Chapter 42 Agents Affecting the Volume and Ion Content of Body Fluids

Chapter 42: Agents Affecting the Volume and Ion Content of Body Fluids 1. A patient who is a chronic alcoholic is admitted to the hospital. Admission laboratory work reveals a magnesium level of 1.2 mEq/L. The prescriber orders intravenous magnesium sulfate in a 10% solution at a rate of 10 mL/min. What will the nurse do? a. Administer the IV dose as ordered and have calcium gluconate on hand. b. Administer the IV dose and make preparations for mechanical ventilation. c. Hold the IV dose until the infusion rate has been clarified with the provider. d. Request an order for renal function tests before administering the IV dose. ANS: C This patient has hypomagnesemia and should be given magnesium sulfate intravenously. The percent of magnesium in solution is correct; however, magnesium should not be infused faster than 1.5 mL/min, so the nurse is correct to question the rate of infusion. Calcium gluconate should be available when magnesium is given, but the nurse needs to clarify the rate of infusion first. Mechanical ventilation is necessary with excessive magnesium. Renal function tests are not indicated. PTS: 1 DIF: Cognitive Level: Application REF: p. 462 TOP: Nursing Process: Diagnosis MSC: NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential 2. A patient who was injured at home is brought to the emergency department. The nurse caring for this patient notes a respiratory rate of 32 breaths per minute and a heart rate of 90 beats per minute. The injuries are minor, but the patient is inconsolable and hysterical. The nurse expects that initial management will include: a. administering a gas mixture of 5% carbon dioxide (CO2). b. providing 100% oxygen via nasal cannula. c. giving sodium bicarbonate IV. d. providing sedatives to calm the patient. ANS: A The patient is at risk for respiratory alkalosis as a result of hyperventilation, and giving the patient a gas mixture containing CO2 will help correct the alkalosis. Administering oxygen would worsen the problem. Sodium bicarbonate is given to correct metabolic acidosis. Sedatives may be necessary if initial measures fail. PTS: 1 DIF: Cognitive Level: Application REF: p. 460 TOP: Nursing Process: Planning MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 3. A child who ingested a handful of aspirin tablets from a medicine cabinet at home is brought to the emergency department. The nurse caring for the child notes a respiratory rate of 48 breaths per minute. The nurse understands that this child’s respiratory rate is the result of the body’s attempt to compensate for: a. metabolic acidosis. b. metabolic alkalosis. c. respiratory acidosis. d. respiratory alkalosis. ANS: A Metabolic acidosis can result from the ingestion of aspirin. The body responds by hyperventilating to reduce CO2, which represents volatile carbonic acid, and raise pH. This child has a rapid respiratory rate in response to metabolic acidosis. In patients with metabolic alkalosis, the body responds with hypoventilation in an effort to increase the CO2 level. Patients with respiratory acidosis usually have retention of CO2 secondary to hypoventilation, and compensation is the result of retention of bicarbonate by the kidneys, which is a slow process. Respiratory alkalosis is caused by hyperventilation; treatment involves having the patient rebreathe CO2 or administering sedatives. PTS: 1 DIF: Cognitive Level: Application REF: pp. 460-461 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 4. A patient with congestive heart failure is admitted to the hospital. During the admission assessment, the nurse learns that the patient is taking a thiazide diuretic. The nurse notes that the admission electrolyte levels include a sodium level of 142 mEq/L, a chloride level of 95 mEq/L, and a potassium level of 3 mEq/L. The prescriber has ordered digoxin to be given immediately. What will the nurse do initially? a. Give the digoxin and maintain close cardiac monitoring. b. Hold the digoxin and report the laboratory values to the provider. c. Hold the thiazide diuretic and give the digoxin. d. Request an order for an electrocardiogram (ECG). ANS: B Potassium depletion is common with thiazide diuretics, and hypokalemia is especially dangerous for patients receiving digoxin, because the drug can precipitate a fatal dysrhythmia and digoxin toxicity. The provider should be notified of the serum potassium level so that it can be corrected before the digoxin is administered. Giving the digoxin could produce a fatal adverse effect, so this is not an appropriate course of action. Holding the thiazide