Fluid & Electrolyte
A patient with diabetes presents with profound hyperglycemia. What type of acid-base imbalance does the nurse anticipate may affect the patient? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
1) Metabolic acidosis Diabetic ketoacidosis can occur in cases of uncontrolled hyperglycemia. This condition lead 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.
When evaluating a patient arterial blood gases (ABGs) the nurse determines there is an increase in the anion gap. What condition does the nurse interpret this to mean for the patient? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
1) Metabolic acidosis The anion gap increases in patients with metabolic acidosis due to increase in the concentration of acid. Metabolic alkalosis, respiratory acidosis, and respiratory alkalosis do not increase the anion gap.
A patient is considered to have acidosis if his or her blood pH drops below what number? 1) 7.25 2) 7.35 3) 7.45 4) 7.55
2) 7.35 Blood pH normally ranges from 7.35 to 7.45, so acidosis occurs when the blood pH drops below 7.35. Though the patient will have acidosis if the blood pH is at 7.25 or lower, the patient will also have acidosis if the blood pH is between 7.25 and 7.35. A blood pH of 7.45 is normal. A blood pH of 7.55 indicates alkalosis, not acidosis.
The nurse is caring for a patient admitted with heart failure. The morning laboratory results reveal a serum potassium level of 2.9 mEq/L. What classification of medications should be withheld until consulting with the health care provider? 1) Antibiotics 2) Loop diuretics 3) Bronchodilators 4) Antihypertensives
2) Loop diuretics Loop diuretics are contraindicated during episodes of hypokalemia because these medications cause the kidneys to excrete sodium and potassium. Thus administration of this type of medication at this time would worsen the hypokalemia, putting the patient at risk for dysrhythmias. The prescribing health care provider should be consulted for potassium replacement therapy, and the drug should be withheld until the potassium has returned to normal range. Antibiotics, bronchodilators, and antihypertensives are not an issue in this case.
What is the function of a buffer? 1) To excrete weak acids 2) To secrete hydrogen ions 3) To convert strong acids to weak acids 4) To convert ammonia to ammonium ions
3) To convert strong acids to weak acids Buffers convert strong acids to weak acids. Excretion of weak acids, secretion of hydrogen ions into the renal tubule, and conversion of ammonia to ammonium ions takes place in the kidneys.
A patient is admitted with alcohol abuse. Laboratory data reveals a phosphate level of 1.8 mg/dL. Which assessment finding is consistent with this data? 1) Tetany 2) Diarrhea 3) Weakness 4) Seizure activity
3) Weakness Signs of hypophosphatemia include weakness, confusion, coma, and diminished reflexes. Seizure activity, diarrhea, and tetany are not associated with this electrolyte imbalance.
The nurse is caring for a patient that has a nasogastric tube (NGT) on intermittent suction. The patient asks why they cannot have something to drink. What is the best response by the nurse? 1) "It will cause sodium retention." 2) "It will disrupt the intermittent suction." 3) "It will increase nausea and vomiting." 4) "It will increase the loss of electrolytes."
4) "It will increase the loss of electrolytes." Allowing a patient with an NGT to drink water increases the loss of electrolytes. It will not cause sodium retention, but sodium depletion. The free water will pull electrolytes into the stomach and the NGT will suck the fluids and electrolytes out of the stomach. Depending on the patient's condition and amount of water being ingested, it may increase nausea and vomiting. However, this would most likely happen if the suction was not working properly; it is not the primary reason for withholding oral fluids. Oral intake of water would not disrupt the intermittent suction.
