Gastric emptying during and following resolution of moderate diabetic ketoacidosis in type 1 diabetes: a case series.

INTRODUCTION: To use the 'gold standard' technique of scintigraphy to quantify gastric emptying (GE) as soon as practicable during an admission with diabetic ketoacidosis (DKA) and following its resolution at least 7 days later. RESEARCH DESIGN AND METHODS: Five patients with type 1 diabetes, age 29±12 years; Body Mass Index 23±3 kg/m2; hemoglobin A1c 11.3%±1.9%, were studied during an admission with DKA and following its resolution. Solid and liquid GE were measured using scintigraphy. Solid emptying was assessed via the percentage intragastric retention at 100 min and that of liquid by the 50% emptying time. RESULTS: There was no difference in either solid or liquid GE at the initial study compared with the follow-up. Median (IQR) solid retention was 47±20 versus 38%±33%, respectively; p=0.31, and time to empty 50% of liquid was 37±25 min versus 35±15 min, p=0.31, at the initial and follow-up GE study, respectively. CONCLUSIONS: GE of solids and liquids is not affected by moderate DKA, inferring that earlier reintroduction of oral intake may be appropriate.

Gastric emptying of a glucose drink is predictive of the glycaemic response to oral glucose and mixed meals, but unrelated to antecedent glycaemic control, in type 2 diabetes.

BACKGROUND: Gastric emptying (GE), with wide inter-individual but lesser intra-individual variations, is a major determinant of postprandial glycaemia in health and type 2 diabetes (T2D). However, it is uncertain whether GE of a carbohydrate-containing liquid meal is predictive of the glycaemic response to physiological meals, and whether antecedent hyperglycaemia influences GE in T2D. We evaluated the relationships of (i) the glycaemic response to both a glucose drink and mixed meals with GE of a 75 g glucose drink, and (ii) GE of a glucose drink with antecedent glycaemic control, in T2D. METHODS: Fifty-five treatment-naive Chinese adults with newly diagnosed T2D consumed standardised meals at breakfast, lunch and dinner with continuous interstitial glucose monitoring. On the subsequent day, a 75 g glucose drink containing 150 mg 13C-acetate was ingested to assess GE (breath test) and plasma glucose response. Serum fructosamine and HbA1c were also measured. RESULTS: Plasma glucose incremental area under the curve (iAUC) within 2 hours after oral glucose was related inversely to the gastric half-emptying time (T50) (r = -0.34, P = 0.012). The iAUCs for interstitial glucose within 2 hours after breakfast (r = -0.34, P = 0.012) and dinner (r = -0.28, P = 0.040) were also related inversely to the T50 of oral glucose. The latter, however, was unrelated to antecedent fasting plasma glucose, 24-hour mean interstitial glucose, serum fructosamine, or HbA1c. CONCLUSIONS: In newly diagnosed, treatment-naive, Chinese with T2D, GE of a 75 g glucose drink predicts the glycaemic response to both a glucose drink and mixed meals, but is not influenced by spontaneous short-, medium- or longer-term elevation in glycaemia.

Gastrointestinal radionuclide imaging in pediatric age group.

Pediatric gastrointestinal imaging plays a crucial role in evaluating and managing digestive system disorders in children. This comprehensive review dives into the nuances of pediatric gastrointestinal imaging techniques, focusing on three specific modalities: gastric emptying scintigraphy (GES), intestinal transit scintigraphy (ITS), and gastrointestinal bleeding scintigraphy. GES involves real-time monitoring of stomach emptying using radiotracers and gamma camera technology. While challenges exist in standardizing protocols due to age-specific meal compositions, GES remains pivotal in diagnosing motility disorders, gastroesophageal reflux, and abdominal pain in children. ITS, utilizing [67Ga], provides insights into gastrointestinal motility disorders such as Hirschsprung disease. It aids in whole-gut transit evaluation, guiding surgical interventions and improving long-term clinical outcomes. Gastrointestinal bleeding scintigraphy, employing [99mTc], assists in diagnosing conditions like Meckel's diverticulum and occult bleeding, offering continuous monitoring to pinpoint the bleeding site along the entire gastrointestinal tract. SPECT-CT improves the accuracy and the standards of care. Each technique's protocol details, clinical indications, and diagnostic capabilities are thoroughly discussed, highlighting the importance of these non-invasive, functional imaging modalities in pediatric gastroenterology.

