Chapter 23 Flashcards
- 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. Antidiuretic hormone (ADH)
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.
- 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
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
- 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. Immature kidney functioning
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.
- 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. 1200
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.
- 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. Water depletion
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.
- 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
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.
- 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. Decreased hematocrit
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.
- 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
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.
- 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
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.
- 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. 50 to 90 ml/kg
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.
- 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. Fluid shift from interstitial space to intravascular space
Compensatory mechanisms attempt to maintain fluid volume. Initially, interstitial fluid moves into the
intravascular compartment to maintain blood volume. Aldosterone is released to promote sodium retention and
conserve water in the kidneys. Hemoconcentration results from the fluid volume loss. With less circulating
volume, tachycardia results. Vasoconstriction of peripheral arterioles occurs to help maintain blood pressure.
- Ongoing fluid losses can overwhelm the childs ability to compensate, resulting in shock. What early
clinical sign precedes shock?
a. Tachycardia
b. Slow respirations
c. Warm, flushed skin
d. Decreased blood pressure
ANS: A. Tachycardia
Shock is preceded by tachycardia and signs of poor tissue perfusion and decreased pulse oximetry values. Respirations are increased as the child attempts to compensate. As a result of the poor peripheral circulation,
the child has skin that is cool and mottled with decreased capillary refilling after blanching. In children,
lowered blood pressure is a late sign and may accompany the onset of cardiovascular collapse
- The presence of which pair of factors is a good predictor of a fluid deficit of at least 5% in an infant?
a. Weight loss and decreased heart rate
b. Capillary refill of less than 2 seconds and no tears
c. Increased skin elasticity and sunken anterior fontanel
d. Dry mucous membranes and generally ill appearance
ANS: D. Dry mucous membranes and generally ill appearance
A good predictor of a fluid deficit of at least 5% is any two four factors: capillary refill of more than 2 seconds, absent tears, dry mucous membranes, and ill general appearance. Weight loss is associated with fluid deficit, but the degree needs to be quantified. Heart rate is usually elevated. Skin elasticity is decreased, not increased. The anterior fontanel is depressed.
- The nurse suspects fluid overload in an infant receiving intravenous fluids. What clinical manifestation is
suggestive of water intoxication?
a. Oliguria
b. Weight loss
c. Irritability and seizures
d. Muscle weakness and cardiac dysrhythmias
ANS: C. Irritability and seizures
Irritability, somnolence, headache, vomiting, diarrhea, and generalized seizures are manifestations of water
intoxication. Urinary output is increased as the child attempts to maintain fluid balance. Weight gain is usually
associated with water intoxication. Muscle weakness and cardiac dysrhythmias are not associated with water
intoxication.
- What physiologic state(s) produces the clinical manifestations of nervous system stimulation and
excitement, such as overexcitability, nervousness, and tetany?
a. Metabolic acidosis
b. Respiratory alkalosis
c. Metabolic and respiratory acidosis
d. Metabolic and respiratory alkalosis
ANS: D. Metabolic and respiratory alkalosis
The major symptoms and signs of alkalosis include nervous system stimulation and excitement, including
overexcitability, nervousness, tingling sensations, and tetany that may progress to seizures. Acidosis (both
metabolic and respiratory) has clinical signs of depression of the central nervous system, such as lethargy, diminished mental capacity, delirium, stupor, and coma. Respiratory alkalosis has the same symptoms and
signs as metabolic alkalosis
- What is an approximate method of estimating output for a child who is not toilet trained?
a. Have parents estimate output.
b. Weigh diapers after each void.
c. Place a urine collection device on the child.
d. Have the child sit on a potty chair 30 minutes after eating.
ANS: B. Weigh diapers after each void.
Weighing diapers will provide an estimate of urinary output. Each 1 g of weight is equivalent to 1 ml of urine. Having parents estimate output would be inaccurate. It is difficult to estimate how much fluid is in a diaper. The urine collection device would irritate the childs skin. It would be difficult for a toddler who is not toilet
trained to sit on a potty chair 30 minutes after eating
- The nurse is selecting a site to begin an intravenous infusion on a 2-year-old child. The superficial veins on
his hand and arm are not readily visible. What intervention should increase the visibility of these veins?
a. Gently tap over the site.
b. Apply a cold compress to the site.
c. Raise the extremity above the level of the body.
d. Use a rubber band as a tourniquet for 5 minutes.
ANS: A. Gently tap over the site.
Gently tapping the site can sometimes cause the veins to be more visible. This is done before the skin is
prepared. Warm compresses (not cold) may be useful. The extremity is held in a dependent position. A
tourniquet may be helpful, but if too tight, it could cause the vein to burst when punctured. Five minutes is too
long.
- When caring for a child with an intravenous (IV) infusion, what is an appropriate nursing action?
a. Change the insertion site every 24 hours.
b. Check the insertion site frequently for signs of infiltration.
c. Use a macrodropper to facilitate reaching the prescribed flow rate.
d. Avoid restraining the child to prevent undue emotional stress
ANS: B. Check the insertion site frequently for signs of infiltration.
The nursing responsibility for IV therapy is to calculate the amount to be infused in a given length of time; set
the infusion rate; and monitor the apparatus frequently, at least every 1 to 2 hours, to make certain that the
desired rate is maintained, the integrity of the system remains intact, the site remains intact (free of redness, edema, infiltration, or irritation), and the infusion does not stop. Insertion sites do not need to be changed every
24 hours unless a problem is found with the site. This exposes the child to significant trauma. A minidropper
(60 drops/ml) is the recommended IV tubing in pediatric patients. Intravenous sites should be protected. This
may require soft restraints on the child.
- The nurse determines that a childs intravenous infusion has infiltrated. The infused solution is a vesicant. What is the most appropriate nursing action?
a. Stop the infusion and apply ice.
b. End the infusion and notify the practitioner.
c. Slow the infusion rate and notify the practitioner.
d. Discontinue the infusion and apply warm compresses.
ANS: B. End the infusion and notify the practitioner.
A vesicant causes cellular damage when even minute amounts escape into the tissue. The intravenous infusion
is immediately stopped, the extremity is elevated, the practitioner is notified, and the treatment protocol is
initiated. The applying of heat or ice depends on the fluid that has extravasated. The catheter is left in place
until it is no longer needed.
- Several types of long-term central venous access devices are used. What is a benefit of using an implanted
port (e.g., Port-a-Cath)?
a. You do not need to pierce the skin for access.
b. It is easy to use for self-administered infusions.
c. The patient does not need to limit regular physical activity, including swimming.
d. The catheter cannot dislodge from the port even if the child plays with the port site.
ANS: C. The patient does not need to limit regular physical activity, including swimming.
No limitations on physical activity are needed. The child is able to participate in all regular physical activities,
including bathing, showering, and swimming. The skin over the device is pierced with a Huber needle to
access. Long-term central venous access devices are difficult to use for self-administration. The port is placed