The nurse is caring for a patient that is in respiratory acidosis. What cardiovascular condition should the nurse closely monitor the patient for? 1) Diarrhea 2) Confusion 3) Abdominal pain 4) Ventricular fibrillation
4) Ventricular fibrillation Respiratory acidosis causes compensatory hyperkalemia, which leads to ventricular fibrillation. Diarrhea, confusion, and abdominal pain are manifestations of metabolic acidosis
Which phosphate level would the nurse be likely to find in the patient who has alcohol withdrawal symptoms? 1) 1.4 mg/dL 2) 2.4 mg/dL 3) 3.8 mg/dL 4) 4.8 mg/dL
1) 1.4 mg/dL Alcohol withdrawal can result in hypophosphatemia. Phosphate levels of less than 2.4 mg/dL indicate hypophosphatemia. The nurse would be likely to find the patient's phosphate level at 1.4 mg/dL. Phosphate levels of 2.4, 3.8, and 4.8 mg/dL indicate hyperphosphatemia. The patient with symptoms of alcohol withdrawal does not have hyperphosphatemia.
A patient has a prescription to receive D5W with 20 mEq KCl/L at 100 mL/hour. The nurse should select which solution from the intravenous supply cart? 1) 5% dextrose in water with 20 mEq of KCl 2) 5% dextrose in 0.9% sodium chloride with 20 mEq of KCl 3) 5% dextrose lactated Ringer's solution with 20 mEq of KCl 4) 5% dextrose in 0.45% sodium chloride with 20 mEq of KCl
1) 5% dextrose in water with 20 mEq of KCl D5W stands for 5% dextrose in water, which is different than normal saline, half normal saline, or lactated Ringer's.
The primary health care provider has prescribed parenteral nutrition for a patient. The nurse administers a 10% dextrose solution with amino acids, electrolytes, vitamins, and trace elements. What does the nurse need to know regarding the 10% dextrose solution? 1) It is a hypertonic solution. 2) It is used as a plasma expander. 3) It expands the extracellular compartment. 4) It should be administered only through a central line.
1) It is a hypertonic solution A 10% dextrose solution with amino acids, electrolytes, vitamins, and trace elements is used in parenteral nutrition to provide additional calories. It is a hypertonic solution, which provides free water, expanding both the extracellular and intracellular compartments. Solutions with a dextrose concentration of 10% or more should be administered only through a peripheral line. Solutions with a higher dextrose concentration should be administered through a central line. Hypertonic solutions are not used as plasma expanders because they do not stay in the vascular space.
A nurse is caring for a patient three days after abdominal surgery who continues to have poorly controlled abdominal pain with green bilious nasogastric output. The patient's respiratory rate is 32 and heart rate is 128. Which acid-base imbalance does the nurse suspect is occurring? 1) Mixed acidosis 2) Mixed alkalosis 3) Metabolic alkalosis 4) Respiratory acidosis
2) Mixed alkalosis 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 in a critically ill patient in shock with hypoperfusion and hypoventilation, and will often cause a more profoundly acidotic pH than either condition could independently create.
A patient is recovering from a surgical procedure with pain rating at a 10 on a scale of 0-10 and has a nasogastric (NG) tube draining copious amounts of contents. The patient's respiratory rate is 32. What condition is this patient at greatest risk for? 1) Hypoxia and respiratory alkalosis 2) Mixed respiratory and metabolic alkalosis 3) Sedative overdose and respiratory acidosis 4) Diabetic ketoacidosis and metabolic acidosis
2) Mixed respiratory and metabolic alkalosis A mixed acid-base disorder is a condition in which two or more disorders that affect the acid-base balance are present at the same time. Septicemia causes respiratory alkalosis, which causes 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 losing acid secondary to NG suctioning.
The nurse is preparing to administer sodium polystyrene sulfonate rectally to a patient with an irregular pulse and weakness of the lower extremities. What laboratory finding does the nurse determine is the reason for this treatment? 1) Hypokalemia 2) Hypocalcemia 3) Hyperkalemia 4) Hypercalcemia
3) Hyperkalemia Irregular pulse and weakness of the lower extremities are generally seen in patients with hyperkalemia. Sodium polystyrene sulfonate binds with potassium in exchange for sodium, thereby reducing hyperkalemia. Hypokalemia can be treated with potassium chloride. Hypocalcemia can be treated with calcium supplements. Hypercalcemia can be treated by administering furosemide.
