Detailed Study Notes on Intestinal Obstruction, Assessment, and Management

Intestinal Obstruction

Definition of Intestinal Obstruction

Intestinal obstruction is a medical condition in which there is a blockage that prevents the normal passage of contents through the intestine. It can be classified into three main categories:

• Mechanical Obstruction: Physical blockages occur due to external problems affecting the intestine. These might include:

  • Adhesions: Scar tissue that can bind intestines together.
  • Chron's Disease: Inflammatory bowel disease can cause scarring and narrowing of the intestinal lumen.
  • Tumors: Both benign and malignant masses can obstruct intestinal flow.

• Nonmechanical Obstruction: Involves a failure of peristalsis without a physical blockage. This is often referred to as paralytic ileus and is caused by:

  • Neuromuscular Disturbance: Conditions that affect nerve function can lead to reduced or absent peristalsis.
  • Functional Obstruction: Occurs when the bowel doesn’t move contents as it should, often due to surgical handling of the intestine.

• Strangulated Obstruction: A severe form of blockage where blood supply to the affected areas of the intestine is compromised, leading to potential life-threatening conditions.

Etiology and Genetic Risk

• Etiology of Mechanical Obstruction: Causes may include:

  • Adhesions: Scar tissue from previous surgeries can lead to blockage.
  • Tumors: Both benign and malignant tumors can hinder the passage of intestinal contents.
  • Appendicitis Complications: Inflammation can lead to scarring.
  • Hernias: Protrusion of intestine through the abdominal wall can result in obstruction.
  • Fecal Impaction: Particularly common in elderly populations.
  • Strictures: Narrowing due to previous radiation or chronic diseases like Crohn’s disease.
  • Intussusception: Telescoping of a segment of the intestine into itself.
  • Volvulus: Twisting of the intestine.
  • Fibrosis: Associated with disorders, including endometriosis.

• Causes of Non-mechanical Obstruction: Often results from:

  • Handling of Intestines During Surgery: May disrupt normal motility.

Incidence and Prevalence

• Obstruction is most commonly observed in patients who have undergone bowel surgery or those with intestinal tumors. It is important as reduced peristalsis with aging can lead to constipation, leading to fecal impaction and subsequent obstruction if not treated.

Health Promotion and Disease Prevention

• To prevent constipation and potential obstruction, strategies include:
  • Ensuring Adequate Fluid Intake: Staying hydrated promotes softer stools.
  • Encouraging Regular Exercise: Physical activity helps stimulate bowel function.
  • Incorporating Fiber: A diet rich in fiber aids in proper bowel movements.
  • Routine Colon Screening: Monitoring colon health is essential.

Historical Assessment

• Key areas of focus during patient evaluation:
  • Symptoms: Color of emesis; presence of green/yellow, bilious, or hematemesis.
  • Surgical History: Previous surgeries can shed light on potential complications.
  • Pain Assessment: Sudden severe pain changing to tenderness may indicate perforation; report to PCP immediately.
  • Nausea/Vomiting (N/V): Recent episodes can hint at obstruction.
  • Elimination Patterns: Document any changes including constipation or obstipation, which indicates a lack of stool or gas passage.
  • Presence of Hiccups (Singultus): Commonly associated with obstruction.
  • Family History of Colon Cancer: Increased risk parameters.
  • Temperature: Rarely elevated above 100°F in uncomplicated obstruction.
  • Elevated Heart Rate/Blood Pressure: Signs to monitor include fever, abdominal pain, rigidity, or changing skin color, which may indicate strangulated obstruction, peritonitis, or ischemia.

Physical Signs/Symptoms

Mechanical Obstruction of Small Intestine

• Signs:

  • Crisp-Like Stool: Indicative of dehydration and constipation.
  • Abdominal Distension/Obstipation: May be present.
  • Mid-Abdominal Pain/Cramping: Typically mild and intermittent, often described as colicky.

• Strangulation Symptoms: Pain becomes localized and persistent, affecting fluid and electrolyte balance.

  • Vomiting: Often accompanies obstruction and may be more profuse when involving the proximal small intestine; vomit can be bile/mucus or foul-smelling orange-brown.

• Obstipation: Characterized by no stool or gas passage representing complete obstruction, though diarrhea may occur with partial obstruction.

• Blood in Stool: Could indicate diverticulitis or colorectal cancer if present with obstruction, in addition to possible abdominal distension.

• Observation of Peristaltic Waves: May be visible on examination, especially in cases of mechanical obstruction.

• Bowel Sounds: On auscultation above the obstruction:

  • High-Pitched Bowel Sounds/Borborygmi: Indicate cramping and increased activity attempting to bypass the obstruction.
  • Later Stages: Absent bowel sounds, abdominal tenderness, and rigidity may develop, with fluid-filled bowel loops sometimes mimicking a palpable abdominal mass.

Signs of Nonmechanical Obstruction

• Pain: Constant and diffuse discomfort.

Key Features

Lab Assessment

• No definitive tests for obstruction. However:

  • WBC: Normal unless accompanied by strangulation or infarction.
  • HAA/BUN: Elevated.
  • Sodium, Chloride, Potassium: May decrease.
  • Serum Amylase: Elevated in cases of strangulation.

• Diagnostic Studies: Include imaging tests such as:

  • CT Scan: Detects obstructions and their causes.
  • MRI: Modalities for obstruction visualization.
  • Ultrasound: Useful in certain cases.
  • Endoscopy: Including sigmoidoscopy and colonoscopy for visual assessment.

Nursing Care for Patients with Intestinal Obstruction

• Vital Signs Monitoring: Especially BP and pulse for fluid balance.
• Assessment: Check the patient’s abdomen twice a day for bowel sounds, distension, and bowel gas passage.
• Fluid and Electrolyte Balance Monitoring: Include regular lab checks.
• NG Tube Management: Assess every four hours:
  • Monitor drainage and ensure tube patency.
  • Confirm tube placement via X-ray.
  • Irrigate as ordered.
  • Maintain NPO (nothing by mouth) status with frequent mouth/nasal care.
  • Maintain semi-Fowler’s position to promote comfort and drainage.
• Medication Administration:
  • Administer analgesics for pain management as needed.
  • Maintain IV for fluid and electrolyte replacement, often isotonic solutions or Lactated Ringer's (LR).
  • Administer alvimopan for postoperative ileus as prescribed.
  • Consider parenteral nutrition if ordered as a nutritional strategy during recovery.

Reducing Risk of Life-Threatening Complications

• Nonsurgical Management: Appropriate for partial obstructions without strangulation evidence. Options include:
  • Use of a nasogastric (NG) tube (Salem sump tube) attached to low continuous suction, which comes with a vent (pig-tail) to prevent damage to stomach mucosa during suction.
  • Tube should be irrigated with 30mL of normal saline every four hours.

Conclusion

These notes cover the various aspects of intestinal obstruction, which include definitions, clinical signs, diagnostic evaluations, and nursing management for patients experiencing this condition. They emphasize the significance of timely assessment and intervention to mitigate potentially life-threatening complications. Further key areas of emphasis include recommendations for health promotion to prevent bowel-related issues, particularly in susceptible populations such as the elderly, and patients with a history of bowel surgery or disorders.