🥗Nutrition for Nurses Unit 17 – Gastrointestinal Nutrition for Nurses

What's This Unit All About?

• Focuses on the gastrointestinal (GI) system and its role in digestion, absorption, and utilization of nutrients
• Explores the anatomy and physiology of the GI tract, including the mouth, esophagus, stomach, small intestine, large intestine, and accessory organs (liver, gallbladder, and pancreas)
• Discusses the various nutrients (carbohydrates, proteins, fats, vitamins, and minerals) and their roles in maintaining health
• Examines the process of digestion and absorption, including mechanical and chemical breakdown of food and the absorption of nutrients into the bloodstream
• Covers common GI disorders, their causes, symptoms, and management strategies
• Delves into nutritional interventions for GI disorders and the role of nurses in patient care and education
• Emphasizes practical nursing considerations, such as assessing nutritional status, administering enteral and parenteral nutrition, and monitoring patient outcomes

Key Anatomy and Physiology

• The GI tract consists of a series of hollow organs that form a continuous pathway from the mouth to the anus
• The mouth initiates digestion through mastication (chewing) and salivary enzymes (amylase) that begin carbohydrate breakdown
• The esophagus transports food from the mouth to the stomach via peristalsis (rhythmic muscle contractions)
• The stomach secretes hydrochloric acid and pepsin to break down proteins and stores food for further digestion
  • The stomach lining is protected by a mucous layer to prevent self-digestion
• The small intestine is divided into three sections: duodenum, jejunum, and ileum
  • The duodenum receives digestive enzymes from the pancreas and bile from the liver and gallbladder to aid in digestion
  • The jejunum and ileum are responsible for the majority of nutrient absorption
• The large intestine (colon) absorbs water and electrolytes, forms feces, and houses gut bacteria that ferment undigested material and produce vitamins (vitamin K and biotin)
• The liver produces bile, metabolizes nutrients, and detoxifies harmful substances
• The gallbladder stores and concentrates bile, which is released into the duodenum to emulsify fats
• The pancreas secretes digestive enzymes (lipase, amylase, and trypsin) and bicarbonate to neutralize stomach acid

Nutrients and Their Roles

• Carbohydrates are the primary energy source for the body and are broken down into simple sugars (glucose) for absorption
  • Complex carbohydrates (starches and fiber) are found in whole grains, legumes, and vegetables
  • Simple carbohydrates (sugars) are found in fruits, milk, and processed foods
• Proteins are essential for growth, repair, and maintenance of body tissues and are broken down into amino acids for absorption
  • Complete proteins (contain all essential amino acids) are found in animal products (meat, fish, eggs, and dairy)
  • Incomplete proteins (lack one or more essential amino acids) are found in plant sources (legumes, grains, and vegetables)
• Fats provide energy, insulation, and cushioning for organs and are broken down into fatty acids and monoglycerides for absorption
  • Saturated fats (solid at room temperature) are found in animal products and tropical oils (coconut and palm)
  • Unsaturated fats (liquid at room temperature) are found in plant oils (olive, canola, and avocado), nuts, and seeds
• Vitamins are essential micronutrients that support various bodily functions and are classified as water-soluble (B vitamins and vitamin C) or fat-soluble (vitamins A, D, E, and K)
• Minerals are inorganic elements that play crucial roles in body processes, such as calcium for bone health, iron for oxygen transport, and sodium for fluid balance

Digestion and Absorption Basics

• Digestion involves the mechanical and chemical breakdown of food into smaller particles and molecules that can be absorbed by the body
• Mechanical digestion begins in the mouth with chewing and continues in the stomach with churning and mixing
• Chemical digestion involves the action of digestive enzymes secreted by the salivary glands, stomach, pancreas, and small intestine
  • Carbohydrate digestion begins in the mouth with salivary amylase and continues in the small intestine with pancreatic amylase
  • Protein digestion starts in the stomach with pepsin and continues in the small intestine with pancreatic enzymes (trypsin and chymotrypsin)
  • Fat digestion occurs primarily in the small intestine with the help of bile and pancreatic lipase
• Absorption is the process by which nutrients are transported from the GI tract into the bloodstream or lymphatic system
  • Most nutrient absorption takes place in the small intestine through passive diffusion, facilitated diffusion, and active transport
  • The large intestine absorbs water, electrolytes, and some vitamins produced by gut bacteria
• The liver, gallbladder, and pancreas play crucial roles in digestion and absorption by secreting bile and digestive enzymes into the small intestine

