Ultrasound assessment of gastric residual volume in patients over 60 years of age undergoing gastroscopy under sedation: a prospective cohort study

Abstract

Background: We aimed to assess the accuracy of ultrasonographic measurement of the antral cross-sectional area (CSA) in the preprocedural evaluation of gastric contents and volume in fasted patients > 60 yr of age scheduled for gastroscopy under sedation. Methods: We included n = 81 patients > 60 yr of age and n = 79 younger controls scheduled to undergo elective gastroscopy in a prospective cohort study. A gastric ultrasound examination was performed to measure the antral CSA in both semisitting and right lateral decubitus (RLD) positions. Afterward, patients were graded using the Perlas qualitative grading scale. The actual gastric volume was endoscopically suctioned. Full stomach was defined as gastric volume > 1.5 mL·kg–1 and/or the presence of solid particles. We constructed receiver operating characteristic curves to determine the accuracy of ultrasonographic measurement of RLD CSA to detect a gastric volume > 1.5 mL·kg–1 and calculated the diagnostic test attributes of RLD CSA for the identification of a gastric volume > 1.5 mL·kg–1 Results: The incidence of full stomach was 8/81 (9.8%) in patients > 60 yr of age and 1/79 (1.2%) in young patients (risk difference, 8.6%; 95% CI, 1.3 to 15.8; P = 0.03). The cut-off value of RLD CSA was 10.4 cm2 for the detection of gastric volume > 1.5 mL·kg–1 in patients > 60 yr of age, with a sensitivity of 75%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 98.6%. Conclusion: Patients > 60 yr of age scheduled for gastroscopy under sedation had a higher incidence of a full stomach detected with ultrasound compared with a younger cohort, which is potentially associated with a higher aspiration risk. We calculated a cut-off value of RLD CSA for detecting gastric volume in patients > 60 yr of age of approximately 10 cm2, which may help to quickly assess patients at risk of aspiration. Trial registration: www.chictr.org.cn (ChiCTR2100048994); registered 19 July 2021.