Gastrointestinal System Review

Gastrointestinal System Overview

Introduction

• Instructor Information: Nena Jaramillo, DNP, MSN Ed, OB-RNC; Revised by Marie Cusack MSN-Ed, RN, Ventura College, NS 20.

General Categories of GI Disorders

• Motility Disorders

• Inflammation

• Obstruction

Motility Disorders

Gastroesophageal Reflux Disease (GERD)

• Definition: Chronic condition characterized by the reflux of stomach acid into the lower esophagus, causing mucosal damage.

• Associated Condition: Hiatal Hernia.

Pathophysiology

• Mechanism: In GERD, the esophageal sphincter fails to close properly, which results in the stomach contents refluxing back into the esophagus.

Manifestations

• Pyrosis: A burning sensation in the chest, also known as heartburn.

• Dyspepsia: General discomfort or pain in the upper abdomen.

• Regurgitation: The sensation of acid backing up into the throat or mouth.

• Respiratory Symptoms: Wheezing, coughing, dyspnea (breathlessness).

• Sleep Disturbances: Altered sleep patterns.

• Voice Changes: Sore throat, hoarseness.

Complications

• Esophagitis: Inflammation of the esophagus due to acid damage.

• Esophageal Ulcerations: Erosion of the esophageal lining.

• Barrett’s Esophagus: A precancerous condition where esophageal cells transform from flat epithelial cells to columnar epithelial cells.

• Respiratory Complications: Increased risk of aspiration pneumonia.

• Dental Erosion: Damage to teeth due to acid exposure.

Collaborative Care

• Diagnostic Procedures:
    - Endoscopy
    - Biopsy
    - Manometric Studies (pressure measurements)

• Lifestyle Modifications:
    - Smoking cessation
    - Weight reduction
    - Nutrition therapy (diet changes)

• Drug Therapy:
    - Proton Pump Inhibitors (PPIs)
    - H2 Receptor Blockers
    - Antacids

• Surgical Interventions: Antireflux surgery such as Nissen fundoplication.

• Postural Management: Elevating head of bed (HOB).

Drug Therapy

1. Proton Pump Inhibitors (PPIs)
      - Mechanism: Decrease HCl acid secretion by inhibiting proton pumps responsible for H+ secretion, reducing irritation of mucosal surfaces.
      - Side Effects: Headache, abdominal pain, nausea, diarrhea, vomiting, flatulence.

2. H2 Receptor Blockers
      - Mechanism: Block histamine action on H2 receptors to reduce HCl acid secretion and pepsinogen to pepsin conversion.
      - Side Effects: Headache, abdominal pain, constipation, diarrhea.

3. Antacids
      - Function: Provide short-term relief of heartburn by neutralizing stomach acid; typically taken 1-3 hours post-meal.
      - Examples: Aluminum carbonate, aluminum hydroxide, calcium carbonate (Tums), magnesium oxide, sodium bicarbonate (Alka-Seltzer), sodium citrate (Bicitra).

Surgical Management

• Nissen Fundoplication: Surgical wrapping of the top of the stomach around the lower esophagus to prevent reflux.

Postoperative Nursing Management

• Care Protocols:
    - Monitor bowel sounds.
    - Gradual advancement of diet from fluids to solids post-operatively.
    - Educate patients to report persistent regurgitation, eat smaller, frequent meals, and sit up after eating.
    - Instruct on taking PPIs prior to the morning meal.

Hiatal Hernia

Definition

• Hiatal Hernia: Herniation of a portion of the stomach into the esophagus through a diaphragmatic opening.

Classifications

1. Sliding Hiatal Hernia: Occurs when the esophagogastric junction and part of the stomach slide into the thoracic cavity.

2. Paraesophageal Hiatal Hernia: Part of the stomach herniates alongside the esophagus; this type poses a higher risk of complications.

Pathophysiology

• Weakness in the diaphragm muscles increases intra-abdominal pressure due to:
    - Obesity
    - Pregnancy
    - Ascites (fluid accumulation in the abdominal cavity)
    - Tumors
    - Exertion or heavy lifting.

