Qualitative and quantitative gastric ultrasound assessment in highly skilled regional anesthesiologists

Abstract

Background Pulmonary aspiration is a major complication in anesthesia, and various studies have shown that gastric sonography can reliably provide valuable information relative to both the qualitative and quantitative aspects of gastric content. This study aimed to determine the accuracy of ultrasound assessment of gastric content compared between two novice anesthesiologist gastric sonographers. Methods This prospective cohort study of two anesthesiologists learning to perform qualitative and quantitative ultrasound assessment of gastric content on healthy volunteers was conducted at Siriraj Hospital (Bangkok, Thailand). This trial was registered with ClinicalTrials.gov (reg. no. NCT04760106). Results Of the 50 enrolled participants, three were excluded due to study protocol violation. Each anesthesiologist performed a qualitative assessment on 47 participants for an overall total of 94 scans. There were 15 males and 32 females (age 42 ± 11.7 years, weight 61.2 ± 13.1 kg, height 160.7 ± 7.3 cm, and BMI 23.6 ± 4.3 kg/m2). The overall success rate for all gastric content categories was approximately 96%. From antral cross-sectional area measurement, as the ingested volume increased, there was a tendency toward increased deviation from the actual ingested volume. Interrater agreement between anesthesiologists was analyzed using intraclass correlation coefficients (ICCs). A larger fluid volume was found to be associated with a lower level of agreement between the two anesthesiologists. The ICCs were 0.706 (95% CI: −0.125 to 0.931), 0.669 (95% CI: −0.254 to 0.920), 0.362 (95% CI: −0.498 to 0.807) for the 100 ml, 200 ml, and 300 ml fluid volumes, respectively. The mean duration to perform an ultrasound examination for each gastric content category and for the entire examination did not differ significantly between anesthesiologists (p > 0.05). Conclusion Our results indicate that qualitative ultrasound assessment of gastric content is highly accurate and can be easily learned. In contrast, quantification of gastric volume by novice gastric sonographers is more complex and requires more training. Trial registration ClinicalTrials.gov no. NCT04760106 Date registered on Feb 11, 2021. Prospectively registered.

Diagnostic performance of ultrasound in the assessment of gastric contents: a meta-analysis and systematic review

“…The nine articles included four randomized controlled studies [ 4 , 28 – 30 ] and five cohort studies [ 23 – 27 ]. Seven articles used randomization to fluid intake (clarified liquids/milk), solid food, or fasting in subgroups as the gold standard for assessing the accuracy of gastric ultrasound, and six of these studies were conducted in healthy volunteers [ 4 , 23 , 25 , 28 – 30 ], whereas the study by Arzola et al was conducted in women with late-term pregnancies [ 24 ]. Segura-Grau et al studied patients requiring upper gastrointestinal endoscopy, using endoscopic findings of gastric contents as the gold standard [ 26 ].…”

“…Overall, a high risk of bias was identified in the majority of studies, and in terms of case selection, 2 articles had case controls in the study design and did not explicitly describe the inclusion of cases as consecutive or randomized, resulting in a high risk of bias (22%) [ 28 , 29 ]. Regarding the trials to be evaluated, three articles were at high risk (40%) [ 24 , 25 , 28 ], mainly because the threshold for diagnosing “high-risk stomach” was not given in these articles. There was an article that excluded patients with uncertain qualitative ultrasound evaluation and did not analyze all the included subjects, so there was a high risk in the case progress process [ 27 ].…”

“…Previous studies have shown that the measurement of gastric sinus cross-sectional area is highly reliable for sonographers with a lot of clinical experience, whether performed by the same operator or by different operators; whereas, although gastric ultrasonographic assessment is easy to learn, it should be performed before the operation, for both novice operators and non- sonographers. For less experienced operators, although gastric ultrasound assessment is easier to learn, a series of relevant trainings should be performed before the procedure [ 25 , 32 , 33 ]. Therefore, when performing gastric ultrasonography, the potential impact of differences in operator clinical experience should be carefully considered.…”

Feasibility and Utility of Routine Point‐of‐Care Gastric Ultrasonography in Patients Undergoing Upper Gastrointestinal Endoscopy Procedures: A Prospective Cohort Study

“…Several studies have evaluated the utility of gastric POCUS in the context of anesthesia care, a majority of them have utilized designs where fasting volunteers drank a premeasured quantity of liquids with subsequent measurement of gastric antral CSA 8,10 . While the formula and the nomogram showed good correlation between estimated and measured volume in the first validation study of the technique, some studies have shown poor correlation of ultrasound measurements between observers 12,25 or between the estimated and measured gastric volume 11,14 and could be due to operator experience or the differences in the technique of delineating the cross‐sectional area. While we found a strong correlation between nomogram and formula‐based measurements, only a moderate degree of correlation was found between estimated volumes (nomogram or formula based) and measured volumes despite a majority of patients having low residual, and is an important finding of our study.…”