HESI CONCEPT- Acid/Base

Which symptom is caused by respiratory acidosis? a) Headache b) Muscle cramps c) Abdominal pain d) Numbness and tingling of fingers

a) Headache Rationale: Headache is a symptom of respiratory acidosis that occurs because of alveolar hypoventilation, which increases carbonic acid levels in the body. Confusion is a symptom of respiratory alkalosis. Muscle cramps are symptoms of metabolic alkalosis. Abdominal pain is a symptom of metabolic acidosis. Numbness and tingling of fingers, toes, and the circumoral region are found in patients with respiratory alkalosis and metabolic alkalosis.

Which condition is characterized by severe hyperthyroidism, confusion, increased respiratory rate, and a pH of arterial blood gas below 7.35? a) Metabolic acidosis b) Metabolic alkalosis c) Respiratory acidosis d) Respiratory alkalosis

a) Metabolic acidosis Rationale: Hyperthyroidism may cause increased metabolism, leading to an accumulation of metabolic acids. A laboratory finding of an arterial blood gas pH below 7.35 is indicative of metabolic acidosis. The patient may have increased respirations as a compensatory mechanism to clear out the acid and may experience confusion as a result of increased pH. Metabolic alkalosis symptoms include numbness in the fingers and toes. Respiratory acidosis may manifest as confusion, coma, and headache. Respiratory alkalosis manifests as an arterial blood gas pH above 7.45 with physical symptoms of headache, numbness, and excitement.

A patient has been brought to the hospital in an unconscious state. On assessment, the nurse learns that the patient has engaged in binge drinking, and the laboratory reports reveal a high anion gap level. Which condition does the nurse suspect? a) Metabolic acidosis b) Metabolic alkalosis c) Respiratory acidosis d) Respiratory alkalosis

a) Metabolic acidosis Rationale: The patient is at risk of metabolic acidosis because of formation of ketoacids in the blood as a result of excessive alcohol intake. A high anion gap also indicates that the patient has metabolic acidosis. Metabolic alkalosis usually occurs either because of conditions associated with bicarbonate excess or increased excretion of metabolic acids. Respiratory acidosis is seen in conditions associated with alveolar hypoventilation. Respiratory alkalosis occurs as a result of alveolar hyperventilation.

A patient who is comatose is admitted to the hospital with an unknown history. Respirations are deep and rapid. Arterial blood gas levels on admission are pH of 7.20; partial pressure of carbon dioxide (PaCO2) of 21 mm Hg; partial pressure of oxygen (PaO2) of 92 mm Hg; and bicarbonate (HCO3) of 8 mEq/L. Which condition do these laboratory values indicate? a) Metabolic acidosis b) Metabolic alkalosis c) Respiratory acidosis d) Respiratory alkalosis

a) Metabolic acidosis Rationale: The low pH indicates acidosis. The low PaCO, is caused by the hyperventilation, either from primary respiratory alkalosis (not compatible with the measured pH) or as a compensation for metabolic acidosis. The low HCO3 indicates metabolic acidosis or compensation for respiratory alkalosis (again, not compatible with the measured pH). Thus metabolic acidosis is the correct interpretation.

Which statement is correct regarding partial pressure of carbon dioxide (PaCO2)? a) PaCO2 is a measure of how well the lungs are excreting CO2. b) PaCO2 is a measure of how well the kidneys are excreting metabolic acids. c) PaCO2 is a measure of how well gas exchange is occurring in the lungs. d) PaCO2 is the ability of hemoglobin to carry as much O2 as possible.

a) PaCO2 is a measure of how well the lungs are excreting CO2. Rationale: The PaCO2 measures how well the lungs are excreting CO2 produced by the cells during metabolism. A higher than normal PaCO2 level indicates the accumulation of carbon dioxide in the blood. A low PaCO2 indicates excessive excretion of carbon dioxide. Bicarbonate (HCO2) measures how well the kidneys are excreting metabolic acids. Partial pressure of oxygen (PaO2) measures how well gas exchange occurs in the lungs. Oxygen saturation (SaO2) is the percentage of hemoglobin that carries as much O2 as possible.

