Point-of-care paediatric gastric sonography: can antral cut-off values be used to diagnose an empty stomach?

Background: Gastric sonography is emerging as a valuable clinical point-of-care tool to assess aspiration risk. A recent study proposed that a single cut-off cross-sectional area (CSA) in the supine position could diagnose an empty stomach in the parturient. This study establishes the sensitivity and specificity of a single CSA cut-off measurement in both supine and right lateral decubitus (RLD) positions in the diagnosis of an empty antrum in paediatric patients.

Methods: Following induction of anaesthesia, antral sonography was performed in supine and RLD positions in 100 fasted paediatric patients prior to upper endoscopic evaluation. Following upper endoscopy, any residual stomach content was suctioned under direct visualization and antral sonography was immediately performed. Antral CSA values were compared using Wilcoxon signed rank test. Receiver operator characteristic (ROC) curves were plotted to estimate the discriminating power of antral sonography position in the diagnosis of an empty antrum.

Results: Significant differences were found between pre-suctioned and post-suctioned CSA values in the RLD position. The cut-off CSAs of the empty antrum in the supine and RLD positions were 2.19 cm2 (sensitivity 75%, specificity 36%) and 3.07 cm2 (sensitivity 76%, specificity 67%), respectively.

Conclusions: The RLD position produces the most sensitive and specific CSA cut-off value where an antral CSA of ≤ 3.07 cm2 in the RLD position presents with acceptable performance in the ability to discriminate an empty antrum in paediatric patients over 1 yr of age. As age increases, the sensitivity and specificity of this test increases in the RLD position.