Module 1 Chapter 12: Assessment and Care of Patients with Acid-Base Imbalances

A client is admitted with chronic anemia. What physiologic imbalance does the nurse suspect the client is at risk of developing? 1 Acidosis 2 Ineffective ventilation 3 Hypokalemia 4 Alkalosis

1 Acidosis Protein buffers, especially hemoglobin buffers, are the primary buffer of hydrogen ions. When clients are anemic, there is less hemoglobin to buffer hydrogen ions and a reduced ability for the body to prevent acidosis. There is no information that suggests the client is at risk for ineffective ventilation, hypokalemia, or alkalosis.

The lab values for a client admitted for an exacerbation of chronic obstructive pulmonary disease (COPD) reveal a pH of 7.29 with a decreased Pao2 and an elevated Paco2. Which initial treatment does the nurse expect the provider to most likely order? 1 Bronchodilator therapy 2 Intravenous fluids t3 High-flow oxygen 4 Sodium bicarbonate

1 Bronchodilator therapy This client has signs of respiratory acidosis, so the first intervention is to improve ventilation. To accomplish this, bronchodilators are often used. Oxygen may be used, but should be given cautiously to clients with COPD who may rely on hypoxia and not hypercarbia as a stimulus to breathe. Low-flow oxygen would be more appropriate. Intravenous fluids and sodium bicarbonate are used to treat metabolic acidosis.

A new nurse graduate is caring for a postoperative client with the following arterial blood gases (ABGs): pH, 7.30; Paco2, 60 mm Hg; Pao2, 80 mm Hg; bicarbonate, 24 mEq/L; and O2 saturation, 96%. Which of these actions by the new graduate is indicated? 1 Encourage the client to use the incentive spirometer and cough. 2 Administer oxygen by nasal cannula. 3 Request a prescription for sodium bicarbonate from the health care provider. 4 Inform the charge nurse that no changes in therapy are needed.

1 Encourage the client to use the incentive spirometer and cough. Respiratory acidosis is caused by CO2 retention and impaired chest expansion secondary to anesthesia. The nurse takes steps to promote CO2 elimination, including maintaining a patent airway and expanding the lungs through breathing techniques. O2 is not indicated because Pao2 and oxygen saturation are within the normal range. Sodium bicarbonate is not indicated because the bicarbonate level is in the normal range; promoting excretion of respiratory acids is the priority in respiratory acidosis. Postanesthesia, the client will need interventions related to promoting CO2 elimination or the client may progress to a state of somnolence and unresponsiveness.

A client is admitted with severe diabetic ketoacidosis. Arterial blood gas results reveal a pH of 7.21. What is this client's acidosis most likely in response to? 1 Excessive breakdown of fatty acids 2 Anaerobic metabolism 3 Excessive intake of alcoholic beverages 4 Excessive intake of insulin

1 Excessive breakdown of fatty acids Metabolic acidosis can result from the overproduction of hydrogen ions, underelimination of hydrogen ions, or insufficient bicarbonate ions. Excessive breakdown of fatty acids that occurs with diabetic ketoacidosis or starvation results in overproduction of hydrogen ions and metabolic acidosis. Anaerobic metabolism produces lactic acid as a cause of metabolic acidosis. Excessive intake of alcoholic beverages will also cause metabolic acidosis because of the high concentration of hydrogen ions in alcohol. Excessive intake of insulin will not result in diabetic ketoacidosis. Test-Taking Tip: Read carefully and answer the question asked; pay attention to specific details in the question.

The nurse is caring for a critically ill client with septic shock. The serum lactate level is 6.2. For which acid-base disturbance should the nurse assess? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis

1 Metabolic acidosis Increased lactate levels are associated with hypoxia and metabolic acidosis secondary to anaerobic metabolism. Metabolic alkalosis is related to bicarbonate therapy, diuretic use, vomiting, and nasogastric suction. Respiratory acidosis is caused by CO2 retention and impaired pulmonary function, which is inconsistent with elevated lactate levels. Respiratory alkalosis is caused by excessive loss of CO2 through hyperventilation, inconsistent with elevated lactate levels.

