Upper Gastrointestinal

Upper Gastrointestinal Overview

University of Kentucky
College of Nursing

HCl Secretion in the Stomach

  • Cells responsible for HCl secretion:

    • G-cells

    • Parietal cells

    • Chief cells

    • Epithelial cells

Esophageal Disorders

Common Disorders

  • GERD (Gastroesophageal Reflux Disease)

  • Upper GI Problems

  • Inflammatory Disorders of the Stomach

    • Gastritis

    • Hiatal Hernia

    • Acute Gastroenteritis

    • Peptic Ulcer Disease (PUD)

Dysphagia

  • Definition: Difficulty swallowing

  • Characteristics:

    • Begins with solids and progresses to liquids

  • Causes of Dysphagia:

    • Mechanical obstruction:

    • Stenosis or stricture

    • Diverticula

    • Tumors

    • Neuromuscular dysfunction:

    • Cerebrovascular accident (CVA)

    • Achalasia (Lower Esophageal Sphincter (LES) cannot open properly)

GERD

Definition

  • Gastroesophageal Reflux Disease:

    • Backflow of highly acidic material from the stomach into the esophagus via the lower esophageal sphincter (LES)

    • Potential results:

    • Inflammation

    • Pain

    • Complications: ulceration, scarring, strictures, Barrett esophagus

Etiology

  • Factors that alter closure strength of LES or increase abdominal pressure:

    • Fatty foods

    • Caffeine

    • Large amounts of alcohol

    • Cigarette smoking

    • Sleep position

    • Obesity

    • Pregnancy

    • Pharmacologic agents

Clinical Manifestations

  • Heartburn (pyrosis)

  • Dyspepsia

  • Regurgitation

  • Chest pain

  • Dysphagia

  • Pulmonary symptoms (Asthma related to GERD)

Esophagitis

Causes

  • Other causes of esophagitis include:

    • Infection

    • Chemical ingestion

    • Drugs

    • Frequent emesis (bulimia)

Hiatal Hernia

Definition

  • Hiatal Hernia: Defect in the diaphragm allowing part of the stomach to pass into the thorax

  • Types of Hiatal Hernia:

    • Sliding hernia

    • Paraesophageal hernia

Pathophysiology

  • Risk Factors for Hiatal Hernia:

    • Age

    • Conditions that loosen the muscular band around the gastroesophageal junction

  • Clinical Manifestations:

    • Asymptomatic

    • Symptoms similar to those of GERD

Contributing Factors to Gastroesophageal Reflux

  • Factors contributing to reflux:

    • Decreased LES strength

    • Increased abdominal pressure

    • Excessive gastric motility

    • Overproduction of HCl

    • Mucosal injury and inflammation

    • Barrett’s esophagus and esophageal cancer

Gastritis

Acute Gastritis

  • Definition: Temporary inflammation of the stomach lining

  • Etiology:

    • Irritating substances (e.g., alcohol)

    • Drugs (NSAIDs)

    • Infection

Chronic Gastritis

  • Definition: Progressive disorder featuring chronic inflammation in the stomach

  • Main Etiologies:

    • Autoimmune causing attack on parietal cells

    • H. pylori infection

H. pylori

Overview

  • What is H. pylori?

    • Helicobacter pylori

    • Thrives in acidic environment, causing persistent inflammation

    • Implications: Chronic gastritis, PUD, stomach cancer

  • Transmission: Not specified in transcript

Acute and Chronic Gastritis: Clinical Manifestations

  • Common symptoms:

    • Sometimes none present

    • Anorexia

    • Nausea and Vomiting (N/V)

    • Postprandial discomfort

    • Hematemesis

    • Anemia

    • Vomiting blood

    • Stomach burning

    • Loss of appetite

    • Black stool

Acute Gastroenteritis

  • Definition: Inflammation of the stomach and small intestine

  • Etiology:

  • Clinical Manifestations:

    • Diarrhea

    • Abdominal pain

    • N/V

    • Fever, malaise

  • Complication: Fluid volume depletion

Peptic Ulcer Disease (PUD)

Overview

  • Definition: Ulcerative disorders affecting the upper GI tract including esophagus, stomach, duodenum

  • Cause of Development: Exposure of GI tract to acid and pepsin

Balancing Act in Upper GI Health

Aggressive Factors

  • H. pylori

  • NSAIDs

  • Acid

  • Pepsin

  • Smoking

Defensive Factors

  • Mucus

  • Bicarbonate

  • Blood flow

  • Prostaglandins

PUD Etiology

  • Primary causes include:

    • H. pylori

    • Injury-causing substances (NSAIDs, ASA, alcohol)

    • Excessive secretion of acid

    • Stress

    • Smoking

    • Family history

Mechanism of H. pylori in PUD

  • Process:

  1. Secretes an endotoxin destroying the mucus layer

  2. Secretes protease destroying gastric epithelium

  3. Secretes urease, irritating mucosal cells

  4. Triggers inflammatory response in colonization area

NSAID Induced Gastric Injury

  • Mechanisms:

