Upper Gastrointestinal System: Structure & Function

• Upper Gastrointestinal System: Structure, Function, & Clinical Considerations

Theory Objectives

• Explore the anatomy and physiology of the gastrointestinal system
• Understand the impact of age and culture on gastrointestinal function
• Learn about diagnostic tests and procedures for gastrointestinal deviations
• Identify nursing considerations for nasogastric tube (NGT) insertion, care, maintenance, and patency
• Discuss nursing considerations for enteral nutrition and medication administration via NGT/GT/JT, including complications and safety precautions
• Differentiate between total parenteral nutrition (TPN) and peripheral parenteral nutrition (PPN)
• Recognize risk factors for oral and esophageal cancer
• Explain hiatal hernia, including causes, symptoms and treatment
• Describe gastritis and gastroesophageal reflux disease (GERD)
• Identify risk factors associated with GERD
• Explain the etiology, pathophysiology, medications, and diet considerations for peptic ulcer disease (PUD)
• Discuss risk factors associated with gastric cancer
• Discuss gastric procedures like total gastrectomy, including possible complications like hemorrhage, dumping syndrome, and nutritional issues
• Discuss bariatric surgery and its potential complications

Introduction to the Gastrointestinal System

• The gastrointestinal (GI) system is responsible for the digestion and absorption of nutrients
• Extends from the mouth to the anus
• Includes accessory organs like the liver, gallbladder, and pancreas

Functions of the GI System

• Ingestion: Taking in food and liquid.
• Digestion: Breaking down food into absorbable nutrients.
• Absorption: Uptake of nutrients into the bloodstream.
• Elimination: Removal of undigested waste.

Assessment

• History: Includes chief complaint, length of symptoms, and details
• Nutrition: Assesses ability to eat, type of diet, and tolerance of foods
• Stools: Evaluates characteristics and presence of occult blood using a Guaiac test
• Medications/Herbs/Rx: Review of current medications, herbs, and prescriptions
• Weight: Notes any recent gain or loss
• Medical and Surgical History: Includes information about past medical conditions and surgeries
• Family History: Explores any relevant family medical history
• Allergies: Identifies any known allergies
• Physical Examination: Includes general appearance, skin assessment, mouth examination, abdominal assessment, and anus examination when appropriate

Abdominal Assessment

• Inspection: Visual examination of the abdomen.
• Auscultation: Listening to bowel sounds.
• Percussion: Tapping on the abdomen to assess underlying structures.
• Palpation: Feeling the abdomen to detect tenderness or abnormalities.

Four Quadrants of the Stomach

• Right Upper Quadrant (RUQ): Contains the gallbladder, duodenum, right lobe of the liver, head of the pancreas, right adrenal gland, part of the right kidney, and portions of the ascending and transverse colon
• Left Upper Quadrant (LUQ): Contains the spleen, stomach, body of the pancreas, left lobe of the liver, left adrenal gland, part of the left kidney, and portions of the transverse and descending colon
• Right Lower Quadrant (RLQ): Contains the appendix, cecum, portion of the ascending colon, right ovary, right ureter, right spermatic cord, and lower portion of the kidney
• Left Lower Quadrant (LLQ): Contains the sigmoid colon, portion of the descending colon, left ovary, left ureter, left spermatic cord, and lower portion of the kidney

Diagnostic Tests

• Radiographic Studies:
• Radiopaque contrast media is used with fluoroscopy.
• They help identify the location and structural appearance of organs in the abdomen, chest, or GI system.
• Small Bowel Series:
• Involves fluoroscopy of the small intestine to the lower part.
• It helps to identify obstructions in the jejunum or ileum, tumors, and inflammation.
• Uses more barium and typically takes 5-6 hours.
• Barium Swallow or Upper Gastrointestinal Series:
• Fluoroscopic observation to observe swallowing of barium from the esophagus to the stomach and the beginning of the small intestines.
• It helps identify structural abnormalities in the esophagus, swallowing discoordination, and oral aspiration
• Pre-procedural requisites include: Low-residue diet, Laxative, Smoking
• Post-procedural requisites include: Drink fluids liberally; Obtain stool specimens; Laxative; Obtain stool specimens after barium has passed
• Ultrasonography:
• High-frequency sound waves are used to determine the size and location of organs.
• Outlines structures, abnormalities, cholelithiasis, and pyloric stenosis changes; Appendicitis changes
• Gastrointestinal Endoscopy (EGD - esophagogastroduodenoscopy):
• Visual examination of the lumen of the GI tract using a flexible fiberoptic endoscope.
• Evaluates the appearance and integrity of the GI mucosa and aids in detecting lesions
• Priority Post care includes gag reflex, monitor for bleeding, fever, abdominal distention, and vomiting
• NPO before procedure, use of a local anesthetic, and anxiolytic are needed.
• Laboratory Tests: Includes complete blood count, urinalysis, serum bilirubin, cholesterol, serum ammonia level, prothrombin time, protein electrophoresis, enzymes, common tumor marker blood studies, gastric analysis (H. pylori test), hydrogen breath testing, and stool analysis

