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Glucose infusion test: A new screening test for vascular access recirculation. Background Vascular access recirculation is an important cause of diminished dialysis efficiency. We propose a new screening test based on glucose infusion as a tracer for recirculation. Methods The glucose infusion test (GIT) protocol comprises a basal blood sample (A) from the arterial port, a 5 mL bolus of 20% glucose into the venous chamber (time 0), followed by a second sample (B) in four seconds (from 13 to 17 s with Q B 300 mL/min) from the same port. The blood glucose level is determined at the bedside on A and B with a reflectance photometer (CV 1.8%). Interpretation of the test is straightforward: If B=A, there is no recirculation, whereas if B > A, recirculation can be calculated from the regression equation: 0.046 × (B - A) + 0.07, obtained from in vitro tests reproducing artificial recirculation at 0, 5, and 10%. To validate this new method in vivo, we compared GIT and the urea test on 39 hemodialysis patients, obtaining a good correlation ( r = 0.93). The two tests were considered positive (recirculation present) when the lower 95% confidence intervals were more than zero. Results Our patients were divided into two groups: those with (22 out of 39, mean recirculation 11.8%) or without recirculation (17 out of 39, mean 0.06%). The urea test did not recognize 7 out of 22 patients because they had a small recirculation below the urea test limit of detection. Conclusions GIT was more sensitive (detection limit 0.3%), simpler, and immediate in showing the results than the urea test. It is an accurate and low-cost technique for screening and follow-up of vascular access in a dialysis unit.

With the purpose of establishing interrelationship between the urea test in dental plaque and gastric biopsy samples to determine the presence of Helicobacter pylori, this study was performed in 50 patients from the National Police Central Hospital. Simultaneously, samples from the dental plaque and gastric biopsies were taken from patients of the Gastroenterology Department, the same that were submitted to endoscopies by their medical attendant. Samples of their stomachs were obtained by a punching method, which were placed in urea broth and transported to the laboratory of the hospital for their incubation. The dental plaque samples were placed directly in the urea broth and taken to the Microbiology laboratory of the School of Dentistry of the San Marcos Major National University for their incubation at 37 ºC. The results were obtained 12, 48 and 72 hours later, and recorded into a database. The results from the gastric biopsies were obtained from the Histopathology laboratory of the Hospital. The analysis of the results obtained corroborates the hypothesis about the existence of a relationship between the determination of the positive urea test in dental plaque samples and the ones obtained from the gastric biopsies, since a 68 % coincidence of values was obtained, both positive and negatives. The specificity of the cases was of 62 % and the sensibility of 75 %. However, the interrelationship level is not high., Con el objetivo de establecer la interrelación de la Prueba de urea en muestras de placa dental y la de biopsia gástrica para la determinación de la presencia del Helicobacter pylori; se realizó el estudio en 50 pacientes del Hospital Central de la Policía Nacional. Se tomaron simultáneamente muestras de placa dental y de biopsias gástricas en pacientes del servicio de Gastroenterología, a quienes se les indicó endoscopias por el médico tratante, obteniéndose muestras del estómago mediante sacabocado, las cuales fueron colocadas en caldo urea y transportadas al laboratorio del hospital para su incubación. Las muestras de placa dental fueron colocadas directamente en el caldo urea y llevados al laboratorio de Microbiología del la Facultad de Odontología de la Universidad Nacional Mayor de San Marcos para su incubación a 37 ºC y los resultados fueron leídos a las 24, 48 y 72 horas, y registrados en una base de datos. Los resultados de las biopsias gástricas fueron obtenidos del laboratorio de histopatología del Hospital. El análisis de los resultados obtenidos corrobora la hipótesis que señala que existe relación entre la determinación de la prueba de urea positiva en muestras de placa dental con las obtenidas en biopsias gástricas ya que se obtuvo un 68 % de coincidencias de valores tanto positivos como negativos para ambos. La especificidad fue de 62 % de los casos y la sensibilidad de 75 %; sin embargo, el nivel de interrelación no es elevado.