Upon assessment of laboratory data, the nurse notes a calcium level of 6.4 mg/dL. Which physical assessment finding is consistent with this data? 1) Polyuria 2) Bone pain 3) Paresthesias 4) Diminished deep tendon reflexes
3) Paresthesias Signs of hypocalcemia include paresthesias, tetany, and muscle weakness. Bone pain, diminished reflexes, and polyuria are signs of hypercalcemia.
A nurse is caring for a patient in the intensive care unit with respiratory acidosis. The family is concerned about the treatment for this disease. Which statement is the nurse's best response to the family? 1) "This disease is treated with mechanical ventilation." 2) "This disease is treated with medications such as bicarbonate." 3) "Respiratory acidosis is not something to worry about in the overall treatment regimen." 4) "Respiratory acidosis is not a disease but a symptom of a larger disease process that we will treat separately."
4) "Respiratory acidosis is not a disease but a symptom of a larger disease process that we will treat separately." 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, 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 complication.
The patient has a one-time prescription for potassium chloride 20 mEq in 250 mL of normal saline intravenous (IV) to be given immediately. The nurse would seek clarification for this prescription if the patient's more recent potassium level is at what level? 1) 1.7 mEq/L 2) 2.9 mEq/L 3) 3.6 mEq/L 4) 4.5 mEq/L
4) 4.5 mEq/L The normal range for serum potassium is 3.5 to 5 mEq/L. The IV prescription provides a substantial amount of potassium, so the patient's potassium level must be low. A level of 4.5 mEq/L would not warrant this medication.
The nurse is caring for a patient receiving calcium carbonate for the treatment of osteopenia. Which serum laboratory result would be identified as an adverse effect related to this therapy? 1) Sodium falling to 138 mEq/L 2) Potassium rising to 4.1 mEq/L 3) Magnesium rising to 2.9 mg/dL 4) Phosphorus falling to 2.1 mg/dL
4) Phosphorus falling to 2.1 mg/dL Calcium has an inverse relationship with phosphorus in the body. When phosphorus levels fall, calcium rises, and vice versa. Because hypercalcemia rarely occurs as a result of calcium intake, the patient's phosphorus falling to 2.1 mg/dL (normal 2.4-4.4 mg/dL) may be a result of the phosphate-binding effect of calcium carbonate. Sodium falling, potassium rising, and magnesium rising are not adverse reactions to the treatment.
The nurse is performing an assessment on a client that is experiencing hyperreflexia. What condition should the nurse review the arterial blood gas results for? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
4) Respiratory alkalosis Respiratory alkalosis is manifested by hyperreflexia. Metabolic acidosis is manifested by abdominal pain and Kussmaul respirations. Tachycardia, anorexia, and muscle cramps are the manifestations of metabolic alkalosis. Headache, seizures, and hypotension are the manifestations of respiratory acidosis.
When assessing the patient with a multilumen central line, the nurse notices that the cap is off one of the lines. On assessment, the patient is in respiratory distress and the vital signs show hypotension and tachycardia. What is the nurse's priority action? 1) Administer oxygen 2) Notify the health care provider 3) Reposition the patient to the right side 4) Rapidly administer more intravenous (IV) fluid
1) Administer oxygen The cap off the central line could allow entry of air into the circulation. For an air embolus, the priority is to administer oxygen; next, the catheter is clamped and the patient is positioned on the left side with the head down. Then the health care provider is notified.
While taking a patient's blood pressure, a nurse notices that a carpal spasm occurs. What laboratory test should the nurse review after assessing this finding? 1) Calcium 2) Sodium 3) Potassium 4) Magnesium
1) Calcium Trousseau's sign (carpal spasm when blood pressure cuff is inflated for a few minutes) is indicative of hypocalcemia. It does not occur with changes in sodium, potassium, or magnesium levels. The nurse should expect the primary health care provider to prescribe a calcium level be drawn.
