EAQ ABGs
Which statement would the intensive care nurse use to address the family's concern about the patient's respiratory acidosis? 1 "This disease is treated with mechanical ventilation to ensure oxygenation of tissues." 2 "This disease is treated with medications such as bicarbonate because the kidneys are injured." 3 "Respiratory acidosis is not something to worry about within the overall treatment regimen." 4 "Respiratory acidosis is not a disease but a symptom of a larger disease process we will treat separately."
Correct answer "Respiratory acidosis is not a disease but a symptom of a larger disease process we will treat separately." Rationale: An acid-base imbalance like respiratory acidosis is not a disease but a symptom of an underlying health problem that must be treated to correct the imbalance. Medications such as sodium bicarbonate may be used to treat acidosis in critically ill patients; however, the acidosis is related to respirations, not kidney injury. Also, the acidosis is not a disease, but a symptom. Mechanical ventilation may assist in correcting the respiratory components of acid-base imbalances, but acidosis is a symptom of respiratory dysfunction (in this case), not a disease. Respiratory acidosis is a potentially deadly imbalance that warrants monitoring and treatment to prevent further complications.
An emergency department patient presents with lethargy and confusion, and arterial blood gases reflect metabolic acidosis. The family reports a history of "heart problems" and voices concern about the acidosis affecting the heart. Which response would the nurse use to address the family's concern? 1 "Acidosis may affect the patient's blood pressure but not the heart's electrical pathways." 2 "Acidosis is often temporary and never life-threatening; this situation is nothing to worry about." 3 "Metabolic acidosis is a symptom of an underlying disorder for which we will evaluate and treat during this admission." 4 "Uncompensated acidosis can cause hypotension and cardiac dysrhythmias; we will monitor and work to prevent these complications."
Correct answer "Uncompensated acidosis can cause hypotension and cardiac dysrhythmias; we will monitor and work to prevent these complications." Rationale: Uncompensated and untreated acidosis of any type can prove life-threatening because of its untoward downstream effects on the cardiac system in the form of hypotension and dysrhythmias. The nurse should assure the family that the medical team will monitor for and work to prevent these complications. Metabolic acidosis is a symptom of an underlying disease that must be treated; however, profound acidosis must be monitored and treated as well. Acidosis can in fact be life-threatening. Changes in blood pressure have a direct effect on the heart and the circulatory systems, both of which are affected in untreated and uncompensated acidosis.
In which order does neutralization of an acidic state in the body occur?
Correct answer 1. There is a drop in pH with an increase of hydrochloric acid 2. Bicarbonate is released. 3. Water and carbon dioxide are formed 4. The lungs excrete the waste products. Rationale: A drop in pH from an increase of hydrochloric acid places the body in acidosis. The body reacts by releasing a strong base in the form of bicarbonate. The bicarbonate joins with the hydrochloric acid, resulting in the formation of water and carbon dioxide. The lungs excrete the water and carbon dioxide through breathing.
The nurse determines that a patient's multilumen central venous access device (CAVD) is missing one of the injection caps, and the patient is exhibiting clinical manifestations of respiratory distress, hypotension, and tachycardia. Which action would the nurse implement first? 1 Administer oxygen via nasal cannula. 2 Notify the health care provider. 3 Reposition patient to left side, head down. 4 Adjust the IV fluids via the CAVD.
Correct answer Administer oxygen via nasal cannula. Rationale: The cap off the central line could potentially allow entry of air into the circulation. For an air embolus from any source, the priority is to administer oxygen. Next, clamp the CAVD catheter and position the patient on the left side with the head down. Then the health care provider is notified. IV fluid is not needed in this scenario and could worsen the patient's respiratory status. However, use of the CAVD and rate adjustments depend on provider orders.
A patient with diabetes mellitus presents to the emergency room with a blood sugar of 400 mg/dL. Which type of acid-base imbalance would the nurse monitor for the clinical manifestations? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer Metabolic acidosis Rationale: Diabetic ketoacidosis can occur in cases of uncontrolled hyperglycemia. This condition leads to acid accumulation, which causes metabolic acidosis. Respiratory acidosis is typically associated with chronic pulmonary diseases, such as chronic obstructive pulmonary disease. Respiratory alkalosis occurs in cases of hyperventilation; this condition leads to a decreased amount of acid in the blood and an elevated pH. Metabolic alkalosis occurs with the loss of acid and causes an elevated (alkalotic) pH.