Universal Fasting Glucose Screening Before Gastric Emptying Scintigraphy and the High Prevalence of Undiagnosed Diabetes and Prediabetes.

The aim of this study was to assess the rates of undiagnosed diabetes mellitus (DM) and pre-DM in patients undergoing gastric emptying scintigraphy (GES). Diabetes is an epidemic in the United States, and the disease is associated with altered gut motility. As a result, we suspected that a significant number of patients referred for GES may have undiagnosed DM or pre-DM. Given that established procedure standards for GES require all patients to prepare with an 8-h fast, an opportunity is provided to measure the fasting blood glucose (FBG) in all individuals before they undergo the examination. Methods: The charts of patients undergoing GES were reviewed for a history of DM and correlated with FBG and GES results. FBG values, obtained by point-of-care testing, were categorized as normal, pre-DM, or DM. Results: Patients with known DM made up 23% of those referred for GES, and most (55%) had a normal FBG. In those without a history of DM, there were a significant number with undiagnosed pre-DM (12%) and DM (33%). Conclusion: Our study provides the first measure of the likely prevalence of undiagnosed DM and pre-DM and characterizes the different gastric emptying patterns among patients with normal FBG, likely undiagnosed pre-DM, likely undiagnosed DM, and known DM.

Gastric Emptying Studies in Pediatrics: A Cincinnati Children's Hospital Experience.

Gastric emptying studies are routinely performed in many nuclear medicine departments; however, there are many different techniques used to perform the procedure across the country. Creating consistency in clinical practice will aid gastroenterologists in diagnosing and treating illnesses associated with abnormalities related to gastric emptying. In 2017, Cincinnati Children's Hospital adopted adult standards for pediatric gastric emptying studies that included a standard meal along with imaging over the course of 4 h. Gastric emptying studies are the second-highest-volume examination performed in the nuclear medicine section at Cincinnati Children's Hospital. Accommodating this volume required changes in the scheduling template, scheduling questionnaire, and epic order sets, as well as identification of specific days and locations for gastric emptying studies. Both protocol standardization and workflow optimization are critically important in creating consistency in patient care. Gastric emptying can be evaluated with solid food, liquid food, or solid and liquid food simultaneously. The methodology of the study is initially determined by the ordering provider but may require special accommodations based on what the patient will tolerate. In coordination with the ordering and interpreting physicians, the nuclear medicine technologists at Cincinnati Children's Hospital have the decision-making ability to deviate from the provider's request as necessary, which helps expedite workflow and eliminates wasted time. Any deviation from the standardized protocol is documented by the nuclear medicine technologist and incorporated into the final report by the interpreting physician, as dietary information is meaningful to the ordering provider. Reference values associated with the standardized or modified protocol are also included in the final report.

Glucagonlike Peptide-1 Receptor Agonists: The Good, the Bad, and the Ugly-Benefits for Glucose Control and Weight Loss with Side Effects of Delaying Gastric Emptying.

Glucagonlike peptide-1 (GLP-1) receptor agonists (RAs) are being increasingly used for glycemic control in patients with diabetes and for weight loss and weight management in obese subjects. There has been recent public awareness of the potential of GLP-1 RAs to delay gastric emptying and cause gastroparesis. By delaying gastric emptying, these agents can complicate the clinical evaluation of patients on these drugs by affecting diagnostic testing for gastroparesis. This article discusses GLP-1 RAs and their effects on gastric emptying, gastric food retention, and gastroparesis. This article highlights how physicians should be attuned to the gastric side effects of these popular therapeutic agents for blood glucose control in people with diabetes and for weight loss and weight management in obese patients.

Gastric Emptying Solid-Meal Content and Misinformation on Social Media Platforms.

Several nuclear medicine technologist-specific groups exist on social media sites such as Facebook and LinkedIn. Although these sites provide a valuable resource and forum for technologists to interact and pose questions, any recommendations, especially those regarding patient care, should be carefully scrutinized and evaluated on the basis of scientific merit and not opinion. Recently, an assortment of unvalidated ingredients for solid-meal gastric emptying scintigraphy has been suggested on these social media sites. Often, these ingredients do not comply with the peer-reviewed guidelines and can potentially produce unreliable results and misdiagnosis. Thus, before implementing advice from an unvetted source, technologists must distinguish between low- and high-quality information. Currency, reliability, authority, and purpose-a test of the trustworthiness of an information source-can help technologists evaluate recommendations and avoid the use of unsupported solid-meal gastric emptying scintigraphy ingredients.

