Relationship of gastrointestinal symptoms and psychosocial distress to gastric retention in children.

OBJECTIVES: To determine whether gastrointestinal (GI) symptoms (abdominal pain, nonpain GI symptoms, nausea) and/or psychosocial distress differ between children with/without gastroparesis and whether the severity of GI symptoms and/or psychosocial distress is related to the degree of gastroparesis. STUDY DESIGN: Children aged 7-18 years (N = 100; 63 female patients) undergoing a 4-hour gastric emptying scintigraphy study completed questionnaires evaluating GI symptoms, anxiety, and somatization for this prospective study. Spearman correlation, Mann-Whitney, t-test, and χ(2) tests were used as appropriate for statistical analysis. RESULTS: Children with gastroparesis (n = 25) were younger than those with normal emptying (12.6 ± 3.5 vs 14.3 ± 2.6 years, P = .01). Because questionnaire responses from 7- to 10-year-old children were inconsistent, only patient-reported symptoms from 11- to 18-year-olds were used. Within this older group (n = 83), children with gastroparesis (n = 17) did not differ from children with normal emptying in severity of GI symptoms or psychosocial distress. In children with gastroparesis, gastric retention at 4 hours was related inversely to vomiting (r = -0.506, P = .038), nausea (r = -0.536, P = .019), difficulty finishing a meal (r = -0.582, P = .014), and Children's Somatization Inventory score (r = -0.544, P = .024) and positively correlated with frequency of waking from sleep with symptoms (r = 0.551, P = .022). CONCLUSIONS: The severity of GI symptoms and psychosocial distress do not differ between children with/without gastroparesis who are undergoing gastric emptying scintigraphy. In those with gastroparesis, gastric retention appears to be inversely related to dyspeptic symptoms and somatization and positively related to waking from sleep with symptoms.

Decreased relative diagnostic yield of esophagogastroduodenoscopy in children with gastroparesis.

BACKGROUND: Esophagogastroduodenoscopy (EGD) and gastric emptying scintigraphy (GES) are commonly performed in the evaluation of children with upper gastrointestinal symptoms. It has been presumed, but not clarified, that gastroparesis increases the likelihood of identifying abnormalities on EGD. We sought to determine whether the presence of gastroparesis influenced the diagnostic yield of EGD in children. METHODS: We conducted a retrospective chart review of children who underwent both an EGD and GES within 3 months of each other for evaluation of upper gastrointestinal symptoms (eg, abdominal pain). Clinical history (symptoms, comorbidities, medications, and surgical procedures), GES results, and EGD histology reports were captured. RESULTS: A total of 125 children (46% female) were included, of whom, 70 (56%) had gastroparesis. Thirty-three (26%) children had liquid meal GES (1.2 ± 1.1 y of age, mean ± SD) and 92 (64%) had solid meal GES (12.4 ± 3.6 y of age). There was an overall trend toward a decreased frequency of biopsy abnormalities in those with gastroparesis (P=0.09). Those with gastroparesis identified through liquid meal GES were less likely to have reflux esophagitis on biopsy (P=0.002). Those with gastroparesis identified on solid meal GES were less likely to have gastritis (P=0.04). Symptoms, comorbidities, or medications were not predictive of GES or EGD results. CONCLUSIONS: Children with gastroparesis may be less likely to have biopsy abnormalities identified on EGD in comparison to those without gastroparesis. Further prospective, larger, and multicenter studies are needed to validate our findings.

Implantable drug delivery device using frequency-controlled wireless hydrogel microvalves.

This paper reports a micromachined drug delivery device that is wirelessly operated using radiofrequency magnetic fields for implant applications. The controlled release from the drug reservoir of the device is achieved with the microvalves of poly(N-isopropylacrylamide) thermoresponsive hydrogel that are actuated with a wireless resonant heater, which is activated only when the field frequency is tuned to the resonant frequency of the heater circuit. The device is constructed by bonding a 1-mm-thick polyimide component with the reservoir cavity to the heater circuit that uses a planar coil with the size of 5-10 mm fabricated on polyimide film, making all the outer surfaces to be polyimide. The release holes created in a reservoir wall are opened/closed by the hydrogel microvalves that are formed inside the reservoir by in-situ photolithography that uses the reservoir wall as a photomask, providing the hydrogel structures self-aligned to the release holes. The wireless heaters exhibit fast and strong response to the field frequency, with a temperature increase of up to 20°C for the heater that has the 34-MHz resonant frequency, achieving 38-% shrinkage of swelled hydrogel when the heater is excited at its resonance. An active frequency range of ~2 MHz is observed for the hydrogel actuation. Detailed characteristics in the fabrication and actuation of the hydrogel microvalves as well as experimental demonstrations of frequency-controlled temporal release are reported.