The correlation between patient satiety sensation and total gastric fluid volume: a prospective observational study

Surgical patients are asked to adhere to preoperative fasting guidelines to minimize gastric contents. Large fluid volumes or solid content can still be present as shown with gastric ultrasound. It has been suggested that additional rating of patients' satiety, measured as the feeling of hunger and thirst, could help clinicians to better judge emptying of the stomach.

We performed a prospective observational study in fasted elective surgical patients. The primary objective was to investigate the correlation between hunger measured on a 0-10 numeric rating scale and total gastric fluid volume measured with gastric ultrasonography. Secondary objectives included the correlation between 1) thirst and total gastric fluid volume and 2) hunger, thirst, and the Perlas grading scale score.

We included 515 patients. The exam was inconclusive in 14 individuals (2.7%). The Spearman correlation coefficient between gastric fluid volumes and hunger was 0.11 (95% confidence interval [CI], 0.02 to 0.20) (P = 0.01). The correlation between gastric fluid volumes and thirst was 0.11 (95% CI, 0.02 to 0.20) (P = 0.02). Between antral grades and numeric rating scale, the correlation coefficient was 0.00 (95% CI, -0.09 to 0.09) (P = 1.00) for thirst and 0.00 (95% CI, -0.08 to 0.09) (P = 0.94) for hunger. Ten patients (2.0%) had solid content, 24 presented a grade 2 antrum (4.8%).

This study suggests that the correlation between total gastric fluid volume and satiety sensation is very weak. Satiety did not reliably predict total gastric fluid volume.

ClinicalTrials.gov (NCT04884373); registered 13 May 2021.