Ultrasonographic assessment of preoperative gastric volume in patients with dyspepsia: a prospective observational study

Abstract

Background: Patients undergoing gastroenteroscopy during sedation are prone to aspiration, and most patients with dyspepsia have delayed gastric emptying. This study aimed to investigate the feasibility of measuring the gastric antrum cross-sectional area (CSA) to supply a novel clinical diagnostic reference value in patients with dyspepsia.

Methods: Patients with dyspepsia undergoing elective gastroscopy were included. The Perlas qualitative 0-2 grading scale score was determined before the operation. The anteroposterior diameter (D1) and craniocaudal diameter (D2) between gastric antrum serosal surfaces were measured perpendicular to each other in the supine and right lateral decubitus (RLD) positions. CSA values in the supine position and RLD position were determined. Gastric contents were endoscopically suctioned with the volumes measured and noted as actual gastric volume. Multiple regression analysis was used to fit a mathematical model for estimating the gastric volume. Receiver operating characteristic (ROC) curves were constructed to determine the accuracy of RLD CSA to detect gastric volumes of > 0.8 ml/kg.

Results: A total of 117 patients were enrolled and divided into a functional dyspepsia (FD) group and an organic dyspepsia group according to gastroscopy findings. For a gastric volume of > 0.8 ml/kg, cut-off values for FD and organic dyspepsia were 6.7 cm² and 10.0 cm², respectively. Two new modified mathematical models were derived to predict an estimated gastric volume for FD and organic dyspepsia: volume = 3.93 × RLD CSA - 0.47 × age; and volume = 6.15 × RLD CSA - 0.61 × age.

Conclusion: We used the cut-off value of the antral area for the fast diagnosis of gastric volumes in patients with dyspepsia, which may assist clinicians in identifying patients at risk of aspiration.

Trial registration: www.chictr.org.cn ( CHICTR-DDD-17010871 ); registered 15 March 2017.

Keywords: Dyspepsia; Gastric antral cross-sectional area; Gastric volume; Gastroscopy; Ultrasonography.

Fig. 1

Transducer position to scan the gastric antrum (a). Antral ultrasound image (b)

Fig. 2

ROC curve of gastric antrum CSA in patients with FD. Receiver operating characteristic curves for the detection of a gastric volume greater than 0.8 ml/kg by the measurement of antral area in the RLD positions. AUC = area under the receiver operating characteristic curve with 95% confidence interval. P = 0.0001

Fig. 3

ROC curve of gastric antrum CSA in patients with organic dyspepsia. Receiver operating characteristic curves for the detection of a gastric volume greater than 0.8 ml/kg by the measurement of antral area in the RLD positions. AUC = area under the receiver operating characteristic curve with 95% confidence interval. P = 0.0001

Fig. 4

Grey zone approach indicates two cut-offs, between which the diagnosis of a gastric volume greater than 0.8 ml/kg by the measurement of antral area in the RLD positions in patients with FD remains uncertain

Fig. 5

Grey zone approach indicates two cut-offs, between which the diagnosis of a gastric volume greater than 0.8 ml/kg by the measurement of antral area in the RLD positions in patients with organic dyspepsia remains uncertain