Ch 16: Fluid, Electrolyte, and Acid-Base Imbalances

A patient who had surgery for a perforated gastric ulcer has been receiving nasogastric suction for 3 days. The patient's serum sodium level is 127 mEq/L (127 mmol/L). Which prescribed therapy should the nurse question? a. Infuse 5% dextrose in water intravenously at 125 mL/hr. b. Administer IV morphine sulfate 4 mg every 2 hours PRN. c. Give IV metoclopramide 10 mg every 6 hours PRN for nausea. d. Administer 3% saline intravenously at 50 mL/hr for a total of 200 mL.

ANS: A Because the patient's gastric suction has been depleting electrolytes, the IV solution should include electrolyte replacement. Solutions such as lactated Ringer's solution would usually be ordered for this patient. The other orders are appropriate for a postoperative patient with gastric suction.

A patient with renal failure is on a low phosphate diet. Which food should the nurse instruct unlicensed assistive personnel (UAP) to remove from the patient's food tray? a. Skim milk b. Grape juice c. Mixed green salad d. Fried chicken breast

ANS: A Foods high in phosphate include milk and other dairy products, so these are restricted on low-phosphate diets. Green, leafy vegetables; high-fat foods; and fruits and juices are not high in phosphate and are not restricted.

A patient receives 3% NaCl solution for correction of hyponatremia. Which assessment is most important for the nurse to monitor while the patient is receiving this infusion? a. Lung sounds b. Urinary output c. Peripheral pulses d. Peripheral edema

ANS: A Hypertonic solutions cause water retention, so the patient should be monitored for symptoms of fluid excess. Crackles in the lungs may indicate the onset of pulmonary edema and are a serious manifestation of fluid excess. Peripheral pulses, peripheral edema, or changes in urine output are also important to monitor when administering hypertonic solutions, but they do not indicate acute respiratory or cardiac decompensation.

A patient has a serum calcium level of 7.0 mEq/L. Which assessment finding is most important for the nurse to report to the health care provider? a. The patient is experiencing stridor. b. The patient reports generalized fatigue. c. The patient's bowels have not moved for 4 days. d. The patient has numbness and tingling of the lips.

ANS: A Hypocalcemia can cause laryngeal stridor, which may lead to respiratory arrest. Rapid action is required to correct the patient's calcium level. The other data are also consistent with hypocalcemia, but do not indicate a need for as immediate action as laryngospasm.

A patient who has been receiving diuretic therapy is admitted to the emergency department with a serum potassium level of 3.0 mEq/L. The nurse should alert the health care provider immediately that the patient is on which medication? a. Digoxin (Lanoxin) 0.25 mg/day b. Ibuprofen 400 mg every 6 hours c. Lantus insulin 24 U every evening d. Metoprolol (Lopressor) 12.5 mg/day

ANS: A Hypokalemia increases the risk for digoxin toxicity, which can cause serious dysrhythmias. The nurse will need to do more assessment about the other medications, but they are not of as much concern with the potassium level.

A patient has a magnesium level of 1.3 mg/dL. Which assessment would help the nurse identify a likely cause of this value? a. Daily alcohol intake b. Dietary protein intake c. Multivitamin with minerals d. Over-the-counter (OTC) laxative

ANS: A Hypomagnesemia is associated with alcoholism. Protein intake would not have a significant effect on magnesium level. OTC laxatives (such as milk of magnesia) and use of multivitamin/mineral supplements tend to increase magnesium levels.

A patient with renal failure who arrives for outpatient hemodialysis is unresponsive to questions and has decreased deep tendon reflexes. Family members report that the patient has been taking aluminum hydroxide/magnesium hydroxide suspension (Maalox) at home for indigestion. Which action should the nurse take first? a. Notify the patient's health care provider. b. Obtain an order to draw a potassium level. c. Review the last magnesium level on the patient's chart. d. Teach the patient about magnesium-containing antacids.

ANS: A The health care provider should be notified immediately. The patient has a history and manifestations consistent with hypermagnesemia. The nurse should check the chart for a recent serum magnesium level and make sure that blood is sent to the laboratory for immediate electrolyte and chemistry determinations. Dialysis should correct the high magnesium levels. The patient needs teaching about the risks of taking magnesium-containing antacids. Monitoring of potassium levels also is important for patients with renal failure, but the patient's current symptoms are not consistent with hyperkalemia.

