Dehydration is a frequent cause of hospital admission. It can cause morbidity and mortality on its own and complicates many medical conditions. Dehydration affects clients of all ages, however, it is most common among older age clients. Dehydration is easily treatable and preventable, as long as a thorough understanding of the causes and diagnosis is made to improve client care (Taylor & Jones, 2022).
Definition
Worldwide, dehydration secondary to diarrheal illness is the leading cause of infant and child mortality. The negative fluid balance that causes dehydration results from decreased intake, increased output, or fluid shift. The decrease in total body water causes reductions in both intracellular and extracellular fluid volumes (Huang & Corden, 2018).
Pathophysiology
The human body is 55% to 65% of water. Two-thirds of that water is intracellular, and one-third is extracellular. One-fifth of extracellular water is intravascular. The primary control of water homeostasis is through osmoreceptors in the brain. As perceived by these osmoreceptors, dehydration stimulates the thirst center in the hypothalamus, which leads to water consumption. When the hypothalamus detects lower water concentration, it causes the posterior pituitary to release antidiuretic hormone (ADH), which stimulates the kidneys to reabsorb more water. Decreased blood pressure, which often accompanies dehydration, triggers renin secretion, which converts angiotensin I to angiotensin II and increases aldosterone release from the adrenals. Aldosterone increases the absorption of sodium and water from the kidney. Using these mechanisms, the body regulates body volume and sodium and water concentration (Taylor & Jones, 2022).
Etiology
Body water is lost through the skin, lungs, kidneys, and GI tract. The loss of body water without sodium causes dehydration. Determination of the cause of dehydration is essential. Poor fluid intake, excessive fluid output, increased insensible fluid losses, or a combination of the above may cause intravascular volume depletion (Huang & Corden, 2018). Common causes of dehydration include the following:
- Gastroenteritis. This is the most common cause of dehydration. If both vomiting and diarrhea are present, dehydration may rapidly progress (Huang & Corden, 2018).
- Stomatitis. Stomatitis refers to oral inflammation and ulcers, which can be mild or extremely painful. Pain may severely limit oral intake (Huang & Corden, 2018).
- Diabetic ketoacidosis (DKA). Dehydration is caused by osmotic diuresis. Weight loss is caused by both excessive fluid losses and tissue catabolism (Huang & Corden, 2018).
- Febrile illness. Fever causes increased insensible fluid losses and may affect appetite (Huang & Corden, 2018).
- Pharyngitis. Pharyngitis is the inflammation of the mucous membranes of the oropharynx. This may decrease oral intake (Huang & Corden, 2018).
- Burns. Burns are injuries to the skin involving two layers: the thin, outer epidermis and the thicker, deeper dermis (Lopez, 2021). Fluid losses may be extreme with burns (Huang & Corden, 2018).
- Congenital adrenal hyperplasia. Congenital adrenal hyperplasia is an autosomal recessive disease emerging from mutations of genes for enzymes that lead to the production of glucocorticoids, mineralocorticoids, and sex steroids by the adrenal glands (Momodu et al., 2022). The disease is associated with hypoglycemia, hypotension, hyperkalemia, and hyponatremia (Huang & Corden, 2018).
- GI obstruction. This is often associated with poor intake and emesis. Bowel ischemia can result in extensive capillary leak and shock.
- Heat stroke. Heat stroke is a severe heat-related illness that involves an elevation in body temperature which typically, but not always, is greater than 40℃ (104℉) (Morris & Patel, 2022). Hyperpyrexia, dry skin, and mental status changes may occur (Huang & Corden, 2018).
- Cystic fibrosis. Cystic fibrosis is an autosomal recessive disorder of exocrine gland function most commonly affecting persons of Northern European descent (Dulebohn, 2021). This results in excessive sodium and chloride losses in sweat, placing clients at risk for severe hyponatremic hypochloremic dehydration (Huang & Corden, 2018).
- Diabetes insipidus. The excessive output of very dilute urine can result in large free water losses and severe hypernatremic dehydration, especially when the child is unable to self-regulate water intake in response to thirst (Huang & Corden, 2018).
- Thyrotoxicosis. Thyrotoxicosis is the clinical state associated with excess thyroid hormone activity, usually due to inappropriately high-circulating thyroid hormones. Weight loss is observed, despite increased appetite, and diarrhea also occurs (Huang & Corden, 2018).
Epidemiology
Dehydration has been reported to occur in 17% to 28% of older adults in the United States. They are more prone to developing dehydration due to immobility, impaired thirst mechanism, diabetes, renal disease, and falls (Taylor & Jones, 2022). Diarrheal illnesses in children cause 3 million physician visits, 220,000 hospitalizations (10% of all children who require hospitalization), and 400 deaths per year. Children younger than 5 years are at a higher risk (Huang & Corden, 2018).
Diarrheal illnesses with subsequent dehydration account for nearly 4 million deaths per year in infants and children. The overwhelming majority of these deaths occur in developing nations (Huang & Corden, 2018).