Change in Management After Radionuclide Gastric Emptying Studies Showing Slow Emptying.

The radionuclide gastric emptying study is the gold standard for the diagnosis of gastroparesis. Methods: We performed a retrospective analysis of 510 patients to evaluate how often a diagnosis of slow gastric emptying determined by gastric emptying scintigraphy (GES) changes clinical management at our institution. Results: We found evidence of gastroparesis in 100 patients. A change in management was recommended for 62% within 1 mo of the GES. Conclusion: Our results illustrate the importance of performing GES on patients with clinically suspected gastroparesis.

An Evaluation of Gastric Emptying Scintigraphy Protocols in Health Care Institutions When Compared with the Society of Nuclear Medicine and Molecular Imaging Procedure Guidelines.

This study aimed to analyze the compliance of health care institutions with the Society of Nuclear Medicine and Molecular Imaging (SNMMI) procedure guidelines for gastric emptying scintigraphy (GES). Methods: A 19-question survey on demographics and the GES protocol was conducted using a Google form. The demographic questions covered position, number of technologists in the department, location, type of health care institution, and number of GES studies per month. The protocol questions included patient preparation, meal preparation, withholding of scheduled medications, radiopharmaceutical type, and radiopharmaceutical dose. The survey was sent to 7 nuclear medicine Facebook groups and a list of clinical affiliates provided by the Indiana University School of Medicine Nuclear Medicine Program. Descriptive statistics were compiled for most questions. A Fisher exact test with a significance level of 0.05 was used to compare the type of health care institution with compliance with the SNMMI GES protocol regarding radiolabeling time, meal preparation, and meal components, as well as to compare the type of health care institution with the number of GES studies performed per institution. Results: In total, 240 people responded to the survey. Most were nonsupervisory nuclear medicine technologists (72%) in nonacademic institutions (72%) and groups with 4 or more technologists (62%). Of the respondents, 72% followed the SNMMI guideline of adding the radiopharmaceutical before cooking, but only 37% followed the meal component guideline. There was no significant association between the type of institution or the number of GES studies and compliance with radiolabeling time or with meal preparation or components. Most respondents asked patients to withhold medications per SNMMI guidelines and used the recommended radiopharmaceutical (99mTc-sulfur colloid, 95%) at the recommended dose (18.5-37 MBq, 84%). Conclusion: Although most respondents followed most aspects of the SNMMI guidelines for GES, more than half did not use the recommended meal of liquid egg whites. Compliance did not vary between academic and nonacademic institutions or between groups performing a large or a small number of GES studies.

Real-world safety and effectiveness of Pistacia lentiscus (mastic gum) in patients with diabetic gastroparesis: 24-week interim analysis postintervention.

INTRODUCTION: Gastrointestinal neuropathies are frequently found in diabetic patients. AIM: The aim of this study was to find out the safety, adverse reactions, and long-term effectiveness of Pistacia lentiscus plant extract (mastic gum) in diabetic gastroparesis (DG) with respect to sustainable improvement in gastroparesis symptoms (Gastrointestinal Cardinal Symptom Index [GCSI] score) by observational follow-up study of a single-centric double-blind noninferiority randomized control trial. MATERIALS AND METHODS: Thirty-eight individuals were recruited and equally randomized in two study groups based on GCSI score and TC99 radionuclide gastric emptying scintigraphy (GES), i.e. the mastic gum group and the levosulpiride group. After 24 weeks, the GCSI score was recalculated in both the groups, and patients were evaluated for the safety, adverse reactions, and long-term effectiveness of mastic gum and the standard drug levosulpiride. RESULTS: In the extended study, mean GCSI score changes at 24 weeks were statistically significant (P < 0.001) (t-test) between the two groups. In the mastic gum arm, the change in mean GCSI score at 24 weeks was statistically nonsignificant mean ± (standard deviation [SD]) 16.7± (3.81) compared to the GCSI score at 2-month postintervention mean (SD) 16.35± (2.27) (intragroup P = 0.89) (repeated measures ANOVA). It strongly indicates that mastic gum provided a sustainable improvement in DG symptoms in comparison to levosulpiride, with excellent subjective well-being postintervention, without any obvious significant adverse effects. CONCLUSION: Six-month (24-week) interim analysis of patients suggests that mastic gum gives a sustainable improvement in DG symptoms without any obvious adverse effects as compared to levosulpiride.