A patient who is lethargic and with deep, rapid respirations has the following arterial blood gas (ABG) results: pH 7.32, PaO2 88 mm Hg, PaCO2 35 mm Hg, and HCO3 16 mEq/L. How should the nurse interpret these results? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis

ANS: A The pH and HCO3 indicate that the patient has a metabolic acidosis. The ABGs are inconsistent with the other responses.

The nurse notes a serum calcium level of 7.9 mg/dL for a patient who has chronic malnutrition. Which action should the nurse expect to take first? a. Monitor ionized calcium level. b. Give oral calcium citrate tablets. c. Check parathyroid hormone level. d. Administer vitamin D supplements.

ANS: A This patient with chronic malnutrition is likely to have a low serum albumin level, which will affect the total serum calcium. A more accurate reflection of calcium balance is the ionized calcium level. Most of the calcium in the blood is bound to protein (primarily albumin). Alterations in serum albumin levels affect the interpretation of total calcium levels. Low albumin levels result in a drop in the total calcium level, although the level of ionized calcium is not affected. The other actions may be needed if the ionized calcium is also decreased.

Which action can the registered nurse (RN) who is caring for a critically ill patient with multiple IV lines and medications delegate to a licensed practical/vocational nurse (LPN/VN)? a. Titrate vasoactive IV medications. b. Flush a saline lock with normal saline. c. Remove the patient's central venous catheter. d. Verify blood products prior to administration.

ANS: B A LPN/VN has the education, experience, and scope of practice to flush a saline lock with normal saline. Administration of blood products, adjustment of vasoactive infusion rates, and removal of central catheters in critically ill patients require RN level education and scope of practice.

A patient who comes to the clinic reports frequent, watery stools for 2 days. Which action should the nurse take first? a. Obtain the baseline weight. b. Check the patient's blood pressure. c. Draw blood for serum electrolyte levels. d. Ask about extremity numbness or tingling.

ANS: B Because the patient's history suggests that fluid volume deficit may be a problem, assessment for adequate circulation is the highest priority. The other actions are also appropriate but are not as essential as determining the patient's perfusion status.

A patient is receiving a 3% saline continuous IV infusion for hyponatremia. Which assessment data will require the most rapid response by the nurse? a. The patient's radial pulse is 105 beats/min. b. There are crackles throughout both lung fields. c. There is sediment and blood in the patient's urine. d. The patient's blood pressure increases to 142/94 mm Hg.

ANS: B Crackles throughout both lungs suggest that the patient may be experiencing pulmonary edema, a life-threatening adverse effect of hypertonic solutions. The increased pulse rate and blood pressure and the appearance of the urine should also be reported, but they are not as dangerous as the presence of fluid in the alveoli.

A patient with multiple draining wounds is admitted for hypovolemia. What would be the most accurate way for the nurse to evaluate fluid balance? a. Skin turgor b. Daily weight c. Urine output d. Edema presence

ANS: B Daily weight is the most easily obtained and accurate means of assessing volume status. Skin turgor varies considerably with age. Considerable excess fluid volume may be present before fluid moves into the interstitial space and causes edema. Urine outputs do not take account of fluid intake or of fluid loss through insensible loss, sweating, or loss from the gastrointestinal tract or wounds.

A patient who has a small cell cancer of the lung develops syndrome of inappropriate antidiuretic hormone (SIADH). The nurse should notify the health care provider about which assessment finding? a. Serum hematocrit of 42% b. Serum sodium of 120 mg/dL c. Urinary output of 280 mL in 8 hours d. Reported weight gain of 2.2 pounds (1 kg)

ANS: B Hyponatremia is the most important finding to report. SIADH causes water retention and a decrease in serum sodium level. Hyponatremia can cause confusion and other central nervous system effects. A critically low value needs to be treated. At least 30 mL/hr of urine output indicates adequate kidney function. The hematocrit level is normal. Weight gain is expected with SIADH because of water retention.

IV potassium chloride (KCl) 60 mEq is prescribed for a patient with severe hypokalemia. Which action should the nurse take? a. Administer the KCl as a rapid IV bolus. b. Infuse the KCl at a maximum rate of 10 mEq/hr. c. Discontinue cardiac monitoring during the infusion. d. Refuse to give the KCl through a peripheral venous line.

