Emergent Treatment of Gastroenteritis Treatment & Management

Prehospital care is directed toward early and aggressive fluid therapy in patients who are unstable.

The following discussion involves management in the emergency department (ED).

Goals of therapy

Goals of ED therapy include the following:

• Rehydrate orally (PO) or intravenously (IV) as needed.

• Treat symptoms (eg, fever, pain) as indicated.

• Identify complications.

• Prevent the spread of infections.

• Identify public health concerns and treat certain cases with specific or empiric antibiotic therapy.

Rehydration

Note the following:

• Administration of 1-2 L dextrose 5% in 0.5 isotonic sodium chloride solution with 50 mEq NaHCO₃ and 10-20 mEq KCl over 30-45 minutes may be necessary in patients who are severely dehydrated.

• Clinical assessment and serum electrolyte concentrations should guide therapy.

• To give fluids more rapidly, KCl may be given orally or in the second or third liter bag or as a supplemental IV of 20 mEq KCl in 100 mL of isotonic sodium chloride solution over 1 hour. Ensure normal renal function prior to KCl administration.

• Rehydrate patients until mental status and signs of perfusion and pulse are normal (caution in elderly patients with congestive heart failure [CHF]), such as a urine output of 1-2 mL/kg/h.

• For pediatric patients, administer 20 mL/kg of isotonic sodium chloride solution initially for resuscitation. Repeat as necessary and add KCl as indicated.

• Indications for IV rehydration include severe intractable vomiting, altered consciousness, severe dehydration, ileus, excessive choleralike stools, and time or environment not conducive to oral rehydration therapy (ORT).

Solutions for oral rehydration

Consider the following:

• The World Health Organization solution is 90 mEq/L Na⁺, 20 mEq/L K⁺, 80 mEq/L Cl^-, 20 g/L glucose; osmolarity is 310; CHO:Na = 1.2:1; administer 250 mL (approximately 8 oz) every 15 minutes until fluid balance is clinically restored, then 1.5 L of oral fluid per liter of stool.

• Other oral rehydration products include Naturalyte, Cera Lyte, Rehydralyte, and Pedialyte.

• Oral rehydration may not decrease the duration or volume of diarrhea.

• Small amounts of oral fluids may be given repeatedly while the patient is still vomiting.

• Oral rehydration has been largely responsible for the tremendous decrease in the death rate in underdeveloped countries from infectious diarrhea, including cholera.

• The glucose/sodium transport mechanism remains intact despite enterotoxigenic illness. Coupled transport is one of several mechanisms of sodium and water absorption in the bowel. It is the direct entry of sodium and water across the cell at the intestinal brush border membrane via the linking (coupling) of 1 organic molecule, such as glucose, to 1 sodium molecule. This is the principle upon which ORT is based. Optimally, therefore, the ratio of carbohydrate to sodium should approach 1:1. Glucose is necessary to stimulate the absorption of water and electrolytes by the small intestines.

• The solution must be iso-osmolar or hypo-osmolar to avoid an increased osmotic load in the small intestines contributing to an osmotic diarrheal effect, pulling fluid into the lumen.

• Studies have shown oral and IV rehydration to be equivalent therapies in patients who can tolerate the oral fluid.

• Although standard glucose-electrolyte solutions achieve and maintain rehydration, they may not reduce stool volume or duration of diarrheal illness, affecting compliance.

• Newer solutions with complex carbohydrates and short chain polypeptides of cereals and legumes are now available to provide additional organic cotransport molecules with no increase in osmolarity. These appear to offer the advantage of decreased stool volumes and shortened duration of illness.

Refeeding

Early age-appropriate refeeding in children (and adults) is important to initiate as soon as rehydration is complete. Note the following:

• Early refeeding with complex carbohydrates provides additional cotransport molecules without osmotic penalty and stimulates mucosal repair.

• Consider rice, wheat, bread, potatoes, and lean meats, especially chicken.

• Milk can be safely given early. Despite the potential for lactose intolerance, clinical evidence of acute lactase deficiency is uncommon, and most children can tolerate nonhuman milk without difficulty during acute diarrheal illnesses.

• What has been learned from studies of early pediatric refeeding probably can be generalized to the adult population. Initiate early feeding with the above dietary recommendations once rehydration has been accomplished and vomiting is controlled.

Empiric therapy

Empiric therapy for infectious diarrhea is sometimes indicated. Food-borne toxigenic diarrhea usually requires only supportive treatment, not antibiotics. Note the following:

• The duration of traveler's diarrhea (E coli, Shigella) can be shortened by half or more with trimethoprim-sulfamethoxazole (TMP/SMZ) or ciprofloxacin administered for 3 days. Single doses have also been used effectively. The duration of treatment may be extended by 2-3 days for moderate-to-severe cases.

