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 el