After review of the morning laboratory reports, the nurse calculated a patient's anion gap because an arterial blood gas (ABG) was not available. Which acid-base imbalance would the nurse associate with an increased anion gap? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer Metabolic acidosis Rationale: The anion gap = Na+ - (HCO3- + Cl-). The anion gap helps to determine the source of the acidosis when metabolic acidosis is present. The anion gap increases with metabolic acidosis due to increases in the concentration of acid (lactic acidosis, diabetic ketoacidosis), but the anion gap is normal when the metabolic acidosis is caused by the loss of bicarbonate (diarrhea). Metabolic alkalosis, respiratory acidosis, and respiratory alkalosis do not increase the anion gap.
The patient's arterial blood gas (ABG) values are pH 7.30, PaCO2 35 mm Hg, and bicarbonate (HCO3-) 16 mEq/L. Which interpretation would the nurse use when updating the patient's plan of care? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer Metabolic acidosis Rationale: Use the memory device ROME. For respiratory conditions, the pH and the PaCO2 go in opposite directions. Respiratory alkalosis: pH high and PaCO2 is low. Respiratory acidosis: pH is low and the PaCO2 is high. In metabolic conditions, the pH and HCO3- go in the same direction (equal). The PaCO2 may also go in the same direction. Metabolic alkalosis: pH and HCO3- are high. Metabolic acidosis: pH and HCO3- are high.Normal ABG values fall in the range of pH 7.35 to 7.45, PaCO2 35 to 45 mm Hg, and HCO3- 22 to 26 mEq/L. Bicarbonate and pH values are less than the normal values (same direction) and indicate metabolic acidosis. A pH value less than 7.35 and a high PaCO2 (opposite direction) indicates respiratory acidosis.
A hospitalized patient reports abdominal pain, nausea, and vomiting. Suspecting a bowel obstruction, for which primary acid-base imbalance would the nurse plan the patient's care, if the obstruction is high in the intestinal tract? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Mixed alkalosis
Correct answer Metabolic alkalosis Rationale: Because gastric secretions are rich in hydrochloric acid, the patient who is vomiting will lose a significant amount of gastric acid and be at an increased risk for metabolic alkalosis. Metabolic acidosis is more likely with diarrhea than vomiting. Respiratory acidosis is associated with the lungs, not the gastrointestinal system. Mixed alkalosis may occur when a patient is hyperventilating because of pain and has a nasogastric (NG) tube to suction; each system is losing acid. The patient has metabolic alkalosis.
For the patient who sought medical treatment after vomiting for three days, which acid-base imbalance would the nurse determine the patient is at risk of developing? Metabolic acidosis Metabolic alkalosis Respiratory acidosis Respiratory alkalosis
Correct answer Metabolic alkalosis Rationale: Metabolic alkalosis can occur with prolonged vomiting secondary to the loss of strong gastric acids. Respiratory acidosis is caused by hypercarbia of respiratory origin. Metabolic acidosis is an increase in acid levels related to a metabolic dysfunction such as lactic acidosis, starvation, or diarrhea. Respiratory alkalosis occurs with hypocarbia related to hyperventilation.
When receiving long-term mineralocorticoid therapy, for which patient condition would the nurse evaluate associated clinical manifestations? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer Metabolic alkalosis Rationale: Mineralocorticoids are used to maintain salt and water balance. Excessive use of mineralocorticoids may cause loss of strong acids, resulting in metabolic alkalosis. Metabolic acidosis is caused by conditions that increase the acid concentration in the body, such as diabetic ketoacidosis. Respiratory acidosis occurs as a result of hypoventilation. Respiratory alkalosis occurs because of hyperventilation.
A patient's arterial blood gas (ABG) report was pH 7.48, PaCO2 38, and HCO3- 30. For which acid-base imbalance would the nurse plan the patient's care? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer Metabolic alkalosis Rationale: Use the memory device ROME. For respiratory conditions, the pH and the PaCO2 go in opposite directions. Respiratory alkalosis: pH high and PaCO2 is low. Respiratory acidosis: pH is low and the PaCO2 is high. In metabolic conditions, the pH and HCO3- go in the same direction (equal). The PaCO2 may also go in the same direction. Metabolic alkalosis: pH and HCO3- are high. Metabolic acidosis: pH and HCO3- are high.Normal pH is 7.35 to 7.45. Values greater than 7.45 indicate alkalosis. Normal value for HCO3- is 22 to 26 mEq/L. Because the PaCO2 is normal and the HCO3- is elevated, the source of the alkalosis is metabolic. The patient is in metabolic alkalosis.
