Practice Questions: Chapter 8 Fluid Imbalance
The nurse who is providing care for several clients recognizes which client is at the highest risk for developing an acid-base imbalance?
A client who is being treated for acute kidney injury and who requires dialysis Explanation: Because of the key role that the kidneys play in the maintenance of acid-base balance, individuals with kidney disease are vulnerable to acid-base disorders. Anaphylaxis, syphilis, and fistulas do not present particular risks for acid-base imbalances. Page 174
The nurse is caring for a client who has excessive diarrhea. Which acid-base disturbance does the nurse anticipate will result from having excessive diarrhea?
Metabolic acidosis Explanation: The client who has diarrhea has increased loss of bicarbonate from the intestinal tract, which results in metabolic acidosis. The pH value would be decreased, and the bicarbonate would be decreased. Page 180
The renal control mechanism of restoring the acid-base balance is accomplished through which process?
Reabsorption of HCO3 and excretion of H+ restores acid-base balance through the renal control mechanisms. Explanation: Reabsorption of HCO3 and excretion of H+ restores acid-base balance through the renal control mechanisms. Respiratory control mechanisms of restoring acid-base balance are done via regulation of production of carbonic acid and stimulation of the chemoreceptors in the brain. Page 175
A client who has just completed running a marathon reports muscle weakness, cramping, and general fatigue despite drinking adequate amounts of water. The nurse suspects which type of hypotonic hyponatremia?
hypovolemic Explanation: Hypovolemic hypotonic hyponatremia develops when both water and sodium have been lost (as in sweating) but only water, rather than electrolyte-containing liquids, is used to replace fluids lost. This may also be caused by gastrointestinal sodium loss caused by frequent irrigation with distilled water as well as by adrenal insufficiency. Hypervolemic hyponatremia is caused when excess water is retained compared to sodium, resulting in a dilutional hyponatremia. Because the intravascular sodium is low, there is less osmotic pressure, and the water often ends up moving into the interstitial spaces due to osmosis resulting in edema or ascites. This is why it is termed hypervolemic even if the intravascular volume is low. The terms "euvolemic" and "normovolemic" are synonymous and occur when hyponatremia is present in a client with a normal total body water balance. Page 151
The nurse is teaching an older adult about adapting to age-related physiologic changes. Which statement by the client prompts the nurse to provide additional teaching?
"I will reduce my total daily fluid intake." Explanation: Older adults are at greater risk for dehydration because of reduced capacity to concentrate urine and a blunted sense of thirst in combination with a lower composition of total body water. Therefore, the nurse will correct the client's belief that reduced fluids should be taken. The nurse must first confirm the client is not prescribed a fluid restriction for a condition such as left-sided heart failure. Skin becomes dryer with aging, so moisturizer is helpful. Visual adaptation between light and dark is slower, so well-lit rooms reduce risk of injury. Arteries become less flexible, reducing vascular accommodation when changing positions. Therefore, older adults should change position more slowly to allow the body to adapt. Making these three statements is evidence of accurate understanding. Page 148-149
A client is admitted to the emergency department with possible internal bleeding after being involved in an automobile accident. What type of isotonic intravenous (IV) solution does the nurse prepare to infuse?
0.9% NaCl Explanation: Cells placed in an isotonic solution, which has the same effective osmolality as the ICF, neither shrink nor swell. An example of an isotonic solution is 0.9% NaCl. Page 139
In which client would the nurse be most likely to assess the signs and symptoms of an acid-base imbalance?
A client with chronic obstructive pulmonary disease (COPD) whose most recent arterial blood gases reveal a PCO2 of 51 mm Hg Explanation: An elevated PCO2 is commonly associated with respiratory acidosis because excess CO2 ultimately increases the concentration of H+ ions. Increased intracranial pressure, oxytocin infusion, and the administration of hypotonic fluids are not directly linked to common alterations in acid-base balance. Page 174
In which client would the nurse be most likely to assess the signs and symptoms of an acid-base imbalance?
