-analysis to summarize evidence on the diagnostic accuracy of LUS for childhood pneumonia.

Methods: We performed a systematic search in PubMed, Embase, the Cochrane Library, Scopus, Global Health, World Health Organization-Libraries, and Latin American and Caribbean Health Sciences Literature of studies comparing LUS diagnostic accuracy against a reference standard. We used a combination of controlled key words for age <18 years, pneumonia, and ultrasound. We identified 1475 studies and selected 15 (1%) for further review. Eight studies (765 children) were retrieved for analysis, of which 6 (75%) were conducted in the general pediatric population and 2 (25%) in neonates. Eligible studies provided information to calculate sensitivity, specificity, and positive and negative likelihood ratios. Heterogeneity was assessed by using Q and I(2) statistics.

Results: Five studies (63%) reported using highly skilled sonographers. Overall methodologic quality was high, but heterogeneity was observed across studies. LUS had a sensitivity of 96% (95% confidence interval [CI]: 94%-97%) and specificity of 93% (95% CI: 90%-96%), and 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. Limitations included the following: most studies included in our analysis had a low number of patients, and the number of eligible studies was also small.

Conclusions: Current evidence supports LUS as an imaging alternative for the diagnosis of childhood pneumonia. Recommendations to train pediatricians on LUS for diagnosis of pneumonia may have important implications in different clinical settings.

Keywords: practice management; pulmonology; respiratory tract; standard of care.

FIGURE 1

Flowchart of articles retrieved from the search of databases and reasons for exclusions.

FIGURE 2

Forest plots showing the diagnostic accuracy of lung ultrasound for the diagnosis of pneumonia. A, sensitivity; B, specificity; C, negative likelihood ratio (LR); and D, positive LR. Inconsistency (I²) describes the percentage of total variation across studies due to heterogeneity.

FIGURE 3

Summary receiver operating characteristic curve for the use of LUS for the diagnosis of childhood pneumonia. Values for sensitivity and (1-specificity) for each study are represented with a square; 95% CIs for sensitivity and (1-specificity) are shown with vertical and horizontal lines, respectively.