EXAM # 5
RNSG 2201
CH. 23, 24, 25, 26
Chapter 23: The Child with Fluid and Electrolyte Imbalance
MULTIPLE CHOICE
1. What substance is released from the posterior pituitary gland and promotes
water retention in the renal system?
a. Renin
b. Aldosterone
c. Angiotensin
d. Antidiuretic hormone (ADH)
ANS: D ADH is released in response to increased osmolality and decreased volume of
intravascular fluid; it promotes water retention in the renal system by increasing the
permeability of renal tubules to water. Renin release is stimulated by diminished
blood flow to the kidneys. Aldosterone is secreted by the adrenal cortex. It enhances
sodium reabsorption in renal tubules, promoting osmotic reabsorption of water. Renin
reacts with a plasma globulin to generate angiotensin, which is a powerful
vasoconstrictor. Angiotensin also stimulates the release of aldosterone.
2. Nurses should be alert for increased fluid requirements in which
circumstance?
a. Fever
b. Mechanical ventilation
c. Congestive heart failure
d. Increased intracranial pressure
ANS: A Fever leads to great insensible fluid loss in young children because of
increased body surface area relative to fluid volume. The mechanically ventilated
child has decreased fluid requirements. Congestive heart failure is a case of fluid
overload in children. Increased intracranial pressure does not lead to increased fluid
requirements in children.
,3. What factor predisposes an infant to fluid imbalances?
a. Decreased surface area
b. Lower metabolic rate
c. Immature kidney functioning
d. Decreased daily exchange of extracellular fluid
ANS: C The infants kidneys are functionally immature at birth and are inefficient in
excreting waste products of metabolism. Infants have a relatively high body surface
area (BSA) compared with adults. This allows a higher loss of fluid to the
environment. A higher metabolic rate is present as a result of the higher BSA in
relation to active metabolic tissue. The higher metabolic rate increases heat
production, which results in greater insensible water loss. Infants have a greater
exchange of extracellular fluid, leaving them with a reduced fluid reserve in
conditions of dehydration.
4. What is the required number of milliliters of fluid needed per day for a 14-kg
child?
a. 800
b. 1000
c. 1200
d. 1400
ANS: C For the first 10 kg of body weight, a child requires 100 ml/kg. For each
additional kilogram of body weight, an extra 50 ml is needed.
10 kg 100 ml/kg/day = 1000 ml
4 kg 50 ml/kg/day = 200 ml
1000 ml + 200 ml = 1200 ml/day
Eight hundred to 1000 ml is too little; 1400 ml is too much.
5. An infant is brought to the emergency department with the following clinical
manifestations: poor skin turgor, weight loss, lethargy, tachycardia, and
tachypnea. This is suggestive of which situation?
a. Water excess
b. Sodium excess
c. Water depletion
d. Potassium excess
,ANS: C
These clinical manifestations indicate water depletion or dehydration. Edema and
weight gain occur with water excess or overhydration. Sodium or potassium excess
would not cause these symptoms.
6. Clinical manifestations of sodium excess (hypernatremia) include which signs
or symptoms?
a. Hyperreflexia
b. Abdominal cramps
c. Cardiac dysrhythmias
d. Dry, sticky mucous membranes
ANS: D Dry, sticky mucous membranes are associated with hypernatremia.
Hyperreflexia is associated with hyperkalemia. Abdominal cramps, weakness,
dizziness, nausea, and apprehension are associated hyponatremia. Cardiac
dysrhythmias are associated with hypokalemia.
7. What laboratory finding should the nurse expect in a child with an excess of
water?
a. Decreased hematocrit
b. High serum osmolality
c. High urine specific gravity
d. Increased blood urea nitrogen
ANS: A The excess water in the circulatory system results in hemodilution. The
laboratory results show a falsely decreased hematocrit. Laboratory analysis of blood
that is hemodiluted reveals decreased serum osmolality and blood urea nitrogen. The
urine specific gravity is variable relative to the childs ability to correct the fluid
imbalance.
