2 Small and Large Intestines Small intestine (longest organ in the GI tract)Three major divisions: duodenum, jejunum, ileumMain function is complete digestion of foodMost nutrients and water are absorbed in 6- to 8- hour passageLarge intestineSegments: cecum; appendix; ascending, transverse, descending, and sigmoid colon; rectumMain functions are elimination of waste and absorption of water
3 Bowel ObstructionOccurs in the small (most common) or large intestine (sigmoid colon most common)Can be partial or completeSeverity depends on the region of the bowel, the degree of occlusion, and the degree of vascular disruption
4 Bowel ObstructionIn small bowel obstruction, large amounts of fluid and gases are trapped above the area of obstruction, leading to abdominal distentionDehydration can develop from loss of water and sodiumHypovolemia occurs as fluids are pulled from the vascular bed to the site of the obstructionPeristalsis below the obstruction decreases, which leads to bacterial overgrowth and may lead to peritonitisIf the blood supply is cut off, it can lead to necrosis
5 Causative Factors Extrinsic bowel obstruction Begins outside the GI tractAdhesions, herniations, or massesIntrinsic bowel obstructionLumen blockageCaused by acute or chronic bowel disease inflammation, congenital defects, or tumorsIntraluminal bowel obstructionCaused by the inability of material to pass through the GI tract (meconium, foreign bodies, impactions)
6 Mechanical CausesAdhesions: Loops of intestine become adherent to areas that heal slowly or scar after abdominal surgery (most common cause of small bowel obstruction)Herniations: The intestine protrudes through a weakened area in the abdominal muscle or wallVolvulus: Bowel twists and turns on itself; laxative use may be the causeIntussusceptions: Bowel slips into itselfTumorsDiverticulitis: Pouches push out of mucosal lining of bowel
7 Functional CausesIntestinal muscles are unable to propel contents forward, such as in:Muscular dystrophyEndocrine disorders (such as diabetes)Neurological disorders (such as Parkinson’s disease)Electrolyte imbalancesUremiaSpinal cord lesions
8 Signs & Symptoms: Small Bowel Obstruction Crampy abdominal pain (usually seen in small bowel obstruction)Reflux vomiting if obstruction is completeFecal-smelling breathDehydration signs: thirst, drowsiness, malaise, achiness, and parched tongue and mucous membranes
9 Signs & Symptoms: Large Bowel Obstruction Develop and progress slowlyConstipation may be the only symptom for monthsWeakness, weight loss, and anorexiaMarked abdominal distentionCrampy lower abdominal pain
10 AssessmentPast medical history and history of events leading to seeking care (pain is usually the symptom that causes patient to seek care)Assess pain characteristics (quality and intensity)Assess abdomenAuscultate bowel sounds (Bowel sounds: high-pitched, hyperactive, tinkling, and almost metallic in the area over the obstruction; quiet or absent below the obstruction)
11 Diagnostic TestsLab values will determine fluid and electrolyte managementEmesis causes loss of sodium, potassium, chloride, and hydrogenSodium, blood urea nitrogen, and creatinine levels will be elevated as fluid shifts out of the vascular bedWhite blood cell count will be elevated as inflammation developsHemoglobin and hematocrit will be elevated relative to fluid loss
12 Diagnostic TestsLiver enzymes will be elevated in response to other GI organsMetabolic acidosis may occur as perfusion decreasesFrank blood is an indication of perforation (requires immediate surgical intervention)X-ray of the abdomen will show dilation of the bowelCT scan may show mechanical changes (addition of contrast may show vascular changes)
13 TreatmentFor incomplete obstructions, medical management is the treatment of choiceThe patient will have an NG tube inserted, which may provide resolution for many bowel obstructionsUrinary catheter to monitor outputI.V. therapy to replace fluids and electrolytesAdministration of broad-spectrum antibioticsConservative control of pain
15 Confirming NG Tube Placement To confirm placement after the initial X-ray is done, a combination of three methods is recommended:Measure the length of the exposed portion of the tube every shift and compare it with the original measurement. An increase in length of exposed tube may indicate dislodgment or a leaking or ruptured balloon if the tube has a balloon.Visually assess the color of aspirate to help distinguish between gastric and intestinal placement.Measure the pH of aspirate, which is a more accurate method of confirming tube placement than measuring the exposed tube length or assessing tube aspirate.
16 Surgical Treatment Depends largely on the cause In some cases, the portion of the affected bowel may be resected and anastamosedSome patients will undergo a temporary colostomy or ileostomy
19 Preventing Complications Monitor prothrombin time and INRAssess skin for petechiae, color, and temperatureAssess body fluids for presence of bloodAssess nutritional status (monitor albumin and prealbumin)Use an air mattress to prevent skin breakdown
20 Patient TeachingDiscuss bowel regime with patient, including avoiding laxative use, increasing fluids, and increasing fiberTeach personal care to a patient who has undergone surgery with an ileostomy or colostomy (selection of the proper size of appliances, care of the site and skin near the ileostomy or colostomy, and dietary changes to help reduce gas production)
21 Guidelines for Changing an Ileostomy Appliance Changing an ileostomy appliance is necessary to prevent leakage (the whole appliance, including the flange or wafer, is usually changed every 5 to 7 days). Routine changes should be performed early in the morning before breakfast or 2 to 4 hours after a meal, when the bowel is least active.Have the patient assume a relaxed position, provide privacy, and explain the details of the procedure.Remove the appliance. Have the patient sit on the toilet or on a chair facing the toilet. A patient who prefers to stand should face the toilet. The appliance (pouch) can be removed by gently pushing the skin away from the adhesive.
22 Guidelines for Changing an Ileostomy Appliance Clean the skin. Wash the skin gently with a soft cloth moistened with tepid water and mild soap; the patient may prefer to bathe before putting on a clean appliance. Rinse and dry the skin thoroughly after cleaning.Apply an appropriate skin barrier to the peristomal skin before applying the appliance. Remove the cover from the adherent surface of the disk of the disposable plastic appliance and apply it directly to the skin. Press firmly in place for 30 seconds to ensure adherence.When skin irritation is present, clean the skin thoroughly, but gently; pat dry. Apply triamcinolone acetonide spray, blot excess moisture with a cotton pledget, and dust lightly with nystatin powder.Check the pouch bottom for closure; use the rubber band or clip provided.