[Pilot test for Helicobacter pylori detection with ammonia breath test]. / Prueba piloto para la detección de Helicobacter pylori con test de amoníaco en aire espirado.

BACKGROUND: In Argentina we have little access to the more sensitive and specific non-invasive diagnostic methods for the detection of Helicobacter pylori (HP), such as the urea breath test. The upper gastrointestinal videoendoscopy, with biopsy for histological analysis and rapid urease test remains as the usual method in our country, but the cost is high and the accessibility is also limited. For this reason we propose to develop a new fast, accurate, accessible and inexpensive method for measuring the concentration of expired NH in order to achieve a diagnosis of active infection. OBJECTIVE: To determine the utility of a non-invasive method for detecting HP through the measurement of ammonia in the breathing. MATERIALS AND METHODS: We studied 3 patients older than 21 years, attending the Gastroenterology clinic. All patients who meet the inclusion criteria were evaluated with an upper gastrointestinal videoendoscopy and gastric biopsies (antrum, body and incisura angularis). Samples were analyzed by histopathological examination and urease test. The subjects with both negative tests (non-infected) or positive (infected) were selected for ammonia measurement in exhaled air. RESULTS: The prevalence of HP infection was 60.9% (14 patients). Ten of these patients had significant differences between the baseline ammonia and the ammonia after urea ingestion, yielding a specifcity of 88.9% and a sensitivity of 71.43%, with a Jouden index higher than 50%. CONCLUSION: Although the experience must be carried forward, the results of this pilot study suggest that the measurement of ammonia in breath test after ingestion of unmarked urea would be applicable as a diagnostic test for HP, taking into account its low cost and easy management compared to conventional non-invasive methods.

Validation of the number connection test for identifying patients with minimal hepatic encephalopathy.

OBJECTIVES: Hepatic encephalopathy is a serious neuropsychiatric complication in advanced liver disease. The affected patients exhibit alterations in psychomotor and intellectual functions. The aims of this study were to identif the set ofnormal values for the number connection tests (NCT-A and NCT-B) in a population of volunteers without liver disease, to compare the values from this reference population with those from patients with cirrhosis without hepatic encephalopathy. MATERIALS AND METHODS: This study was performed in two referral hospitals in an urban setting from the city of La Plata. We evaluated the Number Connection Tests in 112 healthy subjects and 30 patients with cirrhosis without manifestations of hepatic encephalopathy. Time for performing the tests was measured in seconds. Results were compared according to age, gender, level of education and fine motor skills in both groups. RESULTS: Mean age in the control group was 45.3years; 56 (50%) were women. Mean age in the cirrhotic group was 54.5 years; 8 (27%) were women. In the control group, the mean time for completing NCT-A and NCT-B was 60 s +/- 36s and 140 s +/- 60 s, respectively. In the cirrhotic group, the mean time for completing NCT-A and NCT-B was 114 s +/- 64 y 232 s +/- 87 s, respectively (P = 0.00001 for both tests). 56.6% of cirrhotic patients took more than 2 SD to perform the NCT-A and 53.3%, more than 2 SD to perform the NCT-B. CONCLUSION: We have obtained reference values for NCT-A and NCT-B completing times in our healthy population. Cirrhotic patients without overt hepatic encephalopathy took double time than controls to complete NCT-A and NCT-B and over half of our patients would have minimal hepatic encephalopathy.