A patient with cancer is found to have a serum phosphate level of 5.4 mg/dL. What does the nurse determine is the probable reason for the increase in phosphate levels in this patient? 1) Chemotherapy 2) Insulin therapy 3) Total parenteral nutrition 4) Phosphate-binding antacids
1) Chemotherapy Phosphate levels greater than 4.4 mg/dL indicate hyperphosphatemia. Chemotherapy drugs increase the patient's phosphate levels. Insulin therapy decreases the phosphate levels to less than 2.4 mg/dL. Patients with total parenteral nutrition have decreased phosphate levels. Phosphate-binding antacids remove phosphates from the body, resulting in hypophosphatemia.
A patient's potassium level is 2.9 meq/L. Which health care provider order should the nurse expect? 1) Continuous ECG monitoring 2) Increase digoxin (Lanoxin) to 0.25 mg every day 3) Add 20 meq KCL to the present IV bag hanging and give over four hours 4) 40 meq KCL in 100 cc D5W intravenous piggyback (IVPB) to infuse over 30 minutes
1) Continuous ECG monitoring Hypokalemia can cause lethal ventricular rhythms. Therefore continuous cardiac monitoring should be expected. Patients with hypokalemia are at risk for digoxin toxicity. The nurse should watch for signs of digoxin toxicity and question an increase in dosage. KCL infusion must be diluted and given at a rate not to exceed 10 meq/hour. 40 meq KCL in 100 cc of fluid is too concentrated and should be given over at least two hours. To prevent bolusing, KCL should never be added to an IV bag that already is hanging.
A patient's ECG tracing has a short QT interval and a high peaked T wave. Which prescription should the nurse question? 1) D5W with 20 meq KCL to run at 125 mL/hr 2) Sodium polystyrene sulfonate 30 grams by mouth 3) 10 units regular insulin IVP and one-half ampule D50W IVP 4) 2 grams calcium gluconate intravenous (IV) administered over two minutes
1) D5W with 20 meq KCL to run at 125 mL/hr A short QT interval and a high peaked T wave are indicative of hyperkalemia. The prudent nurse should question any prescription that could increase the potassium level in the patient. IV insulin with D50W and calcium gluconate are given to force the potassium back into the cells, temporarily correcting the hyperkalemia. Polystyrene sulfonate binds with potassium in the gastrointestinal (GI) tract and excretes it via feces.
A patient has low levels of parathyroid hormone. What other laboratory finding does the nurse expect in the patient? 1) Decreased calcium levels 2) Increased potassium levels 3) Decreased phosphate levels 4) Increased magnesium levels
1) Decreased calcium levels Low levels of parathyroid hormone cause hypocalcemia, or decreased calcium levels, because of reduced renal activity, which limits calcium absorption. The nurse would suspect increased potassium levels with hyperkalemia if the patient had adrenal insufficiency. Hypoparathyroidism causes hyperphosphatemia because of impaired renal phosphate excretion. Hypoparathyroidism can result in magnesium deficiency.
The nurse assesses the present of Trousseau's sign in a patient that had an inadvertent removal of the parathyroids during a thyroidectomy. What electrolyte disturbance should the nurse check the laboratory studies for? 1) Hypocalcemia 2) Hypercalcemia 3) Hypermagnesemia 4) Hyperphosphatemia
1) Hypocalcemia Trousseau's sign refers to carpal spasms induced by inflating a blood pressure cuff on the arm. Hypocalcemia can be identified by Trousseau's sign. Hypercalcemia, hypermagnesemia, and hyperphosphatemia cannot be identified by Trousseau's sign.
Which is a priority nursing action when providing care to a patient who is being treated for hypernatremia that developed slowly over several days? 1) Initiating seizure precautions 2) Administering prescribed diuretics 3) Monitoring the patient's weight each day 4) Restricting the patient's dietary sodium intake
1) Initiating seizure precautions A rapid reduction in the sodium level can cause a rapid shift of water back into the cells, resulting in cerebral edema and neurologic complications. This risk is greatest in a patient who developed hypernatremia over several days or longer. The priority nursing action in this case is to implement seizure precautions due to the risk of neurologic complications. Monitoring the patient's weight each day, restricting dietary sodium intake, and administering prescribed diuretics are all appropriate nursing actions; however, these are not the priority given this patient's risk for neurologic complications.
