Intereference of the forward flow of intestinal contents. This may be partial, complete, mechanical (physical blockage), or non-mechanical (neurogenic).
Mechanical Intestinal Obstruction
Physical barriers to the passage of intestinal contents with subsequent distention by fluid and gas. Its causes include:
- Adhesions: bands of granulation and scar tissue that develop as a result of inflammation. This encircles the intestines and constricts its lumen.
- Hernias: protrusions of organs or structures through a weakened abdominal muscle.
- Volvulus: twisting (“knotting”) of the intestines.
- Intussusception: telescopic insertion of one section of the intestine into another section.
- Inflammatory bowel diseases, foreign bodies, strictures, neoplasms, and fecal impaction
Non-Mechanical Intestinal Obstruction
Causes for this are neurogenic, paralytic, and adynamic in nature. This is brought about by the interference with the nerve or blood supply to the intestine, resulting in decreased or absent peristalsis.
- Handling of the intestines during abdominal surgery (paralytic ileus occurs in around half of major abdominal surgeries)
- Hypokalemia
- Peritonitis
- Shock
- Vascular obstructions result in intestinal ischemia and gangrene. May be caused by an embolus or atherosclerosis.
Assessment Findings
High-pitched bowel sounds may be heard above the level of the obstruction, while decreased or absent bowel sounds may be heard below the level of the obstruction.
- Complete Intestinal Obstructions: cardinal signs include abdominal pain, abdominal distention, obstipation, and vomiting. Other signs include malnutrition, flatulence (from indigestion), weakness, electrolyte imbalances, and ascites.
- Small Intestine Obstructions: abdominal discomfort or pain, visible peristaltic waves in upper and middle abdomen, upper or epigastric abdominal distention, nausea and vomiting (early and profuse), obstipation, severe fluid and electrolyte imbalances, metabolic alkalosis
| Small Intestine Obstructions | Large Intestine Obstructions | |
|---|---|---|
| Pain | Discomfort, Pain, Peristaltic Waves | Lower Abdominal Cramping |
| Distention | Upper/Epigastric | Lower Abdomen |
| N&V | (+), profuse and early | minimal or no vomiting (may contain fecal material) |
| Stool | Obstipation | Obstipation, potentially ribbon-like stools |
| Fluid and Electrolyte Imbalances | Severe | None or Minor |
| Acid-Base Imbalance | Metabolic Alkalosis | Metabolic Acidosis |
Diagnostic Examinations
- Flat-plate (KUB) and upright abdominal x-ray reveal gas and fluid build-up
- Increased Hgb/Hct, BUN and Creatinine (all indicative of dehydration)
- Decreased serum sodium, chlorine, and potassium.
- Sigmoidoscopy, Colonoscopy, Barium Enema, CT Scan
Nursing Interventions
- Monitor fluid and electrolyte balance. Keep the client on NPO and administer IVF as ordered.
- Obstruction is often indicative for an NGT. Measure drainage accurately from the NG/Intestinal Tube.
- Place the patient in a fowler’s position to relieve pressure from the diaphragm.
- Encourage nasal breathing in order to minimize air swallowing, which worsens abdominal distention.
- Employ comfort measures associated with NG intubation and intestinal decompression.
- Prevent complications. Measure abdominal circumference daily to assess for distention. Check for signs and symptoms of peritonitis, and monitor urinary output.
Medical Management
Drug Therapy
- Antiemetics (relieve vomiting)
- Antispasmodics (relieve cramping)
- Analgesics (narcotics)
- Antibiotics (prevention of infection)
- Anthelminthic Drugs (if caused by a bolus of ascaris)
- Electrolyte Replacement
Surgical Management
Depends on the cause, but include:
- Exploratory Laparotomy
- Tumor Resection followed by anastomosis
- Adhesiolysis: destruction of adhesions (scar tissue)