diuretic will not correct the potassium deficiency. An ECG is not the initial priority. PTS: 1 DIF: Cognitive Level: Application REF: p. 461 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential 5. A patient collapses after running a marathon on a hot day and is brought to the emergency department to be treated for dehydration. The nurse will expect to provide which therapy? a. Intravenous hypertonic fluids given slowly over several hours b. Intravenous hypotonic fluids administered in stages c. Intravenous isotonic fluids given as a rapid bolus d. Oral electrolyte replacement fluids with potassium ANS: B Because this patient is experiencing fluid volume loss as the result of excessive sweating, this is most likely hypertonic dehydration, in which loss of water exceeds loss of electrolytes. This should be treated with a hypotonic solution or with fluids that contain no solutes at all. Initial treatment may consist of having the patient drink water. When intravenous therapy is provided, volume replenishment should occur in stages. Hypertonic fluids are used to treat hypotonic contraction, usually caused by excessive sodium loss through the kidneys as the result of diuretic therapy. Isotonic fluids are used to treat isotonic contraction, which is generally caused by vomiting and diarrhea. An oral electrolyte solution would only increase the hypertonicity; if oral rehydration is used in this case, the patient should drink plain water. PTS: 1 DIF: Cognitive Level: Application REF: pp. 459-460 TOP: Nursing Process: Planning MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies 6. A nurse is caring for a child whose respirations are shallow and marked by a prolonged expiratory phase. The nurse auscultates wheezes and poor air movement bilaterally. The child’s respiratory rate is 26 breaths per minute, and the oxygen saturation is 89%. What does the nurse suspect? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: C Respiratory acidosis results from retention of CO2 secondary to hypoventilation caused either by depression of the medullary respiratory center in the central nervous system (CNS) or by a pathologic lung condition, such as asthma. This child has shallow respirations with evidence of airway obstruction and poor ventilation. Metabolic acidosis occurs in chronic renal failure, loss of bicarbonate with severe diarrhea, metabolic disorders, and ingestion of acids such as salicylates; hyperventilation is a compensatory mechanism. Metabolic alkalosis is usually caused by excessive loss of gastric acid or by ingestion of alkalinizing salts; hypoventilation is a compensatory mechanism. Respiratory alkalosis is produced by hyperventilation and can occur in any condition that increases the respiratory rate and depth. PTS: 1 DIF: Cognitive Level: Application REF: pp. 460-461 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Physiologic Adaptation 7. A nurse is caring for a postoperative patient who has a nasogastric tube with continuous suction. The nurse notes that the patient has shallow respirations and suspects that this patient has developed: a. metabolic acidosis. b. metabolic alkalosis. c. respiratory acidosis. d. respiratory alkalosis. ANS: B Metabolic alkalosis occurs with excessive loss of acid, such as gastric acid, or an excessive increase in alkalinizing salts. The body compensates for metabolic alkalosis by hypoventilating in an attempt to retain CO2. Metabolic acidosis is usually caused by ingestion of acids or excessive loss of bicarbonate and is compensated by hyperventilation. Respiratory acidosis results from hypoventilation. Respiratory alkalosis is the result of hyperventilation. PTS: 1 DIF: Cognitive Level: Application REF: pp. 460-461 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Physiologic Adaptation 8. While performing an admission assessment on a patient, the nurse learns that the patient is taking furosemide [Lasix], digoxin, and spironolactone [Aldactone]. A diet history reveals the use of salt substitutes. The patient is confused and dyspneic and complains of hand and foot tingling. Which is an appropriate nursing action for this patient? a. Contact the provider to request orders for an electrocardiogram and serum electrolyte levels. b. Evaluate the patient’s urine output and request an order for intravenous potassium. c. Hold the next dose of furosemide and request an order for intravenous magnesium sulfate. d. Request an order for intravenous insulin to help this patient regulate extracellular potassium. ANS: A This patient is taking a potassium-sparing diuretic and is ingesting dietary potassium in salt substitutes. The patient shows