8. What clinical manifestation(s) is associated with calcium depletion
(hypocalcemia)?
a. Nausea, vomiting
b. Weakness, fatigue
c. Muscle hypotonicity
d. Neuromuscular irritability
, ANS: D Neuromuscular irritability is a clinical manifestation of hypocalcemia. Nausea
and vomiting occur with hypercalcemia and hypernatremia. Weakness, fatigue, and
muscle hypotonicity are clinical manifestations of hypercalcemia.
9. What type of dehydration occurs when the electrolyte deficit exceeds the water
deficit?
a. Isotonic dehydration
b. Hypotonic dehydration
c. Hypertonic dehydration
d. Hyperosmotic dehydration
ANS: B Hypotonic dehydration occurs when the electrolyte deficit exceeds the water
deficit, leaving the serum hypotonic. Isotonic dehydration occurs in conditions in
which electrolyte and water deficits are present in balanced proportion. Hypertonic
dehydration results from water loss in excess of electrolyte loss. This is the most
dangerous type of dehydration. It is caused by feeding children fluids with high
amounts of solute. Hyperosmotic dehydration is another term for hypertonic
dehydration.
10. What amount of fluid loss occurs with moderate dehydration?
a. <50 ml/kg
b. 50 to 90 ml/kg
c. <5% total body weight
d. >15% total body weight
ANS: B Moderate dehydration is defined as a fluid loss of between 50 and 90 ml/kg.
Mild dehydration is defined as a fluid loss of less than 50 ml/kg. Weight loss up to 5%
is considered mild dehydration. Weight loss over 15% is severe dehydration.
11. Physiologically, the child compensates for fluid volume losses by which
mechanism?
a. Inhibition of aldosterone secretion
b. Hemoconcentration to reduce cardiac workload
c. Fluid shift from interstitial space to intravascular space
d. Vasodilation of peripheral arterioles to increase perfusion
ANS: C Compensatory mechanisms attempt to maintain fluid volume. Initially,
interstitial fluid moves into the intravascular compartment to maintain blood volume.
RNSG 2201
CH. 23, 24, 25, 26
Chapter 23: The Child with Fluid and Electrolyte Imbalance
MULTIPLE CHOICE
1. What substance is released from the posterior pituitary gland and promotes
water retention in the renal system?
a. Renin
b. Aldosterone
c. Angiotensin
d. Antidiuretic hormone (ADH)
ANS: D ADH is released in response to increased osmolality and decreased volume of
intravascular fluid; it promotes water retention in the renal system by increasing the
permeability of renal tubules to water. Renin release is stimulated by diminished
blood flow to the kidneys. Aldosterone is secreted by the adrenal cortex. It enhances
sodium reabsorption in renal tubules, promoting osmotic reabsorption of water. Renin
reacts with a plasma globulin to generate angiotensin, which is a powerful
vasoconstrictor. Angiotensin also stimulates the release of aldosterone.
2. Nurses should be alert for increased fluid requirements in which
circumstance?
a. Fever
b. Mechanical ventilation
c. Congestive heart failure
d. Increased intracranial pressure
ANS: A Fever leads to great insensible fluid loss in young children because of
increased body surface area relative to fluid volume. The mechanically ventilated
child has decreased fluid requirements. Congestive heart failure is a case of fluid
overload in children. Increased intracranial pressure does not lead to increased fluid
requirements in children.
,3. What factor predisposes an infant to fluid imbalances?
a. Decreased surface area
b. Lower metabolic rate
c. Immature kidney functioning
d. Decreased daily exchange of extracellular fluid
ANS: C The infants kidneys are functionally immature at birth and are inefficient in
excreting waste products of metabolism. Infants have a relatively high body surface
area (BSA) compared with adults. This allows a higher loss of fluid to the
environment. A higher metabolic rate is present as a result of the higher BSA in
relation to active metabolic tissue. The higher metabolic rate increases heat
production, which results in greater insensible water loss. Infants have a greater
exchange of extracellular fluid, leaving them with a reduced fluid reserve in
conditions of dehydration.
