Intestinal Obstruction Concept Map

Disease: Intestinal Obstruction Intestinal contents cannot pass through the GI tract Can occur in the small intestine or colon Can be partial or complete; simple or strangulated Complete obstruction: totally occludes lumen and usually requires surgery Simple obstruction: intact blood supply; not a strangulated one Mechanical obstruction: Physical obstruction in lumen Causes Surgical adhesions are most common cause of small bowel obstruction Hernia strictures from crohns disease intussusception after bariatric abd surgery colorectal cancer diverticular disease sigmoid volvulus: bowel twists in on itself non-mechanical: occurs with reduced or absent peristalsis due to altered neuromuscular transmission of the parasympathetic innervation to the bowel. Paralytic ileus: lack of intestinal peristalsis and bowel sounds; occurs to some degree after surgery Causes of p.ileus: peritonitis, inflammatory responses, electrolyte abnormalities, thoracic or lumbar spinal fractures Pseudo obstruction: mechanical obstruction of the intestines w/o any cause found on radiologic imaging. Diseases associated with pseudo obstruction: myocardial infarction, renal failure, parkinsons diseases, trauma, recent major or orthopedic surgery, opiate use, metabolic disturbances Vascular obstructions: Rare and are the result of an interference with blood supply to a portion of the intestines Causes: emboli and atherosclerosis of the mesenteric arteries Emboli may originate from thombi in pts whon have chronic atrial fibrillation, diseased heart valves, and prosthetic valves Venous thrombosis may occur in condition of lo blood flow such as heart failure or shock. Eitology: Fluid, gas, and intestinal secretions build up proximal to obstruction Distal to obstruction, the bowel empties then collapses Distention reduces fluid absorption and initially stimulates intestinal secretion Increased distention increases pressure; increased pressure leads to increased capillary permeability and extravasion of fluids and electrolytes into peritoneal cavity Intestinal muscle fatigues and peristalsis stops Retention of fluids leads to a severe reduction of circulating blood volume; leading to hypotension and hypovolemic shock Inadequate blood flow leads to ischemia then necrosis; perforation may also occur leading to infection, septic shock, and death Intestinal strangulation or intestinal infarction: bowel becomes so distended that the blood flow stops, causing edema, cyanosis, and gangrene of bowel segment High obstruction s/s: metabolic alkalosis due to loss of HCL though vomiting or NG tube suction. Small intestine: dehydration occurs rapidly Large intestine: dehydration and electrolyte imbalances do not usually occur Proximal colon: solid fecal material accumulates until symptoms of discomfort appear S/S: TABLE 42-20 - Abd pain Vomiting Distention Constipation Colicky abdominal pain(1st sign of an obstruction) Proximal obstruction: N/V; may be projective and contain bile Higher obstructions: vomiting can relieve pain Small bowel obstruction: more gradual in onset and more fecal and foul smelling High pitched bowel sounds above area of obstruction Absent with p.ileus Colonic obstruction s/s: - Abd distention Constipation or lack of flatus Persistent, cramping abd pain Hypoactive bowel sounds Vomiting is rare Strangulation with acute pain Abd tenderness and rigidity Fever above 100F Dx studies: CT scans x-rays sigmoidoscopy colonoscopy CBC and blood chemistries Elevated wbc count; indication of strangulation or perforation Elevated hematocrit; indication of hemoconcentration Decreased h&h indicate bleeding from neoplasm or strangulation with necrosis Serum electrolytes, BUN, creatinine to monitor hydration Metabolic alkalosis due to vomiting Interprofessional care: Surgery: colectomy, colostomy, ileostomy, colostomy(remove polyps, dilate strictures remove tumors) NPO status NG tube for decompression IV fluid therapy: NS or lactated ringers(fluid losses from GI tract are isotonic) Adding potassium to IV fluids after determining renal function giving pain meds parenteral nutrition if needed giving meds such as corticosteroids and antiemetics Nursing management: Pt history Physical examination Pain assessment Vomit assessment Bowel function assessment Listen for bowel sounds Inspect abdomen for scars, masses and distention Inspect for abd tenderness or rigidity Abd girth Check for signs of peritoneal irritation(muscle guarding, rebound pain, pain if bed is shaken) Frequent vital assessment Assess for changes in bowel sounds Assess for changes in urinary output Maintain strict I&O record Report urinary output less than 0.5ml/kg/hr; indicates inadequate vascular volume and potential for acute kidney injury Rising creatinine and BUN levels indicate acute kidney injury Nursing implementation: Monitor for signs of dehydration and electrolyte balance Give IV fluids as ordered Monitor for fluid overload High intestinal obstruction: m.alkalosis Low obstruction: m.acidosis Promote comfort and pain relief Oral care for NG tube Check nose for irritation from ng tube Check ng tube patency every 4 hours