Forms
Dehydration results when water losses from the body exceed water replacement. There are several forms of dehydration
- Isonatremic/isotonic dehydration. It occurs when the lost fluid is similar in sodium and concentration to the blood. Sodium and water losses are of the same relative magnitude in both the intravascular and extravascular fluid compartments (Huang & Corden, 2018).
- Hyponatremic/hypotonic dehydration. This occurs when the lost fluid contains more sodium than the blood. Relatively more sodium than water is lost. Because the serum sodium is low, intravascular water shifts to the extravascular space, exaggerating intravascular volume depletion for a given amount of total body water loss (Huang & Corden, 2018).
- Hypernatremic/hypertonic dehydration. This occurs when the lost fluid contains less sodium than the blood. Relatively less sodium than water is lost. Because the serum sodium is high, extravascular water shifts to the intravascular space, minimizing intravascular volume depletion for a given amount of total body water loss (Huang & Corden, 2018).
Signs and symptoms
The determination of dehydration severity should be based on the overall constellation of symptoms. Literature reviews have suggested that delayed capillary refill, delayed skin turgor, and abnormal respiratory pattern are the most reliable clinical signs of dehydration in children. The clinical findings of mild, moderate, and severe dehydration are as follows:
- Mild dehydration. The client is alert; with a capillary refill of two seconds; normal mucous membranes and tears; slight tachycardia; normal respiratory rate, blood pressure, and pulse rate; normal skin turgor; normal fontanels in pediatric clients; and decreased urine output.
- Moderate dehydration. In moderate dehydration, the client becomes lethargic; with a capillary refill of two to four seconds; dry mucous membranes; decreased tear production; tachycardia, tachypnea, and orthostatic hypotension are slightly noted; thready pulse; slow skin turgor; depressed fontanels and sunken eyes; and oliguria.
- Severe dehydration. Severe dehydration presents an obtunded client with a capillary refill of more than four seconds and cool limbs, the mucous membranes are parched or cracked, absence of tear production, severe tachycardia, severe tachypnea, and hyperpnea, decreased blood pressure, faint or impalpable pulse, tenting of the skin, sunken fontanels and very sunken eyes, and oliguria, even anuria.
Interventions
The treatment of dehydration is aimed at rapid fluid replacement as well as identification of the cause of fluid loss.
- Parenteral fluid administration. Clients with fluid deficits should be given isotonic fluid boluses specific to the individual condition. Clients diagnosed with more severe dehydration get larger boluses of isotonic fluid. A more careful approach is needed in elderly clients and clients diagnosed with heart failure and kidney failure. In these clients, small boluses should be given, followed by frequent reassessment and additional bolus as needed. Normal saline, lactated Ringer’s solution, and a balanced crystalloid solution may all be used (Taylor & Jones, 2022).
- Oral rehydration solutions. Rapid oral rehydration with the appropriate solution has been shown to be as effective as intravenous fluid therapy in restoring intravascular volume and correcting acidosis. All commercially available rehydration fluids are acceptable for oral rehydration therapy (ORT). Traditional clear fluids are not appropriate for ORT. Mild or moderate dehydration can usually be treated very effectively with ORT (Huang & Corden, 2018).
- Management of hypovolemic shock. Initial management of shock includes placement of an intravenous or intraosseous line and rapid administration of 20ml/kg of an isotonic crystalloid (lactated Ringer’s, 0.9% sodium chloride). If improvement is not observed after 60 ml/kg of fluid administration, other etiologies of shock should be considered (Huang & Corden, 2018).
- Measure intake and output. Maintenance fluid requirements are equal to measured fluid losses (urine, stool) plus insensible fluid losses. Normal insensible fluid loss is approximately 400-500 mL/m² of body surface area and may be increased by factors such as fever and tachypnea (Huang & Corden, 2018).
- Diet. Foods that contain complex carbohydrates such as rice, wheat, potatoes, bread, and cereals; lean meats; fruits; and vegetables are encouraged. Fatty foods and simple carbohydrates are avoided (Huang & Corden, 2018).
- Administer medications as ordered. In an emergency department study, ondansetron was shown to decrease the likelihood of vomiting, increase oral intake, and decrease emergency department length of stay. It is a selective 5-HT3-receptor antagonist that prevents nausea and vomiting associated with emetogenic cancer chemotherapy and complete body radiotherapy (Huang & Corden, 2018).
