Ultrasonographic Measurement Of Antral Area Research Articles

Ultrasound Assessment of Prevalence of ‘At Risk Stomach’ in Children Undergoing Elective Surgery- Prospective, Observational Study

Children may be at increased risk of pulmonary aspiration because of retention of gastric contents caused by pain or inadequate fasting. We performed this study to analyze the use of ultrasound for evaluation of gastric ultrasound in children less than 12 years. Two hundred children, 1-12 years of age belonging to ASA physical status I to II, scheduled to undergo elective surgery were included in the study. Patients were scanned in supine position followed by right lateral decubitus position (RLD). In qualitative assessment, the antrum was judged to contain fluid if it appeared to have an endocavitary lumen with hypoechoic content and distended walls. All measurements were taken with antrum at rest (between contraction) to avoid underestimating volume. It was observed that majority of the children were in Perlas grade 0, 116(58%) followed by 75 children in grade 1 and 9 children in grade 2. Using Karl Pearson’s Correlation coefficient, low positive correlation was found between gastric volume and fasting status solid (in hours) and the variation (correlation) was found to be statistically non-significant (r=0.139; p>0.05). There is no proportionate decline in gastric volume with increased duration of preoperative fasting. Ultrasonographic measurement of antral area can be of interest to anesthesiologist for accurate qualitative and quantitative estimation of preoperative gastric contents and volume. However, gastric ultrasonography has to be validated in further trials involving a larger patient population before it can become a routine standard of care in perioperative period.

Ultrasonographic measurement of antral area for estimating gastric fluid volume in pregnant women

Study objectiveTo calculate the stomach volume according to the antral area in pregnant women. DesignProspective observational study. SettingOne of the maternity units in our hospital. Patients24 singleton pregnancy women, over 18-year-old, non-laboring, gestational age ≥ 36 weeks, ASA physical status I to II were involved in our study. Interventions and measurementsAn ultrasound assessment of the antrum was performed to the pregnant women after 8 hours fasting for the first time. Those lacking of visualization of any gastric contents in the antrum in both the supine and the right lateral decubitus positions were included in our study. Thereafter 50 ml of water was ingested, 4 times, 200 ml in total. The antrum area was examined 2mins after each 50 ml ingest of water. Main resultsA high correlation between CSA and volume of liquid ingested (r = 0.90,P < 0.01) was found. We can construct a formula for the prediction of volume values based on the measured CSA values and demographic variables. The equation is: Volumeml=270.76+13.68∗CSA−1.20∗gestationalage ConclusionsBedside antrum area examination by ultrasonography can provide quantitative information for the assessment of the gastric content and volume in the pregnant women. We can calculate the actual stomach capacity according to the CSA of the gastric antrum.

Preoperative Assessment of Ultrasonographic Measurement of Antral Area for Gastric Content.

BackgroundPulmonary aspiration of the gastric contents is a serious perioperative complication. The aim of this study was to evaluate the efficacy of portable ultrasonography in the preoperative evaluation of the gastric contents of patients. The secondary aim was to examine the relationship between gastric antrum cross-sectional area and age and body mass index (BMI).Material/MethodsThis single-center, prospective, cross-sectional study included 120 patients who underwent surgery. Measurements the gastric antral cross-sectional areas and quantitative and qualitative measurements of the stomach were taken by ultrasonography guidance in all patients.ResultsWith the patient in a supine position, the mean gastric antrum cross-sectional area was found to be 3.4±2.43 cm2 (range, 0.79–17.3 cm2). As the number of hours of fasting increased, the gastric antral cross-sectional area statistically significantly decreased (P<0.05). Increased age and BMI values were determined to increase the gastric antrum cross-sectional area in a linear correlation; r=0.209, P<0.05 and r=0.252, P=0.05, respectively. It was determined that 20.8% of the patients exceeded the high-risk stomach antral cutoff cross-sectional area that was defined as 340 mm2 in patients fasting for at least 8 hours.ConclusionsIt was determined that bedside ultrasonography is a useful, non-invasive tool in the determination of gastric content and volume. A significant proportion of surgical patients may not present with an empty stomach despite the recommended fasting protocols.

