Ultrasound assessment of gastric emptying after breakfast in healthy preschool children.

BACKGROUND

In current guidelines, 6 hours of fasting is recommended for solids to limit the risk of pulmonary aspiration during anesthesia in children. Ultrasonography has recently been introduced to evaluate gastric volumes in children in the context of preanesthetic fasting. Therefore, in this study, we firstly evaluated the precision of ultrasound assessment of gastric volume in an experimental setting and secondly studied gastric emptying times after a normal breakfast in healthy preschool children using ultrasound.

METHODS

In a preliminary experiment, a pear-shaped elastic balloon was filled and emptied in 50 mL steps from 0 to 500 mL with water. After each step, the balloon antral area was measured using ultrasonography. Thereafter, gastric emptying was examined in healthy preschool children after normal breakfast by sonographic measurements of the gastric antral area in right lateral decubitus position at two consecutive timepoints. Correlation coefficients (Pearson, 95% CI) between the balloon antral area and the balloon volume or gastric antral area and fasting time were calculated and gastric emptying time was extrapolated by linear regression. Data are presented as mean (range).

RESULTS

In the balloon experiment, the balloon volume correlated significantly with the balloon antral area (63 measurements, r=.96, P<.0001, 95% CI 0.93 to 0.97). In the preschool child measurements, a total of 30 children (age 47 (36-66) months) were included. The gastric antral area correlated significantly with fasting time (r=-.69, P<.0001, 95% CI -0.8 to -0.51). The first gastric antral area after breakfast was significantly higher when compared to the second gastric antral area before lunch (10.4 ± 3.7 (1.7-17.8) vs 5.5 ± 2.6 (1.4-11.8) cm ; mean difference -5.04, 95% CI -6.3 to -3.8, P<.0001). The calculated mean gastric emptying time was 236 minutes.

CONCLUSION

The results of the balloon experiment showed a high correlation between balloon antral area and balloon volume. In the preschool child measurements, gastric antral area correlated with fasting time, and the mean gastric emptying time was lower than 4 hours after breakfast. These results support a more liberal perioperative fasting regimen after a light meal or breakfast in routine pediatric anesthesia.