UMobileNetV2 model for semantic segmentation of gastrointestinal tract in MRI scans.

Gastrointestinal (GI) cancer is leading general tumour in the Gastrointestinal tract, which is fourth significant reason of tumour death in men and women. The common cure for GI cancer is radiation treatment, which contains directing a high-energy X-ray beam onto the tumor while avoiding healthy organs. To provide high dosages of X-rays, a system needs for accurately segmenting the GI tract organs. The study presents a UMobileNetV2 model for semantic segmentation of small and large intestine and stomach in MRI images of the GI tract. The model uses MobileNetV2 as an encoder in the contraction path and UNet layers as a decoder in the expansion path. The UW-Madison database, which contains MRI scans from 85 patients and 38,496 images, is used for evaluation. This automated technology has the capability to enhance the pace of cancer therapy by aiding the radio oncologist in the process of segmenting the organs of the GI tract. The UMobileNetV2 model is compared to three transfer learning models: Xception, ResNet 101, and NASNet mobile, which are used as encoders in UNet architecture. The model is analyzed using three distinct optimizers, i.e., Adam, RMS, and SGD. The UMobileNetV2 model with the combination of Adam optimizer outperforms all other transfer learning models. It obtains a dice coefficient of 0.8984, an IoU of 0.8697, and a validation loss of 0.1310, proving its ability to reliably segment the stomach and intestines in MRI images of gastrointestinal cancer patients.

Rapunzel syndrome in children: a retrospective review of ten cases combined with literature review in a tertiary referral center.

PURPOSE: Rapunzel syndrome is an uncommon condition in children, and its clinical features remain unclear. This study presents the largest single-center series of pediatric cases to date, with the objective of documenting the clinical characteristics and treatment approaches for children with Rapunzel syndrome. METHODS: A retrospective study was conducted in children with Rapunzel syndrome from 2019 to 2023. We recorded age, gender, symptoms, locations of bezoar, complications, and treatment options. RESULTS: Ten patients with Rapunzel syndrome were included. The median age was 9.1 years, with all of whom were female. The most common clinical symptoms were upper abdominal mass (90%), abdominal pain (80%), and nausea and vomiting (50%). Complications occurred in six cases (60%), including small bowel obstruction (20%), severe gastric dilatation (10%), intestinal perforation (10%), choledochodilation (10%), acute pancreatitis with cholecystitis (10%). Preoperative ultrasonography suggested low-echoic foreign bodies continuing to the jejunum or ileocecal region in five cases (50%). Preoperative gastroscopy attempted in four cases (40%) to remove the foreign bodies, all of which failed. All patients underwent surgical treatment, with nine cases undergoing gastric incision foreign body removal, and one case undergoing gastric incision foreign body removal combined with intestinal perforation repair. All patients recovered well. No recurrence was observed during follow-up. CONCLUSION: The accuracy of ultrasound diagnosis in identifying Rapunzel syndrome is high; however, it may lead to misdiagnosis if not complemented with the patient's medical history. Endoscopic presents a heightened treatment risk and a reduced success rate. The condition commonly presents with severe complications, thus making laparotomy a safe and effective option for intervention.

Implementing an electromagnetic tracking navigation system improves the precision of endoscopic transgastric necrosectomy in an ex vivo model.

Endoscopic transgastric necrosectomy is crucial in the management of complications resulting from necrotizing pancreatitis. However, both real-time and visual-spatial information is lacking during the procedure, thereby jeopardizing a precise positioning of the endoscope. We conducted a proof-of-concept study with the aim of overcoming these technical difficulties. For this purpose, a three-dimensional (3D) phantom of a stomach and pancreatic necroses was 3D-printed based on spatial information from individual patient CT scans and subsequently integrated into a silicone torso. An electromagnetic (EM) sensor was adjusted inside the endoscope´s working channel. A software interface enabled real time visualization. The accuracy of this novel assistant system was tested ex vivo by four experienced interventional endoscopists who were supposed to reach seven targets inside the phantom in six different experimental runs of simulated endoscopic transgastric necrosectomy. Supported by endoscopic camera view combined with real-time 3D visualization, all endoscopists reached the targets with a targeting error ranging between 2.6 and 6.5 mm in a maximum of eight minutes. In summary, the EM tracking system might increase efficacy and safety of endoscopic transgastric necrosectomy at the experimental level by enhancing visualization. Yet, a broader feasibility study and further technical improvements are mandatory before aiming at implementation into clinical setting.