• Generally, fluoroquinolones are the drugs of choice for acute infectious gastroenteritis when used empirically. They do not appear to increase carrier states; however, they are contraindicated in pregnant women and in children.

• Erythromycin or azithromycin is effective in Campylobacter infections, although erythromycin is not well tolerated in the patient who is vomiting.

• Metronidazole (oral or parenteral) is effective in mild-to-moderate cases of C difficile diarrhea (in addition to discontinuance of the causative agent). Patients who are severely ill may require orally administered vancomycin, which may require delivery via nasogastric tube or colonoscope.

• Mild cases of suspected Yersinia infection should be treated with TMP/SMZ or a fluoroquinolone, while patients who are more ill and require admission benefit from IV ceftriaxone.

• Intestinal salmonellosis in an immunocompetent host does not require antimicrobials because they may prolong fecal shedding of organisms.

• Metronidazole is effective against parasitic infestations with Giardia or Entamoeba.

Antiemetics

Antiemetics may be useful in the treatment of nausea and vomiting in adults. They are usually not recommended in children.

In a multicenter Italian pediatric ED study that evaluated antiemesis in 832 children (aged 1-6 years) with acute gastrenteritis who underwent successful first attempt with oral rehydration solution, of which 356 were randomized to either placebo (n = 118) or domperidone (1 dose, 0.5 mg/kg) or ondansetron (1 dose, 0.15 mg/kg) (n = 119, each), ondansetron administration reduced the risk of IV hydration by half compared to placebo and domperidone. ^[22]  The investigators suggested that in the emergency care setting, 60% of children in this age group with gastroenteritis-associated emesis without severe dehydration can be effectively managed with oral rehydration alone. ^[22]

Antidiarrheals (antimotility agents)

These agents have traditionally been discouraged because of concerns with causing bacteremia; however, they appear to have a role in the symptomatic treatment of mild-to-moderate diarrhea, especially with nonbloody and traveler's diarrhea.

The most common agents include bismuth subsalicylate (Pepto-Bismol). For patients older than 14 years, give 2 tablets or 20 mL PO q30min as needed to a maximum of 8 doses. Loperamide (Imodium) is useful as an adjunct to rehydration for symptomatic relief. The American Academy of Pediatrics (AAP) does not recommend this for children.

Octreotide (Sandostatin), an analog of somatostatin, may be used subcutaneously and intravenously to control severe secretory diarrhea. It has been approved for this purpose in the treatment of carcinoid tumors and VIPomas. Octreotide is under investigation for other uses, including secretory diarrhea associated with acquired immunodeficiency syndrome (AIDS), short bowel syndrome, dumping syndrome, radiation, and chemotherapy.

Inpatient care

If the patient is hospitalized, the following are treatment strategies in addition to those discussed above:

• Continue rehydration and management of electrolytes if ED response is inadequate.

• Manage sepsis in the toxic-appearing patient.

• Evaluate for underlying etiology if the diagnosis is uncertain.

• Manage complications.

Transfer

Transfer of the unstable patient is inappropriate under Emergency Medical Treatment and Active Labor Act (EMTALA) regulations unless benefits clearly outweigh risks.

Unless the patient requires admission and has a complicated medical condition that would be better managed in another facility, transfer is neither necessary nor recommended.

A consultation with an infectious diseases specialist may be necessary for patients with chronic diarrhea, those who may have a parasitic infection, individuals infected with C difficile when vancomycin use is contemplated, patients who relapse, and those with acquired immunodeficiency syndrome (AIDS) who have diarrhea.

A consultation with a gastroenterologist may also be indicated in the above circumstances and when pseudomembranous colitis, ulcerative colitis, or Crohn disease are in the differential diagnosis.

If a surgical abdomen is suspected or if the patient is status post gastric bypass bariatric surgery, a consultation with a surgeon may be appropriate.

Outpatient care includes the following:

• Rehydrate orally with balanced sodium and glucose solutions.

• Ensure appropriate early oral refeeding.

• Ensure appropriate deterrence and infection control procedures and activities, including notification of common source or close contact exposures, as appropriate.

• Administer antibiotic, antimotility, and antiemetic treatment only as indicated and directed.

• Wash buttocks after each diarrheal stool to avoid effects of stool enzyme on the skin.

• Instruct the patient to return upon experiencing bloody stools, worsening abdominal pain, severe vomiting, and/or concerns regarding dehydration.

• Instruct the patient to seek follow-up care if diarrhea persists longer than 10 days.

Outpatient medications may include antibiotics, antiemetics, and/or antimotility agents.

