11.7 Gastroenteritis

Gastroenteritis is an inflammation of the stomach and small intestine. It is classified as an increase in bowel movements that may also be associated with fever, vomiting, and abdominal pain. Although most cases of gastroenteritis are acute and last fewer than 14 days, it is also possible to have a chronic case lasting over 30 days.^[1]

Gastroenteritis can be caused by bacteria, viruses, fungi, or parasites, but most cases are caused by viruses. Transmission generally occurs via the fecal-oral route, via contaminated food or water, or even airborne routes. Common bacterial causes of gastroenteritis in the United States are Salmonella and Campylobacter. Leading viral causes of gastroenteritis are rotavirus and norovirus. Antibiotics can also cause gastroenteritis as a side effect. This section will focus on viral and bacterial forms of gastroenteritis.^[2]

Risk factors for contracting gastroenteritis include traveling to developing countries and consuming improperly prepared food. Viral outbreaks are also common in close quarters, putting clients who attend daycare, live in nursing facilities, or vacation on cruise ships at risk. Clients who are immunocompromised, very young, older adults, or suffer from chronic diseases are at the highest risk for complications related to dehydration.^[3]

Pathophysiology

Fluids are normally absorbed in the small intestine, but during gastroenteritis this absorption does not occur normally due to inflammation. Additionally, toxins associated with various bacteria and viruses can cause the lining of the intestine to also excrete fluid. These factors cause frequent, watery diarrhea that is associated with gastroenteritis.^[4]

Assessment

Physical Exam

Signs and symptoms of gastroenteritis usually occur suddenly and improve within one to three days. Common signs and symptoms include the following^[5]:

• Diarrhea (Diarrhea may or may not contain blood depending on the causative organism.)
• Nausea
• Vomiting
• Fever
• Abdominal pain

Dehydration can occur quickly in cases of gastroenteritis, so nurses must assess for signs and symptoms of fluid volume deficit that include the following:

• Dry mucous membranes
• Change in mental status
• Elevated heart rate
• Decreased blood pressure
• Poor skin turgor

Common Laboratory and Diagnostic Tests

Lab Tests

Lab tests performed to diagnose gastroenteritis are a complete blood count, a metabolic panel, and stool testing^[6],[7]:

• A complete blood count (CBC) may show mildly elevated white blood cells with viral causes of gastroenteritis. Bacterial causes of gastroenteritis often cause a significantly elevated white blood cell count. Due to dehydration and the subsequent hemoconcentration, levels of red blood cells, hemoglobin, and hematocrit may appear falsely elevated.
• A complete metabolic panel (CMP) may show an elevated BUN and creatinine if dehydration is severe enough to cause injury to the kidneys. Additionally, vomiting and diarrhea may cause decreased electrolyte levels, particularly potassium.
• Various stool studies may be performed to establish a diagnosis. Specific stool studies can detect certain viral or bacterial causes of gastroenteritis. Stool may also be checked for ova and parasites, as well as the presence of white blood cells.

Review normal reference ranges for common diagnostic tests in “Appendix A – Normal Reference Ranges.”

Imaging

In the majority of cases of gastroenteritis, imaging will be normal. However, a CT scan of the abdomen may show inflammation in the bowel that is nonspecific.^[8],[9]

Nursing Diagnoses

Nursing priorities for those suffering from gastroenteritis include preventing/treating dehydration, promoting good skin care, consuming optimal nutrition, and managing diarrhea.

Nursing diagnoses for clients with gastroenteritis are created based on the specific needs of the client, their signs and symptoms, and the etiology of the disorder. These nursing diagnoses guide the creation of client specific care plans that encompass client outcomes and nursing interventions, as well the evaluation of those outcomes. These individualized care plans then serve as a guide for client treatment.

