Clinical Research Directory

The Almond Yogurt Study

The goal of this clinical trial is to explore how almond food structure influences gastric emptying rates when consumed by healthy adult women as part of a standardized breakfast meal. The main questions it aims to answer are: * Does the structure of almonds (whole, chopped, buttered) influence gastric emptying? * What is the correlation between chewing behaviour, gastric emptying, and changes in postprandial triacylglycerols and satiety (hormones and ratings) within the context of these different food structures?

Gastric Emptying and Enteral Nutrition Tolerance According to Vasopressor Dose in ICU Patients

This study investigates whether the dose of vasopressor medications (drugs that maintain blood pressure in shock) affects gastric emptying during tube feeding in the intensive care unit (ICU). Critically ill patients receiving vasopressors often develop impaired gastric motility, which reduces the effectiveness of enteral nutrition and increases the risk of aspiration. Gastric emptying will be objectively measured using bedside point-of-care ultrasound - a safe, painless imaging method - at three time points: before feeding (T0), at 1 hour (T1), and at 2 hours (T2) after restarting enteral nutrition following a 2-hour fasting period. Patients will be stratified into three groups based on norepinephrine equivalent dose (NEQ): Group 1 (no vasopressor, NEQ=0), Group 2 (low-to-moderate dose, NEQ \>0 to \<0.3 μg/kg/min), and Group 3 (high dose, NEQ ≥0.3 μg/kg/min). The primary outcome is gastric emptying rate (GER = (T0 volume - T2 volume) / 2 hours). Gastroparesis is defined as GER ≤0 mL/hour. Secondary outcomes include antrum cross-sectional area, agreement between ultrasound and aspirated gastric residual volume (Bland-Altman analysis), and enteral nutrition intolerance incidence. A subgroup analysis by shock type (septic, cardiogenic, hypovolemic, obstructive) will also be performed. The study aims to identify the vasopressor dose threshold at which gastric emptying is significantly impaired, and to support the use of bedside gastric ultrasound as an objective, non-invasive monitoring tool for enteral nutrition management in the ICU.

Assessments of Metabolic Responses to Acute Oral Administration of Sucrose, Glucose, and Fructose

This project aims to compare the acute metabolic effects of the three sweeteners sucrose, glucose, and fructose on GI hormones (GLP-1, PYY, CCK, GIP, and ghrelin). Furthermore, glycemic control, erythritol and xylitol concentrations, blood coagulation function , blood lipids, uric acid, high-sensitive C-reactive protein (hsCRP), complete blood count, gastric emptying, appetite-related sensations, and GI symptoms will be investigated.

Prevalence and Measurement of Delayed Gastric Emptying in Patients Receiving Extracorporeal Membrane Oxygenation

* The goal of this observational study is to learn whether the stomach takes longer to empty in patients on the intensive care unit who are receiving ECMO (a machine that temporarily takes over the role of the lungs and heart) compared to patients receiving support through a breathing machine (mechanical ventilation) only. It will also find the best way to measure stomach emptying at the bedside. * The main questions it aims to answer are: * What is the prevalence of slow stomach emptying and other stomach or bowel problems in patients receiving ECMO, compared to patients receiving mechanical ventilation but not receiving ECMO? (Stage A) * What is the best bedside method to measure stomach emptying in patients receiving ECMO? (Stage B) * Stage A of the study will involve measuring stomach emptying in study participants within four days of ICU admission, using two bedside methods: * 'Residual volumes' (removing liquid nutrition left in the stomach with a syringe, after this has been given through the participant's usual feeding tube) * A stomach ultrasound scan The researchers will check for differences between patients receiving ECMO versus no ECMO, and how this relates to the nutrition patients receive and how well or unwell they become in ICU. * In a smaller subgroup of patients receiving ECMO and participating in Stage B of the study, the researchers will also use scintigraphy. This is a standard research scan that tracks how the stomach empties by mixing a small, safe amount of radioactivity in the participant's usual liquid nutrition. The researchers will compare stomach emptying results from 'residual volumes' and stomach ultrasound with scintigraphy.

