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510(k) Data Aggregation
(166 days)
HemaPrompt Gastric is a guaiac-based in-vitro method for the qualitative detection of occult blood in gastric aspirate or vomitus by medical professionals only. A separate segment of pH paper is provided on the slide for estimation of pH of the gastric juice.
It is used for the early detection of occult blood in such conditions as gastric trauma, gastric or duodenal ulceration, gastric cancer, esophageal varices, situations of exogenous or endogenous gastritis, leukemia, and hereditary telangiectasia. These conditions may be encountered in the emergency room, recovery room or intensive care.
The HemaPrompt Gastric slide, used with a buffered developer and a buffered guaiac paper, is a guaiac based test for the detection of occult blood in gastric samples. The test is not affected by low pH, and is free from interferences by normal therapeutic concentrations of iron, ranitidine, and antacids. A separate area is provided to test for the pH of the specimen.
When a gastric specimen containing blood is applied to the HemaPrompt Gastric test paper, hemoglobin from the lysed blood cells in the sample comes in contact with the guaiac in the paper. The developer, a buffered solution of alcohol and hydrogen peroxide, which is applied with two drops to the guaiac on the slide, creates a peroxidase-like reaction in the presence of hemoglobin which in turn causes a blue coloration in the test paper. This test will turn blue in the presence of more than 100 mcg Hb/ ml gastric juice.
The HemaPrompt Gastric device detects occult blood in gastric samples. The provided information details several studies to assess its performance.
1. Acceptance Criteria and Reported Device Performance:
The document implies an acceptance criterion for sensitivity at 100 mcg Hb/ml gastric juice.
| Acceptance Criteria | Reported Device Performance | Study |
|---|---|---|
| Positive reaction at > 100 mcg Hb/ml gastric juice | 100% positive reaction at 200 mcg Hb/ml or greater | Patient Gastric Samples, Intubated Volunteer Samples, PBS Samples |
| Positive reaction at > 100 mcg Hb/ml gastric juice | 81.25% positive reaction at 100 mcg/ml (PBS samples) | PBS Samples |
| Not affected by low pH | Tested across pH 1.0 to 7.0 (via PBS samples) | PBS Samples |
| Not affected by normal therapeutic concentrations of iron, ranitidine, and antacids | Concentrations of ranitidine, ferrous sulfate, and an antacid (Mylanta) did not alter results | PBS Samples |
| Excellent reproducibility above 100 mcg/ml gastric juice | Excellent reproducibility demonstrated over a two-week period, with samples stored up to 10 days at 5% | Reproducibility study (not explicitly named or detailed) |
| Monitors react as expected | All monitors reacted in the expected manner (+ve turned blue and the "negative" monitor remained non-reactive) | Monitor reaction study (not explicitly named or detailed) |
2. Sample Sizes and Data Provenance:
- Test Set:
- Patient Gastric Samples: 12 samples (retrospective/clinical, origin not specified, but implies a clinical setting).
- Healthy Volunteer Gastric Samples: 8 samples obtained by intubation (prospective, volunteer, origin not specified).
- Synthetic Gastric Juice (PBS): Not explicitly stated how many distinct PBS samples were used, but they were subjected to titration for pH (1.0 to 7.0) and spiked with hemoglobin (50, 100, 200, 500 mcg/ml). This implies a controlled laboratory setting.
3. Number of Experts and Qualifications:
Not applicable. The assays are chemical reactions, and the results are read by observing a color change. The document does not mention any expert interpretation for establishing ground truth for the device's performance.
4. Adjudication Method:
Not applicable. The tests are based on chemical reactions resulting in a visual color change. There is no mention of human interpretation requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No. This is a qualitative chemical test, not an imaging or diagnostic algorithm requiring human interpretation and a multi-reader study.
6. Standalone Performance:
Yes, the studies described are standalone performance evaluations of the HemaPrompt Gastric device. The document explicitly describes the device's reaction to various hemoglobin concentrations and conditions.
7. Type of Ground Truth Used:
The ground truth for the test set was established by:
- Known Hemoglobin Concentrations: For the patient samples and healthy volunteer samples, known concentrations of hemoglobin were added to the samples. For the PBS samples, known concentrations of hemoglobin were titrated into the solutions. This represents a ground truth based on spiking with known analytes/concentrations.
- Clinical observation: The initial positive results in intubated volunteer samples (37.5% with no added blood) imply that some intrinsic bleeding occurred due to the intubation procedure itself, which would be considered a clinical ground truth for the presence of blood, though not quantified.
8. Sample Size for Training Set:
Not applicable. This device is a chemical test, not a machine learning algorithm that requires a training set.
9. How Ground Truth for Training Set Was Established:
Not applicable, as there is no training set for this type of device.
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