Reinforcing the valuable role of gastric ultrasound for volume and content assessment: an observational study

Abstract Background Pulmonary aspiration is one of the most important complications in anesthesiology. Assessment of gastric content by ultrasound is a good method to quantify gastric volume and to determine the risk of intraoperative pulmonary aspiration. The aim of this study is to determine the accuracy of the gastric ultrasonography in the qualitative analysis of gastric content, mainly in the analysis of small amounts of liquid content. Methods Gastric ultrasound was performed to 36 patients before upper gastrointestinal endoscopy (UGI), making two longitudinal scans at the epigastric level, one in supine position and the other in right lateral decubitus position, measuring two diameters and the area of the gastric antrum and assessing the content characteristics determining whether it was an empty stomach or contained fluid or solid content. Subsequently, the ultrasound findings were compared with UGI findings. Results Gastric areas were analyzed by the trace and the lengths of the craniocaudal and anteroposterior axes concluding that there are no significant differences between the two methods. No statistically significant difference was found between UGI and US assessment technics. No statistically significant difference was found between the estimated volume by UGI and US. Conclusions Though our study has some limitations, qualitative analysis of gastric content using ultrasound followed by endoscopy enabled the conclusion that there are no differences in the qualitative assessment regarding these two techniques, supporting the important role of point-of-care gastric ultrasound (POCGUS) in the assessment of pulmonary aspiration risk by the anesthesiologist in the perioperative period.

Measurement of Gastric Volume Before and After Laparoscopic Sleeve Gastrectomy / 中国微创外科杂志

[Summary] Laparoscopic sleeve gastrectomy ( LSG) as a sole and definitive bariatric surgery has achieved well results in terms of decreasing the body mass index ( BMI ) and percentage of excess weight loss (%EWL ) , therefore reducing the obesity-related complications , but the mechanism remains unclear .As a restrictive surgical procedure , the most important mechanism of LSG might be the reduction of the volume of the stomach resulting in a limited food intake .Therefore, to achieve the best weight loss after surgery , measuring the gastric volume is an indispensable technology .Currently, gastric capacity measurement methods include imaging measurements and intraoperative direct measurement . Imaging methods include upper gastrointestinal radiography , CT three-dimensional reconstruction , MRI and radionuclide scanning , with each having its advantages and disadvantages .In this article, the measurement methods of gastric capacity before and after LSG were reviewed .

Gastric Volume and Acidity in Pregnant and Non-pregnant Women / 대한마취과학회지

BACKGROUND: Studies of gastric volume and pH during various stages of pregnancy have not confirmed a consistently evaluated volume or acidity, but point out that these patients may be at risk. The aim of this study was to evaluate the volume and acidity of gastric contents in pregnant and non-pregnant patients. METHODS: Thirty pregnant patients scheduled for elective cesarean section under spinal anesthesia (pregnant group) and thirty non-pregnant female patients that underwent gynecologic surgery with general anesthesia (non-pregnant group) were enrolled. Preoperative fasting times and anxiety score, using a visual analogue scale from 0 to 10, were obtained from all patients. After the induction of anesthesia, gastric contents were aspirated gently using a 14-F multiorifice nasogastric tube and syringe. Gastric volume and acidity were measured. RESULTS: The gastric volume (ml) in the pregnant group was 42.8 +/- 35.0 (mean +/- SD, range: 5-130), and in the non-pregnant group 15.8 +/- 11.9 (range: 3-50). The gastric pH in the pregnant group was 2.1 +/- 0.9 (range: 1.3-5.4), and in the non-pregnant group 2.8 +/- 1.7 (range: 1.3-6.5). CONCLUSIONS: We confirm that pregnant women have more acidic and greater gastric volumes than non-pregnant women.