Breastfeeding

The following are factors to consider with breastfeeding:

• Decreased incidence of rotavirus but does not eliminate this diagnosis

• Formula supplementation with nonpathogenic bacteria such as Bifidobacterium bifidum

Precautions

General precautions

Note the following:

• Take enteric precautions to avoid spread to family members, especially by washing hands before eating and after each stool or diaper change.

• Avoid shellfish served in unregulated environments, in areas with known red tides, or areas of recently reported outbreaks, including Vibrio species and Norwalk virus. Individuals with a history of any liver disease should avoid raw shellfish.

• Wash all produce prior to consumption, especially if imported.

• Avoid cross-contamination of foods during preparation (eg, cutting boards).

• Avoid raw or undercooked eggs or poultry.

Travelers

As many as 40% of travelers to high-risk areas (South and Southeast Asia, Africa, and Latin America) contract diarrhea. Dietary precautions, in addition to the above, which will reduce this risk are as follows:

• Eat steaming hot foods (cooked foods) and drink steaming hot beverages (eg, coffee, tea).

• Consume acidic foods, such as citrus.

• Consume dry foods, such as bread and nuts.

• Drink carbonated beverages.

• Avoid water, ice, raw fruits without a skin or peel, raw vegetables, unpasteurized milk and dairy products, and foods sold in the streets.

• Avoid moist foods served at room temperature, leafy green vegetables, and ripened fruit with broken skin.

• Take the above precautions when aboard an aircraft leaving the high-risk area.

• Travelers who request prophylaxis can take 2 tablets of Pepto-Bismol with each meal and at bedtime, not exceeding a daily dose of 8 tablets.

• Although prophylactic antimicrobial therapy generally should be discouraged in the young and healthy traveler, if chemoprophylaxis is requested, a daily single dose of TMP/SMZ or a fluoroquinolone can be provided.

• Travelers with certain underlying conditions should be encouraged to use prophylactic antibiotics. These include patients with AIDS, inflammatory bowel disease, systemic malignancy, insulin dependency, or achlorhydria and patients taking omeprazole or chronically using H2 antagonists. Sporadic or intermittent H2 antagonist use is not an indication for prophylaxis.

• Avoid drinking from unfamiliar fresh water sources, such as lakes and rivers.

Norovirus

There are very few ways to entirely eliminate norovirus. Alcohol-based hand sanitizers, used by a number of cruise lines and recommended by hospital-based practices, need a minimum of 15-30 seconds of contact time to be effective and should not be considered a substitute for aggressive handwashing and mechanical drying. In addition, sanitizing the finger tips and under the finger nails with alcohol hand gels is difficult, and this may be another factor in their relative ineffectiveness in comparison to handwashing with soap and water. Because norovirus is an unencapsulated virus, alcohol-containing products are less effective and require higher concentrations of alcohol. Several popular commercially available products containing 62-70% alcohol demonstrate varying results, on average a log reduction between 2 and 4. Testing methodology and surrogates vary among the studies.

Alcohol-based hand gels are relatively ineffective in the disinfection and/or removal of norovirus from the hands. The recent increase in norovirus infection in acute care hospitals may be the result of the increased availability of alcohol-based hand gels, and the possible resultant reduction in the frequency of staff handwashing with soap and water and drying with a paper towel.

During an outbreak on board a cruise ship, most surfaces that can be safely disinfected are treated with sodium hypochlorite (bleach), with a concentration of 1000 ppm, freshly constituted (higher concentrations quoted are not freshly constituted and may have varying efficacy). A 1-minute contact time is required, and a >4.0 log reduction is anticipated. However, this concentration is not approved for food handling surfaces and cannot be used on fabrics and many other surfaces.

Steam cleaning to >70^o C is recommended for carpets and certain furnishings.

Benzethonium chloride is a synthetic quaternary ammonium, surfactant, antiseptic, and anti-infective compound used as a topical antimicrobial agent and in antibacterial moist towelettes and wipes. While many of these compounds have limited efficacy for unencapsulated viruses, newer products seem more effective. However, studies show a contact time of >10 minutes may be required.

Accelerated and stabilized hydrogen peroxide is another product used for virucidal disinfecting. It requires a 5-minute contact time. It can be expensive, and, currently, no hand wipes are available.

Phenolic-based products have been used with some success in the past, but concerns about toxicity and their mucosal irritation when "fogged" have meant most cruise lines have moved away from their primary use in mitigating norovirus.

Oil of thyme, which has bactericidal and virucidal properties, is another hand wipe alternative.

Numerous new products are always becoming available, and objective third-party evaluations are critical in the decision-making processes.