Ultrasonographic measurement of gastric volume in critically ill patients nourished with different enteral feeding protocols

Background: Gastric residual volume monitoring is still widely used in clinical practice for early detection of gastric intolerance. This study investigated the compatibility of gastric volume measurements by ultrasound with the free drainage method in intensive care patients receiving enteral nutrition with three different protocols. Methods: Patients were divided into 3 groups according to different nutrition protocols applied in our clinic. Gastric ultrasound was performed in the right lateral decubitus position. Antral cross-sectional area was calculated using the Bolondi formula and gastric volume was calculated using Perlas and Tacken formulas. After, the patient was placed supine, a nasogastric feeding catheter was placed in gravity/free drainage for one hour in all groups and gastric residual volumes were recorded. Results: 82 intensive care unit patients were included. Spearman’s correlation analysis showed a correlation between gastric residual volume and the other three values (cross-sectional area, gastric volume obtained by Perlas and Tacken formula) (p < 0.05) in each feeding group. Based on the Bland-Altman analysis, Perlas seems to be a more reliable alternative to GRV due to the smaller differences and less variability. Conclusions: We found a positive correlation between gastric volume determined by gastric ultrasound and gastric residual volume determined by the drainage method, with no difference between the different feeding protocols. Using ultrasound assessment, gastric volume can be predicted without interruption of enteral nutrition in patients fed semi-solid feeding solutions. Clinical Trial Registration: NCT06700759.