Effect of Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RA) on Gastric Emptying

This study aims to assess the effect of using Glucagon-like peptide-1 receptor agonists (GLP-1) receptor agonists on gastric emptying on surgical patients and whether specific guidelines need to be established for these patients. GLP-1 receptor agonists are mainly used for the treatment and mitigation of obesity and metabolic syndromes. One of their mechanisms of action is by delaying gastric emptying, hence increasing satiety. However, patients need to abstain from eating for a set amount of time before surgery to reduce the risk of aspiration. Hence patients who use GLP-1 receptor agonists may need more time to abstain eating (nil-per-os). In this study we aim to assess how much time is sufficient before surgery in these specific population of patients.

Exploring the Effects of Varying Fat:Carbohydrate Diet Permutations on Gastric Emptying and Metabolic Status Using Human Postprandial Model

The aim of this clinical trial is to investigate the effects of the meals moderated by fat and carbohydrate (CHO) quality along with varying macronutrient distribution (CHO: fat) on gut physiology and metabolic outcomes using the human postprandial model with healthy subjects. The main question\[s\] it aims to answer are: 1. How does meal composition with different polyunsaturated/saturated (P/S) ratio, glycemic index and macronutrient quantity affect lipemia and glycemia? 2. How does meal composition with different P/S ratio, Glycemic index and macronutrient quantity affect gastric emptying?

Effect of a Nutritional Formula Composed of Proteins and Carbohydrates on Gastric Emptying in Elderly Individuals

The objective of this clinical trial is to evaluate the effect of a nutritional formula composed of carbohydrates and proteins on gastric emptying in elderly individuals aged between 60 and 90 years. The main questions this study aims to answer are: * Does the nutritional formula composed of carbohydrates and proteins delay gastric emptying when compared to a formula composed only of carbohydrates? * Does the formula composed of carbohydrates and proteins cause gastrointestinal symptoms in the study population? The researchers will compare both formulas (carbohydrates and proteins vs. carbohydrates only) to answer the main question. Participants will be required to: * Attend the Nuclear Medicine Department after an 8-hour fast, on two separate days with a minimum interval of seven days for scintigraphy procedures. * Consume the offered formula in a randomized and blinded manner. * Report any gastrointestinal symptoms and complete visual analog scales for sensations such as hunger, satiety, and desire to eat.

Comparison of Residual Gastric Volume Between Children Who Drink Different Clear Oral Fluid Volume

According to the American Society of Anesthesiologists (ASA) fasting guideline for patients undergoing elective surgery, the 2-hour fasting period is suggested for clear oral fluid (including water, pulp-free juice and tea or coffee without milk). This guideline does not give any suggestions for proper volume of clear oral fluid intake. This study is a prospective randomized control trials in children aged 13 through 17 years who are scheduled for an elective upper GI endoscopy procedure in the Gastroenteral Procedure Unit (GPU) at Boston Children's Hospital. The participants will be randomly assigned into one of four groups: Group 1 will consume 3 ml/kg of clear fluid by mouth at 2-hour period before surgical scheduled time, Group 2 will consume 5 ml/kg, Group 3 will consume 7 ml/kg, and Group 4 will consume 10 ml/kg. The investigators plan to recruit 72 patients in each group and 288 patients for the whole study. Research team will collect patient's demographic data, vital signs, information about their EGD procedure. Then actual volume of the stomach content and acidity will be measured from the content that is suctioned from patient's stomach during upper GI endoscopy procedure. The investigators believe that the information from this study will help establish a comprehensive NPO guideline.

Gastric Emptying in Neonates and Infants After Formula Feeding

Ultrasound imaging will be used to evaluate time for gastric emptying in healthy, fasting newborns, and infants following feeding of clear liquids and/or milk (including breast or formula).

Cold vs Warm Enteral Feeding and Gastric Emptying in Adult ICU Patients

In critically ill patients receiving enteral nutrition in the intensive care unit, the functional capacity of the gastrointestinal system can be significantly influenced by the mode of nutritional support. The temperature of enteral feeding may exert potential effects on gastric emptying, intestinal motility, and nutrient absorption. However, the existing literature on the impact of feeding temperature is limited, and randomized or cross-over controlled studies directly comparing warm and cold enteral feeding are scarce. This study aims to systematically evaluate the effects of enteral feeding temperature on feeding tolerance (vomiting and aspiration), gastric emptying rate (gastric residual volume), and the incidence of diarrhea, thereby providing evidence to inform clinical practice.