Clinical Manifestations

• Symptoms:
    - Chest pain, severe heartburn, abdominal pain.
    - Frequent burping; difficulty swallowing (dysphagia).
    - Sore throat, belching, nausea.

Collaborative Care

• Management Goals: Reduce intra-abdominal pressure by advising against tight garments and heavy lifting, facilitating weight loss, and providing education on the condition.

• Diagnostics: Barium swallow and X-ray studies; endoscopic evaluation for further assessment.

• Surgical Options: Antireflux surgeries may be indicated based on the patient's condition.

Inflammatory Disorders

Definitions

• Inflammatory Bowel Disease (IBD): Chronic inflammatory conditions of the GI tract, including Crohn’s Disease and Ulcerative Colitis.

• Peptic Ulcer Disease: Erosion of the GI mucosa due to the digestive action of HCl acid and pepsin.

• Diverticulitis: Inflammation of diverticula in the colon.

Inflammatory Bowel Disease (IBD)

• Describes conditions characterized by inflammation of the GI tract with no cure available.

Subtypes

1. Crohn’s Disease: Can affect any part of the GI tract from the mouth to anus; involves all layers of the bowel wall, creating deep, longitudinal ulcerations with a cobblestone appearance.

2. Ulcerative Colitis: Limited to the mucosal layer of the colon and rectum; presents with bloody stools and is well localized without fistulas.

Pathophysiology

• Etiological Factors:
    - Autoimmune processes influenced by genetics, environment, diet, NSAIDs, stress, smoking (particularly in those of white, Jewish descent).
    - Alterations in the immune system lead to inflammation.

Comparisons Between Crohn’s Disease and Ulcerative Colitis

Surgical Options

• Total Proctocolectomy W/ Ileostomy: Removal of the entire colon and rectum, with the end of the ileum brought out to form a stoma.

• Type of Ostomies: Stomas can be temporary or permanent depending on excised areas.

Postoperative Considerations

• Care of Stoma:
    - The stoma is pink to red, should be round to oval, may protrude slightly, and has no nerve endings.
    - Monitor output, which may be up to 1500-2000 mL/24 hours in ileostomies.
    - Address skin integrity around the stoma.

Drug Therapy for IBD

1. 5-Aminosalicylic Acid Compounds: Reduce GI inflammation through direct contact with bowel mucosa (e.g., Azulfidine, Pentasa).

2. Antimicrobials: Prevent or treat infections (e.g., Flagyl).

3. Corticosteroids: Reduce inflammation (e.g., Prednisone).

4. Immunosuppressants: Suppress immune response (e.g., Imuran, Methotrexate).

5. Biologics: Inhibit cytokine tumor necrosis factor (TNF) (e.g., Remicade).

Nutritional Therapy Goals

• Objectives:
    - Provide adequate nutrition without exacerbating symptoms.
    - Correct and prevent malnutrition.
    - Replace fluid and electrolyte losses and prevent weight loss.

Nursing Management

• Physically monitor hemodynamic stability, pain control, fluid and electrolyte balance, nutritional support, and patient education.

Peptic Ulcer Disease

Definition

• Peptic Ulcer Disease: Refers to erosions in the GI mucosa caused by acid and pepsin, which may affect any part of the GI tract.

Types

1. Acute Ulcers: Characterized by sudden onset and inflammation.

2. Chronic Ulcers: Develop gradually and persist over a longer period.

Pathophysiology of Ulcer Formation

• Contributing Factors:
    - Acids, bile salts, NSAIDs, alcohol, and ischemia.
    - Disruption of the gastric mucosal barriers leading to:
      - Acid back diffusion into the mucosa
      - Destruction of mucosal cells
      - Increased histamine release (causing vasodilation and increased capillary permeability).

Types of Lesions

Complications of Peptic Ulcers

• Perforation: An ulcer penetrates the serosal surface, leading to peritoneal cavity contamination, potentially leading to rapid clinical deterioration characterized by:
    - Sudden upper abdominal pain
    - Rigid abdomen
    - Shallow respirations
    - Tachycardia and vomiting.

