[Predictive value of ultrasound-assessed gastric motility for feeding intolerance in critically ill patients: a prospective cohort study].

Objective

To investigate the predictive value of bedside ultrasound-assessed gastric motility parameters for feeding intolerance (FI) during enteral nutrition in critically ill patients.

Methods

A prospective cohort study was conducted. Critically ill patients who received continuous nasogastric enteral nutrition in the intensive care unit (ICU) of Peking Union Medical College Hospital from March 2025 to November 2025 were consecutively enrolled. On the day of enteral nutrition initiation (D0) and the first day after initiation (D1), bedside ultrasound was performed to obtain a single-section image of the gastric antrum and measure the antral contraction frequency (ACF), antral contraction amplitude (ACA), and motility index (MI). Superior mesenteric artery blood flow parameters were also measured. All patients were followed up for 7 days after enteral nutrition initiation, or until the first occurrence of FI. Univariate analyses and multivariate logistic regression analyses, along with decision tree analysis, were used to evaluate the predictive performance of these gastric motility parameters for FI.

Results

A total of 261 patients were enrolled, comprising 167 males (64.0%) and 94 females (36.0%), with a median age of 60.0 (interquartile range: 50.0, 69.0) years. The overall incidence of FI was 29.9% (78/261). Univariate analysis showed that ACA, ACF, and MI at both D0 and D1 were significantly lower in the FI group than in the non-FI group [D1 ACA: 0.31 (0.21, 0.40) vs. 0.42 (0.30, 0.51), D1 ACF: 2.00 (2.00, 3.00) vs. 4.00 (3.00, 5.00), D1 MI: 0.68 (0.41, 1.21) vs. 1.56 (1.06, 2.33); all P<0.001]. Among the superior mesenteric artery blood flow parameters, only the D0 pulsatility index showed a statistically significant difference between the two groups [2.00 (1.70, 2.52) vs. 1.83 (1.53, 2.21), P=0.009]. Multivariate logistic regression analysis showed that D0 ACF (OR=0.57, 95%CI 0.42-0.77, P<0.001) and D1 ACF (OR=0.54, 95%CI 0.40-0.73, P<0.001) were negatively associated with FI risk. Decision tree analysis further revealed that a D1 ACF <2.5 contractions per 2 min was the most critical threshold for identifying patients at high risk for FI, with this subgroup showing an FI incidence of 69.70%.

Conclusions

Bedside ultrasound-assessed gastric motility parameters, particularly ACF, demonstrate strong predictive value for FI in critically ill patients. Dynamic monitoring of antral contraction function enables early identification of patients at high risk for FI and provides an objective basis for optimizing enteral nutrition management in the intensive care setting.