Diagnostic Test Accuracy of Lung Ultrasound for Acute Chest Syndrome in Sickle Cell Disease A Systematic Review and Meta-analysis

BACKGROUND: Acute chest syndrome (ACS) is a leading cause of death in patients with sickle cell disease. Lung ultrasound (LUS) is emerging as a point-of-care method to diagnose ACS, allowing for more rapid diagnosis in the ED setting and sparing patients from ionizing ra-diation exposure. RESEARCH QUESTION: What is the diagnostic accuracy of LUS for ACS diagnosis, using the current reference standard of chest radiography? STUDY DESIGN AND METHODS: Preferred Reporting Items for Systematic Reviews and Meta -Analyses guidelines were followed for this systematic review and meta-analysis. Embase, MEDLINE, Web of Science, and Google Scholar were used to compile all relevant studies. Two reviewers screened the studies for inclusion in this review. Cases of discrepancy were resolved by a third reviewer. Meta-analyses were conducted using both metadta and midas STATA software packages to retrieve summary receiver operating characteristic curves, sensitivities, and speci-ficities. Three reviewers scored the studies with QUADAS-2 for risk of bias assessment. RESULTS: From a total of 713 unique studies retrieved, six studies were included in the final quantitative synthesis. Of these, five studies were in pediatric EDs. Two studies were con-ference abstracts and not published manuscripts. Data were available for 625 possible ACS cases (97% of cases in patients aged # 21 years) and 95 confirmed ACS diagnoses (pretest probability of 15.2%). The summary sensitivity was 0.92 (95% CI, 0.68-0.98) and the sum-mary specificity was 0.89 (95% CI, 0.69-0.97) with an area under the curve of the summary receiver operating characteristic curve of 0.96 (95% CI, 0.94-0.97). INTERPRETATION: LUS has excellent sensitivity and very good specificity for ACS diagnosis and may serve as an initial point-of-care test to facilitate rapid treatment of ACS and spare pediatric patients from ionizing radiation; however, further research is warranted to improve the generalizability to the adult sickle cell disease population.