Role of indocyanine green fluorescence imaging for evaluating blood supply in the gastric conduit via the substernal route after McKeown minimally invasive esophagectomy.

BACKGROUND: Anastomotic leakage (AL) is a determining factor of morbidity and mortality after esophagectomy. Adequate perfusion of the gastric conduit is crucial for AL prevention. This study aimed to determine whether intraoperative angiography using indocyanine green (ICG) fluorescence improves the incidence of AL after McKeown minimally invasive esophagectomy (MIE) with gastric conduit via the substernal route (SR). METHODS: This retrospective cohort study included 120 patients who underwent MIE with gastric conduit via SR for esophageal cancer between February 2019 and April 2023. Of 120 patients, 88 experienced intraoperative angiography using ICG (ICG group), and 32 patients experienced intraoperative angiography without ICG (no-ICG group). Baseline characteristics and operative outcomes, including AL as the main concern, were compared between the 2 groups. In addition, the outcomes among patients in the ICG group with different levels of fluorescence intensity were compared. RESULTS: The ICG and no-ICG groups were comparable in baseline characteristics and operative outcomes. There was no significant difference between the 2 groups regarding the rate of AL (31.0% vs 37.5%; P = .505), median dates of AL (9 vs 9 days; P = .810), and severity of AL (88.9%, 11.11%, and 0.0% vs 66.7%, 16.7%, and 16.7% for grades I, II, and III, respectively; P = .074). Patients in the ICG group with lower intensity of ICG had higher rates of leakage (24.6%, 39.3%, and 100% in levels I, II, and III of ICG intensity, respectively; P = .04). CONCLUSION: The use of ICG did not seem to reduce the rate of AL. However, abnormal intensity of ICG fluorescence was associated with a higher rate of AL, which implies a predictive potential.

Ovarian serous carcinoma with stomach metastasis: a rare case report and literature review.

Ovarian cancer is a common tumor among women. It is often asymptomatic in the early stages, with most cases already at stage III to IVE at the time of diagnosis. Direct spread and lymphatic metastasis are the primary modes of metastasis, whereas hematogenous spread is rare. An initial diagnosis of ovarian cancer that has metastasized to the stomach is also uncommon. Therefore, clear treatment methods and prognostic data for such metastasis are lacking. In our hospital, we encountered a patient with an initial imaging diagnosis of a gastric tumor and a history of an ovarian tumor with endoscopic abdominal metastasis. Based on the characteristics of the case, the two tumors were considered to be the same. After chemotherapy, a partial response was observed in the stomach and pelvic lesions, suggesting the effectiveness of the treatment. Through three treatments of recurrence, gastroscopy confirmed the stomach to be a metastatic site. Therefore, determining the primary source of advanced tumors is crucial in guiding treatment decisions. Clinicians must approach this comprehensively, relying on thorough evaluation and personal experience.

Bridging the gap: understanding Belgian anesthesiologists' proficiency and training demands in gastric point-of-care ultrasound, a case-based survey.

BACKGROUND: Pulmonary aspiration syndrome remains a significant complication of general anesthesia, particularly in unfasted patients. Gastric point-of-care ultrasound (POCUS) allows for both qualitative and quantitative assessment of gastric content, providing a safe and reliable method to assess gastric emptying and reduce the risk of aspiration during general anesthesia. METHODS: The survey was distributed to Belgian certified anesthesiologists and trainees between April 2020 and June 2021. Participants received a simulated clinical case of a patient at risk of gastric aspiration, created and approved by two certified anesthesiologists trained to perform gastric POCUS. The objectives of this study were to assess recognition of high-risk clinical situations for gastric aspiration, awareness of the gastric POCUS and its indications, and knowledge of the technical and practical conditions of the procedure among respondents trained in the technique. Furthermore, the study assessed the state of training in gastric POCUS, the desire for education, and the practical availability of ultrasound equipment. The survey used conditional branching to ensure unbiased responses to POCUS-related questions. It included multiple-choice questions, quantitative variables, and 5-point Likert scales. The margin of error was calculated using Daniel's formula, corrected for a finite population. RESULTS: The survey was conducted among 323 anesthesiologists. Only 20.8% (27) recognized the risk of a full stomach based on the patient's history. Anesthesiologists who recognized the indication for gastric POCUS and were trained in the procedure demonstrated good recall of the practical conditions for performing the procedure and interpreting the results. Only 13.08% (31) of all respondents had received training in gastric POCUS, while 72.57% (172) expressed interest in future training. Furthermore, 80.17% (190) of participants had access to adequate ultrasound equipment and 78.90% (187) supported teaching gastric POCUS to anesthesia trainees. CONCLUSIONS: This survey offers insight into the epidemiology, clinical recognition, knowledge, and utilization of gastric POCUS among Belgian anesthesia professionals. The results emphasize the significance of proper equipment and training to ensure the safe and effective implementation of gastric POCUS in anesthesia practice. Additional efforts should focus on improving training and promoting the integration of gastric POCUS into daily clinical practice.