Which factor increases the risk of metabolic acidosis in an older adult? a) Decreased fluid intake b) Changes in kidney functioning c) Decreased ability to concentrate urine d) Use of multiple medications for chronic diseases

b) Changes in kidney functioning Rationale: A older person undergoes kidney changes that make it more difficult to excrete a large acid load, which increases the risk of metabolic acidosis. Decreased intake of fluid increases the risk of hyponatremia and extracellular volume deficit. Older adults are less able to concentrate urine, increasing the risk of hypernatremia and dehydration. Older adults may use multiple medications for chronic conditions, which can lead to fluid and electrolvte imbalances.

Which condition does the nurse suspect in a patient whose arterial blood pH is 7.50 and who experiences excessive vomiting, excitement, and confusion followed by a decreased level of consciousness? a) Metabolic acidosis b) Metabolic alkalosis c) Respiratory acidosis d) Respiratory alkalosis

b) Metabolic alkalosis Rationale: A patient with metabolic alkalosis has a pH of arterial blood gases above 7.45 as a result of increased bicarbonate levels or a loss of acid, such as what would be seen with excessive vomiting. A laboratory finding of arterial blood gas pH below 7.35 is indicative of metabolic acidosis. Patients with metabolic acidosis exhibit confusion and increased respirations. Respiratory alkalosis can be confirmed with an arterial blood gas pH value above 7.45. Confusion, coma, and headache are indicative of respiratory acidosis. An arterial blood gas pH above 7.45 with physical symptoms of headache, numbness, and excitement are indicative of respiratory alkalosis.

Which arterial blood gas value is abnormal? a) pH 7.35 b) Partial pressure of oxygen (PaO2) 75 mm Hg c) Partial pressure of carbon dioxide (PaCO2) 42 mm Hg d) Oxygen saturation 95.2%

b) Partial pressure of oxygen (PaO2) 75 mm Hg Rationale: The PaO, value of the patient is lower than the normal range of 80 to 100 mm Hg. The pH of 7.35 is in the normal range of 7.35 to 7.45. The PaCO, level of 42 mm Hg is in the normal range of 35 to 45 mm Hg. The oxygen saturation of 95.2% is in the normal range of 95% to 100%.

Which buffer prevents urine from becoming too acidic? a) Protein b) Phosphate c) Bicarbonate d) Hemoglobin

b) Phosphate Rationale: The phosphate buffer provides phosphate ions to ammonium ions to convert the free hydrogen ions into other molecules in the renal tubular fluid, decreasing urine acidity. Protein does not reduce urine acidity. The bicarbonate buffer helps reduce metabolic acidosis or alkalosis. Hemoglobin does not reduce urine acidity.

Which condition may result in excessive metabolic acids in the body of the patient? a) Excess vomiting b) Severe infection c) Bacterial pneumonia d) Psychological distress

b) Severe infection Rationale: Metabolic acid levels increase in a patient who is in a hypermetabolic state, such as severe infection. Metabolic acids decrease with excess vomiting. Respiratory acidosis can occur in patients with bacterial pneumonia. Patients with psychological distress may experience respiratory alkalosis.

A patient has a partial pressure of carbon dioxide (PaCO2) of 30 mm Hg. Which statement is true regarding the meaning of a PaCO, of 30 mm Hg? a) Carbon dioxide (CO2) has accumulated in the blood. b) The PaCO2 is lower than normal. c) The patient is hypoventilating. d) The patient has impaired renal function.

b) The PaCO2 is lower than normal Rationale: PaCO2 is the measure of the partial pressure of CO2 in the blood; it measures how well the lungs are excreting CO2 produced during cellular metabolism. Normal values range from 35 to 45 mm Hg. This patient has a value lower than normal. A high PaCO2 indicates accumulation of CO2 in the blood, caused by hypoventilation. The PaCO2 value denotes lung function; a bicarbonate (HCO3-) value indicates kidney function.

Which finding would the nurse note in the case record for a patient with a pH of 7.3? a) Alkalosis b) Acidosis c) Neutral pH d) Normal pH

b) acidosis Rationale: The normal acceptable range of pH for humans is between 7.35 and 7.45. A pH of less than 7.35 indicates acidosis, which implies that metabolic products acidic in nature are accumulated in the body. A pH of greater than 7.45 indicates alkalosis, which implies that the body has lost hydrogen ions and has accumulated bicarbonate. A pH of 7 is considered a neutral pH; however, it is important to distinguish this from a normal pH. A pH value between 7.35 and 7.45 is considered a normal pH.

