Volume Depletion
- causes and risk factors
- signs, symptoms and diagnosis
- pathophysiology
- treatments
- consequences and course
- the patient
- health care team
- community involvement
- resources and references
Causes and Risk Factors
True volume depletion is caused by decreased effective circulating volume and total ECF volume. The most common causes include:
- gastrointestinal losses: bleeding, vomiting, diarrhea
- renal losses: osmotic or drug-induced diuresis, acute tubular necrosis (recovery phase), diabetes insipidus
- skin and respiratory losses: sweat, burns
- internal sequestration: peritonitis, pancreatitis, rhabdomyolysis
Volume depletion can also occur with decreased effective circulating volume but increased total extracellular fluid volume. Some causes include:
- congestive heart failure
- liver disease
- sepsis
- nephrotic syndrome
- pregnancy
- anaphylaxis
Signs, Symptoms, and Diagnosis
If the cause is extra-renal, urine is highly concentrated, salt poor, and acidic. If the kidneys are involved, urine is inapproporiately dilute but can also be rich in salt.
Clinical manifestations are due to underfilling of the arterial tree and begin with orthostatic hypotension and tachycardia. Recumbent tachycardia soon follows, and urine output diminishes. Severe volume depletion can lead to signs and symptoms of shock, such as mental confusion and cool skin. However, clinical findings may also be absent, such as can occur in people receiving cardiovascular drugs.
Dry mucous membranes, sunken eyes.
Dry axilla is one of the most sensitive (LR 2.8)
Dry mucous membranes not very sensitive, as many people are mouth breathers.
Pathophysiology
Treatments
Quantity and rate of fluid replacement depends on severity of depletion.
Hypodermoclysis: infusion of fluid into sc tissue. Appears as effective IV hydration for mild to moderated hydration. Infuse up to 2L per space, often in back, thighs, or abdomen. Harder for people to pull out. Use gravity or pump at 20-125 mL/hr. Over 24hrs, up to 1.5L can be delivered at one site. Caution if bleeding disorder or skin problems.
Consequences and Course
The Patient
Health Care Team
Community Involvement
References