Use of Magnetic Resonance Imaging for Visualization of Oral Dosage Forms in the Human Stomach: A Scoping Review.

Oral dosage forms are the most widely and frequently used formulations to deliver active pharmaceutical ingredients (APIs), due to their ease of administration and noninvasiveness. Knowledge of intragastric release rates and gastric mixing is crucial for predicting the API release profile, especially for immediate release formulations. However, knowledge of the intragastric fate of oral dosage forms in vivo to date is limited, particularly for dosage forms administered when the stomach is in the fed state. An improved understanding of gastric food processing, dosage form location, disintegration times, and food effects is essential for greater understanding for effective API formulation design. In vitro standard and controlled modeling has played a significant role in predicting the behavior of dosage forms in vivo. However, discrepancies are reported between in vitro and in vivo disintegration times, with these discrepancies being greatest in the fed state. Studying the fate of a dosage form in vivo is a challenging process, usually requiring the use of invasive methods, such as intubation. Noninvasive, whole body imaging techniques can however provide unique insights into this process. A scoping review was performed systematically to identify and critically appraise published studies using MRI to visualize oral solid dosage forms in vivo in healthy human subjects. The review identifies that so far, an all-purpose robust contrast agent or dosage form type has not been established for dosage form visualization and disintegration studies in the gastrointestinal system. Opportunities have been identified for future studies, with particular focus on characterizing dosage form disintegration for development after the consumption food, as exemplified by the standard Food and Drug Administration (FDA) high fat meal.

Blood flow evaluation of reconstructed gastric tube in esophageal surgery using near-infrared imaging and retrospective time-intensity curve analysis.

PURPOSE: Near-infrared fluorescence imaging using indocyanine green (ICG-NIFI) can visualize a blood flow in reconstructed gastric tube; however, it depends on surgeon's visual assessment. The aim of this study was to re-analyze the ICG-NIFI data by an evaluator independent from the surgeon and feasibility of creating the time-intensity curve (TIC). METHODS: We retrospectively reviewed 97 patients who underwent esophageal surgery with gastric tube reconstruction between January 2017 and November 2022. From the stored ICG videos, fluorescence intensity was examined in the four regions of interest (ROIs), which was set around the planned anastomosis site on the elevated gastric tube. After creation the TICs using the OpenCV library, we measured the intensity starting point and time constant and assessed the correlation between the anastomotic leakage. RESULTS: Postoperative leakage occurred for 12 patients. The leakage group had significantly lack of blood flow continuity between the right and left gastroepiploic arteries (75.0% vs. 22.4%; P < 0.001) and tended to have slower ICG visualization time assessed by the surgeon's eyes (40 vs. 32 s; P = 0.066). TIC could create in 65 cases. Intensity starting point at all ROIs was faster than the surgeon's assessment. The leakage group tended to have slower intensity starting point at ROI 3 compared to those in the non-leakage group (22.5 vs. 19.0 s; P = 0.087). CONCLUSION: A TIC analysis of ICG-NIFI by an independent evaluator was able to quantify the fluorescence intensity changes that the surgeon had visually determined.

Comparison of gastric emptying time between breast-fed and formula milk-fed infants less than 6 months old, using gastric ultrasound-An observational study.

