You are in: eMedicine Specialties > Gastroenterology > Intestine IleusArticle Last Updated: Jun 3, 2008AUTHOR AND EDITOR INFORMATIONAuthor: Sandeep Mukherjee, MB, BCh, MPH, FRCPC, Associate Professor, Department of Internal Medicine, Section of Gastroenterology and Hepatology, University of Nebraska Medical Center; Consulting Staff, Section of Gastroenterology and Hepatology, Veteran Affairs Medical Center Sandeep Mukherjee is a member of the following medical societies: Royal College of Physicians and Surgeons of Canada Coauthor(s): Eseroghene Otah, MD, Locum Tenens General Surgeon, Department of Surgery, Our Lady of Mercy Hospital; Kenneth E Otah, MD, MSc, Postdoctorate Fellow, Department of Internal Medicine, Division of Cardiology, Johns Hopkins Hospital; Oluwagbenga Serrano, MD, Consulting Staff, Lake Havasu Gastroenterology, PC; John Walker, MD, Consulting Staff, Department of Gastroenterology, Rogue Valley Medical Center; Avram M Cooperman, MD, Professor of Surgery and Radiation Oncology, Cabrini Medical Center Editors: Ann Ouyang, MBBS, Professor, Department of Internal Medicine, Pennsylvania State University College of Medicine; Attending Physician, Division of Gastroenterology and Hepatology, Milton S Hershey Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Oscar S Brann, MD, FACP, Associate Clinical Professor, Department of Medicine, University of California at San Diego; Consulting Staff, Mecklenburg Medical Group; Alex J Mechaber, MD, FACP, Assistant Dean for Medical Curriculum, Associate Professor of Medicine, Division of General Internal Medicine, University of Miami Miller School of Medicine; Julian Katz, MD, Clinical Professor of Medicine, Drexel University College of Medicine; Consulting Staff, Department of Medicine, Section of Gastroenterology and Hepatology, Hospital of the Medical College of Pennsylvania Author and Editor Disclosure Synonyms and related keywords: postoperative adynamic ileus, paralytic ileus, pseudo-obstruction, Ogilvie syndrome, mechanical bowel obstruction, postoperative adynamic ileus, paralytic ileus, pseudo-obstruction, Ogilvie syndrome, mechanical bowel obstruction, Ogilvie's syndrome, pseudoobstruction, surgical bowel complications, bowel dysfunction, dysmotility, postoperative bowel dysfunction INTRODUCTIONBackgroundAfter abdominal surgery, a normal physiological ileus occurs. This type of ileus spontaneously resolves within 2-3 days after sigmoid motility returns to normal. However, the terms postoperative adynamic ileus or paralytic ileus are defined as ileus of the gut persisting for more than 3 days following surgery.1 Ileus occurs from hypomotility of the gastrointestinal tract in the absence of a mechanical bowel obstruction. This suggests that the muscle of the bowel wall is transiently impaired and fails to transport intestinal contents. This lack of coordinated propulsive action leads to the accumulation of both gas and fluids within the bowel. Although ileus has numerous causes, the postoperative state is the most common scenario for ileus development. Frequently, ileus occurs after intraperitoneal operations, but it may also occur after retroperitoneal and extra-abdominal surgery. The longest duration of ileus is noted to occur after colonic surgery.2, 3 The clinical consequences of postoperative ileus can be profound. Patients with ileus are immobilized, have discomfort and pain, and are at increased risk for pulmonary complications. Ileus also enhances catabolism because of poor nutrition. Overall, ileus prolongs hospital stays; according to a report by Livingston in 1990, it cost $750 million annually ($1500 per patient) in the PathophysiologyAccording to some hypotheses, postoperative ileus is mediated via activation of inhibitory spinal reflex arcs. Anatomically, 3 distinct reflexes are involved: ultrashort reflexes confined to the bowel wall, short reflexes involving prevertebral ganglia, and long reflexes involving the spinal cord.3 The long reflexes are the most significant. Spinal anesthesia, abdominal sympathectomy, and nerve-cutting techniques have been demonstrated to either prevent or attenuate the development of ileus.4, 5 The surgical stress response leads to systemic generation of endocrine and inflammatory mediators that also promote the development of ileus. Rat models have shown that laparotomy, eventration, and bowel compression lead to increased numbers of macrophages, monocytes, dendritic cells, T cells, natural killer cells, and mast cells, as demonstrated by immunohistochemistry.6 Calcitonin gene–related peptide, nitric oxide, vasoactive intestinal peptide, and substance P function as inhibitory neurotransmitters in the bowel nervous system. Nitric oxide and vasoactive intestinal peptide inhibitors and substance P receptor antagonists have been demonstrated to improve gastrointestinal function.7, 8 CLINICALHistoryPatients with ileus typically present with vague, mild abdominal pain and bloating. They may report nausea, vomiting, and poor appetite. Abdominal cramping is usually not present. Patients may or may not continue to pass flatus and stool. PhysicalPatients may have distended and tympanic abdomens, depending on the degree of abdominal and bowel distension. The abdomen may be tender. A distinguishing feature is absent or hypoactive bowel sounds unlike the high-pitched sound of obstruction. The silent abdomen of ileus reveals no discernible peristalsis or succussion splash. CausesMost cases of ileus occur after intra-abdominal operations. Normal resumption of bowel activity after abdominal surgery follows a known and predictable pattern. The small bowel typically regains function within hours. The stomach regains activity in 1-2 days, and the colon regains activity in 3-5 days.9 Serial abdominal radiographs mapping the distribution of radiopaque markers have shown that the colonic gradient for resolution of postoperative ileus is proximal to distal. The return of propulsive activity to the right colon occurs earlier than to the transverse or left colon.10