    • NSAIDs block secretion of protective prostaglandins via COX-1 inhibition

    • Direct irritation to gastric wall

    • Increased pepsin production via COX-2 inhibition

Clinical Manifestations of PUD

  • Some patients may be asymptomatic

  • Common symptoms include:

    • N/V

    • Anorexia

    • Weight loss

    • Bleeding

    • Pain based on ulcer type:

    • Gastric ulcer:

      • Burning, cramping, gas-like

      • Timing: 1-2 hours post meals

    • Duodenal ulcer:

      • Same symptoms as gastric

      • Timing: 2-4 hours post meals

Complications of PUD

  • HOP:

    • H: Hemorrhage

    • O: Obstruction

    • P: Perforation and Peritonitis

    • Mechanism: Spurting artery from erosion into an artery

Drug Treatments for Upper GI Problems

Classes of Drugs

  • Antacids

  • Sucralfate

  • Antibiotics

  • H2 receptor antagonists

  • Proton pump inhibitors

  • Metoclopramide

Antacids

Mechanism of Action

  • Large doses: Neutralizes acid

  • Example Reaction:

    • Mg(OH)<em>2+HClightarrowMgCl</em>2+H2OMg(OH)<em>2 + HCl ightarrow MgCl</em>2 + H_2O

  • Small doses: Increases secretion of mucus, PG, and HCO3

Indications

  • PUD (healing)

  • GERD (symptom relief)

  • Stress ulcers (prophylaxis)

Major Forms of Antacids

  • Aluminum (Al): Basajel; Side Effect: Constipation

  • Calcium (Ca): Tums; Side Effect: Constipation

  • Magnesium (Mg): Milk of Magnesia; Side Effect: Diarrhea

  • Al + Mg: Maalox, Mylanta; Balanced approach

Adverse Effects

  • Diarrhea or constipation

  • Acid rebound

  • Drug interactions: chelation & altered gastric absorption

Sucralfate (Carafate)

Composition

  • Unique drug composed of:

    • Sucrose-base

    • Aluminum hydroxide

Mechanism of Action

  • Alters when exposed to gastric acid, forming a sticky gel providing a protective barrier

Indication

  • Uses:

    • Duodenal ulcers (FDA-approved)

    • Gastric ulcers (evidence supporting use)

Mode of Delivery

  • Oral (tablet or suspension)

Adverse Effects

  • No major adverse effects

  • Interactions: decreased drug absorption (require 2-hour separation)

Treating H. pylori

Treatment Plan

  • Approach: Several antibiotics + gastric acid inhibitor (e.g., Metronidazole, tetracycline, bismuth, different PPI or H2RA)

  • Rationale for Combination Therapy: Minimize resistance (H. pylori thrives in acidic environments)

  • Length of Treatment: 10-14 days

  • Cost: Approximately $200, can involve up to 12 pills

Drug Targets in Gastric Acid Production

  • Compounds involved include:

    • Histamine

    • H2 Receptor

    • Proton Pump

    • Other receptors in parietal cells

Histamine Type 2 Receptor Antagonists (H2RA)

Prototypes

  • Cimetidine (Tagamet)

  • Famotidine (Pepcid)

Mechanism of Action

  • Blocks H2 receptor, reducing gastric acid secretion

Indication

  • GERD (relieves symptoms)

  • PUD (promotes healing, prophylaxis)

Adverse Effects

  • Generally well-tolerated

  • Possible CNS effects in elderly

  • Slightly increased risk for pneumonia in elderly patients

Proton Pump Inhibitors (PPI)

Prototypes

  • Omeprazole (Prilosec)

  • Pantoprazole (Protonix)

Mechanism of Action

  • Binds to proton pump, irreversibly inhibiting the secretion of HCl

Indications

  • Short-term treatment of PUD and GERD

Adverse Effects

  • Short-term effects: Not specified

  • Long-term effects: May include pneumonia, hip fractures, stomach cancer

  • Interactions: Limited

  • Nursing Implications: Short-term use recommended; some PPIs given IV in specific cases

Prokinetic Agent

Metoclopramide (Reglan)

Classification

  • Prokinetic, antiemetic

Mechanism of Action

  • Increases upper GI motility

  • Suppresses emesis

Indications

  • GERD

  • Chemotherapy induced N/V or post-operative N/V

Adverse Effects

  • Multiple side effects noted

  • Neuro effects include: sedation or restlessness

  • Extrapyramidal reactions possible

Extrapyramidal Reactions

  • Definition: Network of neurons in the brain responsible for movement coordination

  • Symptoms can include:

    • Akinesia (difficulty in initiating movement)

    • Akathesia (inability to remain still)

    • Tardive dyskinesias (involuntary movements of the face and extremities)

Tardive Dyskinesias

  • Description: Movement disorder caused by certain medications; symptoms often involve abnormal, involuntary muscle movements.