title: Influence of sucralfate on the detection of occult blood in simulated gastric fluid by two screening tests.
abstract: The influence of sucralfate on the detection of occult blood in simulated gastric fluid by two screening tests was investigated. Two simulated gastric solutions (pH 1.2 and 4.1) containing sucralfate 2.5 or 10 mg/mL were spiked with fresh whole blood (hemoglobin concentration, 15.7 g/dL) to achieve a blood concentration of 1 or 5 microL/mL. Fifty-microliter samples were applied to separate Hemoccult and Gastroccult test slides, which were read by a blinded evaluator at 60, 120, and 180 seconds after the addition of developer. Any trace of blue in the test area was considered a positive result. Sucralfate-free simulated gastric fluid spiked with blood served as a positive control, and fluid with or without sucralfate and containing no blood served as a negative control. No false-positive or false-negative results were obtained with Gastroccult. Hemoccult yielded false-positive results in 3 of 20 determinations at 60 seconds for solution containing sucralfate 10 mg/mL (pH 1.2) and 13 of 20 determinations at 60 seconds for solution containing sucralfate 2.5 mg/mL (pH 1.2). All the results with Hemoccult were positive when the slides were read at 120 and 180 seconds. Also, all the results for the negative controls were positive at 120 seconds. Hemoccult did not produce any false-negative results. False-positive results occurred when Hemoccult was used to test simulated gastric fluid that had a low pH (1.2) and contained sucralfate. Gastroccult did not yield false-positive results.
authors.affiliation: St. Vincent's Medical Center, Jacksonville, FL.
authors.forename: J S
authors.initials: JS
authors.lastname: Holman
authors.forename: J A
authors.initials: JA
authors.lastname: Shwed
mesh_terms: D005189:False Positive Reactions; D005750:Gastric Juice; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009780:Occult Blood; D013392:Sucralfate / Q000494:pharmacology*
chemical_list: D013392:Sucralfate