Gastrostomy Tubes

• Provides Route: Nutrition, Medications, Gastric decompression, Lavage, Treatment
• Placement: Nasogastric (NG), Orogastric, Surgical placement (Gastrostomy, PEG tube, Jejunostomy)
• Long-term Tube Feedings: partial parenteral nutrition (PPN), total parenteral nutrition (TPN)
• A nasogastric tube (NGT) decompression can lead to metabolic alkalosis, often associated with hypokalemia

Nasogastric Tube (NGT) Insertion

• Used for feeding, medication administration, or gastric decompression
• Nursing concerns: proper placement, patient comfort, prevention of complications

NGT Care and Maintenance

• Regular checks for proper placement.
• Flushing the tube to maintain patency
• Monitoring for signs of irritation or infection.

Esophageal Disorders: GERD

• Etiology: Gastroesophageal Reflux Disease (GERD)
• Gastric contents regurgitates into the esophagus
• Cause: Lower Esophagus Sphincter (LES) insufficiently closes Risk factors: Pregnancy, obesity, hiatal hernia Assessment Findings: Signs and Symptoms - Epigastric pain (dyspepsia), Burning (pyrosis), Regurgitation, Dysphagia, and Esophagitis
• Dietary Changes: Avoid meals 2-3 hours before bed and eliminate foods and drinks that can irritate the stomach lining or increase acid production, like OJ, spicy foods, and chocolate
• Lifestyle Changes: Smoking cessation, weight loss (if obese), avoiding constrictive clothing, and stress reduction are recommended
• Patient Positioning: High fowlers after meals and elevate head of bed (HOB) while resting
• Medication education: Use of Ca, aluminum, and Mg based antacids, H2 antagonists, and proton pump inhibitors are used

Hiatal Hernia

• Part of the stomach pushes through the diaphragm, the muscle that separates the chest from the abdomen
• Cause: Congenital, trauma, factors increasing intra-abdominal pressure, straining to pass bowel, persistent cough
• Assessment Findings: GERD symptoms, Heartburn, Belching, pain after eating, Nausea, and Fullness
• Axial (or sliding): Junction of stomach, esophagus slide in and out through weakened portion of diagram
• Paraesophageal: Fundus is displaced upward
• Nursing Interventions: Small frequent meals, Avoid spicy foods, ETOH, caffeine, and smoking; lifestyle changes, decrease weight, and smoking cessation; positioning (elevate HOB 3-4 hours after eating); medication (Antacids); surgery is an option is problematic

Gastric Disorders: Gastritis

• Inflammation of the stomach lining.
• Causes: Intake of irritating foods, caffeine, poisons, duodenal reflux, medications (steroids, aspirin, NSAIDs), lifestyle factors like smoking and ETOH, increased gastric acid production, and Helicobacter pylori
• Signs and Symptoms: Heartburn, epigastric fullness, pressure, pain, anorexia, N & V
• Nursing Management: Diet restriction, track patient's weight, provide electrolyte drinks (ex. Gatorade, pedialyte, IV fluids), and monitor for signs of bleeding

Peptic Ulcer Disease (PUD)

• Source: Sores in the lining of the stomach or small intestine.
• Cause: Infection with Helicobacter pylori (H. pylori); Family history, chronic gastric inflammation, long-term NSAIDs, smoking, stress, ETOН, Imbalance of enzymes, Hyperacidity or chronic reduction in mucous
• Severe Pain ( upper abdomen and back) “burning”
• Assessments Findings: Greater on empty stomach, Relief when eating, Bleeding: Hematemesis, Melena (black tar like stools), Weight loss Medications:
• Antibiotics: Kills H. pylori (Amoxicillin, Flagyl).
• H2 receptors antagonists: Decrease acid secretion (Pepcid, Tagamet).
• Antacids: Neutralize stomach acid (Sucralfate: Carafate, Tums, Rolaids) - Take 1 hour before meals.
• Proton pump inhibitors: Blocks acid production (Prilosec).

Overview of the upper gastrointestinal system, including anatomy, physiology, and clinical considerations. This includes diagnostic tests, nursing considerations for nasogastric tubes, enteral nutrition, and parenteral nutrition. Also covered are risk factors, causes, symptoms and treatment of oral and esophageal cancer, Hiatal hernia, GERD and peptic ulcers.