A patient who is three days post abdominal surgery continues to have green bilious nasogastric (NG) tube output, respiratory rate of 32, and heart rate of 128. Abdominal and surgical site pain are poorly controlled. For which acid-base imbalance would the nurse modify nursing interventions? 1 Mixed acidosis 2 Mixed alkalosis 3 Metabolic alkalosis 4 Respiratory acidosis
Correct answer Mixed alkalosis Rationale: Mixed alkalosis can occur in a patient who is losing CO2 via hyperventilation (possibly related to pain), while also losing acid by another method, such as prolonged suctioning with a nasogastric tube. Respiratory acidosis occurs when the primary loss of acid is via a respiratory "blow off" of CO2. Metabolic alkalosis occurs with a systemic loss of acid via a metabolic process, such as vomiting or suctioning with a nasogastric tube. Mixed acidosis occurs when acid is retained by both respiratory and metabolic systems, such as a critically ill patient in shock with hypoperfusion and hypoventilation, which will often cause a more profoundly acidotic serum pH than either condition could independently create.
A patient with chronic obstructive pulmonary disease (COPD) has arterial blood gas (ABG) results of pH 7.33, PaO2 47 mm Hg, PaCO2 60 mm Hg, HCO3 32 mEq/L, and O2 saturation of 92%. Which interpretation of the data would the nurse report to the primary care provider? 1 Fully compensated respiratory alkalosis 2 Partially compensated respiratory acidosis 3 Normal acid-base balance with hypoxemia 4 Normal acid-base balance with hypercapnia
Correct answer Partially compensated respiratory acidosis Rationale: Use the memory device ROME. For respiratory conditions, the pH and the PaCO2 go in opposite directions. Respiratory alkalosis: pH high and PaCO2 is low. Respiratory acidosis: pH is low and the PaCO2 is high. In metabolic conditions, the pH and HCO3- go in the same direction (equal). The PaCO2 may also go in the same direction. Metabolic alkalosis: pH and HCO3- are high. Metabolic acidosis: pH and HCO3- are high.A low pH (normal 7.35 to 7.45) indicates acidosis. In the patient with a respiratory disease such as COPD, the patient retains carbon dioxide (normal 35 to 45 mm Hg), which acts as an acid in the body. For this reason, the patient has respiratory acidosis. The "other value" assists in compensation: the elevated HCO3 indicates a partial compensation for the elevated PaCO2 because the pH remains abnormal.
A patient, with chronic kidney disease, reports eating many nuts, bananas, peanut butter, and chocolate. The nurse's assessment indicates loss of deep tendon reflexes, somnolence, and altered respiratory status. Which treatment option would the nurse associate with these clinical findings? 1 Renal dialysis 2 IV furosemide (Lasix) 3 IV potassium chloride 4 IV normal saline at 250 mL per hour
Correct answer Renal dialysis Rationale: The patient will need renal dialysis to remove the excess serum magnesium from the increased intake of foods high in magnesium since renal function is not adequate. If renal function were adequate, IV potassium chloride would oppose the effects of magnesium on the cardiac muscle. IV furosemide and increased fluid would increase urinary output, which is the major route of excretion for magnesium.
The arterial blood gas (ABG) results for a patient who overdosed on barbiturates are pH 7.32, PaCO2 52, and HCO3- 23. Which interpretation would the nurse use when planning the patient's care? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer Respiratory acidosis Rationale: Use the memory device ROME. For respiratory conditions, the pH and the PaCO2 go in opposite directions. Respiratory alkalosis: pH high and PaCO2 is low. Respiratory acidosis: pH is low and the PaCO2 is high. In metabolic conditions, the pH and HCO3- go in the same direction (equal). The PaCO2 may also go in the same direction. Metabolic alkalosis: pH and HCO3- are high. Metabolic acidosis: pH and HCO3- are high.Normal pH is 7.35 to 7.45. pH values < 7.35 indicates acidosis. Normal value for PaCO2 is 35 to 45 mm Hg. Because the HCO3- is low normal and the PaCO2 is elevated (opposite direction of pH), the source of the acidosis is respiratory. The patient is in respiratory acidosis. Kidneys are attempting compensation because the other value (HCO3- is low normal) and pH remains < 7.35.