A client with chronic obstructive pulmonary disease (COPD) whose most recent arterial blood gases reveal a PCO2 of 51 mm Hg Explanation: An elevated PCO2 is commonly associated with respiratory acidosis because excess CO2 ultimately increases the concentration of H+ ions. Increased intracranial pressure, oxytocin infusion, and the administration of hypotonic fluids are not directly linked to common alterations in acid-base balance. Page 174
The nurse is caring for a client with an acid-base imbalance. Which of these does the nurse recognize is correct regarding compensation?
A pH moves toward the normal range. Explanation: The client who is compensating for an acid-base imbalance will have a pH that has moved back into the normal range. The other blood gas values will most likely all be out of range. Page 175
The nurse is caring for a client who has developed hypoxemia and tissue hypoxia. Which of these interventions does the nurse set as a priority intervention?
Administration of supplemental oxygen Explanation: Hypoxia and hypoxemia may be corrected by administration of supplemental oxygen. People with hyperventilation may benefit from reassurance, rebreathing from a paper bag during symptomatic attacks, and attention to the psychological stress. The other options are not appropriate for the treatment of hypoxia. Page 181
Which assessment should be prioritized in the care of a client who is being treated for a serum potassium level of 2.7 mEq/L (2.7 mmol/L)?
Cardiac monitoring looking for prolonged PR interval and flattening of the T wave Explanation: The most serious effects of hypokalemia are on the heart, a fact that necessitates frequent electrocardiography or cardiac telemetry. Hypokalemia produces a decrease in the resting membrane potential, causing prolongation of the PR interval. It also prolongs the rate of ventricular repolarization, causing depression of the ST segment, flattening of the T wave, and appearance of a prominent U wave. This supersedes the importance of fluid balance monitoring, arterial blood gases, oxygen saturation, or hemoglobin levels. Page 155
Which of the following is an anion?
Chloride Explanation: The ions found in body fluids carry one charge (i.e., monovalent ion) or two charges (i.e., divalent ion). Negatively charged ions are called anions. Chlorine is a negatively charged ion, or anion. Page 137
Which of the following is an anion?
Chloride Explanation: The ions found in body fluids carry one charge (i.e., monovalent ion) or two charges (i.e., divalent ion). Negatively charged ions are called anions. Chlorine is a negatively charged ion, or anion. Page 137
The nurse notes a client has a low potassium level. Which data would the nurse collect to help determine the cause of the client's hypokalemia? Select all that apply.
Current plasma magnesium levels Evidence of gastrointestinal losses Evidence of increased aldosterone levels The nurse would examine the client for evidence of gastrointestinal losses through vomiting or diarrhea, as this can lead to excessive losses of potassium. The nurse would also examine the client's magnesium levels as low magnesium causes renal potassium wasting and magnesium deficiency often coexists with potassium depletion. Potassium is also lost via urine output, and the degree of this loss is influenced by aldosterone levels which can be increased due to stress response or the use of corticosteroid medications, leading to hypokalemia. Although potassium imbalances can cause alterations in cardiac conduction, electrocardiogram findings will not offer any information related to the cause of hypokalemia. If a client were to have decreased urine output (oliguria or anuria), this would elevate potassium levels rather than lead to hypokalemia
The nurse is caring for a client who receives hemodialysis. The nurse knows that hemodialysis involves movement of charged or uncharged particles along a concentration gradient. Which function best describes this process?
Diffusion Explanation: Diffusion is movement of charged or uncharged particles along a concentration gradient. Osmosis is the movement of water across a semipermeable membrane. Page 137
A client is admitted to the intensive care unit for cardiogenic shock. In the hours since admission, the client's arterial blood gases indicate acidosis, most likely acute lactic acidosis. Which clinical manifestations and diagnostic findings might his care team anticipate before acid--base balance is restored?
Dysrhythmias Explanation: As with any form of acidosis, pH is apt to be lower than normal. Metabolic acidosis is also associated with dysrhythmias, decreased alertness, and nausea and vomiting. Respiration is likely to be increased in both rate and depth. Page 154
The nurse is aware that the major role of the kidneys in regulating acid-base balance is to increase the production of which chemical component?