Possible nursing diagnoses for those with gastroenteritis are as follows^[10]:

• Fluid Volume Deficit
• Impaired Skin Integrity
• Imbalanced Nutrition: Less than Body Requirements
• Diarrhea
• Risk for Electrolyte Imbalance

Outcome Identification

Outcome identification encompasses the creation of short- and long-term goals for the client. These goals are used to create expected outcome statements that are based on the specific needs of the client. Expected outcomes should be specific, measurable, and realistic. These outcomes should be achievable within a set time frame based on the application of appropriate nursing interventions.

Sample expected outcomes for some of the above nursing diagnoses are listed below:

• The client will exhibit blood pressure and heart rate within normal limits for age, moist mucous membranes, and urine output appropriate for age during the course of the illness.
• The client will exhibit skin in the peri-area that is an appropriate color for race and free from skin breakdown during the course of the illness.
• The client will tolerate a bland diet without nausea, vomiting, or diarrhea within 24 hours.
• The client will exhibit a formed stool that occurs at the client’s normal frequency within one week.

Interventions

Medical Interventions

Specific medical interventions depend on the causative factor of gastroenteritis. Generally, viral gastroenteritis is treated with supportive care such as the following^[11],[12]:

• Prevent/treat dehydration by providing adequate fluids. IV fluids may be administered for clients who are dehydrated or cannot tolerate fluids by mouth due to nausea/vomiting.
• Supplement electrolytes as needed via oral or IV routes, depending on the status of the client.
• Antiemetic medications may be prescribed to control nausea and vomiting. Commonly prescribed medications are ondansetron or metoclopramide. Clients are encouraged to adhere to a bland diet while symptomatic.
• Although antidiarrheal medications such as loperamide or diphenoxylate/atropine exist, their use in gastroenteritis (both viral and bacterial) is controversial.

For clients diagnosed with bacterial gastroenteritis, medical interventions include supportive care described above, as well as possible antibiotics to treat the infection. Generally, antibiotics are prescribed for clients with severe cases of bacterial gastroenteritis (defined as over six stools per day, febrile, and hospitalized), have blood in their stool, have Clostridium difficile (C. diff), are over 70 years in age, are immunocompromised, or have other comorbidities.^[13]

Generally, clients with gastroenteritis can be managed at home, but hospital admission may be required for clients who are severely dehydrated, cannot stop vomiting, have significant electrolyte abnormalities or abdominal pain, or those who are pregnant.^[14],[15]

Nursing Interventions

When providing nursing care for clients with gastroenteritis, the following nursing interventions can be divided into nursing assessments, nursing actions, and client teaching^{[16][17],[18]}:

Nursing Assessments

• Assess client vital signs. Vital signs may be altered due to fever or dehydration.
• Assess intake and output.
• Assess for signs of dehydration (dry mucous membranes, decreased urine output, sunken fontanels in infants, poor skin turgor, elevated heart rate, or decreased blood pressure).
• For clients with diarrhea, assess skin in perineal area for breakdown.

Nursing Actions

• Administer IV fluids as prescribed. Encourage oral intake if appropriate.
• Administer antiemetics as prescribed.
• Administer electrolyte supplements as prescribed.
• Ensure a hospitalized client is placed in a room according to transmission-based precautions (typically contact precautions). In cases of norovirus, contact and droplet precautions are also required.

Client Teaching

• Teach proper handwashing before eating, before preparing food, and after using the restroom to prevent the spread of gastroenteritis.
• Teach about consuming a bland diet while symptomatic, such as bananas, rice, and toast. Dairy and spicy/heavily seasoned food should be avoided until symptoms have resolved.
• Teach guidelines for using over-the-counter medications.
• Teach parents with children about the rotavirus vaccine and teach proper food preparation and storage methods as prevention interventions.

Evaluation

Evaluation of client outcomes refers to the process of determining whether or not client outcomes were met by the indicated time frame. This is done by reevaluating the client as a whole and determining if their outcomes have been met, partially met, or not met. If the client outcomes were not met in their entirety, the care plan should be revised and reimplemented. Evaluation of outcomes should occur each time the nurse assesses the client, examines new laboratory or diagnostic data, or interacts with another member of the client’s interdisciplinary team.