Digestive Physiology: Things to Keep in Mind

1. Does High Gastric Acid Secretion (GAS) Cause Increased Blood Urea Nitrogen (BUN)?

When GAS is high, hydrochloric acid (HCl) in the stomach reacts with hemoglobin in the blood, forming hematin and ammonia (NH3). NH3 is absorbed into the circulatory system through the portal vein, and then converted to urea in the liver. This process can lead to increased BUN.

2. Management of Suspected High GAS Due to Peptic Ulcer Disease (PUD)?

• Initial Therapy: Bolus proton pump inhibitor (PPI) (esomeprazole) 80mg.

• Early Endoscopy: Perform upper endoscopy within 24 hours to confirm the diagnosis.

• Continued Management: If PUD is confirmed, continue high-dose PPI 8mg/hour for 72 hours.

3. When to Use Beta-Blockers + Nitrates for GAS?

• Nitrates: Enhance the effects of beta-blockers.

• Timing of Use: Use after 6 days of treatment for high GAS, and may be used prophylactically or to treat patients with a history of hypertension.

• Note: Do not use beta-blockers when the patient is bleeding, as these drugs can reduce cardiac output, constrict visceral vessels, and lead to decreased blood flow to the kidneys.

4. Difficult Locations for Upper Endoscopy Due to Ulcers?

• Gastric Fornix (Fundus): Difficult to rotate the endoscope 180 degrees.

• Duodenal Bulb: Prone to perforation.

• D2 Duodenal Angle: Hidden.

Note: This article provides general information about digestive physiology and is not a substitute for medical advice. If you experience any health concerns, consult a doctor for proper diagnosis and treatment.