Common GI Disorders

• Gastroesophageal reflux disease (GERD) occurs when stomach acid frequently flows back into the esophagus, causing heartburn and potential damage to the esophageal lining
• Peptic ulcers are open sores that develop in the lining of the stomach or duodenum, often caused by Helicobacter pylori (H. pylori) infection or long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs)
• Inflammatory bowel disease (IBD) is a group of disorders, including Crohn's disease and ulcerative colitis, that cause chronic inflammation and damage to the GI tract
• Celiac disease is an autoimmune disorder triggered by the ingestion of gluten (a protein found in wheat, barley, and rye), leading to damage of the small intestine lining and nutrient malabsorption
• Diverticulosis is the presence of small, bulging pouches (diverticula) in the colon wall, which can become inflamed or infected, causing diverticulitis
• Irritable bowel syndrome (IBS) is a functional GI disorder characterized by abdominal pain, bloating, and changes in bowel habits (diarrhea or constipation) without visible damage to the GI tract
• Colorectal cancer is a malignant growth that develops in the colon or rectum, often beginning as a benign polyp and progressing over time

Nutritional Interventions

• Therapeutic diets are modified meal plans designed to manage specific health conditions or nutritional needs
  • Low-FODMAP diet reduces fermentable carbohydrates (oligosaccharides, disaccharides, monosaccharides, and polyols) to alleviate IBS symptoms
  • Gluten-free diet eliminates gluten-containing foods to manage celiac disease and prevent intestinal damage
  • Low-residue diet limits high-fiber foods to reduce bowel movements and allow the GI tract to rest (e.g., during a flare-up of IBD)
• Enteral nutrition involves the delivery of liquid nutrients directly into the GI tract via a feeding tube when oral intake is insufficient or contraindicated
  • Nasogastric (NG) tubes are inserted through the nose and end in the stomach
  • Nasojejunal (NJ) tubes are inserted through the nose and end in the jejunum, bypassing the stomach
  • Percutaneous endoscopic gastrostomy (PEG) tubes are surgically placed through the abdominal wall into the stomach for long-term feeding
• Parenteral nutrition (PN) involves the intravenous infusion of nutrients when the GI tract cannot be used due to severe dysfunction or obstruction
  • PN solutions contain a mixture of carbohydrates, amino acids, lipids, electrolytes, vitamins, and minerals tailored to the patient's specific needs
  • PN can be administered through a peripheral vein (short-term) or a central venous catheter (long-term)

Practical Nursing Considerations

• Assess patients' nutritional status using tools such as body mass index (BMI), dietary recall, and laboratory tests (e.g., albumin, prealbumin, and transferrin levels)
• Monitor patients for signs and symptoms of malnutrition, such as unintentional weight loss, muscle wasting, and skin breakdown
• Educate patients and families about therapeutic diets, food-drug interactions, and the importance of adhering to prescribed nutritional interventions
• Administer enteral and parenteral nutrition as ordered, ensuring proper tube placement, flow rate, and solution compatibility
• Monitor patients receiving enteral or parenteral nutrition for complications, such as aspiration, diarrhea, electrolyte imbalances, and catheter-related infections
• Collaborate with registered dietitians, physicians, and other healthcare professionals to develop and implement individualized nutritional care plans
• Provide emotional support and encourage patients to express their feelings and concerns related to their GI health and nutritional status

Key Takeaways and Study Tips

• Understand the anatomy and physiology of the GI tract and its role in digestion and absorption of nutrients
• Recognize the different types of nutrients (carbohydrates, proteins, fats, vitamins, and minerals) and their functions in the body
• Familiarize yourself with the process of mechanical and chemical digestion and the sites of nutrient absorption along the GI tract
• Know the common GI disorders, their causes, symptoms, and management strategies, including nutritional interventions
• Be able to differentiate between therapeutic diets (e.g., low-FODMAP, gluten-free, and low-residue) and their indications
• Understand the differences between enteral and parenteral nutrition, their routes of administration, and potential complications
• Focus on practical nursing considerations, such as assessing nutritional status, administering nutritional interventions, and monitoring patient outcomes
• Create flashcards or concept maps to visualize the relationships between GI anatomy, physiology, disorders, and nutritional interventions
• Practice applying your knowledge to real-world scenarios or case studies to reinforce your understanding of key concepts