ANS: B IV KCl is administered at a maximal rate of 10 mEq/hr. Rapid IV infusion of KCl can cause cardiac arrest. KCl can cause inflammation of peripheral veins, but it can be administered by this route. Cardiac monitoring should be continued while patient is receiving potassium because of the risk for dysrhythmias.

A student asks the nurse why a peripherally inserted central catheter is needed for a patient receiving parenteral nutrition with 25% dextrose. Which response by the nurse is accurate? a. "The prescribed infusion can be given more rapidly when the patient has a central line." b. "The hypertonic solution will be more rapidly diluted when given through a central line." c. "There is a decreased risk for infection when 25% dextrose is infused through a central line." d. "The required blood glucose monitoring is based on samples obtained from a central line."

ANS: B The 25% dextrose solution is hypertonic. Shrinkage of red blood cells can occur when solutions with dextrose concentrations greater than 10% are administered IV. Blood glucose testing is not more accurate when samples are obtained from a central line. The infection risk is higher with a central catheter than with peripheral IV lines. Hypertonic or concentrated IV solutions are not given rapidly.

The nurse is caring for a patient who has a massive burn injury and possible hypovolemia. Which assessment data should be of most concern to the nurse? a. Urine output is 30 mL/hr. b. Blood pressure is 90/40 mm Hg. c. Oral fluid intake is 100 mL for 8 hours. d. Skin tenting over the sternum is prolonged.

ANS: B The blood pressure indicates that the patient may be developing hypovolemic shock because of intravascular fluid loss because of the burn injury. This finding will require immediate intervention to prevent the complications associated with systemic hypoperfusion. The poor oral intake, decreased urine output, and skin tenting all indicate the need for increasing the patient's fluid intake but not as urgently as the hypotension.

A pregnant patient with eclampsia is receiving IV magnesium sulfate. Which finding should the nurse report to the health care provider immediately? a. The bibasilar breath sounds are decreased. b. The patellar and triceps reflexes are absent. c. The patient has been sleeping most of the day. d. The patient reports feeling "sick to my stomach."

ANS: B The loss of the deep tendon reflexes indicates that the patient's magnesium level may be reaching toxic levels. Nausea and lethargy are also side effects associated with magnesium elevation and should be reported, but they are not as significant as the loss of deep tendon reflexes. The decreased breath sounds suggest that the patient needs to cough and deep breathe to prevent atelectasis.

An older adult patient who is malnourished presents to the emergency department with a serum protein level of 5.2 g/dL. Which clinical manifestation should the nurse expect? a. Pallor b. Edema c. Confusion d. Restlessness

ANS: B The normal range for total protein is 6.4 to 8.3 g/dL. Low serum protein levels cause a decrease in plasma oncotic pressure and allow fluid to remain in interstitial tissues, causing edema. Confusion, restlessness, and pallor are not associated with low serum protein levels.

A patient with new-onset confusion and hyponatremia is being admitted. Which action should the charge nurse take when making room assignments? a. Assign the patient to a semiprivate room. b. Assign the patient to a room near the nurse's station. c. Place the patient in a room nearest to the water fountain. d. Place the patient on telemetry to monitor for peaked T waves.

ANS: B The patient should be placed near the nurse's station if confused for the staff to closely monitor the patient. To help improve serum sodium levels, water intake is restricted. Therefore, a confused patient should not be placed near a water fountain. Peaked T waves are a sign of hyperkalemia, not hyponatremia. A confused patient could be distracting and disruptive for another patient in a semiprivate room.

A patient who has been hospitalized for 2 days has a nasogastric tube to low suction and is receiving normal saline IV at 100 mL/hr. Which assessment finding would be a priority for the nurse to report to the health care provider? a. Oral temperature of 100.1° F b. Decreased alertness since admission c. Weight gain of 2 pounds (1 kg) over 2 days d. Serum sodium level of 138 mEq/L (138 mmol/L)

ANS: B The patient's history and change in LOC could be indicative of fluid and electrolyte disturbances: extracellular fluid (ECF) excess, ECF deficit, hyponatremia, hypernatremia, hypokalemia, or metabolic alkalosis. Further diagnostic information is needed to determine the cause of the change in LOC and the appropriate interventions. The weight gain, elevated temperature, and serum sodium level will be reported but do not indicate a need for rapid action to avoid complications.

