Diagnostic accuracy of qualitative gastric ultrasound assessment for detecting high gastric fluid volume in children: a prospective randomised study

Summary Introduction The diagnostic accuracy of gastric ultrasound in children has not been assessed thoroughly. We aimed to determine the sensitivity and specificity in children of a qualitative ultrasound examination of the gastric antrum in the supine 45° semi‐recumbent position and a clinical algorithm for detecting a gastric fluid volume > 1.25 ml.kg ‐1 , reported to represent an ‘at‐risk stomach’ for pulmonary aspiration. Methods We conducted a prospective, observer‐blinded, randomised trial in healthy children fasted according to current pre‐operative guidelines. An initial ultrasound assessment of gastric contents ensured that the stomach was empty. Children then drank a specific volume of water (0; 0.6; 1; 1.25; 1.5; or 2 ml.kg ‐1 ). Gastric ultrasound was performed after 3 min of fluid ingestion, in children lying supine and then in the right lateral decubitus position, with the head of the bed elevated to 45° (semi‐recumbent). A clinical algorithm combining the qualitative assessment with calculation of gastric fluid volume was also completed. The sensitivity and specificity of the qualitative assessment in the supine semi‐recumbent position and the clinical algorithm for the diagnosis of gastric fluid volume > 1.25 ml.kg ‐1 were estimated. Results Ninety children, median (IQR [range]) age 7 (4.5–9 [1–10]) y, were studied. The sensitivity and specificity of the qualitative assessment for detecting gastric fluid volume > 1.25 ml.kg ‐1 were 75% (95%CI 58–88%) and 85% (95%CI 73–93%), respectively. The sensitivity and specificity of the clinical algorithm were 86% (95%CI 71–95%) and 78% (95%CI 64–88%), respectively. Discussion In order to achieve high sensitivity of gastric ultrasound for the diagnosis of fluid volume > 1.25 ml.kg ‐1 in children, qualitative ultrasound assessment of gastric antrum contents should be combined with calculation of gastric fluid volume when fluid contents are seen in the gastric antrum.