Ultrasonographic measurement of antral area for estimating gastric fluid volume in parturients

BackgroundThe aim of this prospective observational study was to assess the performance of ultrasonographic gastric antral area (GAA) to predict gastric fluid volumes of >0.4, >0.8 and >1.5 ml kg−1, in fasted women in established labour. MethodsA first ultrasound examination of the antrum was performed, in order to confirm gastric vacuity by using a qualitative score. Baselines GAA measurements were obtained in both supine and right lateral decubitus positions. Thereafter, parturients were allowed to drink clear fluids only. Measurement of GAA was repeated 15 min after last fluid intake, in both supine and right lateral positions. Receiver operating characteristics (ROC) curves were constructed to determine the accuracy of GAA to diagnose ingested volumes of >0.4, >0.8 and >1.5 ml kg−1. ResultsData from forty parturients were analysed. The areas under the ROC curves ranged from 80% to 86%. The cut-off value for antral area measured in supine position, to detect a volume >0.4 ml kg−1, was 387 mm2, with a sensitivity of 87%, a specificity of 70% and a negative predictive value of 85%. A cut-off value of 608 mm2 predicted a fluid volume >1.5 ml kg−1, with a specificity of 94%, a sensitivity of 75% and a negative predictive value of 92%. ConclusionsThis study provides cut-off values for GAA that could be used in addition to the qualitative assessment of the antrum to define a full stomach in labouring patients.

Clinical Assessment of the Ultrasonographic Measurement of Antral Area for Estimating Preoperative Gastric Content and Volume

This prospective observational study aimed to assess the feasibility and performance of the ultrasonographic measurement of antral cross-sectional area (CSA) for the preoperative assessment of gastric contents and volume in adult patients and for the diagnosis of risk stomach (defined by the presence of solid particles and/or gastric fluid volume >0.8 ml/kg). A preoperative ultrasonographic measurement of the antral CSA was performed for each patient by a physician (L.B.) blinded to the history of the patient. Immediately after tracheal intubation, an 18-French multiorifice Salem tube was inserted and gastric contents were aspirated in five different patient positions; during this time, the patient's epigastrium was massaged and the tube was moved backward and forward in the stomach. The relationship between the antral area and the volume of aspirated gastric contents was analyzed, as was the performance of ultrasonographic measurement of antral area for the diagnosis of risk stomach. The measurement of antral CSA was performed on 180 of 183 patients. A significant positive relationship between antral CSA and aspirated fluid volume was found. The cutoff value of antral CSA of 340 mm(2) for the diagnosis of risk stomach was associated with a sensitivity of 91% and a specificity of 71%. The area under the receiver operating characteristic curve for the diagnosis of risk stomach was 90%. The ultrasonographic measurement of antral CSA could be an important help for the anesthesiologist in minimizing the risk of pulmonary aspiration of gastric contents due to general anesthesia.

Could a single standardized ultrasonographic measurement of antral area be of interest for assessing gastric contents? A preliminary report

The aim of this preliminary study performed on volunteers was to assess whether a standardized ultrasonographic measurement of the gastric antral cross-sectional area in a single section of the stomach could discriminate between gastric contents after 12 h fasting (fasting stomach) and gastric contents 2 h after ingestion of nonclear liquids or a solid meal. In this crossover study, ultrasonographic measurements of the antral area were performed in the morning in healthy volunteers in three situations in randomized order: after 12 h fasting, 2 h after a solid meal of 300 kcal and 2 h after ingestion of 200 ml of nonclear liquids. These measurements were performed by a physician blinded to the volunteers' status, according to a standardized method, using the abdominal aorta and the left lobe of the liver as internal landmarks. Antral areas were compared among the three sessions, and performance of the test was assessed by plotting receiver operating characteristic curves and calculating the area under the receiver operating characteristic curves for the diagnosis of fasting gastric contents. Twenty-two volunteers were included, and 65 measures were performed. Antral area was significantly smaller in fasting than in postprandial sessions. The receiver operating characteristic curves showed an excellent performance of ultrasonographic measurement of antral area for discriminating gastric contents in fasting session from gastric contents in nonfasting sessions. Results of this preliminary study should be corroborated in further trials. However, one can suppose that ultrasonographic measurement of the antral cross-section area could be of interest for the diagnosis of preoperative gastric vacuity.