BACKGROUND: Fasting before elective anesthesia care is a standardized practice worldwide. The aim is to decrease the risk of aspiration leading to pulmonary complications such as aspiration pneumonitis during anesthesia care. There are different guidelines for elective preoperative fasting in children. However, there is insufficient literature measuring gastric emptying time after breast milk or formula milk feeding in infants. OBJECTIVE: This study used gastric ultrasound to determine the gastric emptying time for breast milk and formula milk in children below 6 months of age. We also compared the calculated gastric volumes among breast-fed and formula milk-fed based on Schmitz's and Spencer's formula. MATERIALS AND METHODS: This prospective observational study was conducted at a tertiary care center in India between November (2017-2019). A total of 52 infants less than 6 months of age were recruited. The study population was divided into two groups (breast-fed and formula milk-fed) of 26 patients each. Ultrasound was used to measure the antral cross-sectional area of the stomach and to calculate the gastric volume using the two classical formulas (Schmitz and Spencer's). Gastric emptying was reported when the bull's eye appearance of the gastric antrum was seen or when the antral cross-sectional area was less than 3.07 cm2. RESULTS: The number of breast-fed children whose antral cross-sectional was greater than 3.07 cm2 (cut-off value for aspiration risk) beyond 1 h was 14/26 (53.84%) while none (0) children went beyond 3 h. The number of formula-fed children whose antral cross-sectional was greater than 3.07 cm2 beyond 1 h was 17/26 (65.38%) while one child (3.84%) went beyond 3 h. Using Schmitz's formula, mean (SD) gastric emptying times were 0.35 ± 0.68 h (95% CI 0.35 ± 0.185, range 0.165-0.535) for breast-fed patients and 0.35 ± 0.69 h (95% CI 0.35 ± 0.188, range 0.162-0.538) for formula-fed patients, and were thus neither clinically nor statistically different (p = .73) Using Spencer's formula, the mean gastric emptying times were 0.12 ± 0.33 h (95% CI 0.12 ± 0.09, range 0.03-0.21) for breast-fed patients and 0.04 ± 0.20 h (95% CI 0.04 ± 0.05, range -0.01 to 0.09) for formula-fed patients, and were also neither clinically nor statistically different p = .13. CONCLUSION: In our series, the gastric emptying times in breast-fed and formula-fed infants less than 6 months old were similar. Our results support the fasting guidelines of the European Society of Anaesthesiology and Intensive Care 2022, that is, 3 h for breastfeeding and 4 h for formula milk feeding. In addition, this shows that the Schmitz's and Spencer's formulae used to calculate the gastric volume based on ultrasound measurement of the antral cross-sectional area are not comparable in infants less than 6 months.

Point-of-Care Gastric Ultrasound to Identify a Full Stomach on a Diabetic Patient Taking a Glucagon-Like Peptide 1 Receptor Agonist.

Recently, there has been increased interest in the relationship between glucagon-like peptide 1 (GLP-1) receptor agonists, delayed gastric emptying, and subsequent risk of aspiration in the perioperative setting. This case illustrates how gastric ultrasound can be incorporated at the bedside to assess the risk of aspiration in patients taking this type of medication for diabetes or weight loss and guide clinical management and anesthetic technique to reduce the risk of aspiration.

Differences in neonatal gastric tubes during insertion into a 3D model in relation to risk of potential perforation.

OBJECTIVES: Perforation of esophagus or stomach is a potential complication during and after insertion of a gastric tube in neonates. The aim of this study was to analyze different types of gastric tubes in a three-dimensional (3D) model of neonatal esophagus and stomach regarding potential perforations. METHODS: A 3D model of esophagus and stomach was created based on computed tomography data of a term neonate. Three types of gastric tubes were inserted into the 3D model, the localization was examined by radioscopy and the behavior, stiffness and manageability of each gastric tube was evaluated. RESULTS: Insertion of gastric tubes with higher stiffness was easier. The rates of correct localization differed significantly between the gastric tubes with the highest rate of correct localization in the softest tube (48.5%) and the lowest rate in the tube with the highest stiffness (21.2%). Additionally, the softest tube showed the lowest rate of localization of its tip at the stomach wall. CONCLUSIONS: The study illustrates differences between various types of gastric tubes regarding stiffness, behavior and resiliency. Softer gastric tubes may be beneficial. These differences may be relevant in neonatal care of very immature and very sick infants.