Nursing Diagnosis for Dehydration
Nursing Diagnosis
Imbalanced Nutrition: Less than Body Requirements
Assessment
Verbalizations of loss of appetite / Weight loss / Nausea and vomiting / Diarrhea / Poor muscle tone / Inadequate fluid intake / Decreased subcutaneous fat / Weakness / Vitamin, minerals, and protein deficiencies
Problem
Insufficient nutrients to meet metabolic needs
Nursing Diagnosis
Risk for Electrolyte Imbalance
Assessment
Vomiting / Diarrhea / Diaphoresis / Adverse effects from medications / Osmotic diuresis / Hyponatremia / Hyperkalemia / Hypotension / Bradycardia / Decreased level of consciousness / Poor skin turgor / Hyperthermia
Problem
Risk for seizures, coma, and cognitive impairment
Altered electrical conduction due to electrolyte imbalances
Nursing Diagnosis
Deficient Fluid Volume
Assessment
Dry skin and mucous membranes / Decreased skin turgor / Tachycardia / Hyperthermia / Hypotension / Weak, thready pulse / Decreased urinary output / Weakness / Altered mental state / Hemoconcentration / Excessive gastric losses / Thirst / Nausea and vomiting / Delayed capillary refill / Weight loss / Decreased fluid intake / Sunken eyes / Depressed fontanels
Problem
Risk for hypovolemic shock, cognitive impairment
Renal failure
Risk of circulatory collapse
Nursing Diagnosis
Risk for Constipation
Assessment
Verbalizations of decreased bowel movement / Decreased bowel sounds / Passage of hard-formed or dry stools / Abdominal cramps / Abdominal distention
Problem
Bowel obstruction
Risk for sepsis
Nursing Diagnosis
Risk for Decreased Cardiac Output
Assessment
Tachycardia / Tachypnea / Diminished peripheral pulses / Sudden or orthostatic hypotension / Weakness / Pallor / Oliguria / Altered preload / Cyanosis / Hypoxia / Hyperthermia
Problem
Altered electrical conduction due to electrolyte imbalances
Impaired kidney perfusion or renal failure
Increased cardiac workload leading to heart failure
Nursing Diagnosis
Risk for Ineffective Peripheral Tissue Perfusion
Assessment
Tachycardia / Diminished peripheral pulses / Weak, thready pulse / Decreased capillary refill / Pallor / Postural hypotension / Flattened neck veins / Decreased central venous pressure / Oliguria / Pale, moist, clammy skin / Tingling of extremities
Problem
Reduced venous blood flow
Cardiac dysrhythmias
Increased blood viscosity leads to thrombus formation
Nursing Diagnosis
Risk for Infection
Assessment
Hyperthermia / Chills / Initial elevation of band cells / Poor skin turgor / Dry mucous membranes / Diarrhea / Decreased fluid intake / Diaphoresis / Altered level of consciousness / Hypotension
Problem
Risk for septic shock
Depression of the immune system/suppressed inflammatory response
Susceptibility to hospital-acquired infections
Delayed recovery
Nursing Diagnosis
Risk for Impaired Oral Mucous Membrane Integrity
Assessment
Verbalized decreased oral fluid intake / Verbalization of oral discomfort/pain / Xerostomia (dry mouth) / Decreased, thickened saliva production / Pooling or drooling of saliva
Problem
Risk for dysphagia or impaired swallowing
Oral ulcerations or leukoplakia
Poor dental health
Increased risk for aspiration
Nursing Diagnosis
Risk for Impaired Skin Integrity
Assessment
Reddened or blanched areas / Emaciation or wasting of the muscles / Dry skin / Decreased sensation in affected areas / Itchiness or pruritus / Prolonged bed rest or immobility / Poor skin turgor /
Problem
Risk for pressure injury
Tissue trauma and ischemia
Delayed wound healing
Sepsis
Nursing Diagnosis
Hyperthermia
Assessment
Increase in body temperature / Flushed, warm skin / Tachycardia / Tachypnea / Diaphoresis / Chills / Dry mucous membranes / Decreased urine output or oliguria / Decreased tear production / Vomiting / Diarrhea / Loss of appetite
Problem
Increased metabolic demand
Impaired thermoregulation
Direct cellular death
Multi-organ failure
Nursing Diagnosis
Risk for Ineffective Thermoregulation
Assessment
Increase in temperature / Chills / Tachycardia / Tachypnea / Hypotension / Diaphoresis / Oliguria / Diarrhea / Nausea and vomiting / High cardiac output
Problem
Risk for hyperthermia
Excessive heat loss
Direct cellular damage
Coagulopathy
References
- Dulebohn, S. (2021, August 11). Cystic Fibrosis – StatPearls. NCBI. Retrieved July 6, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK493206/
- Huang, L. H., & Corden, T. E. (2018, December 7). Dehydration: Background, Pathophysiology, Etiology. Medscape Reference. Retrieved July 6, 2022, from https://emedicine.medscape.com/article/906999-overview#a5
- Lopez, N. (2021, August 11). Burn Evaluation And Management – StatPearls. NCBI. Retrieved July 6, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK430741/
- Momodu, I. I., Lee, B., & Singh, G. (2022, May 12). Congenital Adrenal Hyperplasia – StatPearls. NCBI. Retrieved July 6, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK448098/
- Morris, A., & Patel, G. (2022, April 30). Heat Stroke – StatPearls. NCBI. Retrieved July 6, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK537135/
- Taylor, K., & Jones, E. B. (2022, May 15). Adult Dehydration – StatPearls. NCBI. Retrieved July 6, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK555956/
- Walter, E. J., Hanna-Jumma, S., Carraretto, M., & Forni, L. (2016, July 14). The pathophysiological basis and consequences of fever. NCBI. Retrieved July 8, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944485/