HCO3- Explanation: The kidneys play a critical role in maintaining acid-base balance. They accomplish this through the reabsorption of HCO3-, regulation of H+ secretion, and generation of new HCO3-. The hydrogen/bicarbonate exchange system regulates pH through the secretion of excess H+ and reabsorption of HCO3- by the renal tubules. Bicarbonate is freely filtered in the glomerulus and reabsorbed or reclaimed in the tubules. Each HCO3- that is reclaimed requires the secretion of an H+. H2CO3 is a weak acid. HCl is found in gastric fluid. The kidneys would eliminate, not increase, production of H ion. Page 171
The nurse is caring for a client with ketoacidosis who is complaining of increasing lethargy and occasional confusion following several weeks of rigid adherence to a carbohydrate-free diet. The nurse understands which phenomenon is most likely occurring?
In the absence of carbohydrate energy sources, her body is metabolizing fat and releasing ketoacids. Explanation: Low carbohydrate diets can induce the fat metabolism and consequent metabolic acidosis that is more commonly associated with diabetic ketoacidosis. The acidotic state is not classified as respiratory in nature, and does not involve a buffer role for carbohydrates or insulin deficiency. Page 181
The nurse is evaluating a client's blood gases. The client has a pH of 7.35. How does the nurse interpret this value?
It is within a normal range. Explanation: The normal body range of pH is 7.35 to 7.45. The other answers are incorrect. An acidotic value would be indicated by a pH less than 7.35 and an alkalotic level would be indicated by a pH greater than 7.45. Page 171
A child accidentally consumes a container of wood alcohol. The ED physician knows that the child is at risk of developing which of the following?
Metabolic acidosis Explanation: Ingestion of methanol (wood alcohol) results in the production of metabolic acids and causes metabolic acidosis. Page 179
The nurse is caring for a client with worsening respiratory acidosis. Which of these interventions does the nurse anticipate if the client's condition continues to deteriorate?
Mechanical ventilation Explanation: The treatment of acute and chronic respiratory acidosis is directed toward improving ventilation. In severe cases, mechanical ventilation may be necessary. The remaining options would not effectively treat respiratory acidosis. Page 185
Water movement from the side of the membrane having a lesser number of particles and greater concentration of water to the side having a greater number of particles and lesser concentration of water is termed:
Osmosis Explanation: Osmosis is the force that moves water from the side of the membrane having a lesser number of particles and greater concentration of water to the side having a greater number of particles and lesser concentration of water. Active transport is the movement of ions against an electrical or chemical gradient. Diffusion is the process by which particles in solution move from an area of higher concentration to lower, resulting in equal distribution. Filtration is the process of passing a liquid through a filter that is accomplished by gravity, vacuum, or pressure. Page 138
Pressure generated as water moves across a membrane is also known as which of the following?
Osmotic pressure Explanation: Osmosis is the movement of water across a semipermeable membrane. As with particles, water diffuses down its concentration gradient, moving from the side of the membrane with the lesser number of particles and greater concentration of water to the side with the greater number of particles and lesser concentration of water. As water moves across the semipermeable membrane, it generates a pressure called osmotic pressure. Page 138
What is the nurse's expectation about a client's ability to compensate for a metabolic blood gas disorder?
The client will compensate with the respiratory system. Explanation: The one thing that a nurse can expect is that a client with a metabolic disorder will compensate with the respiratory system. The client cannot compensate with the same system. The nurse cannot expect the client's breathing to slow down as in some cases it will increase, depending on the primary disorder. Page 178
Of the following clients, who would be at highest risk for developing hyperkalemia?
client admitted for acute kidney injury following a drug overdose Explanation: There are three main causes of hyperkalemia: (1) decreased renal elimination; (2) a shift in potassium from the intracellular fluid to extracellular fluid compartment; and (3) excessively rapid rate of administration. The most common cause of serum potassium excess is decreased kidney function. Stroke does not typically have a direct influence on potassium levels, whereas vomiting and diarrhea can precipitate hypokalemia. Loss of the parathyroid influences calcium, not potassium, levels. Page 158