A descriptive study of abdominal complications in patients with mild COVID-19 presenting to the emergency department: a single-center experience in Japan during the omicron variant phase.

BACKGROUND: COVID-19 is widely known to induce a variety of extrapulmonary manifestations. Gastrointestinal symptoms have been identified as the most common extra-pulmonary manifestations of COVID-19, with an incidence reported to range from 3 to 61%. Although previous reports have addressed abdominal complications with COVID-19, these have not been adequately elucidated for the omicron variant. The aim of our study was to clarify the diagnosis of concomitant abdominal diseases in patients with mild COVID-19 who presented to hospital with abdominal symptoms during the sixth and seventh waves of the pandemic of the omicron variant in Japan. METHODS: This study was a retrospective, single-center, descriptive study. In total, 2291 consecutive patients with COVID-19 who visited the Department of Emergency and Critical Care Medicine, Kansai Medical University Medical Center, Osaka, Japan, between January 2022 and September 2022 were potentially eligible for the study. Patients delivered by ambulance or transferred from other hospitals were not included. We collected and described physical examination results, medical history, laboratory data, computed tomography findings and treatments. Data collected included diagnostic characteristics, abdominal symptoms, extra-abdominal symptoms and complicated diagnosis other than that of COVID-19 for abdominal symptoms. RESULTS: Abdominal symptoms were present in 183 patients with COVID-19. The number of patients with each abdominal symptom were as follows: nausea and vomiting (86/183, 47%), abdominal pain (63/183, 34%), diarrhea (61/183, 33%), gastrointestinal bleeding (20/183, 11%) and anorexia (6/183, 3.3%). Of these patients, 17 were diagnosed as having acute hemorrhagic colitis, five had drug-induced adverse events, two had retroperitoneal hemorrhage, two had appendicitis, two had choledocholithiasis, two had constipation, and two had anuresis, among others. The localization of acute hemorrhagic colitis was the left-sided colon in all cases. CONCLUSIONS: Our study showed that acute hemorrhagic colitis was characteristic in mild cases of the omicron variant of COVID-19 with gastrointestinal bleeding. When examining patients with mild COVID-19 with gastrointestinal bleeding, the potential for acute hemorrhagic colitis should be kept in mind.

Low-Error Soil Moisture Sensor Employing Spatial Frequency Domain Transmissometry.

A new type of soil moisture sensor using spatial frequency domain transmissometry (SFDT) was evaluated. This sensor transmits and receives ultrawideband (1 to 6 GHz) radio waves between two separated antennas and measures the propagation delay time in the soil related to the dielectric constant. This method is expected to be less affected by air gaps between the probes and the soil, as well as being less affected by soil electrical conductivity (EC), than typical commercial sensors. The relationship between output and volumetric water content (θ), and the effects of air gaps and EC were evaluated through experiments using sand samples and the prototype SFDT sensor. The output of the SFDT sensor increased linearly with θ and was not affected by even a high salt concentration for irrigation water, such that the EC of the pore water was 9.2 dS·m-1. The SFDT sensor was almost unaffected by polyethylene tapes wrapped around the sensor to simulate air gaps, whereas a commercially available capacitance sensor significantly underestimated θ. Theoretical models of the SFDT sensor were also developed for the calibration equation and the air gaps. The calculation results agreed well with the experimental results, indicating that analytical approaches are possible for the evaluation of the SFDT sensor.