Ultrasound evaluation of gastric residual volume in fasting end-stage renal failure patients.

STUDY OBJECTIVE: To evaluate the gastric contents and gastric residual volume in patient with end-stage renal failure by gastric ultrasound. DESIGN: Prospective observational study. SETTING: Tertiary care teaching hospital. PATIENTS: Adults of either gender with BMI < 40 kg/m2 with end-stage renal failure scheduled to undergo arteriovenous graft or fistula. INTERVENTIONS & MEASUREMENTS: The cross-sectional area of the gastric antrum was measured by gastric ultrasound with patient in both supine and right lateral decubitus positions. The volume of the gastric contents were calculated using suitable validated formula. In addition, the nature of the gastric contents was also determined by gastric ultrasound. MAIN RESULTS: The incidence of delayed gastric emptying was found to be 57.7% in the population studied despite following the prescribed preoperative standard fasting guidelines. CONCLUSIONS: There is a high incidence of delayed gastric emptying in patients with end-stage renal failure presenting for surgery which may predispose them to risk of pulmonary aspiration perioperatively.

The safety of preoperative carbohydrate drinks in extremely elderly patients assessed by gastric ultrasonography: a randomized controlled trial.

BACKGROUND: Modern perioperative guidelines encourage drinking oral carbohydrates 2 h before management. Nevertheless, research on the safety of preoperative carbohydrate drinks, particularly in extremely elderly patients is lacking. We aimed to evaluate the safety of carbohydrate drinks 2 h before surgery in extremely elderly patients (≥ 80 years) using gastric ultrasonography. METHODS: We conducted a randomized prospective comparative study of 70 patients aged over 80 years who were scheduled for total knee arthroplasty, hip fracture or humerus fracture surgery. These patients were randomly assigned to the carbohydrate group (n = 35), which fasted from midnight, except for drinking 355 mL of a carbohydrate-containing fluid 2 h before surgery, or the fasting group (n = 35), which fasted from midnight and drank no fluid before surgery. The primary outcome of the study was the cross-sectional area (CSA) of the gastric antrum in the right lateral decubitus position (RLDP) before surgery. The secondary outcomes included CSA in the supine position, intraoperative blood glucose levels and their variability coefficients, Perlas grade, and the visual analog scale of subjective feelings. RESULTS: The CSA in the RLDP and supine positions revealed no differences between the carbohydrate and fasting groups at 0 h preoperatively (P > 0.05). In the qualitative assessment, preoperative 0-h Perlas grading did not differ significantly between the groups (P > 0.05). From 2 h before surgery to transfer out of the post-anesthesia care unit, the average blood glucose level of patients in the carbohydrate group was significantly higher than that in the fasting group (P < 0.001) but remained within the normal range. Moreover, the blood glucose variability coefficient was significantly lower in the carbohydrate group than in the fasting group (P = 0.009). Oral intake of 355 mL carbohydrates before surgery significantly relieved patients' feelings (P < 0.001). CONCLUSION: Preoperative consumption of carbohydrate drinks 2 h before surgery is safe in "healthy" extremely elderly patients. In addition, preoperative drinking has potential value in maintaining ideal blood glucose levels and stable blood glucose fluctuations perioperatively and improving subjective perceptions of preoperative preparation. This finding warrants further investigation in clinical practice. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Registration Number ChiCTR1900024812), first registered on 29/07/2019.

The Effect of Prolonged Face Mask Ventilation on Gastric Insufflation: A Prospective Observational Study.

