Page 243 - Saunders Comprehensive Review For NCLEX-RN

overhydration results from excessive
fluid in the extracellular fluid
compartment.
b. Only the extracellular fluid
compartment is expanded, and fluid
does not shift between the extracellular
and intracellular compartments.

c. Isotonic overhydration causes

circulatory overload and interstitial
edema; when severe or when it occurs
in a client with poor cardiac function,
heart failure and pulmonary edema
can result.
2. Hypertonic overhydration
a. The occurrence of hypertonic
overhydration is rare and is caused by
an excessive sodium intake.
b. Fluid is drawn from the intracellular
fluid compartment; the extracellular
fluid volume expands, and the
intracellular fluid volume contracts.
3. Hypotonic overhydration
a. Hypotonic overhydration is known as
water intoxication.
b. The excessive fluid moves into the
intracellular space, and all body fluid
compartments expand.

c. Electrolyte imbalances occur as a

result of dilution.

C. Causes

1. Isotonic overhydration
a. Inadequately controlled IV therapy
b. Kidney disease
c. Long-term corticosteroid therapy
2. Hypertonic overhydration
a. Excessive sodium ingestion
b. Rapid infusion of hypertonic saline
c. Excessive sodium bicarbonate therapy
3. Hypotonic overhydration
a. Early kidney disease
b. Heart failure
c. Syndrome of inappropriate antidiuretic
hormone secretion
d. Inadequately controlled IV therapy

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