An older client is admitted with pneumonia. What changes in the client does the nurse expect to assess when obtaining data about the client's acid-base imbalance? Select all that apply. 1 New-onset mental status changes 2 Dry mucous membranes 3 Dark, concentrated urine 4 Clear, straw-colored urine 5 Generalized edema 6 Thready peripheral pulses

1 New-onset mental status changes 2 Dry mucous membranes 3 Dark, concentrated urine 6 Thready peripheral pulses Clients at increased risk of acidosis are older adults and those with impaired breathing. The nurse should assess for changes in mental status, pulse quality and rate, and signs of dehydration. Clear, straw-colored urine suggests the client is not conserving urine in response to dehydration. Generalized edema is not associated with dehydration.

The laboratory reports of a client show the client has metabolic alkalosis. What conditions may result in metabolic alkalosis? Select all that apply. 1 Prolonged vomiting 2 Prolonged diarrhea 3 Nasogastric suctioning 4 Blood transfusion 5 Starvation 6 Total parenteral nutrition

1 Prolonged vomiting 3 Nasogastric suctioning 4 Blood transfusion 6 Total parenteral nutrition Prolonged vomiting and nasogastric suctioning can lead to acid deficits causing metabolic alkalosis. Blood transfusion and total parenteral nutrition increase the base components by parenteral base administration. Therefore, they also cause metabolic alkalosis. Prolonged diarrhea can cause overelimination of bicarbonate ions resulting in metabolic acidosis. Starvation leads to excessive oxidation of fatty acids leading to overproduction of hydrogen ions and metabolic acidosis.

Which conditions and/or symptoms may be most likely responsible for this acid-base imbalance: pH 7.32, Pao2 82 mm Hg, Paco2 50 mm Hg, HCO3- 18 mEq/L? Select all that apply. 1 Respiratory rate of 8 breaths/min 2 Prolonged vomiting 3 Oliguria 4 Dehydration 5 Anxiety 6 Constipation

1 Respiratory rate of 8 breaths/min 3 Oliguria 4 Dehydration The acid-base imbalance is a combined respiratory (Paco2 50 mm Hg) and metabolic acidosis (HCO3- 18 mEq/L). Conditions that may cause a combined acidosis are a decreased respiratory rate, kidney dysfunction (oliguria), and dehydration (dry mucous membranes). Prolonged vomiting and anxiety would result in an alkalosis imbalance. Constipation would not cause an acid-base imbalance; however, diarrhea would place the client at risk for acidosis.

Which assessment finding requires priority nursing intervention in a client with metabolic or respiratory acidosis? 1 Lethargy and confusion 2 Bradycardia with widened QRS complex 3 Rapid respiratory rate 4 Dry skin

2 Bradycardia with widened QRS complex Cardiovascular manifestations that require priority nursing interventions are related to delayed electrical conduction; specifically bradycardia that may progress to heart block, tall T waves, widened QRS complex, and prolonged PR interval. Other changes like lethargy, confusion, rapid respiratory rate, and dry skin are important to address, but may not require priority interventions.

The nurse is caring for a client who has taken a large quantity of furosemide (Lasix) to promote weight loss. The nurse anticipates the finding of which acid-base imbalance? 1 Pao2 of 78 mm Hg 2 HCO3- of 34 mEq/L 3 Paco2 of 56 mm Hg 4 pH of 7.31

2 HCO3- of 34 mEq/L Diuretics (non-potassium-sparing), evidenced by a finding of HCO3- of 34 mEq/L, cause metabolic alkalosis. A Pao2 of 78 mm Hg demonstrates mild hypoxemia consistent with respiratory disorders, not with diuretic use. CO2 retention results from hypoventilation, which is not consistent with diuretic use. A pH of 7.31 is acidotic; diuretics promote metabolic alkalosis.

A client admitted with diabetic ketoacidosis was treated for metabolic acidosis with IV fluids and insulin. Which electrolyte imbalance does the nurse monitor for as the acid-base imbalance resolves? 1 Hyponatremia 2 Hypokalemia 3 Hyperkalemia 4 Hypernatremia

2 Hypokalemia In acidosis, extracellular hydrogen ions move into the cell and potassium moves out, causing hyperkalemia. In diabetic ketoacidosis, by treating the elevated serum glucose with insulin and IV fluids, the acid-base imbalance resolves. As the acidosis resolves, the hydrogen ions move out of the cell, and potassium moves back into the cell, causing hypokalemia in the plasma. Sodium levels are not affected by diabetic ketoacidosis.

