Ready to scan? A systematic review of point of care ultrasound (PoCUS) for screening of obstructive sleep apnea (OSA) in the pediatric population

STUDY OBJECTIVE: Diagnosis of obstructive sleep apnea (OSA) in pediatric practice is challenging, as screening questionnaires are inadequate and sleep studies are resource limited and time-consuming. A recent systematic review and meta-analysis of perioperative point-of-care ultrasound (PoCUS) in adults identified several parameters which correlate with OSA diagnosis and are the subject of an ongoing prospective study. The objective of this systematic review was to evaluate the usefulness of surface airway ultrasound as a PoCUS tool for OSA screening in the pediatric population. DESIGN: Databases were searched for observational cohort studies and randomized controlled trials of patients under 18 years of age undergoing quantitative surface US measurement of extra-thoracic airway structures where correlation or association was examined either directly to OSA diagnosis or indirectly to an alternative reference measure. Diagnostic properties and correlation between US parameters (index test) and reference measures were evaluated where possible. MAIN RESULTS: Of the initial 8499 screened articles, 12 articles (8 airway, 4 non-airway) evaluating 1237 patients were included. Six of these studies were conducted in the sleep/obesity clinic and six in in the perioperative population. Ten studies were prospective and two were cross sectional studies. Airway parameters which correlated with moderate-severe OSA were lateral pharyngeal wall thickness and total neck thickness at the retropharyngeal level. Tonsil volume was not correlated with OSA diagnosis or severity. In tonsillectomy patients, tonsil volume on preoperative ultrasound correlated well with volume of surgical specimens. Adenoid thickness correlated strongly with radiological and endoscopic measures of size and occlusion. CONCLUSION: Ultrasound measurement in children indicates several parameters which correlate with OSA diagnosis or with other reference measurements. This has not yet been validated as a diagnostic tool, however the recent emergence of research in this area is encouraging and the findings from this review will inform future studies.