Saline Loading Test for Gastric Outlet Obstruction (GOO)
I was unable to locate specific guidelines or protocols for a saline loading test in the context of gastric outlet obstruction in the provided evidence. The evidence primarily addresses saline-related procedures in other clinical contexts (primary aldosteronism screening, airway challenges, fetal transfusions, and ankle arthrotomy evaluation).
What the Evidence Does NOT Support
The provided studies discuss:
- Saline infusion tests for primary aldosteronism - involving IV infusion of 1-2 liters of normal saline over 2-4 hours to assess aldosterone suppression 1, 2
- Hypertonic saline challenges for bronchial responsiveness - using nebulized saline for respiratory testing 3
- Saline irrigation for allergic rhinitis - nasal lavage procedures 4
- Saline load tests for traumatic arthrotomy - injecting saline into joints to detect capsular breach 5
None of these protocols are applicable to gastric outlet obstruction assessment.
Clinical Context for GOO Assessment
Based on general medical knowledge, a saline loading test for suspected gastric outlet obstruction typically involves:
- Nasogastric tube placement with aspiration of gastric contents
- Instillation of 750-1000 mL of normal saline into the stomach via the NG tube
- Aspiration after 30 minutes to measure residual volume
- Interpretation: Residual volume >400 mL after 30 minutes suggests significant gastric outlet obstruction
Important Caveats
- This test has largely been replaced by upper endoscopy and cross-sectional imaging in modern practice
- The test lacks standardization and has variable sensitivity/specificity
- Direct visualization via endoscopy provides both diagnostic and potentially therapeutic options
I recommend consulting gastroenterology-specific guidelines or textbooks for validated protocols specific to gastric outlet obstruction assessment, as the provided evidence does not address this clinical scenario.