Which increased value is a cause of metabolic alkalosis? a) Hydrogen ions in the blood b) Lung excretion of carbonic acid c) Bicarbonate ions in the blood d) Lung excretion of carbon dioxide

c) Bicarbonate ions in the blood Rationale: Metabolic alkalosis results from an increase of base or decrease of metabolic acid, which causes an increase of bicarbonate ions in the blood. Hydrogen ions in the blood increase when the kidneys are unable to excrete metabolic acids. This leads to metabolic acidosis. Increased lung excretion of carbon dioxide or carbonic acid causes respiratory alkalosis.

Which effect is noted in the patient with respiratory acidosis? a) Alveolar hyperventilation b) Excitability of cell membranes c) Excessive carbonic acid in the blood d) Decreased levels of bicarbonate

c) Excessive carbonic acid in the blood Rationale: Respiratory acidosis leads to excessive carbonic acid in the blood caused by the increased partial pressure of carbon dioxide. Alveolar hyperventilation leads to respiratory alkalosis. Respiratory alkalosis increases the excitability of cell membranes and leads to neurological excitement and confusion. Decreased bicarbonate levels in the body lead to metabolic acidosis.

Which symptom may indicate respiratory alkalosis in a patient? a) Muscle cramps b) Abdominal pain c) Increased rate of respirations d) Decreased level of consciousness

c) Increased rate of respirations Rationale: Increased respiration rate is associated with respiratory alkalosis. Muscle cramps may be a manifestation of metabolic alkalosis. Abdominal pain/cramps may be a manifestation of metabolic acidosis. A decreased level of consciousness can occur in a patient with respiratory or metabolic acidosis.

Which acid-base imbalance will the nurse suspect in a patient reporting confusion and sleepiness whose arterial blood gas reports include a pH value of 7.29, partial pressure of carbon dioxide (PaCO2) of 49 mm Hg, and bicarbonate (HCO3) of 30 mEg/L? a) Metabolic acidosis b) Metabolic alkalosis c) Respiratory acidosis d) Respiratory alkalosis

c) Respiratory acidosis Rationale: The laboratory reports of the patient indicate respiratory acidosis since the arterial blood gas reports are 49 mm Hg PaCO2, 30 mEg/L HCO3, and 7.29 pH. Metabolic acidosis will be indicated if the reports show PaCO2 below 35 mm Hg, HCO3- below 22 mEg/L, and the pH value below 7.35. Metabolic alkalosis will be indicated if the reports show PaCO2 above 45 mm Hg, HCO3- above 26 mEg/L, and the pH value above 7.45. Respiratory alkalosis would be indicated if the reports show PaCO2 below 35 mm Hg, HCO3- below 22 mEg/L and pH above 7.45.

Which condition is characterized by metabolic acidosis with a high anion gap? a) Circulatory shock b) Renal tubular acidosis c) Severe hyperthyroidism d) Intestinal decompression

c) Severe hyperthyroidism Rationale: Conditions such as severe hyperthyroidism and severe infection increase normal metabolic acid levels, leading to metabolic acidosis. Circulatory shock may cause metabolic acidosis by increasing lactic acid levels. Renal tubular acidosis and intestinal decompression cause excess output of bicarbonate, which causes metabolic acidosis, but the anion gap remains normal.

which side effect will the nurse assess for in the patient prescribed prednisone? a) hyperkalemia b) metabolic acidosis c) metabolic alkalosis d) hypermagnesemia

c) metabolic alkalosis Rationale: Corticosteroids such as prednisone may cause metabolic alkalosis as a result of decreased levels of metabolic acids. Drugs such as captopril and losartan can cause hyperkalemia. Diuretics such as spironolactone can cause metabolic acidosis because of increased levels of metabolic acids. Magnesium levels can increase in patients taking magnesium hydroxide.

Which patient being cared for by the nurse is at risk of developing respiratory acidosis? a) A patient with hypokalemia b) A patient with pulmonary fibrosis c) A patient with salicylate overdose d) A patient with chronic obstructive pulmonary disease (COPD)

d) A patient with chronic obstructive pulmonary disease (COPD) Rationale: Chronic respiratory acidosis is most commonly caused by COPD. Hypokalemia, pulmonary fibrosis, and salicylate overdose do not predispose a patient to respiratory acidosis. Hypokalemia can lead to cardiac dysrhythmias. Pulmonary fibrosis can result in respiratory arrest, and salicylate overdose results in central nervous system changes.

