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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is the leading cause of a public health emergency in the world, accompanying with high mortality in severe corona virus disease 2019(COVID-19 ), thereby early detection and stopping the progress to severe COVID-19 is important. Our aim is to establish a clinical nomogram model to calculate and predict the progress to severe COVID-19 timely and efficiently.Methods: In this study, 65 patients with COVID-19 had been included retrospectively in the Fifth Affiliated Hospital of Sun Yat-sen University from January 17, to February 11, 2020. Patients were randomly assigned to train dataset (n=51 with 15 progressing to severe COVID-19) and test dataset (n=14 with 4 progressing to severe COVID-19). Lasso algorithm was applied to filter the most classification relevant clinical factors. Based on selected factors, logistic regression model was fit to predict the severe from mild/common. Meanwhile in nomogram sensitivity, specificity, AUC (Area under Curve), and calibration curve were depicted and calculated by R language, to evaluate the prediction performance to severe COVID-19.Results:High ratio of sever COVID-19 patients (26.5%) had been found in our retrospective study, and 84% of these cases progress to severe or critical after 5 days from their first clinical examination. In these 65 patients with COVID-19, 77 clinical characteristics in first examination were collected and analyzed, and 37 ones had been found different between non-severe and severe COVID-19. But when all these factors were analyzed in establishment of prediction model, six factors are crucial for predicting progress of severe COVID-19 via Lasso algorithm. Based on these six factors, including increased fibrinogen, hyponatremia, decreased PaO2,multiple lung lobes involved, down-regulated CD3（+）T-lymphocyte and fever, a logistic regression model was fit to discriminate severe and common COVID-19 patients. The sensitivity, specificity and AUC were 0.93, 0.86, 0.96 in the train dataset and 0.9, 1.0, 1.0 in test dataset respectively. Nomogram-predicted probability was more consistent with actual probability by R language.Conclusions:In summary, an efficient and reliable clinical nomogram model had been established, which indicate increased fibrinogen, hyponatremia, decreased PaO2, multiple lung lobes involved, down-regulated CD3（+）T-lymphocyte and fever at the first clinical examination, could predict progress of patients to severe COVID-19.

BackgroundTo investigate the efficacy and procedural skills of metallic stent placement for malignant gastric outlet obstruction.MethodsNine patients with malignant gastric outlet obstruction were performed metallic stent placement. Two stent placement methods were employed, the first, stents were placed under guidance of endoscopy in 7 patients (stent introducer: 140 mm in length and 4-6 mm in diameter); the second, duodenal stents were placed through endoscopic biopsy channel (3.2 or 4.2 mm in diameter) in 2 patients.ResultsThe stent placement succeeded at the first attempt in all 9 patients. Among the 9 patients, 3 placed with 2 x 10 cm stents, and 6 with 2 x 8 cm stents. Pylorus stents, duodenal stents, and esophageal stents were placed in 2 patients, 6 patients and 1 patient, respectively. Stents expanded about 90% confirmed by fluoroscopy 24 - 48 h after the procedure. the patients started liquid food 24 h after stent placement. The common post-procedural complications included nausea, vomiting, upper digestive tract hemorrhage and upper abdominal pain. Post-procedural obstructive jaundice occurred in 1 patient. During the 3 months follow-up, no stent migration, removal and occlusion occurred. Of the 9 patients, 3 survived 10-15 days and 2 survived 1-2 months, the rest 4 patients survived 3 months. The mean stent patency was 53.4 days.ConclusionsExpandable metallic stents placed in patients with malignant obstruction of gastric outlet effectively palliate the obstructive symptoms. Technical skills play important roles in stent placement in treatment of malignant gastric outlet obstruction, and the efficacy of metallic stent placement is associated with the location of metallic stents and therapeutic indications.

This a preprint and has not been peer reviewed. Data may be preliminary.