signs of hyperkalemia: confusion, shortness of breath, and tingling of the hands and feet. The cardiac effects can be fatal, especially if a patient also is taking digoxin. The most appropriate first action would be to obtain an ECG and serum electrolyte levels to evaluate the extent of the patient’s hyperkalemia. The patient does not need increased potassium. Furosemide is a potassium-wasting diuretic and would be helpful. Magnesium sulfate is not indicated. Until the patient’s status has been assessed further, intravenous insulin is not indicated. PTS: 1 DIF: Cognitive Level: Application REF: p. 462 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential 9. A patient arrives in the emergency department complaining of muscle weakness and drowsiness. The nurse notes a heart rate of 80 beats per minute, a respiratory rate of 18 breaths per minute, and a blood pressure of 90/50 mm Hg. The electrocardiogram reveals an abnormal rhythm. The nurse will question the patient about which over-the-counter medication? a. Antacids b. Aspirin c. Laxatives d. Potassium supplements ANS: A Hypermagnesemia can occur when patients are taking magnesium-containing antacids. Symptoms include muscle weakness, sedation, hypotension, and ECG changes. Aspirin would cause metabolic acidosis. Laxatives can contribute to hypokalemia. Potassium supplements would cause hyperkalemia. PTS: 1 DIF: Cognitive Level: Application REF: p. 463 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential 10. A patient arrives in the emergency department after becoming dehydrated. Based on the patient’s history, the provider determines that isotonic dehydration has occurred. Which solution will the nurse expect to infuse to treat this patient? a. 0.45% sodium chloride in sterile water b. 0.9% sodium chloride in sterile water c. 3% sodium chloride in sterile water d. 5% dextrose solution ANS: B Isotonic dehydration should be treated with an isotonic solution of 0.9% NaCl in sterile water. A 0.45% solution or 5% dextrose is used to treat hypertonic dehydration. A 3% NaCl solution is used to treat hypotonic dehydration. PTS: 1 DIF: Cognitive Level: Application REF: p. 459 TOP: Nursing Process: Implementation MSC: NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies MULTIPLE RESPONSE 1. A patient is admitted to the hospital after several days of vomiting and diarrhea. After an initial bolus of isotonic (0.9%) sodium chloride solution, the prescriber orders dextrose 5% in normal saline (D5NS) with 20 mEq potassium chloride to infuse at a maintenance rate. What should the nurse review before implementing this order? (Select all that apply.) a. Electrocardiogram b. Arterial blood gas levels c. Serum electrolyte levels d. Serum glucose level e. Urine output ANS: A, C, E Patients receiving potassium should be monitored for cardiovascular toxicity; an ECG before and during administration can help monitor for this adverse effect. Serum electrolyte levels should be reviewed to make sure the patient is not already hyperkalemic. Because potassium is excreted via the kidneys, it is important to determine that renal function is intact. Intravenous potassium should never be given if the patient has not voided. Patients who are hyperkalemic can be treated with sodium bicarbonate to increase pH and insulin to promote uptake of potassium by cells, but it is not necessary to evaluate the blood gas or glucose levels before administering potassium. PTS: 1 DIF: Cognitive Level: Application REF: pp. 461-462 TOP: Nursing Process: Assessment MSC: NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential 2. Which order for potassium (KCl) would the nurse question? (Select all that apply.) a. NS with 20 mEq KCl to start after patient voids b. NS with 60 mEq KCl for a patient with a serum potassium of 3.2 mEq/L c. K-Dur, 1 tablet daily for a patient in diabetic ketoacidosis d. K-Dur, 1 tablet with a full glass of water e. Potassium chloride, 10 mEq rapid IV push ANS: B, C, E Patients receiving potassium should not receive potassium in solution diluted at more than 40 mEq/L. Diabetic ketoacidosis causes decreased cellular uptake of potassium, and patients in whom acidosis is present should also receive sodium bicarbonate if they need potassium. IV potassium should not be infused faster than 10 mEq/hr. NS with 20 mEq KCl is an appropriate solution for a patient with intact renal function. Oral potassium should be given with a full glass of water to minimize gastrointestinal (GI) effects. PTS: 1 DIF: Cognitive Level: Application REF: pp. 461-462 TOP: Nursing Process: Planning MSC: NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential