Ultrasound assessment of gastric volume in severely obese individuals: a validation study

Abstract

Our results suggest that the existing mathematical model to determine gastric fluid volume based on sonographic assessment performs well in severely obese individuals.

Perioperative point-of-care gastric ultrasound

“…Moreover, the mathematical model used in non-obese subjects to quantify fluid volume performs well in subjects with a BMI of >35 kg m À2 . 20 The key differences in gastric sonography of obese patients is the increased depth at which the antrum is found, with a greater quantity of tissue superficial to the muscles of the anterior abdominal wall.…”

Prevalence and prediction of higher estimated gastric content in parturients at full cervical dilatation: A prospective cohort study

“…For this reason, currently, some authors recommend that the qualitative assessment of gastric content should be combined with the calculation of gastric fluid volume using mathematical models validated in the same population . Various mathematical models, developed in nonpregnant adults and children, have not been used for the estimation of gastric volume in our study, because of potential changes in both the size and position of the antrum at the end of pregnancy which may alter the relationship between the antral CSA and gastric content volume in this context . Even if the ultrasound examination of the antrum is not the gold standard for the assessment of the gastric content, the model used to calculate the gastric fluid volume in the present study was particularly appropriate, because it has been recently described in pregnant women during the third trimester of pregnancy, and validated with high R² value using magnetic resonance imaging which may be considered as an accurate and reliable tool for the measurement of the gastric content volume during pregnancy .…”

Gastric Ultrasound for the Regional Anesthesiologist and Pain Specialist

“…12,35 Also, the mathematical model built for non-severely obese subjects has been shown to perform well in severely obese individuals with a clinically acceptable level of measurement error (mean of 35 mL). 12,35 Fasted severely obese subjects have significantly larger antral CSAs and total gastric volumes compared with non-severely obese subjects. However, the volume per unit of body weight (mean of 0.7 mL/kg) and the distribution of antral grades (grade 0: 42.1%, grade 1: 52.6%, grade 2: 5.3%) are similar to those of the non-severely obese.…”

“…Several mathematical models have been proposed to date. 18,23,29,32 We have favored the model below as it was validated against a robust criterion standard of endoscopically guided gastric suctioning, 23,35 and its accuracy has been established for a wide range of gastric volumes (0-500 mL), patient sizes (body mass index 19-60 kg/m 2 ), and ages (18-85 years). The model is described as follows: gastric volume (mL) = 27.0 + 14.6 Â right-lat CSA − 1.28 Â age.…”

“…However, the volume per unit of body weight (mean of 0.7 mL/kg) and the distribution of antral grades (grade 0: 42.1%, grade 1: 52.6%, grade 2: 5.3%) are similar to those of the non-severely obese. 12,17,35 CONCLUSIONS Point-of-care gastric US is one of the most recently described PoCUS applications. However, given that regional anesthesiologists are often managing patients without a secured airway, the ability to evaluate and document gastric contents and stratify the pulmonary aspiration risk may be clinically useful.…”