Diagnostics

• Tests:
    - Endoscopy for direct visualization and biopsy for H. pylori.
    - Rapid urease testing for H. pylori detection (gold standard).
    - CBC and liver enzyme assessment for other complications.
    - Barium contrast studies for gastric outlet obstruction.

Collaborative Care

• Initial Management:
    - Dietary modifications: Avoid alcohol, NSAIDs for 4-6 weeks.
    - Pharmacological Treatments:
      - PPIs, H2 blockers, antacids, immunosuppressants, and antibiotics for H. pylori eradication.
    - Lifestyle modifications: Smoking avoidance.

Management of Surgical Complications

• Perforation: Surgical intervention to seal perforations, RBC transfusions, NG tube placement.

• Gastric Outlet Obstruction: Involves decompressing the stomach and correcting fluid/electrolyte imbalances.

Surgical Options

• Billroth I: Gastrectomy with duodenal anastomosis.

• Vagotomy: Reducing acid secretion by severing certain vagus nerves.
    - Potential postoperative complications including dumping syndrome and bile reflux gastritis.

Obstructive Disorders

Types of Obstruction

• Ileus: A paralysis of the intestines leading to lack of movement and blockages.

• Tumor-related obstructions: Such as colorectal cancer.

Pathophysiology of Intestinal Obstruction

• Obstruction leads to the accumulation of fluid, air, and intestinal contents, causing:
    - Distension of the proximal bowel
    - Increased pressure leading to capillary permeability alterations (3rd spacing of fluids).
    - Decreased blood volume resulting in hypotension and hypovolemic shock.

Clinical Manifestations

• Symptoms depend upon obstruction location:
    - Colicky abdominal pain
    - Nausea and vomiting
    - Abdominal distention
    - Constipation and reduced flatus.
    - High-pitched bowel sounds near obstruction, while absent sounds beyond the obstruction.

Diagnostics

• Imaging Studies:
    - CT scan
    - Abdominal X-ray
    - CBC for white blood cell (WBC) counts.

Collaborative Care

• Surgical Intervention: Potentially required to remove the obstructed portion of the bowel.

• Pre-operative Care: Maintain strict NPO status, NG tube for decompression, IV fluids for hydration.

• Nursing Responsibilities: Regular assessments of bowel sounds, vomitus analysis, and monitoring of input/output (I/O).

Colorectal Cancer

Risk Factors

• Diet: High red/processed meat intake and low fruits/vegetables.

• Lifestyle Factors: Sedentary behavior, obesity, alcohol use, smoking.

• Genetic Predisposition: Family history of polyps or colorectal cancer; genetic syndromes like familial adenomatous polyposis (FAP).

Clinical Manifestations

• Often asymptomatic until advanced stages but may present early symptoms:
    - Fatigue, weight loss, iron deficiency anemia, rectal bleeding.

• Late symptoms may include specific abdominal pain and changes in bowel habits.

Collaborative Care

• Preoperative Preparation: Bowel cleansing with polyethylene glycol lavage and antibiotics.

• Surgical Options: Removing hyperplastic polyps, local incisions, abdominal perineal resection (APR) with permanent colostomy, or low anterior resection (LAR) with restoration of bowel continuity.

Post-surgical Management

• Ostomy Types:
    - Ileostomy: Involving the ileum where output is typically liquid.
    - Colostomy: More distal; output consistency varies by location in the colon (e.g., semiliquid in ascending, more solid in sigmoid colostomy).

Nursing Management

• Patient education on screening and stoma care, assessment of emotional support needs, and maintenance of skin integrity around the stoma.

Potential Complications

• Post-Surgical Complications: May include bowel obstructions, hemorrhage, perforation, abscesses, and peritonitis.

• Specific considerations for the elderly include increased susceptibility to skin breakdown and potential delayed eliminations.

Conclusion

• These notes encapsulate critical information related to various GI disorders, their manifestations, therapeutic approaches, and management strategies, necessary for a comprehensive understanding of the gastrointestinal system.