Comparison of 'Sip Til Send' Regimens Prior to Elective Caesarean Delivery Using Bedside Gastric Ultrasound

'Sip Til send' is a liberal drinking policy that replaces fasting before a caesarean delivery, meaning that women waiting in hospital can freely drink sips of water until they are called from the ward for their delivery. Studies has shown that 'Sip Til send' is safe and it improves the experience around surgery. Separate from this, drinking carbohydrate-rich drinks at specified time intervals before surgery is also recommended by international guidelines as part of a package of care aimed at enhancing recovery from surgery, and studies demonstrate that carbohydrate drinks significantly lower hunger sensation before caesarean delivery. The aim of this study is to combine these two interventions and compare the effects of sipping water against sipping carbohydrate drinks whilst waiting for a caesarean delivery and look at the stomach contents before delivery to ensure it is a safe practice and look at how women rate the quality of their recovery to see which practice is preferred. We will recruit women due to have an elective caesarean delivery whilst awake with a spinal anaesthetic at the Rotunda Hospital and only include those who are fully fasted on their arrival and would be candidates for the current 'Sip Til Send' policy. They will then be assigned to one of two groups, the "water" group who will be encouraged to sip water whilst waiting for surgery, and the "carbohydrate" group who will be encouraged to sip a standardised carbohydrate-rich drink instead. Using a bedside ultrasound machine, we will image the stomach and estimate the volume of liquid contents on two occasions; first, following recruitment to the study when fully fasted and before starting 'Sip Til Send', and second is immediately prior to surgery. Fluid intake will be closely monitored, and all participants will be asked to complete a short questionnaire the day after their delivery that asks them to rate aspects of their recovery. Participants and their newborns will not undergo any additional invasive testing for the study. Participants and their newborns will not undergo any additional invasive testing for the study, but consent will be sought to test women's urine for ketones (collected from the catheter bag during surgery). Medical notes will also be looked at after discharge to identify adverse outcomes such as nausea or vomiting during surgery and low blood sugar in the newborn. The study should run for approximately 3 to 6 months.

Gastric Emptying of Water and Sports Drink in Labor

To determine the half time of the emptying of the stomach of women in early labor with and without epidural pain relief when drinking either water or a carbohydrate-based sports drink.

Stomach Processing and Emptying Evaluation With Diet and Ultrasound

Gastric content is a key risk factor for aspiration during anesthesia. Although standard fasting times are recommended, various factors-including GLP-1 receptor agonists,-can delay gastric emptying. Gastric ultrasound enables real-time, non-invasive assessment of gastric volume and can help tailor perioperative management. The aim of this study explores the effects of different meal types and physical activity on gastric emptying in healthy individuals.

Reference Values for Gastric Emptying Scintigraphy After Bariatric Surgery

Oesophageal and gastric scintigraphy evaluates the function of the gastrointestinal system including variables such as oesophageal transit and gastric emptying (GE). Some variables are known to change after bariatric surgery. In patients that have symptoms of pain or nausea after bariatric surgery, oesophageal and gastric scintigraphy plays an important role in determining the nature of symptoms and is necessary for adequate treatment. However, literature on reference values in the bariatric population are scarce. At this moment, quantitative evaluation of the scintigraphy cannot be performed and conclusions are based on visual interpretation. There is a need for a standardised scintigraphy protocol for the population that underwent bariatric surgery taking into account the changed anatomy and physiology. Then, reference values that describe the oesophageal transit and GE assessed using scintigraphy have to be determined.

POCUS for Gastric Emptying in Emergency Surgery

The goal of this clinical trial is to learn about the gastric emptying in adult patients that are going to operatin theatre due to an abdominal acute disease, for instance, intestinal obstruction or cholecystitis. This kind of patients are traditionally considered as a full stomach and the induction of anesthesia include rapid sequence intubation (RSI) in order to decrease the risk of aspiration . However, image technologies, like echography, allow the visualization of the stomach and to measure the amount and characteristics of the content lodged in the stomach. This information is vital to decide if RSI is necesary or not. The main question\[s\] it aims to answer are: * What is the percentages of full stomach in patient who come to the operating room due an abodiminal acute disease? * Are different variables, namely, time since diagnosis, use of antibiotics or non steroidal antiinflamatory drugs related with the content of the stomach? Participants will be evaluated with ecography to determinate the amount of content of the stomach before the surgery in the operating room.