BACKGROUND: Pulmonary aspiration is a potentially lethal perioperative complication that can be precipitated by gastric insufflation. Face mask ventilation (FMV), a ubiquitous anesthetic procedure, can cause gastric insufflation. FMV with an inspiratory pressure of 15 cm H2O provides the best balance between adequate pulmonary ventilation and a low probability of gastric insufflation. There is no data about the effects of FMV > 120 seconds. OBJECTIVES: To investigate the effect of prolonged FMV on gastric insufflation. METHODS: We conducted a prospective observational study at a tertiary medical center with female patients who underwent oocyte retrieval surgery under general anesthesia FMV. Pre- and postoperative gastric ultrasound examinations measured the gastric antral cross-sectional area to detect gastric insufflation. Pressure-controlled FMV with an inspiratory pressure of 15 cm H2O was continued from the anesthesia induction until the end of the surgery. RESULTS: The study comprised 49 patients. Baseline preoperative gastric ultrasound demonstrated optimal and good image quality. All supine measurements were feasible. The median duration of FMV was 13 minutes (interquartile range 9-18). In the postoperative period, gastric insufflation was detected in only 2 of 49 patients (4.1%). There was no association between the duration of FMV and delta gastric antral cross-sectional area (ß -0.01; 95% confidence interval -0.04 to 0.01, P = 0.31). CONCLUSIONS: Pressure-controlled FMV with an inspiratory pressure of 15 cm H2O carries a low incidence of gastric insufflations, not only as a bridge to a definitive airway but as an alternative ventilation method for relatively short procedures in selective populations.

Endoscopic sleeve gastroplasty: stomach location and task classification for evaluation using artificial intelligence.

PURPOSE: We have previously developed grading metrics to objectively measure endoscopist performance in endoscopic sleeve gastroplasty (ESG). One of our primary goals is to automate the process of measuring performance. To achieve this goal, the repeated task being performed (grasping or suturing) and the location of the endoscopic suturing device in the stomach (Incisura, Anterior Wall, Greater Curvature, or Posterior Wall) need to be accurately recorded. METHODS: For this study, we populated our dataset using screenshots and video clips from experts carrying out the ESG procedure on ex vivo porcine specimens. Data augmentation was used to enlarge our dataset, and synthetic minority oversampling (SMOTE) to balance it. We performed stomach localization for parts of the stomach and task classification using deep learning for images and computer vision for videos. RESULTS: Classifying the stomach's location from the endoscope without SMOTE for images resulted in 89% and 84% testing and validation accuracy, respectively. For classifying the location of the stomach from the endoscope with SMOTE, the accuracies were 97% and 90% for images, while for videos, the accuracies were 99% and 98% for testing and validation, respectively. For task classification, the accuracies were 97% and 89% for images, while for videos, the accuracies were 100% for both testing and validation, respectively. CONCLUSION: We classified the four different stomach parts manipulated during the ESG procedure with 97% training accuracy and classified two repeated tasks with 99% training accuracy with images. We also classified the four parts of the stomach with a 99% training accuracy and two repeated tasks with a 100% training accuracy with video frames. This work will be essential in automating feedback mechanisms for learners in ESG.

Gastric Volume and Antral Area in the Fasting State: A Meta-analysis of Individual Patient Data.

BACKGROUND: Pulmonary aspiration of gastric content is a serious anesthetic complication. Gastric point-of-care ultrasound can determine the type and volume of gastric content when clinical information is equivocal. However, a cutoff value of either antral cross-sectional area or volume that may be considered as the upper limit of normal in fasting subjects is still controversial. The aim of this study is to characterize the distribution of baseline antral area and volume in fasting adult subjects and to identify an upper limit (95th percentile) of these distributions. METHODS: The authors conducted a meta-analysis of individual participant data of primary studies from an academic research network of investigators collaborating in gastric ultrasound. Studies between January 2009 and December 2020 were included. RESULTS: Twelve primary studies met inclusion criteria and were included in the analysis with a sample size of 1,203 subjects. The 95th percentile of area values (measured in the right lateral decubitus) was 9.9 cm2 (95% CI, 9.4 to 10.4), and of volume, 2.3 ml/kg (95% CI, 2.3 to 2.4). In addition, an antrum grade 0 or 1 indicates a 98% probability of an antral area below the 95th percentile. CONCLUSIONS: An area of 10 cm2 measured in the right lateral decubitus could be a simple, data-driven upper limit of antral area that could serve as a surrogate of upper limit of normal gastric volume values in fasting adults. These results are limited by the highly selected sampling of the studies included.

Ultrasound evaluation of gastric emptying time of standardized high-calorie liquid meals in healthy adults: A double-blind cross-over randomized study.