Comparison of Gastric Volume and Acidity between Children and Adults / 대한마취과학회지

BACKGROUND: Aspiration of gastric contents into the lungs is one of the most feared complications during anesthesia. Various factors combine to make pediatric patients more susceptible to regurgitation and aspiration than adults. We compared the risk of incidence of acid aspiration in two groups, after examining the pH, and volume of gastric contents in pediatric and adult patients. METHODS: This study was carried out with inpatients scheduled for elective surgery under general anesthesia. Sixty patients from 1 to 13 years old were included in the pediatric age group, and sixty patients from 18 to 60 years old were included in the adult age group. After induction of anesthesia and stabilization of the condition of the patient, gastric contents were collected via a 10 - 18 French Salem Sump tube. Gastric volume and pH were measured. RESULTS: The mean gastric volume in the pediatric group was significantly higher than those in the adult group, whereas, The mean gastric pH in the adult group was significantly higher than those in the pediatric group. CONCLUSIONS: We concluded that pediatric patients have a lower gastric pH but a higher gastric volume than adult patients.

The Effects of Preanesthetic Low Dose Famotidine on Gastric pH and Volume in Children / 대한마취과학회지

BACKGROUND: Children undergoing general anesthesia are at increased risk of aspiration pneumonia. Cimetidine and ranitidine, specific histamine (H2-receptor) antagonists, markedly reduce the acidity and volume of gastric content when given 2 3h preoperatively. A newer compound, famotidine, is a more specific antagonist that has no inhibitory effect on the drug metabolizing microsomal enzyme systems of the liver (cytochrome P-450), in contrast to cimetidine. An additional clinical advantage is a possible longer duration of action. The aim of this study is to evaluate the lowest effective dose of famotidine on gastric pH and volume in children. METHODS: Fifty-five children, aged 2 to 14 years (ASA physical status I-II) were divided into four groups (Group I:placebo, normal saline 10 ml, Group II:famotidine 0.1 mg/kg, Group III:famotidine 0.15 mg/kg, Group IV:famotidine 0.2 mg/kg.). Doses were administered intravenously 2 or 3 hours before the operation. Following induction with oxygen, enflurane and pentothal sodium, anesthesia was maintained with N2O/O2 and enflurane. A nasogastric tube was passed into the stomach and the gastric contents were aspirated in a uniform manner. Gastric volume was recorded and pH values were measured with pH meter. The incidence of high risk for aspiration pneumonia, defined as gastric pH 0.4 ml/kg of gastric juice, was measured in all groups. RESULTS: In the placebo group, 10 of 13 children (77%) had a pH 0.4 ml/kg. Group II (famotidine 0.1 mg/kg) was not found to produce a significant increase in the gastric pH. Groups III and IV (famotidine 0.15 mg/kg and 0.2 mg/kg) were found to produce a significant increase in the gastric pH. The gastric juice volume was reduced in all famotidine groups, but was not statistically significant compared with the placebo group. The incidences of high risk for aspirationpneumonitis decreased in all famotidine groups. CONCLUSIONS: The results suggest that the preoperative intravenous administration of famotidine 0.15 mg/kg is enough to decrease both gastric juice acidity and volume in this high-risk group.

Effects of Preoperative Oral Fruit Juices on Gastric olume and pH in Children / 대한마취과학회지

Backgrounds: The purpose of fasting before surgery is to minimize the volume of gastric contents. A short fast after solid food increases gastric volume, but a small drink of clear fluid 2 to 3 hours preoperatively decreases gastric volume. This investigation examined the effects of a small drink of clear fruit juice 2 to 3 hours prior to anesthesia on gastric volume, gastric pH, thirst and hunger. METHODS: Two hundred eighty children whose ages were five to ten years, scheduled for elective surgery were randomly assigned to one of 7 groups. Group 1 continued to fast but in the other 6 groups the children drank 2 ml/kg, 3 ml/kg, or 4 ml/kg of clear fruit juice (orange or grape) 2 to 3 hours preoperatively. The degree of thirsty and hunger was checked. The volume of gastric contents was measured by syringe and the pH by pH meter. RESULTS: The children who drank fruit juice preoperatively had decreased gastric volume. The gastric pH was not significantly different with that of the control group. The degree of thirst and hunger was not significantly different with that of the control group. CONCLUSIONS: We conclude that a small drink of fruit juice 2 to 3 hours preoperatively is more preferable than 8 hours fasting.