Final answer:
Gastric residual is measured to assess the stomach's ability to process enteral feedings in patients with feeding tubes. This measurement, performed before feedings or every 4-6 hours during continuous feedings, evaluates gastric content and ensures proper digestion and absorption.
Step-by-step explanation:
Checking gastric residual refers to the process of measuring the volume and composition of gastric contents, which can be important when assessing a patient's digestion and absorption capabilities. This is typically done in patients who are receiving enteral nutrition through a tube to ensure that the stomach is processing the feeding appropriately. It is recommended to check gastric residuals before each feeding or every 4-6 hours during continuous feedings. Additionally, measuring components such as total chloride, occult blood, free HCl, lactic acid, bile pigments, and peptic activity can help assess the normal functions of the stomach.
Various gastric function tests may utilize methods like the tubeless gastric function test, which involves the oral administration of a quininium resin indicator to detect hydrochloric acid in the stomach. Another method to assess the absorptive function of the gastrointestinal tract involves the oral administration of radioactive substances, such as fatty acids, iron, and vitamin B12, followed by regular blood tests.