Utility of gastrostomy tube placement at the time of pancreaticoduodenectomy.

PURPOSE: The aim of this study is to investigate the utility of gastrostomy tube (G-tube) placement in reducing delayed gastric emptying (DGE) among patients undergoing pancreaticoduodenectomy (PD). METHODS: We retrospectively reviewed consecutive patients undergoing PD from 2015 to 2020 at our institution. Thirty-day patient outcomes including DGE, length of stay (LOS), reoperation rates, and morbidity were analyzed in patients with or without G-tube placement. RESULTS: 128 patients with resectable pancreatic head cancer (54 females, median age 68.50 [59.00-74.00]) underwent PD (66 had G-tube placement and 62 did not). There was no significant difference in the incidence of DGE (n = 17 vs. n = 17, p = 0.612), and LOS between the groups. Postoperative ileus (p = 0.007) was significantly lower while atrial fibrillation (p = 0.037) was higher among the G-tube group. Gastrostomy-related complications (p = 0.001) developed in ten patients: skin-related complications (n = 6), tube dislodgement (n = 3) and clogging (n = 1). Nine patients required reoperation during index admission (n = 4 vs. n = 5, p = 1.000). There was no difference in 30-day readmissions (n = 7 vs. n = 5, p = 0.471) and no difference in 30 or 90-day mortality. CONCLUSION: Gastrostomy tube placement during index PD did not affect the incidence of DGE. However, patients experienced significant morbidities due to G-tube-related complications. Placement of gastrostomy tubes at the index PD offers no clinical benefits.

Understanding the gastrointestinal tract in obesity: From gut motility patterns to enzyme secretion.

BACKGROUND AND PURPOSE: The pathophysiology of obesity has been the product of extensive research, revealing multiple interconnected mechanisms contributing to body weight regulation. The regulation of energy balance involves an intricate network, including the gut-neuroendocrine interplay. As a consequence, research on the gut-brain-microbiota axis in obesity has grown extensively. The physiology of the gastrointestinal tract, far from being underexplored, has significant implications for the development of specific complications in people living with obesity across the fields of gastroenterology, nutrition, and pharmacology. Clinical research indicates higher fasting bile acids serum levels, and blunted postprandial increases in bilious secretions in people living with obesity. Findings are less straightforward for the impact of obesity on gastric emptying with various studies reporting accelerated, normal, or delayed gastric emptying rates. Conversely, the effect of obesity on gastrointestinal pH, gastrointestinal transit, and gastric and pancreatic enzyme secretion is largely unknown. In this review, we explore the current evidence on the gastrointestinal physiology of obesity.

RESIDUAL GASTRIC VOLUME IN MORBIDLY OBESE DIABETICS AFTER AN OVERNIGHT FASTING OR 3 HOURS OF A CARBOHYDRATE-ENRICHED SUPPLEMENT: A RANDOMIZED CROSSOVER PILOT STUDY.

BACKGROUND: To reduce the risk of regurgitation during anesthesia for elective procedures, residual gastric volumes (RGV) have traditionally been minimized by overnight fasting. Prolonged preoperative fasting presents some adverse consequences and has been abandoned for most surgical procedures, except for obese and/or diabetic patients. AIMS: The aim of this study was to assess the RGV in morbidly obese diabetic patients after traditional or abbreviated fasting. METHODS: This study was approved by the Ethics Committee for Research with Human Beings from the Federal University of Mato Grosso, under number 179.017/2012. This is a prospective, randomized, and crossover design study in eight morbidly obese type II diabetic patients. RGV was measured endoscopically after either traditional overnight fasting of at least 8 hours, or after abbreviated fasting of 6 hours for solids and 3 hours for a drink containing water plus 25 g (12.5%) of maltodextrin. Data were expressed as mean and range and differences were compared with paired t-tests at p<0.05. RESULTS: The study population had a mean age of 41.5 years (28-53), weight of 135 kg (113-196), body mass index of 48.2 kg/m2 (40-62.4), and type II diabetes for 4.5 years (1-10). The RGV after abbreviated fasting was 21.5 ml (5-40) vs 26.3 ml (7-65) after traditional fasting. This difference was not significant (p=0.82). CONCLUSIONS: Gastric emptying in morbidly obese diabetic patients is similar after either traditional or abbreviated fasting with a carbohydrate drink.

