Cholera Nursing Care Management (Study Guide)

Cholera kills through dehydration, not the organism itself. The diarrhea is profuse, watery, and painless, and a patient can go into hypovolemic shock fast. Rehydration is the whole game: replace fluid and electrolytes aggressively and keep replacing ongoing losses. Antibiotics are an adjunct, not the cure. The disease tracks poverty, poor sanitation, and unsafe water.

What is Cholera?

Cholera is an acute diarrheal disease caused by Vibrio cholerae.

• Records from Hippocrates (460-377 BCE) and the Indian peninsula describe an illness that might have been cholera.
• The cholera organism is credited to German bacteriologist Robert Koch, who identified V cholerae in 1883 during an outbreak in Egypt. The genus name reflects that the organism appears to vibrate when moving.
• The hallmark is profuse secretory diarrhea. Cholera can be endemic, epidemic, or pandemic.

Pathophysiology

Vibrio cholerae is a comma-shaped, gram-negative aerobic or facultatively anaerobic bacillus, 1-3 µm long by 0.5-0.8 µm in diameter.

• The El Tor biotype of V cholerae O1 is the predominant pathogen. Classical and El Tor biotypes are subdivided into serotypes by the structure of the O antigen.
• Disease from V cholerae O139 is clinically and epidemiologically indistinguishable from O1. Both serogroups produce an enterotoxin that drives fluid and electrolyte secretion into the lumen of the small intestine.
• The organism is not acid-resistant, so it depends on a large inoculum to survive gastric acidity. Antacids, histamine receptor blockers, and proton pump inhibitors increase the risk and severity of infection by reducing gastric acidity.
• Fluid loss originates in the duodenum and upper jejunum; the ileum is less affected. The colon is usually absorbing, but the large fluid volume from the upper intestine overwhelms its absorptive capacity, causing severe diarrhea.
• Without adequate fluid and electrolyte replacement, the patient develops shock from profound dehydration and acidosis from bicarbonate loss.
• The enterotoxin acts locally and does not invade the intestinal wall, so few neutrophils appear in the stool.

Causes

Cholera can be endemic, epidemic, or pandemic.

• Environmental factors. Primary infection is incidentally acquired and facilitated by seasonal increases in organisms, possibly tied to water temperature and algal blooms. Secondary transmission is fecal-oral, through person-to-person contact or contaminated water and food.
• Host factors. Malnutrition increases susceptibility. Because gastric acid can render an inoculum noninfectious, hypochlorhydria or achlorhydria of any cause (including Helicobacter pylori infection, gastric surgery, vagotomy, or H2 blocker use) increases susceptibility. Infection rates among household contacts range from 20-50%, lower in endemic areas where adults may have preexisting vibriocidal antibodies.

Statistics and Incidences

In the United States, cholera has virtually been eliminated through improved hygiene and sanitation.

• Cholera among international travelers returning to the United States has averaged 1 case per 500,000 population, with a range of 0.05-3.7 cases per 100,000 depending on the countries visited.
• Between January 1, 1995, and December 31, 2000, 61 cases were reported in 18 states and 2 US territories.
• In 1990, fewer than 30,000 cases were reported to the WHO.
• From 2005 to 2008, 178,000-237,000 cases and 4000-6300 deaths were reported annually worldwide.
• In nonendemic areas, incidence is similar across age groups, though adults are less likely than children to become symptomatic.

Clinical Manifestations

After a 24- to 48-hour incubation, symptoms start with sudden painless watery diarrhea that can become voluminous, often followed by vomiting.

• Diarrhea. Profuse watery diarrhea is the hallmark. Suspect cholera in a patient older than 5 years with severe dehydration from acute, severe watery diarrhea (usually without vomiting), or in any patient older than 2 years with acute watery diarrhea in an outbreak area.
• Vomiting. A prominent but not universal manifestation. Early in the course it stems from decreased gastric and intestinal motility; later it more likely results from acidemia.
• Dehydration. Untreated, diarrhea and vomiting cause isotonic dehydration, which can progress to acute tubular necrosis and renal failure. Because it is isotonic, water loss is proportional across the 3 body compartments: intracellular, intravascular, and interstitial.

Assessment and Diagnostic Findings

Definitive diagnosis is not required before treating cholera.

