Comparison of calculations to estimate gastric emptying half-time of solids in humans

Gastric half emptying time (T½ ) for 4-h gastric emptying scintigraphy simplifies reporting but reduces detection of gastroparesis

BACKGROUND

Gastric emptying scintigraphy (GES) reports percent retention at 1, 2, and 4 h. Time to empty half the meal (T_½ ) could simplify GE reporting.

AIMS

To compare the performance of GES T_½ to 1-, 2-, and 4-h retention.

METHODS

GES studies were reviewed; results determined according to retention at 1, 2, and 4 h. T_½ was determined using 3 methods: (1) GES curve fitting using 0, 0.5, 1, 2, 3, and 4 h data; (2) linear interpolation using 0, 0.5, 1, 2, 3, and 4 h data; and (3) linear interpolation using only 0, 1, 2, and 4 h data.

RESULTS

Of 495 patients, 265 had normal GE, 4 rapid GE (<30% retention at 1 h), and 226 delayed GE: 17 delayed only at 2 h (>60% ret); 94 delayed only at 4 h (>10% ret); and 115 delayed at both 2 h and 4 h. Strong correlations were seen between each T_½ method and 1, 2, 3, and 4 h %-empty values: curve-fit T_½ (r = -0.851, -0.942, -0.864, -0.744), linear T_½ using all imaging times (r = -0.848, -0.972, -0.878, -0.763), and linear T_½ using standard imaging times (r = -0.853, -0.974, -0.868, -0.760). The 132 min cutoff for delayed GE captures 99.1% to 100% of delayed GE at both 2 h and 4 h, 76.5% to 94.1% delayed at 2 h only, but only 36.7% to 39.4% delayed at 4 h only; 3.5 to 11.3% of patients with normal GE miscategorized as delayed.

CONCLUSIONS

GES T_½ correlates more strongly with retention at 2 h than at 4 h. T_½ alone may misclassify patients, particularly those with late-phase (4 h only) delays, reducing its utility for diagnosing gastroparesis.

Automatic assessment of human gastric motility and emptying from dynamic 3D magnetic resonance imaging

BACKGROUND

Time-sequenced magnetic resonance imaging (MRI) of the stomach is an emerging technique for non-invasive assessment of gastric emptying and motility. However, an automated and systematic image processing pipeline for analyzing dynamic 3D (ie, 4D) gastric MRI data has not been established. This study uses an MRI protocol for imaging the stomach with high spatiotemporal resolution and provides a pipeline for assessing gastric emptying and motility.

METHODS

Diet contrast-enhanced MRI images were acquired from seventeen healthy humans after they consumed a naturalistic contrast meal. An automated image processing pipeline was developed to correct for respiratory motion, to segment and compartmentalize the lumen-enhanced stomach, to quantify total gastric and compartmental emptying, and to compute and visualize gastric motility on the luminal surface of the stomach.

KEY RESULTS

The gastric segmentation reached an accuracy of 91.10 ± 0.43% with the Type-I error and Type-II error being 0.11 ± 0.01% and 0.22 ± 0.01%, respectively. Gastric volume decreased 34.64 ± 2.8% over 1 h where the emptying followed a linear-exponential pattern. The gastric motility showed peristaltic patterns with a median = 4 wave fronts (range 3-6) and a mean frequency of 3.09 ± 0.07 cycles per minute. Further, the contractile amplitude was stronger in the antrum than in the corpus (antrum vs. corpus: 5.18 ± 0.24 vs. 3.30 ± 0.16 mm; p < 0.001).

CONCLUSIONS & INFERENCES

Our analysis pipeline can process dynamic 3D MRI images and produce personalized profiles of gastric motility and emptying. It will facilitate the application of MRI for monitoring gastric dynamics in research and clinical settings.

NB-33, a bioreversible opioid derivative of Nalbuphine, shows enhanced pharmacodynamics

Developing non-addictive and safer opioids for pain management is unmet medical need. Among a number of bioreversible derivatives of Nalbuphine - an equipotent to morphine opioid without serious side effects - NB-33 was identified in silico and confirmed in vivo as a superior analgesic agent. Apart from enhanced pharmacodynamics profile, NB-33 outperformed the parent compound on equimolar bases in cold ethanol tail-flick and mechanical models of pain in rats. With no β-arrestin engagement liability, good stability in simulated gastro-intestinal fluid and slow release of Nalbuphine by plasma NB-33 is being developed as an oral and safer alternative of its parent drug.

Enhancing Scintigraphy for Evaluation of Gastric, Small Bowel, and Colonic Motility

This article reviews the latest enhancements in standards and technology for performing gastric emptying and associated small bowel and colon transit scintigraphic studies. It discusses how developments in appropriate use criteria, American Medical Association Current Procedural Terminology coding, and advanced commercial software permit clinicians to obtain more comprehensive physiologic studies of gastric, small bowel, and colon gastrointestinal motility disorders. It shows how gastrointestinal scintigraphy has expanded to permit assessments of global and regional (fundic and antral) gastric motility and how it permits a single study (whole-gut transit scintigraphy), including measurement of solid and liquid gastric emptying and small bowel and colon transit.