A nurse working in the emergency department is taking care of a patient with respiratory alkalosis. Which statements would be appropriate for the nurse to give as an explanation of the cause of this imbalance to the patient and family? Select all that apply. 1) "This imbalance is never caused by central nervous system disorders." 2) "Hyperventilation can occur without any physiologic need from pain or anxiety." 3) "This imbalance can be caused by hyperventilation, which can occur from fevers." 4) "The primary cause is hypoxemia from acute pulmonary disorders, such as pneumonia." 5) "The primary cause is hypercarbia from an acute pulmonary disorder, such as a pulmonary embolism."
2) "Hyperventilation can occur without any physiologic need from pain or anxiety." 3) "This imbalance can be caused by hyperventilation, which can occur from fevers." 4) "The primary cause is hypoxemia from acute pulmonary disorders, such as pneumonia." Respiratory alkalosis is primarily caused by hypoxemia related to pulmonary disorders that prevent 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 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, which can lead to respiratory alkalosis.
A nurse is caring for a patient with metabolic acidosis. The patient wants to know how the acid-base imbalance will be corrected. Based on the nurse's knowledge of acid-base imbalance, what is the best response? Select all that apply. 1) "Medications are the primary treatment for acute acid-base imbalances." 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, reacting in a matter of minutes." 4) "The heart is vital in managing the acid-base balance by regulating perfusion to increase or decrease pH." 5) "The buffer system is the primary manner in which the body changes strong acids into weaker ones to maintain pH balance."
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, reacting in a matter of minutes." 5) "The buffer system is the primary manner in which the body changes strong acids into weaker ones to maintain pH balance." The buffer system is the primary manner in 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 it 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.
The nurse finds that the patient with renal disease is irritable and has an irregular pulse. ECG changes suggest severe hyperkalemia. What is the first nursing action? 1) Stop all sources of dietary potassium 2) Administer intravenous calcium gluconate 3) Administer ion-exchange resins 4) Administer intravenous insulin with glucose
2) Administer intravenous calcium gluconate In the case of severe hyperkalemia, manifested by irritation, irregular pulse, and changes in ECG findings, the nurse should act immediately to prevent cardiac arrest. The nurse should administer intravenous calcium gluconate to reverse the membrane potential effects of extracellular fluid (ECF) potassium. Administering ion-exchange resins (to increase elimination of potassium) and intravenous insulin with glucose (to force potassium from ECF to intracellular fluid [ICF]) can be done once the patient is stable. Stopping all sources of dietary potassium is an important measure when hyperkalemia is mild.
A patient is being evaluated for acid-base imbalances. Which health information should the nurse assess? Select all that apply. 1) Ask about the patient's vaccination status. 2) Ask about the patient's exercise routines. 3) Ask the patient about any special dietary practices. 4) Ask the patient whether he or she smokes cigarettes. 5) Ask about any deviations from usual bowel and bladder habits.
2) Ask about the patient's exercise routines. 3) Ask the patient about any special dietary practices. 5) Ask about any deviations from usual bowel and bladder habits. Any alterations in elimination (such as diarrhea or oliguria) can cause metabolic acid-base derangements. Weight reduction, fad diets, or eating disorders can all lead to acid-base problems. Vigorous exercise can increase metabolic demands and cause fluid and electrolyte losses that may alter acid-base balance. Vaccination status is an important part of health maintenance, but it will not provide information regarding acid-base deviations. Smoking status is also an important part of health promotion; however, this information is unlikely to help assess for acute acid-base imbalances.
The nurse is reviewing magnesium levels for a patient. What does the nurse recognize is the importance of assessing this level for a patient? 1) It may cause extracellular fluid overload. 2) Can affect neuromuscular excitability and contractility. 3) It is the most abundant intracellular cation present in the body. 4) The patient is at risk for hypotension when the levels decrease.
