Abdominal Pain In Adults – Some Resources

Recently, a well-respected actress, Patty Duke, died unexpectedly at the age of 69 of sepsis resulting from a bowel perforation. This sad event led me to review abdominal pain in the elderly [persons 60 and over]. Below are some of the resources reviewed and some of the points noted.

Resources:

Can’t-Miss Gastrointestinal Diagnoses from Medscape. This is a nice brief 23 slide review of some causes of abdominal pain in adults.

American College of Radiology Appropriateness Criteria [The Complete List]. This is the ACR’s recommendations for appropriate imaging of a large number of clinical conditions.

Here is a link to the post “Imaging Evaluation of Gastrointestinal Problems from the American College of Radiology” which contains just the links to ACR recommendations for gastrointestinal problems.

Abdominal Pain in Elderly Persons Updated: Dec 27, 2015 from Medscape.

The only studies published since the widespread use of advanced imaging showed that nearly 60% [of the elderly presenting to the ED] were hospitalized, and, in the following 2 weeks, 20% underwent surgery and 5% died.[3, 4]

Elderly patients tend to wait much longer to seek medical attention than younger patients, and they are much more likely to present with vague symptoms and have nonspecific findings on examination. . . . They are less likely to have fever, leukocytosis, or elevated C-reactive protein level. In addition, their pain is likely to be much less severe than expected for a particular disease.

Because of these factors, many elderly patients with serious pathology initially are misdiagnosed with benign conditions such as gastroenteritis or constipation. They also are at greater risk of being admitted to the wrong service (eg, internal medicine when a surgeon may be required).

Abdominal pain may be the presenting symptom in a wide range of diseases in elderly patients. Note that elderly patients with intra-abdominal pathology are more likely to present with symptoms other than abdominal pain, such as fever, fatigue, chest pain, or altered mental status.

Causes of abdominal pain in elderly patients are as follows (see Pathophysiology for more information):

  • Biliary tract disease
  • Appendicitis
  • Diverticulitis
  • Mesenteric ischemia (risk factors include  atrial fibrillation, atherosclerotic disease, and low ejection fraction)
  • Peptic ulcer disease
  • Malignancy
  • Gastroenteritis
  • Small bowel obstruction
  • Large bowel obstruction
  • Peritonitis from a ruptured viscus

Small bowel obstruction most often is caused by adhesions from previous surgery. In elderly patients, an incarcerated hernia . . .  causes approximately 30% of cases, and approximately 20% are caused by gallstone ileus.

Large bowel obstruction is most often caused by malignancy or volvulus.

Small-Bowel Obstruction from Medscape.

Obtain plain radiographs  first for patients in whom SBO is suspected. At least 2 views, supine or flat and upright, are required. Plain radiographs are diagnostically more accurate in cases of simple obstruction.

Computed tomography (CT) scanning is the study of choice if the patient has fever, tachycardia, localized abdominal pain, and/or leukocytosis.

Ultrasonography is less costly and invasive than CT scanning and may reliably exclude SBO in as many as 89% of patients; specificity is reportedly 100%.

Large-Bowel Obstruction from Medscape.

Large-bowel obstruction (LBO) is an emergency condition that requires early identification and intervention. It is important to distinguish colonic obstruction from ileus, as well as to differentiate between a true mechanical obstruction and a pseudo-obstruction; treatment differs.

CT scanning is the imaging of choice if a colonic obstruction is clinically suspected; this imaging modality can confirm the diagnosis and identify the cause of large-bowel obstruction.[12] Contrast-enhanced CT (PO and IV) can help to delineate between partial and complete obstruction, ileus, and small-bowel obstruction, as well as exclude large-bowel obstruction. Gastrografin (water-soluble contrast) should be used preferentially if bowel perforation is suspected.

Although at times helpful in the evaluation of suspected bowel obstruction, plain radiography has largely been supplanted by computed tomography (CT) scanning owing to the latter’s abilily to provide far more accurate and detailed images of the relevant pathology.[12]

An upright chest radiograph is useful to screen for free air (see first image below), which would suggest perforation and ileus rather than obstruction. Flat and upright abdominal radiographs can help distinguish severe constipation from bowel obstruction. Plain films may also help localize the site of obstruction (large vs small bowel).

The absence of free air does not exclude perforation (this finding may be absent in half of all perforations).

Intestinal Pseudo-Obstruction from Medscape.

Ogilvie syndrome [acute intestinal pseudo-obstruction] should be considered in all patients with significant abdominal distention. Colonic volvulus may manifest in a fashion similar to colonic pseudo-obstruction and therefore should be considered as well.

Aside from physical examination, the most useful screening test for intestinal pseudo-obstruction is plain abdominal radiography.[41] Films show a dilated colon, with dilatation often extending from the cecum to the splenic flexure and occasionally to the rectum (see the images below). Serial films may be used to follow the clinical course and the response to treatment.

An abdominal CT scan is very helpful to confirm the diagnosis by excluding mechanical obstruction and toxic megacolon.

Episode 42: Mesenteric Ischemia and Pancreatitis from Emergency Medicine Cases. This podcast and the associated notes are outstanding resources. The podcast makes the point that mesenteric ischemia is not reliably ruled out by a routine abdominal CT scan. The speakers suggest that if mesenteric ischemia is high on your differential that you order a triple phase abdominal CT (64 slice with 3-D reconstruction capabilities) and perhaps discuss your concerns with the interpreting radiologist.

Mesenteric Ischemia Imaging from Medscape.

Plain radiographic findings are often normal.

Mesenteric ischemia is rarely, if ever, diagnosed by using plain abdominal images.

Nonenhanced CT scans have an inherent limitation: CT scans obtained without oral contrast enhancement are not helpful in differentiating mucosal thickening from nonopacified bowel loops. Although CT findings may help in localizing a diseased segment of bowel, differentiating a venous origin from an arterial origin in thrombosis often is difficult, even with the proper intravenous administration of contrast material. In addition, differentiating ischemic colitis from infectious colitis often can be difficult using CT scans.

CT is the primary imaging modality (see the images [in the article]), and it has been proven to be highly accurate in the diagnosis of mesenteric ischemia; scans sometimes depict the underlying etiology. Typically, CT scans show mesenteric edema with irregular thickening of the wall of the small or large bowel that is greater than 3 mm. Large-vessel disease (superior mesenteric artery/vein [SMA/SMV]; inferior mesenteric artery/vein [IMA/IMV]) is diffuse, whereas small-vessel arterial or venous disease is more likely to be focal.[9, 2, 3, 4, 11, 12, 13, 14, 5, 6]

Diverticulitis from Medscape.

The clinical presentation of diverticulitis depends on the location of the affected diverticulum, the severity of the inflammatory process, and the presence of complications. Left lower quadrant pain is the most common presenting complaint and occurs in 70% of patients. Pain is often described as crampy and may be associated with a change in bowel habits. Other symptoms include nausea and vomiting, constipation, diarrhea, flatulence, and bloating. Symptoms of mild diverticulitis may be confused with overlapping symptoms of irritable bowel syndrome.

A microperforation, most likely walled off by adjacent structures, may present with no systemic signs of illness or infection. On the other hand, disease may progress from a localized and walled-off process to one with peridiverticular inflammatory phlegmon and localized abscess. Systemic signs of infection (eg, fever) then develop. Because diverticula and, hence, diverticulitis can develop anywhere in the gastrointestinal tract, symptoms may mimic multiple conditions.

The diagnosis of acute diverticulitis can usually be made on the basis of history and physical examination, but laboratory tests may be of help when the diagnosis is in question, . . .

Clinical staging by Hinchey’s classification is geared toward choosing the proper surgical procedure when diverticulitis is complicated, as follows:

  • Stage I: Diverticulitis with phlegmon or localized pericolic or mesenteric abscess
  • Stage II: Diverticulitis with walled-off pelvic, intra-abdominal, or retroperitoneal abscess
  • Stage III: Perforated diverticulitis causing generalized purulent peritonitis
  • Stage IV: Rupture of diverticula into the peritoneal cavity with fecal contamination causing generalized fecal peritonitis

Patients with mild diverticulitis, typically with Hinchey’s stage I disease, can be treated with the following outpatient regimen:

  • A clear liquid diet
  • 7-10 days of oral broad-spectrum antimicrobial therapy
  • Patients can advance the diet slowly as tolerated after clinical improvement occurs, which should be within 48-72 hours [1]

Indications for hospital admission include the following:

  • Evidence of severe diverticulitis (eg, systemic signs of infection or peritonitis)
  • Inability to tolerate oral hydration
  • Failure of outpatient therapy (ie, persistent or increasing fever, pain, or leukocytosis after 2-3 days)
  • Immunocompromise or significant comorbidities
  • Pain severe enough to require parenteral narcotic analgesia

Inpatient treatment is as follows:

  • Initiate bowel rest and intravenous fluid hydration
  • Start broad-spectrum intravenous antibiotic coverage until culture results, if obtained, are available
  • Within 2-3 days of hospitalization, fever, pain, and leukocytosis should begin to resolve
  • The patient can then be started on a clear liquid diet and advanced as tolerated
  • If tolerating oral intake and clinically stable, the patient can be discharged to complete a 7- to 10-day course of oral antibiotic therapy
  • Repeat the abdominal CT scan if patients do not show timely clinical improvement
  • CT–guided percutaneous drainage is indicated for peridiverticular abscesses > 4 cm in diameter

The classic surgical indications include some features characteristic of Hinchey’s stage III or IV disease and are as follows:

  • Free-air perforation with fecal peritonitis
  • Suppurative peritonitis secondary to a ruptured abscess
  • Uncontrolled sepsis
  • Abdominal or pelvic abscess (unless CT-guided aspiration is possible)
  • Fistula formation
  • Inability to rule out carcinoma
  • Intestinal obstruction
  • Failing medical therapy
  • Immunocompromised status
  • Extremes of age

The diagnosis of diverticulitis can be made on clinical grounds, but a CT scan of the abdomen is considered the best imaging method to confirm the diagnosis. The American College of Radiology (ACR) 2008 Appropriateness Criteria for left lower quadrant pain support this recommendation because of the specificity and sensitivity of CT scans, which allow for the diagnosis of causes of left lower quadrant pain that resembles diverticulitis.[8]

  • CT scans are preferred over intraluminal examinations (eg, barium enema), since the bulk of inflammation is extraluminal. CT scans can help assess disease severity, the presence of complications, and clinical staging. In the acute setting, CT scans are safer than contrast studies. Sensitivity and specificity, especially with helical CT and colonic contrast, can be as high as 97%.
  • Possible CT findings include the following: pericolic fat stranding due to inflammation, colonic diverticula, bowel wall thickening, soft tissue inflammatory masses, phlegmon, and abscesses. Peritonitis, fistula formation, and obstruction can also be assessed. It can be used to guide percutaneous drainage of an abscess.

Computed tomography (CT) scanning of the abdomen is considered the best imaging method to confirm the diagnosis. Sensitivity and specificity, especially with helical CT and colonic contrast, can be as high as 97%. Possible CT findings include the following:

  • Pericolic fat stranding due to inflammation
  • Colonic diverticula
  • Bowel wall thickening
  • Soft-tissue inflammatory masses
  • Phlegmon
  • Abscesses
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