A patient who had a transverse colectomy for diverticulosis 18 hours ago has nasogastric suction. The patient reports anxiety and incisional pain. The patient's respiratory rate is 32 breaths/min, and the arterial blood gases (ABGs) indicate respiratory alkalosis. Which action should the nurse take first? a. Check to make sure the nasogastric tube is patent. b. Give the patient the PRN IV morphine sulfate 4 mg. c. Notify the health care provider about the ABG results. d. Teach the patient to take slow, deep breaths when anxious.

ANS: B The patient's respiratory alkalosis is caused by the increased respiratory rate associated with pain and anxiety. The nurse's first action should be to medicate the patient for pain. The health care provider may be notified about the ABGs but is likely to instruct the nurse to medicate for pain. The patient will not be able to take slow, deep breaths when experiencing pain. Checking the nasogastric tube can wait until the patient has been medicated for pain.

Following a thyroidectomy, a patient reports "a tingling feeling around my mouth." Which assessment should the nurse complete first? a. Verify the serum potassium level. b. Test for presence of Chvostek's sign. c. Observe for blood on the neck dressing. d. Confirm a prescription for thyroid replacement.

ANS: B The patient's symptoms indicate possible hypocalcemia, which can occur secondary to parathyroid injury or removal during thyroidectomy. There is no indication of an urgent need to check the potassium level, the thyroid replacement, or for bleeding.

The nurse is caring for a patient who has a central venous access device (CVAD). Which action by the nurse is appropriate? a. Avoid using friction when cleaning around the CVAD insertion site. b. Use the push-pause method to flush the CVAD after giving medications. c. Position the patient's face toward the CVAD during injection cap changes. d. Obtain a prescription from the health care provider to change CVAD dressing.

ANS: B The push-pause enhances the removal of debris from the CVAD lumen and decreases the risk for clotting. To decrease infection risk, friction should be used when cleaning the CVAD insertion site. The dressing should be changed whenever it becomes damp, loose, or visibly soiled. A provider's order is not necessary. The patient should turn away from the CVAD during cap changes.

A patient is admitted to the emergency department with severe fatigue and confusion. Laboratory studies are done. Which laboratory value will require the most immediate action by the nurse? a. Arterial blood pH is 7.32. b. Serum calcium is 18 mg/dL. c. Serum potassium is 5.1 mEq/L. d. Arterial oxygen saturation is 91%.

ANS: B The serum calcium is well above the normal level and puts the patient at risk for cardiac dysrhythmias. The nurse should start cardiac monitoring and notify the health care provider. The potassium, oxygen saturation, and pH are also abnormal, and the nurse should notify the health care provider about these values as well, but they are not immediately life threatening.

The home health nurse cares for an alert and oriented older adult patient with a history of dehydration. Which instructions should the nurse give this patient related to fluid intake? a. "Drink more fluids in the late evening." b. "More fluids are needed if you feel thirsty." c. "Increase the fluids if your mouth feels dry." d. "If you feel confused, you need more fluids."

ANS: C An alert older patient will be able to self-assess for signs of oral dryness such as thick oral secretions or dry-appearing mucosa. The thirst mechanism decreases with age and is not an accurate indicator of volume depletion. Many older patients prefer to restrict fluids slightly in the evening to improve sleep quality. The patient will not be likely to notice and act appropriately when changes in level of consciousness occur.

The long-term care nurse is evaluating the effectiveness of protein supplements for an older resident who has a low serum total protein level. Which assessment finding indicates that the patient's condition has improved? a. Hematocrit 28% b. Absence of skin tenting c. Decreased peripheral edema d. Blood pressure 110/72 mm Hg

ANS: C Edema is caused by low oncotic pressure in individuals with low serum protein levels. The decrease in edema indicates an improvement in the patient's protein status. Good skin turgor is an indicator of fluid balance, not protein status. A low hematocrit could be caused by poor protein intake. Blood pressure does not provide a useful clinical tool for monitoring protein status.

A nurse is assessing a newly admitted patient with chronic heart failure who forgot to take prescribed medications. The patient seems confused and short of breath with peripheral edema. Which assessment should the nurse complete first? a. Skin turgor b. Heart sounds c. Mental status d. Capillary refill

ANS: C Increases in extracellular fluid (ECF) can lead to swelling of cells in the central nervous system, initially causing confusion, which may progress to coma or seizures. Although skin turgor, capillary refill, and heart sounds may also be affected by increases in ECF, these are signs that do not have as immediate impact on patient outcomes as cerebral edema.