When evaluating the laboratory results of a client with diabetic ketoacidosis, which lab value indicates the body has fully compensated from this acid-base imbalance? 1 Normal serum glucose 2 Normal pH on arterial blood gases 3 Normal serum potassium 4 Normal bicarbonate on arterial blood gases

2 Normal pH on arterial blood gases Arterial blood gas pH returns to normal when the body's compensatory efforts are fully effective. Glucose, potassium, and bicarbonate are affected by diabetic acidosis, but their return to normal is not an indicator of acid-base balance.

A client with diabetes mellitus is brought to the emergency department after vomiting for several days. The client has rapid, deep respirations and a urine dipstick reveals ketonuria. Which process does the nurse suspect is occurring with this client? 1 Kidney compensation for metabolic acidosis 2 Respiratory compensation for metabolic acidosis 3 Kidney compensation for metabolic alkalosis 4 Respiratory compensation for metabolic alkalosi

2 Respiratory compensation for metabolic acidosis Clients with diabetes mellitus can develop metabolic acidosis. Respiratory compensation occurs through the lungs as the rate and depth of respirations increase in order to reduce hydrogen ion levels. Kidney compensation is not occurring.

A client has chronic respiratory acidosis. Which nursing assessments are appropriate for this client? Select all that apply. 1 Checking respiratory status once per shift. 2 Assessing the color of nail beds. 3 Assessing for cyanosis of mucous membranes. 4 Checking for the use of accessory muscles. 5 Listening for crackles at lung bases.

2 Assessing the color of nail beds. 3 Assessing for cyanosis of mucous membranes. 4 Checking for the use of accessory muscle For a client with chronic respiratory acidosis, the nurse should assess the color of nail beds and mucous membranes, and assess for the use of accessory muscles when breathing. Assessment of breathing status should be done at least every 2 hours, and lung sounds should be assessed for grunting or wheezing.

Which conditions place a client at risk for developing metabolic alkalosis? Select all that apply. 1 Hypovolemic shock 2 Blood transfusion 3 Total parenteral nutrition 4 Diarrhea 5 Nasogastric suctioning 6 Fever

2 Blood transfusion 3 Total parenteral nutrition 5 Nasogastric suctioning Conditions placing a client at risk for metabolic alkalosis result from an overproduction or underelimination of base. Blood transfusion, administration of total parenteral nutrition, and nasogastric suctioning increase a client's risk for metabolic alkalosis. Hypovolemic shock will result in respiratory alkalosis. Diarrhea and fever will cause metabolic acidosis.

A client has been poisoned by botulinum toxins. What assessment findings suggest the client has acidosis? Select all that apply. 1 Hypertension 2 Confusion 3 Hyperreflexia 4 Warm, flushed, dry skin 5 Pounding peripheral pulse

2 Confusion 4 Warm, flushed, dry skin If the client is confused and has a warm, flushed, and dry skin, it may indicate the client has acidosis. Acidosis decreases the ability of excitable tissues in the blood vessels to respond adequately. So, there is vasodilation leading to hypotension rather than hypertension. Decrease in the ability of the excitable tissues in the muscles to respond adequately to stimulus, and the hyperkalemia associated with acidosis reduce the muscle tone. This leads to hyporeflexia rather than hyperreflexia. Mild acidosis may increase the heart rate, but as the acidosis worsens and there is hyperkalemia, the heart rate decreases making the peripheral pulse hard to find. Therefore, the peripheral pulse is thready rather than pounding.

A client is recovering from an acute episode of chronic obstructive pulmonary disease (COPD). Which nursing action is the greatest priority in the plan of care? 1 Raise the head of the bed 60 degrees. 2 Administer oxygen at 4 L/min per nasal cannula. 3 Monitor the respiratory rate and effort hourly. 4 Assess orientation status every 4 hours.

3 Monitor the respiratory rate and effort hourly. It is most important to monitor respiratory status in the client with respiratory acidosis. Use caution in giving oxygen to clients who have COPD. Raising the head of the bed will improve respiratory expansion, but 60 degrees is excessive. Assessing the client's orientation status is not as great a priority as respiratory status. Test-Taking Tip: Pace yourself during the testing period and work as accurately as possible. Do not be pressured into finishing early. Do not rush! Students who achieve higher scores on examinations are typically those who use their time judiciously.

