Imaging Studies:

• Imaging plays a larger role in the workup of elderly patients with abdominal pain than in younger patients. Preference of imaging modality may vary among institutions according to what is available.

• Plain film radiography

• Although of limited utility in younger patients, an abdominal series may be helpful in elderly patients because of the wide differential diagnosis.

• Plain film radiography can be useful in detecting bowel obstruction, adynamic ileus, nephrolithiasis, and perforation. Occasionally, gallstones may be observed, as well as late findings of mesenteric ischemia (ie, pneumatosis intestinalis). However, the overall sensitivity is very low and a negative abdominal series should not influence management.

• Abdominal ultrasonography

• Generally, this is the initial study of choice when evaluating for biliary tract disease because of availability and speed.

• Bedside ultrasonography is an excellent rapid screening test for AAA.

• Some studies report that it is reasonably sensitive in detecting hydronephrosis and nephrolithiasis, but it is highly operator dependent and not considered the optimal test for urolithiasis.

• CT scan

• CT plays an increasingly important role in the evaluation of elderly patients with abdominal pain, especially when the diagnosis is unclear.

• CT scan is the study of choice for suspected diverticulitis, having a sensitivity of 93%, and is very sensitive in patients with possible appendicitis when the diagnosis is not clear.

  • When performing CT scan to exclude diverticulitis, allow enough time for the oral contrast to reach the distal colon (usually 2-3 h).

  • One study demonstrated that using CT scan with only water-soluble contrast administered by enema without intravenous (IV) or oral contrast had a sensitivity for diverticulitis of 99% and appeared to be safe.

  • Avoid barium enema in patients with suspected diverticulitis.

• In stable patients with suspected AAA, CT scanning with IV contrast is approximately 100% sensitive.

• Noncontrast helical CT scan is reported to be 95-100% sensitive in detecting nephrolithiasis and ureterolithiasis. Unfortunately, many elderly patients have vascular calcifications in the pelvis, making interpretation more difficult. The presence of ureteral dilatation or perinephric stranding can help establish the diagnosis.

• CT scanning combined with CT angiography is increasingly used in the evaluation of suspected mesenteric ischemia. In a 2000 position statement by the American Gastrointestinal Society, it was stated that CT was of limited use in the diagnosis of mesenteric ischemia. Subsequent studies have strongly advocated for the use of multidetector-row CT in the evaluation of mesenteric ischemia (Fleischmann, 2003; Cademartiri, 2004), including one prospective study that found an overall sensitivity of 96%, with specificity of 94% (Kirkpatrick, 2003). Multidetector-row CT scanning had the additional advantage of identifying an alternate diagnosis in 58% of patients without mesenteric ischemia.

• Chest radiography

• Chest radiography is helpful in excluding pneumonia, which is a cause of abdominal pain.

• It may demonstrate free intraperitoneal air under the diaphragm in patients with ruptured viscus. The lateral chest radiography has been demonstrated to be more sensitive in detecting free air.

• Angiography: Although this is difficult to obtain on an emergency basis in some institutions, angiography remains the study of choice for mesenteric ischemia.

• Nuclear medicine imaging (hepatic 2,6 dimethyliminodiacetic acid [HIDA] scan or diisopropyl iminodiacetic acid [DISIDA] scan): This is helpful for patients in whom cholecystitis is suspected when the diagnosis is not clear. HIDA and DISIDA scanning both provide a very high negative predictive value.

Other Tests:

Electrocardiogram: Perform an ECG in all elderly patients with upper abdominal pain and in

Prehospital Care: Patients with severe pain, abnormal vital signs, or altered mental status should undergo the following:

• Large-bore IV placed with either normal saline or lactated Ringer solution (gauge fluid resuscitation by vital signs)

• Cardiac monitor and pulse oximetry

• Oxygen by nasal cannula or 100% face mask, depending on vital signs and pulse oximetry

Emergency Department Care:

• Care in the emergency department is dictated by the severity of presentation. Assess ABCs and vital signs immediately. Place patients on a monitor and start an IV or heparin lock. Administer oxygen to patients who appear to be seriously ill.

• If the diagnosis of AAA is suggested, perform a rapid bedside ultrasound, if available.

• Administer IV boluses of normal saline or lactated Ringer solution to patients with suspected volume loss. Carefully hydrate patients with a history of renal disease or congestive heart failure to avoid volume overload.

• A Foley catheter may be helpful as a guide for volume resuscitation in patients who are sicker. Incontinence is not an indication for a Foley catheter.

• Keep all patients with abdominal pain as nothing by mouth (NPO) until surgical pathology is excluded.

• Place a nasogastric tube in patients in whom bowel obstruction, ileus, or upper GI bleeding is suspected.

• Maintain a low threshold for ordering additional tests such as CT scan or ultrasound.

• If biliary disease is suggested, dicyclomine (Bentyl) or glycopyrrolate (Robinul) may be administered for pain. NSAIDs are very effective for biliary colic but should be administered with caution to elderly patients.

• In patients with undifferentiated abdominal pain, administering small doses of opioids is reasonable. Several studies have demonstrated this to be safe and effective without decreasing diagnostic accuracy.

• Morphine administered IV in doses of 2-4 mg is inexpensive and effective. Morphine has been demonstrated to cause spasm of the sphincter of Oddi and should be avoided in patients in whom biliary disease is suspected.

• Meperidine (Demerol) has been the traditional opioid of choice in biliary tract disease because it causes less sphincter of Oddi spasm.

• Depending on the practice environment, contacting the on-call surgeon prior to administering opioids may be reasonable.

• Initiate appropriate antibiotic coverage for patients in whom sepsis, cholecystitis, appendicitis, diverticulitis, or perforated viscus is suspected. Please refer to the article on the specific diagnosis for choice of antibiotics for a specific disease process (see Differentials).

Consultations:

• In patients in whom ruptured AAA or mesenteric ischemia is suspected, consult a surgeon immediately.

• Consult a gastroenterologist immediately for patients with significant GI bleeding.

• When the diagnosis is uncertain, obtain surgical consultation. Discharge of an elderly patient with abdominal pain should be the exception rather than the rule.

Lesson 8. NEPHROLOGY

Acute nephritis

Nephritis is inflammation of the kidney. The word comes from the Greek nephro- meaning "of the kidney" and -itis meaning "inflammation". Nephritis is often caused by infections, toxins, and auto-immune diseases.