0071643192.pdf

DIAGNOSIS

■ Diagnosis is based on history and physical.

■ If the causative agent is invasive, stool testing will reveal fecal leukocytes

and erythrocytes.

■ Stool culture is expensive and labor intensive, and plays a small role in

ED diagnosis. Reserve for severely ill patients, outbreaks, and patients

recently on antibiotics.

■ Parasitic enteritis may be difficult to distinguish from other invasive

causes. Consider in patients who travel to developing countries, the

immunocompromised, the institutionalized, and patients with a prolonged

course not responsive to traditional therapy. Send stool for ova and parasite

analysis.

TREATMENT

■ Oral rehydration may be acceptable in patients with mild to moderate

dehydration if they are able to tolerate oral intake. These patients may be

discharged with instructions to return if symptoms persist or worsen.

■ Give IV-fluid resuscitation with LR or NS and antiemetics for patients

unable to tolerate PO and those with severe dehydration.

■ Consider hospitalization for the severely dehydrated patient. Other treatment

considerations depend on suspected etiology. (See Tables 11.6 and 11.7.)

COMPLICATIONS

Dehydration, electrolyte imbalances, bacteremia, sepsis, shock

Appendicitis

Acute appendicitis begins with obstruction of the lumen due to food, adhe-

sions, fecalith, or enlarged lymphoid tissue. Mucosal secretion continues with

increasing intraluminal pressure and eventual compromise of venous and lym-

phatic drainage. As a result, epithelialbreakdown with bacterial invasion of the

ABDOMINAL AND GASTROINTESTINAL

EMERGENCIES

TABLE 11.7. Common Causes of Invasive Gastroenteritis (Continued)

CAUSATIVEAGENT INCUBATION ANDTRANSMISSION DESCRIPTION TREATMENT

Enterohemorrhagic 3–8 days; contaminated food Fever, abdominal pain, Supportive care; antibiotics not

Escherichia coli or water; undercooked meats, vomiting, grossly bloody recommended as they may increase the

O157:H7 person-to-person, fecal-oral diarrhea; hemolytic uremic incidence of HUS especially in children

syndrome (HUS) in 5% of

patients fecal WBCs also

common

Entamoeba 8–72 hours; contaminated Common in summer months Self-limiting; supportive care,

histolytica food or water, raw or in adults fever, abdominal antibiotics are not recommended

undercooked shellfish cramps, diarrhea, nausea

with little vomiting;

fecal WBCs and RBCs

common