H. Pylori Diagnostic Test

1. Describe the principal, advantage and limitation of every diagnostic test to detect H.pylori.(1, 2)
Test Principal Advantage Limitation
Rapid urease test In the presence of H. pylori urease, urea is metabolized to ammonia and bicarbonate resulting in an increase in pH, which changes the color of a pH-sensitive indicator. Tests for active H. pylori infection; >90% sensitivity and specificity.
Results are rapid (within 24 hours), and test is less expensive than histology or culture. Withhold H2RAs and PPIs 1 to 2 weeks before testing and antibiotics and bismuth salts 4 weeks before testing to reduce the risk of false-negatives.
Histology • A tissue sample, called biopsy, that is taken from the stomach lining is the most accurate way to tell

Perform a literature search and assess current information on the efficacy of various agents in the prevention of NSAIDS-induced ulcers. (3, 4)

i. Misoprostol
- Early studies in normal volunteers shows marked reduction in incidence of gastrointestinal ulcer in patients receiving NSAIDs with misoprostol compared to those who received NSAIDs + placebo.
- RCT in patient suffering from osteoarthritis and rheumatoid arthritis revealed misoprostol is better than sucralfate and ranitidine.
- A meta analysis of RCT showed misoprostol better that H2 receptor antagonist.
- Recent meta-analysis revealed that co-therapy with misoprostol reduced the incidence of duodenal ulcer by 53% and gastric ulcer by 74%.
- another study has shown that half-dose misoprostol (200 µg twice daily) does not prevent recurrent ulcer complications in high-risk patients with arthritis and a history of ulcer bleeding.

ii. Proton pump inhibitors
- Two RCTs performed in osteoarthritis and rheumatoid arthritis patient with ulcers >3 mm in diameter or >10 mm erosions comparing omeprazole with placebo, misoprostol and ranitidine. Omeprazole co-therapy resulted in significant reduction total number of NSAID related ulcer.
- Two studies reported that omeprazole is superior to ranitidine and

Frank L. Lanza M, FACG 1,2 , Francis K.L. Chan , MD, FRCP, FACG 3, EMMQ, MD, FACG 4, Parameters atP, Gastroenterology CotACo. Guidelines for Prevention of NSAID-Related Ulcer
Complications nature publishing group. 2009.
4. Chan FKL. Primer: Managing NSAID-induced Ulcer Complications - Balancing Gastrointestinal and Cardiovascular Risks2006. Available from: http://www.medscape.com/viewarticle/545617_6.
5. Oscar D. Guillamondegui M, Oliver L. Gunter J, MD, John A. Bonadies M, Jay E. Coates D, Stanley J. Kurek D, Marc A. De Moya M, et al. Stress Ulcer Prophylaxis2008. Available from: https://www.east.org/education/practice-management-guidelines/stress-ulcer-prophylaxis.
6. Rohan C Clarke M, Emmanuel Gbadehan M, Uzodinma R Dim M, Rachael M Ferraro D. Stress-Induced Gastritis Treatment & Management2015. Available from: http://emedicine.medscape.com/article/176319-medication.
7. Ryan J. Daley P. Prevention of stress ulceration: Current trends in critical care Critical Care Medicine October 2004 Volume 32(Issue 10 ).
8. Faisy C, Guerot E, Diehl J-L, Iftimovici E, Fagon J-Y. Clinically significant gastrointestinal bleeding in critically ill patients with and without stress-ulcer prophylaxis. Intensive Care Medicine.