Which acid-base imbalance does the nurse anticipate the client with morbid obesity may develop? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis

3 Respiratory acidosis Respiratory acidosis is related to CO2 retention secondary to respiratory depression, inadequate chest expansion, airway obstruction, or reduced alveolar-capillary diffusion. Respiratory acidosis is common in morbidly obese clients who experience inadequate chest expansion owing to their size and work of breathing. Metabolic acidosis is related to overproduction of hydrogen ions, underelimination of hydrogen ions, underproduction of bicarbonate ions, and overelimination of bicarbonate ions. Metabolic alkalosis is related to loss of bicarbonate or buffers (i.e., vomiting or nasogastric suction). Respiratory alkalosis usually is caused by excessive loss of CO2 through hyperventilation secondary to fever, central nervous system lesions, and salicylates.

What is taking place in the body when hyperventilation occurs? 1 The brain is responding to a rise in lactate. 2 The respiratory system is responding to an increased pH. 3 The central nervous system is responding to a rise in carbon dioxide. 4 The brain and lungs are responding to an increased level of bicarbonate.

3 The central nervous system is responding to a rise in carbon dioxide. When the amount of carbon dioxide in the brain, blood, and tissues rise, the central nervous system responds by increasing the rate and depth of breathing (hyperventilation). Test-Taking Tip: Attempt to select the answer that is most complete and includes the other answers within it. For example, a stem might read, "A child's intelligence is influenced by:" and three options might be genetic inheritance, environmental factors, and past experiences. The fourth option might be multiple factors, which is a more inclusive choice and therefore the correct answer.

The nurse is caring for a client with metabolic alkalosis. What manifestations of metabolic alkalosis is the nurse likely to assess? Select all that apply. 1 Increase in handgrip strength 2 Decrease in heart rate 3 Hyperactivity of deep tendon reflexes 4 Numbness around the mouth 5 Presence of Kussmaul respiration

3 Hyperactivity of deep tendon reflexes 4 Numbness around the mouth Hypocalcemia occurs with alkalosis, which can cause hyperactivity of deep tendon reflexes. Alkalosis overexcites the nervous system leading to tingling or numbness around the mouth. Overstimulation of the nerves may cause contraction of skeletal muscles, but the contractions are weaker because of hypokalemia. Therefore, there is a decrease in handgrip strength. Alkalosis increases myocardial irritability and increases the heart rate. Kussmaul respiration (deep and rapid involuntary breathing) is seen in metabolic acidosis with respiratory compensation.

The nurse is assessing the laboratory reports of a client with impaired kidney function. What changes indicate the client has metabolic acidosis? 1 Increase in arterial blood pH 2 Decrease in partial pressure of arterial oxygen 3 Increase in partial pressure of arterial carbon dioxide 4 Decrease in serum bicarbonate level

4 Decrease in serum bicarbonate level In metabolic acidosis, the bicarbonate level is low.

Which electrolyte abnormality does the nurse anticipate when reviewing laboratory data for a client admitted with metabolic acidosis? 1 Hyponatremia 2 Hypernatremia 3 Hypokalemia 4 Hyperkalemia

4 Hyperkalemia Serum potassium (hyperkalemia) occurs during metabolic acidosis as the body attempts to maintain pH by moving potassium ions from the cell in exchange with hydrogen ions moving into the cell. Hypokalemia may occur as the cause of the metabolic acidosis is corrected. Sodium concentrations (hypernatremia and hyponatremia) are not affected in the buffering process of acid-base balance.

Deep and rapid breaths consistent with Kussmaul respirations are found in clients with which type of acid-base imbalance? 1 Respiratory alkalosis 2 Respiratory acidosis 3 Metabolic alkalosis 4 Metabolic acidosis

4 Metabolic acidosis In metabolic acidosis, the rate and depth of breathing increase as the hydrogen ion levels rise. The breathing pattern becomes deep and rapid and not under voluntary control. This type of breathing is known as Kussmaul respiration, which is not present in respiratory alkalosis, respiratory acidosis, or metabolic alkalosis.

After a motor vehicle crash, the nurse is consoling a client in the emergency department who is hysterical and hyperventilating after being notified of the death of a family member. What acid-base imbalance is this client likely to develop? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis

4 Respiratory alkalosis Hyperventilation leads to excessive loss of CO2 and respiratory alkalosis. The client will not develop respiratory acidosis, which is caused by hypoventilation, nor will the client develop metabolic alkalosis or acidosis.