Figure 49-14. Plain supine abdominal radiograph of a patient with ileus. Air–fluid levels are present in the small intestine (thin

arrow). Gas is seen in the colon (thick arrowhead). These findings are characteristic of, but not specific for, ileus. Surgical drains in

the pelvis and skin staples (short arrow).

Management

10 A normal POI is usually self-limiting. Nevertheless, there are a number of interventions that are

effective in reducing the duration of a normal postlaparotomy ileus (Table 49-9). Midthoracic epidurals

with neuraxial local anesthetics has been shown to hasten the return of bowel function compared to

systemic or epidural opioids.165–167 Midthoracic local anesthetic epidurals block nociceptive afferent

signals from the surgical site as well as sympathetic efferent outflow; this is useful for 48 to 72 hours

postoperatively.

The goals in management in the normal period of postoperative ileus are to prevent uncomfortable

distension, vomiting, and aspiration. Classic studies

6,10 indicate that flatus and the air accumulating

during intestinal distension is derived largely from swallowing. Under normal circumstances, flatus is

passed as early as 30 minutes after a “test bolus” of air is administered by tube into the stomach. Thus,

passage of flatus is used, in reliable patients, as the index indicating coordination of all segments of the

gastrointestinal tract and resolution of ileus.

For many years, the mainstay of therapy was the use of nasogastric suction to prevent accumulation

of swallowed air and secreted fluids in an alimentary tract not yet coordinating flow distally.

Subsequent studies have demonstrated that the putative benefit does not compensate for risks of

aspiration and discomfort of the tube. Thus, in routine abdominal cases such as colectomy, nasogastric

tubes are used selectively175,176 in patients who are felt to be at risk of complications of ileus, based on

the surgeon’s judgments about intraoperative findings or manipulations – prolonged handling and

packing of the bowel, anticipation of intensive use of narcotics or other antikinetic agents, presence of

sepsis or peritonitis, or extensive blood loss. Otherwise, a nasogastric tube is used for a short

postoperative period or never placed, with the expectation that a small percentage of patients will

require placement for symptoms.176 In these patients, the patient is allowed nothing more than sips or

ice chips until there is evidence (by listening for bowel sounds or the patient’s report of “rumbles”) that

ileus is likely resolving. Intravenous fluids are necessary until the patient can be advanced to full intake

of their requirements, usually after flatus is passed.

Table 49-9 Treatment for Postoperative Ileus

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In addition correctable conditions such as electrolyte disturbances or uremia are investigated and

rectified. Mobilization has other benefits in reducing morbidity.177,178 Early feeding is thought to

stimulate gastrointestinal hormones, secretions and motility, and coordinated propulsive activity. In

addition early feeding may improve immune function, reduce179 infectious and catabolic

complications.142,180 Despite the use of laxatives with prokinetic agents, no controlled trial exists to

assess the possible beneficial effects of laxatives on POI.142

One treatment, gum chewing, has attracted attention as a simple and inexpensive method of

accelerating return of bowel function. Mastication stimulates the cephalic vagal cholinergic pathways

that increases gastrointestinal hormone secretion such as gastrin, pancreatic polypeptide, and

neurotensin which affects gastrointestinal motility.181,182 Since the initial publication of one small and

underpowered study,183 a number of prospective randomized trials have been conducted to test the

hypothesis that gum chewing results in earlier passage of flatus and bowel movement in patients

undergoing laparoscopic colectomy.184,185 No conclusive evidence has been obtained to demonstrate a

clear benefit of gum chewing, although subgroup analysis suggests some patients may benefit.185 At the

same time, prospective randomized studies continue to be performed, arguing one conclusion or the

other.186–190 According to one hypothesis sorbitol and other hexitols, the key gradients of “sugar-free”

chewing gums may also play a role in the earlier recovery of POI.191 A recent study192 argued that

nicotine gum might accelerate resolution of postoperative ileus through enhancement of vagal

activation.

Salt and water disturbances in the body also may influence return of bowel function following

laparotomy. In one study, patients undergoing colectomy received a restricted perioperative fluid

resuscitation regimen or a standard, more liberal fluid resuscitation. The “restricted” group had a

quicker passage of flatus and moved their bowels earlier, leading in part to shorter hospital stays.193

Subsequent studies

194,195 have not uniformly suggested that recovery from ileus is faster with

temperance in fluid resuscitation; or have indicated that there is a benefit from fluid restriction

protocols but have not reported return of gastrointestinal function as an endpoint.196 However, this

benefit, as well as others, may be more clearly observed when fluid therapy is directed by physiologic

assessments of volume status, such as esophageal Doppler monitoring of the great vessels and heart

chambers.197,198 A double-blind, randomized controlled clinical trial showed that Doppler-guided

intraoperative fluid management decreases postoperative nausea, vomiting, ileus and wound

infection.199

Experimental evidence of pharmacologic interventions specifically directed at abnormal surges of

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neurotransmitters or hormones that might prolong ileus have provided a useful insight into the

pathophysiology of POI. Opioid antagonists, somatostatin analogs, sympatholytics, injection of local

anesthetics into mesenteric nerve roots, or nonsteroidal anti-inflammatory agents, such as ketorolac,

appear to promote faster recovery to normal myoelectric activity and intestinal transit times.151,200,201

The peripherally acting, selective μ-opioid receptor antagonist alvimopan (EnteregTM) has been reported

to reduce GI recovery time and to facilitate hospital discharge for both open and laparoscopic colorectal

surgery cases,202 after gynecologic surgery,203 after bowel resection, and after radical cystectomy.204

Importantly, in one study, the effect of alvimopan accelerated recovery after open abdominal surgery as

an independent influence in an accelerated recovery program205 from colectomy.

Prokinetic agents such as metoclopramide, cisapride (presently not approved by U.S. Food and Drug

Administration), and erythromycin have been evaluated for their efficacy in shortening the duration of

POI. For ileus following upper gastrointestinal procedures (e.g., pancreaticoduodenectomy), such

medications may be effective in promoting gastric emptying.206–211 For general abdominal procedures

involving the small intestine, colon, and retroperitoneal structures such as the aorta, there has been

limited success in using such agents to shorten recovery times.179 In multiple controlled studies,

metoclopramide did not have significant impact on the duration of ileus.212–214 In other studies, no

benefit was observed when patients were given erythromycin. Promising results have been observed

with cisapride and related agents,179,206,208 which significantly reduced the duration of ileus. The results

would depend on the route of its administration. However, this medication is no longer approved for

use in the United States due to the occurrence of potentially fatal arrhythmias.215 In a Cochrane review

of fifteen systemically acting prokinetic drugs, the conclusion was that erythromycin has no effect and

there are insufficient evidence to recommend cholecystokinin-like drugs, cisapride, dopamine

antagonist, propranolol, or vasopressin. IV lidocaine and neostigmine might show a potential effect but

more evidence is needed.179 Mosapride, a selective 5-hydroxytryptamine 4 receptor agonist has been

shown to reduce the duration of POI in animal and human studies.216 Escin, a natural mixture of

triterpene saponins extracted from dried seeds of horse chestnut (Aesculus hippocastanum or chinensis)

also may shorten time to recovery of gastrointestinal motility.217

Along with pharmacologic measures, it should be emphasized that, in otherwise routine laparotomy

or laparoscopy, gentle handling of tissues, meticulous attention to hemostasis, and applications of sound

principles of wound management are likely to have the greatest impact on optimizing recovery from

ileus and minimizing the incidence of prolonged ileus. Efforts to reduce incision size and time spent

handling the intestines through the use of laparoscopic approaches clearly improves recovery from ileus

in some if not all patients undergoing standardized intra-abdominal procedures such as

appendectomy,218 and colectomy.219 Even in open procedures,220 standardization of management and

effective communication help expedite clinical fast-track pathways and facilitate earlier recovery of

bowel function and discharge from hospital.142,198,221 Currently proposed measures to minimize the

prolongation of ileus are summarized in Table 49-10.

Table 49-10 Measures to Prevent Prolongation of Ileus

Colonic Pseudo-Obstruction (Ogilvie Syndrome)

Etiologic Factors

Acute pseudo-obstruction of the colon, also known as Ogilvie syndrome,222 is a paralytic ileus of the large

bowel, characterized by rapidly progressive abdominal distention, often painless.223 Although the

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distention of the colon is not due to mechanical obstruction, the wall of the bowel, particularly that of

the cecum, can become sufficiently distended so that its blood supply is compromised. Gangrene,

perforation, peritonitis, and shock can follow. In 95% of the cases there are underlying diseases.223,224

Less than 5% of the cases occur in the absence of other conditions.

Major risk factors for development of Ogilvie syndrome include traumatic injury (11%), infections

such as pneumonia, sepsis (10%); obstetric/gynecologic conditions (10%); myocardial infarction and

congestive heart failure (10%); abdominal and pelvic surgery (9%); neurologic conditions such as

Parkinson disease, spinal cord injury, multiple sclerosis, and Alzheimer disease (9%); orthopedic

procedures (7%); other medical conditions including metabolic imbalances, for example, hypokalemia,

hypocalcemia, hypomagnesemia (32%); and other surgical conditions (12%).222,224 Evidence suggests

that Ogilvie syndrome is thought to be related, at least in part to sympathetic nervous overactivity or

interference with sacral parasympathetic efferents, although there is little direct experimental evidence

for this.223 It is postulated that the distal colon becomes atonic on interruption of the S2 to S4

parasympathetic nerve fibers. Other theories about the pathophysiologic causes include autonomic

dysfunction, reduced colonic ganglion cells, and loss of intrinsic nitric oxide activity but the cause

remains unknown.225

Diagnosis

This syndrome is commonly encountered in patients hospitalized over 3 to 7 days, often in men more

than 60 years of age. Primary manifestations variably include gastrointestinal symptoms such as nausea,

vomiting, abdominal pain, constipation, and diarrhea.223,224 Labored breathing, caused by abdominal

distention, may be observed as part of the clinical picture. Other than distension, there are no

characteristic physical or laboratory findings for this syndrome. On percussion the abdomen is resonant

due to the presence of air in dilated segments of small intestine and colon. Sounds from the small

intestine are present and may not be high pitched, as they are in intestinal obstruction.

Laboratory findings associated with this syndrome may include hypokalemia, hypocalcemia,

hypomagnesemia, and hypophosphatemia, which are implicated as etiologic factors. Leukocytosis,

elevation of sedimentation rate or c-reactive protein is also present if low-grade systemic inflammation

is present or perforation is impending.

The diagnosis is usually apparent from plain film radiographs of the abdomen which may reveal air in

the small bowel and distention of discrete segments of the colon (i.e., cecum or transverse colon often

up to splenic flexure) or the entire abdominal colon. Haustral markings disappear with increasing

distension. In doubtful cases and when bowel necrosis is not a significant worry, a hypaque contrast

enema can establish the nonmechanical nature of the dilatation. Alternatively, colonoscopy can be

diagnostic as well as therapeutic. Features suggesting the complication of bowel ischemia may include

localized tenderness, worsening leukocytosis, metabolic acidosis, evidence of sepsis, or a rapidly

deteriorating clinical course.

It is important to differentiate this syndrome from toxic megacolon and mechanical obstruction before

establishing a final diagnosis. Mechanical obstruction of the colon, occurring in volvulus or obturator

obstructions from cancer or diverticular disease, presents with acute pain along with distension. In

contrast, pseudo-obstruction is less often associated with acute pain and more likely to present with

discomfort due to distention. However, lack of pain in postoperative patients on opiates or elderly

patients cannot exclude mechanical obstruction. In plain x-rays, the pathognomonic signs of mechanical

obstruction such as lack of gas in the distal colon or rectum, and air–fluid levels in small intestine on xray can also be seen in Ogilvie syndrome. CT scan is currently the standard method for identifying colon

pseudo-obstruction and excluding other forms of obstruction.223 Patients with toxic megacolon may

manifest typically with symptoms such as fever, tachycardia, abdominal tenderness, bloody diarrhea or

other manifestations of chronic inflammatory bowel disease along with “thumb printing” on the

appearance of the abdomen on plain x-ray film in upright posture. Flexible sigmoidoscopy is

contraindicated if toxic megacolon is thought to be likely, but it or contrast enemas

223 can be useful

diagnostically and therapeutically if toxic megacolon is thought unlikely.

Management

Initial management includes resuscitation and correction of any underlying metabolic or electrolyte

imbalances (Table 49-11). Patients should have physical examination and plain abdominal radiographs

serially to correlate colonic diameters in order to determine which case needs colonoscopic

decompression or surgery. If the patient is not very uncomfortable and the colonic distension is no

greater than 12 cm, conservative treatment can be continued for 1 to 2 days. It may be helpful to place

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