Which condition can cause metabolic alkalosis? a) Acute pain b) Circulatory shock c) Bacterial pneumonia d) Massive blood transfusion

d) Massive blood transfusion Rationale: Massive blood transfusion can be one cause of metabolic alkalosis. Acute pain is a cause of respiratory alkalosis. Circulatory shock is a cause of metabolic acidosis. Bacterial pneumonia is a cause of respiratory acidosis.

Which acid-base imbalance will the nurse assess for when a health care provider prescribes carbenicillin for a patient with a urinary tract infection? a) Hyperkalemia b) Hypercalcemia c) Metabolic acidosis d) Metabolic alkalosis

d) Metabolic alkalosis Rationale: Because penicillin derivatives cause deficient metabolic acids, a side effect is metabolic alkalosis. ACE inhibitors cause hyperkalemia because of high serum potassium concentration. Calcium carbonate antacids cause hypercalcemia because of high serum calcium concentration. Laxatives can cause metabolic acidosis.

Which condition in the patient can lead to respiratory alkalosis? a) Head injury b) Airway obstruction c) Extensive atelectasis d) Psychological distress

d) Psychological distress Rationale: Psychological distress can lead to respiratory alkalosis. Head injury, airway obstruction, and extensive atelectasis can lead to respiratory acidosis.

Which patient condition is associated with respiratory alkalosis? Select all that apply. One, some, or all responses may be correct. (i) Anxiety (ii) Acute pain (iii) Chronic bronchitis (iv) Long periods of sobbing (v) Bacterial pneumonia

(i), (ii), (iii) Rationale: Respiratory alkalosis is associated with anxiety, acute pain, and prolonged sobbing. Chronic bronchitis, and bacterial pneumonia are associated with respiratory acidosis.

Which finding is typical of hypoventilation? Select all that apply. One, some, or all responses may be correct. (i) Respiratory acidosis (ii) Dysrhythmias (iii) Sighing breaths (iv) Changes in mental status (v) Numbness and tingling of hands

(i), (ii), (iv) Rationale: Hypoventilation causes excessive retention of carbon dioxide, which can lead to respiratory acidosis and respiratory arrest. Signs and symptoms of hypoventilation include mental status changes, dysrhythmias, and potential cardiac arrest. If untreated, the patient's status rapidly declines, leading to convulsions, unconsciousness, and death. Sighing breaths and numbness and tingling of the hands are associated with hyperventilation, not hypoventilation.

Which symptom would the nurse find in a patient whose arterial oxygen (PaO2) is 50 mm Hg and arterial oxygen saturation (SpO2) is 76% during early stages of hypoxia? Select all that apply. One, some, or all responses may be correct. (i) Tachypnea (ii) Cough (iii) Fever (iv) Cyanosis (v) Tachycardia

(i), (iv), (v) Rationale: Hypoxia, an oxygen demand-supply mismatch at the cellular level, is a life-threatening condition. Vital sign changes during early stages of hypoxia include an increased rate and depth of respiration. Tachypnea, or an increased respiratory rate, is the body's compensatory mechanism to increase oxygen levels. Cyanosis, the bluish discoloration of the skin and mucous membranes, is caused by an inadequate oxygen supply. With hypoxia, the heart rate increases to compensate for the low oxygen levels. Cough is a normal defense mechanism of the body and is not associated with hypoxia. Fever is caused by infection, not by hypoxia, but fever can worsen hypoxia if the oxygen demands of the body are increased.

Which physiological condition can be identified as a cause of metabolic acidosis? Select all that apply. One, some, or all responses may be correct. (i) Ketoacidosis (ii) Bacterial pneumonia (iii) Extensive atelectasis (iv) Oliguric renal disease (v) Massive blood transfusion

(i),(iv) Rationale: A patient with ketoacidosis may have increased metabolic acids. Patients with oliguric renal disease may not be able to excrete all the acid from the body, leading to its accumulation and resulting in metabolic acidosis. Bacterial pneumonia and extensive atelectasis lead to impaired gas exchange, leading to respiratory acidosis. A massive blood transfusion increases bicarbonate ions in the body, causing metabolic alkalosis.