BACKGROUND AND AIMS: Commercially available high-calorie drinks containing fat and protein can be used as dietary supplements in surgical patients. According to preoperative fasting guidelines, high-calorie drinks are non-clear fluids and should not be consumed 6 h before elective procedures. The aim of this study was to evaluate the gastric emptying time of commercially available high-calorie drink formulations in healthy adults using gastric ultrasound. METHODS: 25 healthy adult volunteers were included in this double-blind, cross-over prospective study. On three study sessions, fasted volunteers ingested one of the three study products: a solution of 75 g of glucose in 200 ml of water, a fat-free liquid meal, and a nutritionally complete liquid meal with equal volume and energy content. Gastric ultrasound examinations were performed to evaluate the gastric contents qualitatively and the volume of the gastric contents was calculated from the cross-sectional area of the gastric antrum measured in right lateral position by using a validated model. Repeated gastric ultrasounds were performed at baseline and half-hourly after ingesting the products in supine and right lateral position until the criteria for an empty stomach were met. RESULTS: The glucose solution and the standard fat-free high-calorie drink with the same caloric content had a median gastric emptying time of 150 min. The nutritionally complete liquid meal had a median gastric emptying time of 180 min. Gastric emptying was complete in all participants before 6 h had elapsed since ingesting the study products. CONCLUSIONS: High calorie liquid meals have a gastric emptying time longer than the recommended fasting time for clear fluids, but shorter than the recommended fasting time for solids in healthy adults.

Bioadhesive behaviors of HPMC E5: comparative analysis of various techniques, histological and human radiological evidence.

Enhancing drug residence duration within the stomach offers distinct advantages for both localized and systemic effects. Numerous strategies have been proposed to extend drug residence time, with mucoadhesive polymers being a notable avenue. In this context, hydroxypropyl methylcellulose E5 has been employed as both a binding agent for granulating contrast metal powder and a mucoadhesive polymer, spanning various concentrations. The in vitro bioadhesion strength of the formulated tablets was gauged against the stomach lining of rabbits, for the quantification of bioadhesive forces. The temporal aspect of bioadhesion was evaluated through two approaches: one centered on gastric fluid dynamics and another proffered by the researchers, focusing on gastric wall kinetics. The results divulged a decline in bioadhesion force concomitant with high polymer concentrations. Histological examination of stained stomach sections revealed mucosal perturbations within the rabbit stomach. These disruptions exhibited an escalating trend in conjunction with elevated polymer concentrations, culminating in extensive disturbance at a 7.5% polymer concentration. The outcomes unveiled a direct relationship between polymer concentration increments and extended contact time. Subsequent radiological tracking of contrast metal behavior within a mature human stomach indicated a residence time of 6 h due to the entrapment of displaced components at disparate locations.

Diagnostic accuracy of a simple qualitative ultrasound assessment for the diagnosis of high-risk gastric contents in the parturient. A prospective observational cohort study.

STUDY OBJECTIVE: Interpretation of gastric ultrasound relies on the use of a clinical algorithm that combines qualitative analysis of the gastric antrum contents with the calculation of the volume of fluid contents. This reference method may be difficult to apply in the parturient. We therefore aimed to assess the diagnostic accuracy of a simple qualitative assessment in the supine position for the diagnosis of high-risk gastric contents in the parturient. We also assessed the diagnostic accuracy of a composite scale and another clinical algorithm based on a mathematical model different to that used in the reference method. DESIGN: Prospective observational cohort study. SETTING: University hospital, Lyon, France. PATIENTS: Adult women admitted to the delivery room. INTERVENTIONS: Qualitative and quantitative gastric ultrasound examination within the first hour following admission. MEASUREMENTS: With respect to the reference method, the diagnostic accuracy of a simple qualitative assessment for the diagnosis of high-risk gastric contents was assessed. The diagnostic accuracy of a composite scale and another clinical algorithm, and the agreement between each approach were also assessed. MAIN RESULTS: A total of 235 parturients were included and analyzed. The simple qualitative assessment led to conclusive ultrasound assessment in 233 (99%) women, while the reference method led to conclusive assessment in 213 (91%) women (P < 0.05). The sensitivity and the specificity of the simple qualitative assessment were 97% (95%CI: 93 to 99%) and 96% (95%CI: 90 to 99%), respectively. These were not significantly different from those of the composite scale and the clinical algorithm. The four approaches showed almost perfect agreement with each other. CONCLUSIONS: These results suggest that simple qualitative assessment may be useful in clinical practice to help the anesthesiologist in the assessment of gastric contents status and risk of aspiration.