For which patient disorder would the nurse closely monitor clinical manifestations associated with respiratory acidosis? 1 Protracted vomiting 2 Pulmonary embolism 3 Severe pneumonia 4 Recovery from diabetic ketoacidosis
Correct answer Severe pneumonia Rationale: Pneumonia is an inflammatory condition causing hypoventilation, which results in increased concentration of serum carbon dioxide and precipitates respiratory acidosis. Severe vomiting may cause loss of strong acids from the body, resulting in metabolic alkalosis. A pulmonary embolism causes hyperventilation, resulting in respiratory alkalosis. Diabetic ketoacidosis causes accumulation of ketone bodies in the body, resulting in metabolic acidosis; however, this patient has recovered and would not present with current clinical manifestations of respiratory acidosis.
Which rationale would the nurse use to explain events occurring when the respiratory center, located in the medulla, senses an increased concentration of carbon dioxide (CO2) or H+? 1 The respiratory center stimulates hyperventilation to get rid of CO2. 2 The respiratory center stimulates a decreased rate of breathing to retain CO2. 3 The respiratory center stimulates an increased depth of breathing to retain H+. 4 The respiratory center stimulates a decreased depth of breathing to get rid of H+.
Correct answer The respiratory center stimulates hyperventilation to get rid of CO2. Rationale: Increased CO2 or H+ signals acidosis, which triggers the respiratory center to hyperventilate and get rid of CO2 to balance the pH. CO2 retention occurs to correct alkalosis. A decreased depth of breathing occurs in respiratory dysfunction. An increased depth of breathing occurs in hyperventilation; in this case, the body will expel CO2 to decrease H+.
For which clinical manifestation would the nurse monitor closely in the patient experiencing respiratory acidosis from chronic obstructive respiratory disease (COPD)? 1 Diarrhea 2 Confusion 3 Abdominal pain 4 Ventricular fibrillation
Correct answer Ventricular fibrillation Rationale: COPD complications may cause respiratory acidosis from hypoventilation and the buildup of carbon dioxide. Respiratory acidosis causes a compensatory hyperkalemia as the H+ move into the cells to maintain the pH of the blood; however, when H+ moves in, potassium is kicked out during the exchange. Increased serum K+ levels affect cardiac conduction and irritability as cardiac depolarization decreases, leading to the loss of P waves, prolonged PR interval, ST segment depression, and widening QRS complexes. Heart block, ventricular fibrillation, or cardiac standstill may occur. Diarrhea, confusion, and abdominal pain are manifestations of metabolic acidosis.
Which statements would the emergency department nurse use to explain the cause of a patient's respiratory alkalosis to the patient and family? Select all that apply. 1 "This acid-base imbalance is not triggered by central nervous system disorders." 2 "Hyperventilation can occur without any physiologic need, such as pain or anxiety." 3 "This acid-base imbalance can be caused by hyperventilation as a result of increased body temperatures." 4 "Hypoxemia from acute pulmonary disorders, such as pneumonia, is the primary cause of this acid-base imbalance." 5 "The primary cause of the acid-base imbalance is hypercarbia from an acute pulmonary disorder, such as a pulmonary embolism."
Correct answer 2, 3, 4 "Hyperventilation can occur without any physiologic need, such as pain or anxiety." "This acid-base imbalance can be caused by hyperventilation as a result of increased body temperatures." "Hypoxemia from acute pulmonary disorders, such as pneumonia, is the primary cause of this acid-base imbalance." Rationale: Respiratory alkalosis is primarily caused by hypoxemia related to pulmonary disorders preventing appropriate gas exchange. Such examples of pulmonary disorders include pulmonary embolism or pneumonia. Hyperventilation decreases the level of CO2 in the blood; this condition can lead to respiratory alkalosis. Hyperventilation can occur with or without physiologic need from increased body temperatures (fevers), pain, or anxiety. Hypercarbia is an increase in CO2 in the blood, which is not associated with hyperventilation or hypoxemia. Some central nervous system disorders can cause hyperventilation without physiologic need and can lead to respiratory alkalosis.
A patient with metabolic acidosis asks how the acid-base imbalance will be corrected. Which response would the nurse use? Select all that apply. 1 "Medications are the primary treatment for acute acid-base imbalances occurring in critically ill patients." 2 "The renal system compensates slowly, usually reacting to pH changes within 24 hours." 3 "The respiratory system can compensate quickly to changes in pH and reacts in a matter of minutes." 4 "The heart is vital in managing the acid-base balance and regulates perfusion to increase or decrease pH." 5 "The buffer system is the primary manner by which the body changes strong acids into weaker ones to maintain pH balance."