4. What is the required number of milliliters of fluid needed per day for a 14-kg
child?
a. 800
b. 1000
c. 1200
d. 1400
ANS: C For the first 10 kg of body weight, a child requires 100 ml/kg. For each
additional kilogram of body weight, an extra 50 ml is needed.
10 kg 100 ml/kg/day = 1000 ml
4 kg 50 ml/kg/day = 200 ml
1000 ml + 200 ml = 1200 ml/day
Eight hundred to 1000 ml is too little; 1400 ml is too much.
5. An infant is brought to the emergency department with the following clinical
manifestations: poor skin turgor, weight loss, lethargy, tachycardia, and
tachypnea. This is suggestive of which situation?
a. Water excess
b. Sodium excess
c. Water depletion
d. Potassium excess
,ANS: C
These clinical manifestations indicate water depletion or dehydration. Edema and
weight gain occur with water excess or overhydration. Sodium or potassium excess
would not cause these symptoms.
6. Clinical manifestations of sodium excess (hypernatremia) include which signs
or symptoms?
a. Hyperreflexia
b. Abdominal cramps
c. Cardiac dysrhythmias
d. Dry, sticky mucous membranes
ANS: D Dry, sticky mucous membranes are associated with hypernatremia.
Hyperreflexia is associated with hyperkalemia. Abdominal cramps, weakness,
dizziness, nausea, and apprehension are associated hyponatremia. Cardiac
dysrhythmias are associated with hypokalemia.
7. What laboratory finding should the nurse expect in a child with an excess of
water?
a. Decreased hematocrit
b. High serum osmolality
c. High urine specific gravity
d. Increased blood urea nitrogen
ANS: A The excess water in the circulatory system results in hemodilution. The
laboratory results show a falsely decreased hematocrit. Laboratory analysis of blood
that is hemodiluted reveals decreased serum osmolality and blood urea nitrogen. The
urine specific gravity is variable relative to the childs ability to correct the fluid
imbalance.
8. What clinical manifestation(s) is associated with calcium depletion
(hypocalcemia)?
a. Nausea, vomiting
b. Weakness, fatigue
c. Muscle hypotonicity
d. Neuromuscular irritability
, ANS: D Neuromuscular irritability is a clinical manifestation of hypocalcemia. Nausea
and vomiting occur with hypercalcemia and hypernatremia. Weakness, fatigue, and
muscle hypotonicity are clinical manifestations of hypercalcemia.
9. What type of dehydration occurs when the electrolyte deficit exceeds the water
deficit?
a. Isotonic dehydration
b. Hypotonic dehydration
c. Hypertonic dehydration
d. Hyperosmotic dehydration
ANS: B Hypotonic dehydration occurs when the electrolyte deficit exceeds the water
deficit, leaving the serum hypotonic. Isotonic dehydration occurs in conditions in
which electrolyte and water deficits are present in balanced proportion. Hypertonic
dehydration results from water loss in excess of electrolyte loss. This is the most
dangerous type of dehydration. It is caused by feeding children fluids with high
amounts of solute. Hyperosmotic dehydration is another term for hypertonic
dehydration.
10. What amount of fluid loss occurs with moderate dehydration?
a. <50 ml/kg
b. 50 to 90 ml/kg
c. <5% total body weight
d. >15% total body weight
ANS: B Moderate dehydration is defined as a fluid loss of between 50 and 90 ml/kg.
Mild dehydration is defined as a fluid loss of less than 50 ml/kg. Weight loss up to 5%
is considered mild dehydration. Weight loss over 15% is severe dehydration.
11. Physiologically, the child compensates for fluid volume losses by which
mechanism?
a. Inhibition of aldosterone secretion
b. Hemoconcentration to reduce cardiac workload
c. Fluid shift from interstitial space to intravascular space
d. Vasodilation of peripheral arterioles to increase perfusion
ANS: C Compensatory mechanisms attempt to maintain fluid volume. Initially,
interstitial fluid moves into the intravascular compartment to maintain blood volume.