2) Can affect neuromuscular excitability and contractility. Alterations in serum magnesium levels profoundly affect neuromuscular excitability and contractility because magnesium directly acts on the myoneural junction. A decrease in blood magnesium levels increases the blood pressure. Magnesium is the second most abundant intracellular cation. The majority of the body's magnesium is present in the bones. Causing extracellular fluid overload, being the most abundant intracellular cation, and the patient being at risk for hypotension are not relevant to this situation.
A patient comes to the emergency department after three days of continuous vomiting. This patient is at risk for which acid-base imbalance? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
2) Metabolic alkalosis 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.
The nurse is reviewing a patient's arterial blood gases (ABGs) that reveal pH 7.48, PaCO2 38, HCO3- 30. What does the nurse interpret the results indicate? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
2) Metabolic alkalosis Normal pH is 7.35-7.45. Values greater than 7.45 indicate alkalosis. Normal value for HCO3- is 22-26 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.
The nurse is monitoring a patient with hyperkalemia. Which conditions should the nurse conclude may cause this condition? Select all that apply. 1) Alkalosis 2) Renal failure 3) Low blood volume 4) Large urine volume 5) Adrenal insufficiency
2) Renal failure 5) Adrenal insufficiency Hyperkalemia is a condition in which there is an abnormal increase of potassium in the blood. Renal failure may cause hyperkalemia, because the kidneys cannot remove potassium from the body. Adrenal insufficiency causes aldosterone deficiency, which leads to the retention of potassium ions and also may result in hyperkalemia. Alkalosis is seen in hypocalcemia. Low blood volume and a large urine volume can result in hypokalemia.
An older adult patient with dementia arrives in the emergency department with a family member; the patient is found to be hypercarbic. The patient has an advanced directive and does not want any invasive procedure. The family member asks if this issue will resolve by itself. Which is the nurse's most appropriate response? 1) "The kidneys will compensate for increased levels of CO2 after about 24 hours." 2) "The kidneys sense increased levels of CO2 in the blood and reabsorb additional bicarbonate." 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."
3) "Older adults have a harder time compensating because they have 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 in 24 hours, if kidney function is normal.
A patient has the following arterial blood gas results: pH 7.32; PaCO2 56 mm Hg; HCO3- 24 mEq/L. What does the nurse determine these results will indicate for the patient? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
3) Respiratory acidosis The normal ranges are as follows: pH 7.35-7.45; PaCO2 35-45 mm Hg; HCO3- 22-26 mEq/L. Respiratory acidosis (carbonic acid excess) occurs whenever a person experiences hypoventilation. Hypoventilation leads to a buildup of CO2, resulting in an accumulation of carbonic acid in the blood. Carbonic acid dissociates, liberating H+, and there is a decrease in pH. The patient is not experiencing metabolic acidosis. These results are not indicative of metabolic alkalosis or respiratory alkalosis (because the pH is high).
A patient has the following arterial blood gas results: pH 7.16, PaCO2 80 mm Hg, PaO2 46 mm Hg, HCO3- 24 mEq/L, and SaO2 81%. How does the nurse interpret this information? 1) Metabolic acidosis 2) Metabolic alkalosis 3) Respiratory acidosis 4) Respiratory alkalosis
3) Respiratory acidosis The pH is less than 7.35, indicating acidosis. This eliminates metabolic and respiratory alkalosis as possibilities. Because the PaCO2 is high at 80 mm Hg (normal range is 35 to 45 mm Hg) and the metabolic measure of HCO3- is normal (range is 22 to 28 mEq/L), the patient is in respiratory acidosis, not alkalosis.
The nurse is caring for a group of patients. Which patient should the nurse closely monitor for the development of respiratory acidosis? 1) The patient with severe vomiting 2) The patient with a pulmonary embolism 3) The patient being treated for severe pneumonia 4) A patient that has recovered from diabetic ketoacidosis
3) The patient being treated for severe pneumonia Pneumonia is an inflammatory condition that causes hypoventilation, which results in increased concentration of carbon dioxide in blood 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.