DIFFERENTIALSOgilvie Syndrome
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| Ileus | Pseudo-obstruction | Mechanical Obstruction (Simple) | |
| Symptoms | Mild abdominal pain, bloating, nausea, vomiting, obstipation, constipation, | Crampy abdominal pain, constipation, obstipation, nausea, vomiting, anorexia | Crampy abdominal pain, constipation, obstipation, nausea, vomiting, anorexia |
| Physical Examination Findings | Silent abdomen, distension, tympanic | Borborygmi, tympanic, peristaltic waves, hypoactive or hyperactive bowel sounds, distension, localized tenderness | Borborygmi, peristaltic waves, high-pitched bowel sounds, rushes, distension, localized tenderness |
| Plain Radiographs | Large and small bowel dilatation, diaphragm elevated | Isolated large bowel dilatation, diaphragm elevated | Bow-shaped loops in ladder pattern, paucity of colonic gas distal to lesion, diaphragm mildly elevated, air-fluid levels |
Most cases of postoperative ileus resolve with watchful waiting and supportive treatment. Patients should receive intravenous hydration. For patients with vomiting and distension, use of a nasogastric tube provides symptomatic relief; however, no studies in the literature support the use of nasogastric tubes to facilitate resolution of ileus. Long intestinal tubes have no benefit over nasogastric tubes.
For patients with protracted ileus, mechanical obstruction must be excluded with contrast studies. Underlying sepsis and electrolyte abnormalities, particularly hypokalemia, hyponatremia, and hypomagnesemia, may worsen ileus. These contributing conditions are easily diagnosed and corrected.
Discontinue medications that produce ileus (eg, opiates). In one study, the amount of morphine administered directly correlated with the time of bowel sound occurrence and the passage of flatus and stool.13
The use of postoperative narcotics can be diminished by supplementation with nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDS may improve ileus by improving local inflammation and by decreasing the amount of narcotics used. Myoelectric activities recorded from electrodes placed on the colon have revealed faster resolution from ileus in patients given ketorolac versus those given morphine14; however, the drawbacks of NSAID use include platelet dysfunction and gastric mucosal ulceration. Consider the use of cyclooxygenase-2 agents, which negate these adverse effects.
No single objective variable accurately predicts the resolution of ileus. A clinician must assess the overall status of the patient and evaluate for adequate oral intake and good bowel function. A patient's report of flatus, bowel sounds, or stool passage may prove misleading; therefore, clinicians must not rely solely on self-reporting.
Generally, delay oral feeding until ileus resolves clinically. However, the presence of ileus does not preclude enteral feeding. Postpyloric feeding into the small bowel can be cautiously performed. Start feeds at one-quarter or one-half strength at a slow rate and gradually advance.
One report showed that gum chewing as a form of sham feeding enhanced early recovery from postoperative ileus after laparoscopic colectomy.15 Nineteen patients who underwent elective laparoscopic colectomy were randomized. Ten patients were assigned to a gum-chewing group and 9 to a control group. The gum-chewing group used gum 3 times a day from the first postoperative morning until oral intake. Passage of flatus occurred earlier in the gum-chewing group than in the control group (2.1 d vs 3.2 d). The first bowel movement was noted in 3.1 days in the gum-chewing group versus 5.8 days in the control group. These values were statistically significant. Laparoscopic colon resection has been associated with shorter periods of ileus than open colon resection.16
Conventional wisdom and wide practice foster the notion that ambulation stimulates bowel function and improves postoperative ileus, although this has not been shown in the literature.
In a nonrandomized study evaluating 34 patients, seromuscular bipolar electrodes were placed in segments of the gastrointestinal tract after laparotomy. Ten patients were assigned to ambulate on postoperative day 1, and the other 24 were assigned to ambulate on postoperative day 4. No significant difference between the 2 groups was displayed in myoelectric recovery in the stomach, jejunum, or colon.17 Hence, postoperative ambulation remains beneficial in preventing the formation of atelectasis, deep vein thrombosis, and pneumonia but has no role in treating ileus.