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.

Investigating biomechanical alterations and emptying patterns after various gastrojejunostomy strategy.

Gastrojejunostomy is a prominent approach in managing distal gastric cancer that is unresectable due to gastric outlet obstruction (GOO). Research has demonstrated that stomach-partitioning gastrojejunostomy (SPGJ) exhibits superior clinical efficacy compared to conventional gastrojejunostomy (CGJ), however, the underlying mechanism of this phenomenon remains elusive. This study constructed 3D models of the SPGJ and CGJ based on the computed tomography (CT) images obtained from a patient diagnosed with distal gastric cancer. The biomechanical patterns of these procedures in the digestive system were subsequently compared through numerical simulations and in vitro experiments. The results of the numerical simulation demonstrated that the model following SPGJ promoted the discharge of food through the anastomotic orifice and into the lower jejunum. Furthermore, a decrease in passage size after partitioning, the low-level velocity of esophageal, and an increase in contents viscosity effectively inhibited the flow through the passage to the pylorus, ultimately reducing stimulation to tumor. The study also revealed that favorable gastric emptying is associated with a smaller passage and faster inlet velocity, and that lower contents viscosity. ​The experimental findings conducted in vitro demonstrated that SPGJ exhibited superior efficacy in obstructing the flow near the pylorus in comparison to CGJ. Moreover, a decrease in passage size correlates with a reduction in fluid flow towards the pylorus. These results provide the foundation of theory and practice for the surgical management of patients with GOO resulting from unresectable distal gastric cancer, and have potential implications for clinical interventions.

Gastroparesis might not be uncommon in patients with diabetes mellitus in a real-world clinical setting: a cohort study.

BACKGROUND: This study investigated the frequency of diabetic gastroparesis and associated risk factors in a real-world clinical setting. METHODS: This retrospective cross-sectional study included patients who underwent assessments of solid gastric emptying time (GET) by technetium-99 m scintigraphy between May 2019 and December 2020. We categorized patients into three groups according to gastric retention of technetium-99 m: rapid (< 65% at 1 h or < 20% at 2 h), normal (≤60% at 2 h and/or ≤ 10% at 4 h), and delayed (> 60% at 2 h and/or > 10% at 4 h). RESULTS: Patients with diabetes mellitus (DM) were more likely to show abnormal GET than those without DM (119 [70.8%] vs. 16 [44.4%]). The mean glycated A1c was 10.3% in DM patients. DM patients with normal GET were significantly younger (57.2 years, P = 0.044) than those with delayed (65.0 years) or rapid GET (60.2 years). Fasting glucose levels were the lowest in the normal GET group and the highest in the rapid GET group (delayed: 176.3 mg/dL, normal: 151.2 mg/dL, rapid: 181.0 mg/dL, P = 0.030). However, glycated A1c was not significantly different among the delayed, normal, and rapid GET groups in patients with DM. Patients with delayed and rapid GET showed a higher frequency of retinopathy (6.0 vs. 15.5%, P = 0.001) and peripheral neuropathy (11.3 vs. 24.4%, P = 0.001) than those with normal GET. In the multinomial logistic regression analysis, retinopathy demonstrated a positive association with delayed GET, while nephropathy showed a significant negative correlation. CONCLUSION: DM gastroparesis in the clinical setting was not uncommon. Abnormal GET, including delayed and rapid GET, was associated with DM retinopathy or peripheral neuropathy.

Phenylalanine requirements using the direct amino acid oxidation technique, and the effects of dietary phenylalanine on food intake, gastric emptying, and macronutrient metabolism in adult cats.