Gastroparesis

Gastroparesis is a disorder characterized by delayed gastric emptying of solid food in the absence of a mechanical obstruction of the stomach, resulting in the cardinal symptoms of early satiety, postprandial fullness, nausea, vomiting, belching and bloating. Gastroparesis is now recognized as part of a broader spectrum of gastric neuromuscular dysfunction that includes impaired gastric accommodation. The overlap between upper gastrointestinal symptoms makes the distinction between gastroparesis and other disorders, such as functional dyspepsia, challenging. Thus, a confirmed diagnosis of gastroparesis requires measurement of delayed gastric emptying via an appropriate test, such as gastric scintigraphy or breath testing. Gastroparesis can have idiopathic, diabetic, iatrogenic, post-surgical or post-viral aetiologies. The management of gastroparesis involves: correcting fluid, electrolyte and nutritional deficiencies; identifying and treating the cause of delayed gastric emptying (for example, diabetes mellitus); and suppressing or eliminating symptoms with pharmacological agents as first-line therapies. Several novel pharmacologic agents and interventions are currently in the pipeline and show promise to help tailor individualized therapy for patients with gastroparesis.

The Pancreatic Duct Ligated (Mini)pig as a Model for Pancreatic Exocrine Insufficiency in Man

Modern therapy of pancreatic exocrine insufficiency (PEI) using pancreatic enzyme replacement therapy (PERT) has largely been very effective and has greatly helped in improving the nutritional status of patients with PEI and in increasing the life expectancy in cystic fibrosis. It is believed that the use of predictable large animal models could play an important role in assessing and developing new therapies. This article reviews the pancreatic duct ligated (adult) minipig as a chronic model of total PEI, with a detailed look at the influence of PEI and response to PERT on prececal compared to fecal digestibility, to directly investigate effects on protein and starch digestion and absorption. In addition, the piglet with PEI is reviewed as a model for PEI in young patients with the aim of further improving the therapy and nutritional status of young patients with cystic fibrosis.

Gastroparesis in children

PURPOSE OF REVIEW

Gastroparesis is a disorder with delayed gastric emptying in the absence of mechanical obstruction. It is one of the more common dysmotilities that occur in the gastrointestinal tract, and is thought to primarily affect adults. Pediatric cases of gastroparesis were considered rare; however, recent evidence suggests growing recognition in children and adolescents. Therefore, it is important for the pediatric caregiver to understand the condition and the treatment options available.

RECENT FINDINGS

The majority of patients are women, and presentation is usually with symptoms of persistent nausea, emesis, postprandial pain and bloating, and early satiety. Weight loss may occur in some cases, though this is not universal. The majority of cases are idiopathic, with diabetes mellitus the second most common cause.

SUMMARY

Treatment consists of symptomatic relief with medication to counteract the nausea, emesis, pain, bloating, gastroesophageal reflux, early satiety, and improve gastric emptying. Dietary modification is also used with small meals and avoidance of high fiber and fat-containing foods. Recalcitrant cases of gastroparesis require the use of additional approaches such as jejunal feeds, intrapyloric botulinum toxin, gastric emptying procedures such as pyloroplasty, and gastric electrical stimulation. We will review these options in this article.

Randomised clinical trial: the effects of daikenchuto, TU-100, on gastrointestinal and colonic transit, anorectal and bowel function in female patients with functional constipation

BACKGROUND

Daikenchuto, a Japanese herbal medicine used for post-operative ileus and constipation, dose dependently stimulates gastrointestinal (GI) motility and decreases rectal compliance and sensation. Effects of TU-100 (commercial form of daikenchuto) in adults with constipation are unknown.

AIM

To compare the effects of oral TU-100, 2.5 g t.d.s. or 5 g t.d.s. and placebo t.d.s. on GI and colonic transit (CT), rectal compliance (RC) and sensation thresholds (RST), anal sphincter pressures (ASP) and bowel function in female patients with functional constipation (FC).

METHODS

We conducted a single-centre, randomised, parallel-group, double-blind, pharmacodynamic study; 45 female patients with FC without evidence of rectal evacuation disorder were assigned to 28 days' treatment with oral placebo or TU-100 (Tsumura USA, Princeton, NJ, USA). Demographic data and CT were measured at baseline and randomisation stratified by baseline CT (GC> or <1.9) and by BMI (<25 or ≥25 kg/m(2) ). At the end of treatment period, we measured GI and CT by scintigraphy, RST and RC by barostat, ASP by manometry, psychosensory sensations, bowel function by daily diary and quality of life (QOL). The study had power to detect effect sizes of 33% (CT), 40% (RC) and 46% (RST). Statistical analysis included BMI as covariate.

RESULTS

TU-100 had no significant effects on GI or CT, RC, ASP, recto-anal pressure difference, or RST. The 5 g t.d.s./day dose was associated with lower RST for first sensation and gas (unadjusted P: 0.045 and 0.024 respectively). There were no treatment effects on psychosensory symptoms, stool frequency, stool consistency or QOL.

CONCLUSION

Mechanisms underlying the observed clinical benefit of TU-100 remain unclear (ClinicalTrials.gov NCT01139216).