No randomized trials have assessed the benefits of suppositories and enemas for the treatment of ileus. In one nonrandomized study, 20 gynecological patients were given milk of magnesia and biscolic suppositories. For these patients, the length of hospital stay was 4 days, and their ileus resolved in 4 days.18
Use of prokinetic agents has had moderate success. Rectal cisapride (Propulsid), a serotonin agonist, has reportedly been successful in treating ileus, but the US Food and Drug Administration (FDA) has withdrawn this agent because of the possibility it causes cardiac dysrhythmias.
Erythromycin, a motilin receptor agonist, has been used for postoperative gastric paresis but has not been shown to be beneficial for ileus.
Metoclopramide (Reglan), a dopaminergic antagonist, has antiemetic and prokinetic activities. Data have shown that the drug may actually worsen ileus.
Thoracic epidural administration has been shown to be beneficial. Epidural blockade with local anesthetics improves postoperative ileus by blockage of inhibitory reflexes and efferent sympathetics. Studies have shown that combinations of thoracic epidurals containing bupivacaine alone or in combination with opioids improve postoperative ileus.19, 20
Methylnaltrexone and ADL 8-2698 (alvimopan [Entereg]) are now approved by the FDA in the United States. These agents inhibit peripheral mu-opioid receptors. Receptor blockade abolishes the adverse gastrointestinal effects of opioids without impairing the analgesic effects of such drugs.21 Methylnaltrexone is indicated for opioid-induced constipation in patients with advanced illness receiving palliative care, when response to laxatives has not been sufficient. In a study of 14 healthy volunteers evaluating the use of morphine plus oral methylnaltrexone in increasing doses, methylnaltrexone significantly reduced morphine-induced delay in oral-cecal transit.22
Alvimopan is indicated to help prevent postoperative ileus following bowel resection. Taguchi et al examined 78 postoperative patients randomized to receive either placebo or alvimopan.23 Fifteen patients underwent partial colectomy, 36 were status post simple hysterectomy, and the remaining 27 underwent radical hysterectomy. All of the patients were on patient-controlled analgesia pumps using either meperidine or morphine. Compared with patients on placebo, patients on alvimopan had their first bowel movement 2 days earlier, resumed a solid diet 1.3 days earlier, and returned home 1.4 days earlier. Other recent trials have been completed, including a meta-analysis comparing alvimopan with placebo24 and a study that found alvimopan to accelerate GI tract recovery after bowel resection, regardless of age, gender, race, or concomitant medication.25
Both methylnaltrexone and alvimopan do not traverse the blood-brain barrier, and the latter agent has the advantage of being long acting.
Indicated to prevent postoperative ileus.
| Drug Name | Alvimopan (Entereg) |
|---|---|
| Description | Peripherally acting mu-opioid receptor antagonist. Binds mu-opioid receptors in gut, thereby selectively inhibiting negative opioid effects on GI function and motility. Indicated for postoperative ileus following bowel resection with primary anastomosis. Five clinical studies with enrollment >2500 patients demonstrated accelerated recovery time of upper and lower tract GI function with alvimopan compared with placebo. Decrease of hospital days also observed in alvimopan group compared with placebo. Only available to hospitals after they complete a registration process designed to maintain the benefits associated with short-term use and prevent long-term, outpatient use (Entereg Access Support and Education [EASE] program). |
| Adult Dose | 12 mg PO as single dose 0.5-5 h preoperatively, followed by 12 mg PO bid starting the day after surgery; not to exceed treatment duration of 7 days (or 15 doses) |
| Pediatric Dose | Not established |
| Contraindications | Documented hypersensitivity; >7 consecutive days of opioids immediately prior to alvimopan |
| Interactions | Data limited; substrate for p-glycoprotein; does not inhibit or induce CYP 1A2, 2C9, 2C19, 3A4, 2D6, and 2E1; does not inhibit p-glycoprotein |
| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals |
| Precautions | Patients recently exposed to opioids may be more sensitive to alvimopan effects and experience abdominal pain, nausea, vomiting, and diarrhea; not recommended with severe hepatic impairment or end-stage renal disease; common adverse effects include anemia, dyspepsia, hypokalemia, back pain, and urinary retention; higher number of MIs reported in alvimopan group compared with placebo over a 12-mo period, but causality has not been established |
| Media file 1: Postoperative ileus after an open cholecystectomy. | |
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| Media file 2: Mechanical bowel obstruction due to a left colon carcinoma. Note the paucity of bowel gas throughout the colon. | |
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| Media file 3: Contrast study showing the classic "apple-core lesion" of colon carcinoma. | |
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| Media file 4: CT scan of abdomen revealing metastases to the liver in the same patient as in Media file 3. | |
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| Media file 5: Ogilvie pseudo-obstruction in a septic elderly patient. Note the massive dilatation of the colon, especially the right colon and cecum. | |
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Article Last Updated: Jun 3, 2008