Which condition will place a patient at risk of hyperventilation? Select all that apply. One, some, or all responses may be correct. (i) Atelectasis (ii) Acute anxiety (iii) Salicylate poisoning (iv) Diabetic ketoacidosis (v) Cardiac dysrhythmias

(ii), (iii), (iv) Rationale: Acute anxiety leads to hyperventilation and exhalation of excessive amounts of carbon dioxide. Hyperventilation is sometimes chemically induced. For example, salicylate (aspirin) poisoning results in excess carbon dioxide production, stimulating the respiratory center to compensate by increasing the rate and depth of respiration. Patients with diabetes in ketoacidosis produce large amounts of metabolic acids. The respiratory system tries to correct the acid-base balance by overbreathing. A patient who has atelectasis is at risk of hypoventilation, not hyperventilation. A patient who has hypoxia (not hyperventilation) may develop cardiac dysrhythmias.

Which statement is appropriate regarding acid-base balance? Select all that apply. One, some, or all responses may be correct. (i) "The kidneys excrete all acids produced in the patient's body." (ii) "Patients with obstructive lung diseases may have more acid in the blood." (iii) "Patients experience deeper respirations when the carbon dioxide level in the blood rises." (iv) "Patients experience shallow respirations when the carbon dioxide level in the blood rises." (v) "Patients with kidney disease have difficulty excreting metabolic acids."

(ii), (iii), (v) Rationale: Patients with obstructive lung diseases may have more acid in their blood. This can be the result of a difficulty in normal excretion of carbonic acid. When the level of carbon dioxide in the blood rises, the chemoreceptors are triggered quickly. The patient hyperventilates to excrete the excess carbonic acid. The excretion of metabolic acids occurs in the renal tubules of the kidneys. This is one of the major contributing factors for difficulty in normally excreting metabolic acids. The kidneys excrete all acids except carbonic acid. When the carbon dioxide level in the blood rises, the chemoreceptors trigger hyperventilation to facilitate excretion of excess carbonic acid. The patient also experiences shallow respirations in response to decreased levels of carbon dioxide in the blood to enable the cells to produce more carbon dioxide and make up for the deficit.

Which condition will the nurse suspect in a patient whose laboratory report shows metabolic acidosis with a normal anion gap and excessive bicarbonate output from the body? Select all that apply. One, some, or all responses may be correct. (i) Circulatory shock (ii) Pancreatic fistula (iii) Acute kidney injury (iv) Severe hyperthyroidism (v) Intestinal decompression

(ii),(v) Rationale: A patient who has a pancreatic fistula and/or intestinal decompression can have excessive bicarbonate output from the body and metabolic acidosis with a normal anion gap. Circulatory shock can lead to a high anion gap and metabolic acidosis along with increased lactic acid in the body. Acute kidney injury and severe hyperthyroidism will result in excessive metabolic acids with a high anion gap and metabolic acidosis.

Which class of drugs may cause mild metabolic alkalosis? Select all that apply. One, some, or all responses may be correct. (i) Laxatives (ii) Antidepressants (iii) Calcium carbonate antacids (iv) Potassium-wasting diuretics (v) Nonsteroidal antiinflammatory drugs

(iii), (iv) Rationale: Calcium carbonate antacids and potassium-wasting diuretics such as furosemide can cause mild metabolic alkalosis as a side effect. Laxatives can cause metabolic acidosis and hypomagnesemia. Antidepressants such as fluoxetine can cause hyponatremia. Nonsteroidal antiinflammatory drugs such as ibuprofen cause hyponatremia and mild extracellular volume excess.

Which statement indicates a need for further teaching regarding acid-base balance? Select all that apply. One, some, or all responses may be correct. (i) The normal range of pH is 7.35 to 7.45 for arterial blood in adults. (ii) The acid-base balance can be monitored via arterial blood gases. (iii) The higher the H+ ion count in the body, the more alkaline the body is. (iv) The excretion of acids from the body indicates an abnormality in the body. (v) The body maintains a balance between acids and bases for proper cell functioning.

(iii), (iv), (v) Rationale: As the number of Ht ions increases, the blood becomes more acidic, not alkaline. A normal acid-base balance will be maintained in the body when the excretion of acid from the body is equal to the production of acid in the body. A pH of 7.35 to 7.45 is the normal range for the arterial blood of adults. The acid-base balance of the body can be monitored by measuring arterial blood gases. The cells in the body function properly when there is a balance between acids and bases in the body.

What is the minimum recommended daily intake of macrominerals in the body? Record your answer using whole number.

100 mg Rationale: Macrominerals help balance the body's pH. The recommended daily intake of macrominerals is 100 mg.