Correct answer 2, 3, 5 "The renal system compensates slowly, usually reacting to pH changes within 24 hours." "The respiratory system can compensate quickly to changes in pH and reacts in a matter of minutes." "The buffer system is the primary manner by which the body changes strong acids into weaker ones to maintain pH balance." Rationale: The buffer system is the primary method by which the body maintains acid-base balance. This system is also the quickest, often working within seconds of sensing an imbalance. The respiratory system can compensate by changing the rate and depth of breathing within minutes of sensing an acid-base derangement; the renal system is slower to react, often working within hours to days. The heart is vital in regulating perfusion but does not have a major role in managing acid-base balance. Medications can be used to regulate acid-base imbalances, but the primary treatment is to resolve the underlying cause of the imbalance.
A family member takes an older adult patient with dementia to the emergency room; the patient is found to be hypercarbic. The patient's advanced directive indicates use of noninvasive procedures only. Which statement would be the nurse's best response when the family asks if this issue will resolve by itself? 1 "The kidneys will begin to compensate for increased levels of CO2 within 24 hours." 2 "The kidneys sense increased levels of CO2 in the blood and conserve HCO3- and secrete increased H+." 3 "Older adults have a harder time compensating because they have decreased respiratory and kidney functions." 4 "The respiratory center senses increased levels of CO2 in the blood and stimulates hyperventilation to compensate."
Correct answer: "Older adults have a harder time compensating because they have decreased respiratory and kidney functions." Rationale: All statements are true; however, the best response to the family's question addresses the difficulty older adults have with acid-base compensation because of the decreased respiratory and kidney functions. Hypercarbia is an increased level of CO2 in the blood, which is a hallmark of respiratory acidosis. Older adults have difficulty compensating for acid-base imbalances because of decreased functional capacity in the respiratory and renal systems. Hyperventilation is a normal physiologic response to hypercarbia; hyperventilation may not be possible with decreased functional respiratory reserves. Normal kidneys can sense hypercarbia and begin to reabsorb buffer to normalize pH; however, older adults may lack the functional capacity or have some degree of kidney disease. Normal renal compensation is slow and will often begin within 24 hours, if kidney function is normal.
A patient admitted with gastroenteritis has an arterial blood gas (ABG) report of pH 7.30, PaO2 80 mm Hg, PaCO2 46 mm Hg, HCO3 14. Which interpretation would the nurse use to affirm nursing interventions? 1 Metabolic acidosis 2 Metabolic alkalosis 3 Respiratory acidosis 4 Respiratory alkalosis
Correct answer: Metabolic acidosis Rationale: Use the memory device ROME. For respiratory conditions, the pH and the PaCO2 go in opposite directions. Respiratory alkalosis: pH high and PaCO2 is low. Respiratory acidosis: pH is low and the PaCO2 is high. In metabolic conditions, the pH and HCO3- go in the same direction (equal). The PaCO2 may also go in the same direction. Metabolic alkalosis: pH and HCO3- are high. Metabolic acidosis: pH and HCO3- are low.A low pH (normal 7.35 to 7.45) indicates acidosis. In the patient with gastroenteritis and diarrhea, bicarbonate is lost from the excessive stool, which would result in a low bicarbonate level and resulting metabolic acidosis. There is not a respiratory component associated with gastroenteritis.
A patient, recovering from a surgical procedure, has a nasogastric (NG) tube draining copious secretions and reports surgical site pain of 10 on a scale of 0 to 10. The patient's respirations are 32 breaths/minute. Which condition would the nurse associate with these clinical manifestations? 1 Hypoxia and respiratory alkalosis 2 Mixed respiratory and metabolic alkalosis 3 Sedative overdose and respiratory acidosis 4 Diabetic ketoacidosis and metabolic acidosis
correct answer Mixed respiratory and metabolic alkalosis Rationale: A mixed acid-base disorder is a condition in which two or more disorders affecting the acid-base balance are present at the same time. Septicemia causes respiratory alkalosis, which causes an acid-base imbalance. Metabolic alkalosis also affects the acid-base balance. Thus septicemia and metabolic alkalosis are examples of a mixed acid-base disorder. Hypoxia causes respiratory alkalosis. Overdose of sedatives causes respiratory acidosis. Diabetic ketoacidosis results in metabolic acidosis. An example of a mixed acidosis is a patient in severe shock with poor perfusion and hypoventilation. Mixed alkalosis can occur in a patient hyperventilating because of postoperative pain and loss of acid secondary to NG suctioning.