• Stool examination. The characteristic motility of Vibrio cannot be seen on Gram stain but is easily seen on direct dark-field examination of the stool.
• Stool culture. V cholerae is not nutritionally fastidious but needs adequate buffering if fermentable carbohydrate is present, because viability is severely compromised if pH is less than 6, often causing autosterilization of the culture.
• Serotyping and biotyping. Specific antisera are used in immobilization tests. A positive result (cessation of motility) occurs only if the antiserum is specific for the Vibrio type present; the second antiserum is a negative control.
• Hematologic tests. Hematocrit, serum-specific gravity, and serum protein are elevated in dehydrated patients from hemoconcentration. Patients generally show leukocytosis without a left shift.
• Metabolic panel. Serum sodium is usually 130-135 mmol/L, reflecting sodium loss in the stool. Serum potassium is usually normal in the acute phase, reflecting exchange of intracellular potassium for extracellular hydrogen ion to correct acidosis. Hyperglycemia may be present from systemic release of epinephrine, glucagon, and cortisol due to hypovolemia. Blood urea nitrogen and creatinine are elevated, consistent with prerenal azotemia.

Medical Management

Rehydration is the first priority and is done in 2 phases: rehydration and maintenance.

• Rehydration phase. Restore normal hydration in no more than 4 hours. In severely dehydrated patients, set IV infusion at 50-100 mL/kg/hr. Lactated Ringer solution is preferred over isotonic sodium chloride because saline does not correct metabolic acidosis.
• Maintenance phase. Maintain hydration by replacing ongoing losses. The oral route is preferred, with oral rehydration solution (ORS) at 500-1000 mL/hr.
• Cholera cots. In endemic areas, a cholera cot (a cot with a plastic sheet and a center hole draining into a calibrated bucket) is used to measure ongoing stool losses.
• Diet. Resume a normal diet when vomiting stops. Continue breastfeeding infants and young children.

Pharmacological Management

Antimicrobial therapy is an adjunct to fluid therapy, not an essential component.

• Antibiotics. Empiric therapy must be comprehensive and cover all likely pathogens. Though not curative, an antibiotic to which the organism is susceptible shortens the duration and volume of fluid loss and speeds clearance of the organism from stool.
• Vaccines. In June 2016, the first US cholera vaccine was approved by the FDA. It contains live attenuated cholera bacteria that replicate in the recipient's GI tract to provide immunity, indicated for active immunization against Vibrio cholerae serogroup O1 in adults aged 18-64 y traveling to cholera-affected areas.

Nursing Management

Nursing Assessment

• Assess for dehydration. Check skin color and temperature, skin turgor, mucous membranes, eyes, crown, body temperature, pulse, respiration, behavior, and weight loss.
• Observe for diarrhea. Watch for sudden diarrhea, fever, anorexia, vomiting, nausea, abdominal cramps, increased bowel sounds, and bowel movements more than 3 times a day with liquid stool, with or without mucus or blood.
• Assess family knowledge. Check knowledge of home management of diarrhea, diet, and prevention of recurrence.

Nursing Diagnosis

• Deficient fluid volume related to excessive fluid loss through stool or emesis.
• Imbalanced nutrition, less than body requirements, related to fluid loss through diarrhea and inadequate intake.
• Risk for infection related to microorganisms penetrating the GI tract.
• Impaired skin integrity (perianal) related to irritation from diarrhea.
• Anxiety related to separation from parents, unfamiliar environment, and stressful procedures.

Nursing Care Planning and Goals

• Maintain adequate hydration.
• Consume adequate nutritional requirements.
• Prevent infection.
• Maintain skin integrity.
• Reduce anxiety.

Nursing Interventions

• Monitor intake and output. Note the number, character, and amount of stools; estimate insensible losses such as diaphoresis; measure urine specific gravity and watch for oliguria.
• Weigh daily. Daily weight indicates overall fluid and nutritional status.
• Maintain hydration. Replace ongoing fluid losses until diarrhea stops.
• Administer medications as indicated. Give an oral antibiotic to the patient with severe dehydration as prescribed.

Evaluation

Goals are met when the patient maintains adequate hydration and nutrition, avoids infection, keeps skin integrity intact, and has reduced anxiety.

Documentation Guidelines

• Individual findings, including factors affecting, interactions, nature of social exchanges, and specifics of individual behavior.
• Cultural and religious beliefs and expectations.
• Plan of care.
• Teaching plan.
• Responses to interventions, teaching, and actions performed.
• Attainment or progress toward the desired outcome.