Despite Phe being an indispensable amino acid for cats, the minimum Phe requirement for adult cats has not been empirically defined. The objective of study 1 was to determine the minimum Phe requirement, where Tyr is in excess, in adult cats using the direct amino acid oxidation (DAAO) technique. Four adult male cats were used in an 8 × 4 Latin rectangle design. Cats were adapted to a basal diet for 7 d, top dressed with Phe to meet 140% of the adequate intake (NRC, 2006. Nutrient requirements of dogs and cats. Washington, DC: Natl. Acad. Press). Cats were randomly assigned to one of eight experimental Phe diets (0.29%, 0.34%, 0.39%, 0.44%, 0.54%, 0.64%, 0.74%, and 0.84% Phe in the diet on a dry matter [DM] basis). Following 1 d of diet adaptation, individual DAAO studies were performed. During each DAAO study, cats were placed into individual indirect calorimetry chambers, and 75% of the cat's daily meal was divided into 13 equal meals supplied with a dose of L-[1-13C]-Phe. Oxidation of L-[1-13C]-Phe (F13CO2) during isotopic steady state was determined from the enrichment of 13CO2 in breath. Competing models were applied using the NLMIXED procedure in SAS to determine the effects of dietary Phe on 13CO2. The mean population minimum requirement for Phe was estimated at 0.32% DM and the upper 95% population confidence limit at 0.59% DM on an energy density of 4,200 kcal of metabolizable energy/kg DM calculated using the modified Atwater factors. In study 2, the effects of a bolus dose of Phe (44 mg kg-1 BW) on food intake, gastric emptying (GE), and macronutrient metabolism were assessed in a crossover design with 12 male cats. For food intake, cats were given Phe 15 min before 120% of their daily food was offered and food intake was measured. Treatment, day, and their interaction were evaluated using PROC GLIMMIX in SAS. Treatment did not affect any food intake parameters (P > 0.05). For GE and macronutrient metabolism, cats were placed into individual indirect calorimetry chambers, received the same bolus dose of Phe, and 15 min later received 13C-octanoic acid (5 mg kg-1 BW) on 50% of their daily food intake. Breath samples were collected to measure 13CO2. The effect of treatment was evaluated using PROC GLIMMIX in SAS. Treatment did not affect total GE (P > 0.05), but cats receiving Phe tended to delay time to peak enrichment (0.05 < P ≤ 0.10). Overall, Phe at a bolus dose of 44 mg kg-1 BW had no effect on food intake, GE, or macronutrient metabolism. Together, these results suggest that the bolus dose of Phe used may not be sufficient to elicit a GE response, but a study with a greater number of cats and greater food intake is warranted.

Two studies were conducted to evaluate 1) the minimum requirement for dietary Phe and 2) the effects of Phe on gastric emptying (GE) and food intake in adult cats. In study 1, the minimum Phe requirement was estimated using the direct amino acid oxidation (DAAO) technique. Four cats were used and received all diets in random order in a Latin rectangle design (0.29%, 0.34%, 0.39%, 0.44%, 0.54%, 0.64%, 0.74%, and 0.84% Phe in the diet on a dry matter [DM] basis). The minimum Phe requirement, in the presence of excess of Tyr, for adult cats was estimated to be 0.59% DM on an energy density of 4,200 kcal of metabolizable energy/kg DM calculated using the modified Atwater factors; higher than current recommendations set in place by the National Research Council and the American Association of Feed Control Officials. In study 2, we first validated the use of the 13C-octanoic acid breath test (13C-OABT) in cats. Then, the effects of an oral bolus of Phe on food intake, GE, and macronutrient metabolism were evaluated. Phe supplementation did not influence food intake, macronutrient metabolism, or total GE, but tended to delay the time to peak GE.

Perioperative management of long-acting glucagon-like peptide-1 (GLP-1) receptor agonists: concerns for delayed gastric emptying and pulmonary aspiration.

Prescriptions and use of glucagon-like peptide-1 (GLP-1) receptor agonists are increasing dramatically, as indications are expanding from the treatment of diabetes mellitus to weight loss for people with obesity. As GLP-1 receptor agonists delay gastric emptying, perioperative healthcare practitioners could be concerned about an increased risk for pulmonary aspiration during general anaesthesia. We summarise relevant medical literature and provide evidence-based recommendations for perioperative care for people taking GLP-1 receptor agonists. GLP-1 receptor agonists delay gastric emptying; however, ongoing treatment attenuates this effect. The risk of aspiration during general anaesthesia is unknown. However, we advise caution in patients who recently commenced on GLP-1 receptor agonists. After over 12 weeks of treatment, standard fasting times likely suffice to manage the risk of pulmonary aspiration for most otherwise low-risk patients.