The nurse is caring for a patient who has a calcium level of 12.1 mg/dL. Which nursing action should the nurse include on the care plan? a. Maintain the patient on bed rest. b. Auscultate lung sounds every 4 hours. c. Encourage fluid intake up to 4000 mL daily. d. Monitor for Trousseau's and Chvostek's signs.

ANS: C To decrease the risk for renal calculi, the patient should have a fluid intake of 3000 to 4000 mL daily. Ambulation helps decrease the loss of calcium from bone and is encouraged in patients with hypercalcemia. Trousseau's and Chvostek's signs are monitored when there is a possibility of hypocalcemia. There is no indication that the patient needs frequent assessment of lung sounds, although these would be assessed every shift.

An older adult patient receiving iso-osmolar continuous enteral nutrition develops restlessness, agitation, and weakness. Which laboratory result should the nurse report to the health care provider immediately? a. K+ 3.4 mEq/L (3.4 mmol/L) b. Ca+2 7.8 mg/dL (1.95 mmol/L) c. Na+ 154 mEq/L (154 mmol/L) d. PO4 ?2-3 4.8 mg/dL (1.55 mmol/L)

ANS: C The elevated serum sodium level is consistent with the patient's neurologic symptoms and indicates a need for immediate action to prevent further serious complications such as seizures. The potassium, phosphate, and calcium levels vary slightly from normal and should be reported, but do not require immediate action by the nurse.

After placement of a centrally inserted IV catheter, a patient reports acute chest pain and dyspnea. Which action should the nurse take first? a. Notify the health care provider. b. Offer reassurance to the patient. c. Auscultate the patient's breath sounds. d. Give prescribed PRN morphine sulfate IV.

ANS: C The initial action should be to assess the patient further because the history and symptoms are consistent with several possible complications of central line insertion, including embolism and pneumothorax. The other actions may be appropriate, but further assessment of the patient is needed before notifying the health care provider, offering reassurance, or administration of morphine.

After receiving change-of-shift report, which patient should the nurse assess first? a. Patient with serum sodium level of 145 mEq/L who is asking for water b. Patient with serum potassium level of 5.0 mEq/L who reports abdominal cramping c. Patient with serum magnesium level of 1.1 mEq/L who has tremors and hyperactive reflexes d. Patient with serum phosphorus level of 4.5 mg/dL who has soft tissue calcium-phosphate precipitates

ANS: C The low magnesium level and neuromuscular irritability suggest that the patient may be at risk for seizures. The other patients have mild electrolyte disturbances or symptoms that require action, but they are not at risk for life-threatening complications.

Spironolactone (Aldactone), an aldosterone antagonist, is prescribed for a patient. Which statement by the patient indicates that the teaching about this medication has been effective? a. "I will try to drink at least 8 glasses of water every day." b. "I will use a salt substitute to decrease my sodium intake." c. "I will increase my intake of potassium-containing foods." d. "I will drink apple juice instead of orange juice for breakfast."

ANS: D Because spironolactone is a potassium-sparing diuretic, teach patients to choose low-potassium foods (e.g., apple juice) rather than foods that have higher levels of potassium (e.g., citrus fruits). Because the patient is using spironolactone as a diuretic, the nurse would not encourage the patient to increase fluid intake. Teach patients to avoid salt substitutes, which are high in potassium.

A patient who is taking a potassium-wasting diuretic for treatment of hypertension reports generalized weakness. Which action is appropriate for the nurse to take? a. Assess for facial muscle spasms. b. Ask the patient about loose stools. c. Recommend the patient avoid drinking orange juice with meals. d. Suggest that the health care provider order a basic metabolic panel.

ANS: D Generalized weakness is a manifestation of hypokalemia. After the health care provider orders the metabolic panel, the nurse should check the potassium level. Facial muscle spasms might occur with hypocalcemia. Orange juice is high in potassium and would be advisable to drink if the patient is hypokalemic. Loose stools are associated with hyperkalemia.

A patient who was involved in a motor vehicle crash has had a tracheostomy placed to allow for continued mechanical ventilation. How should the nurse interpret the following arterial blood gas results: pH 7.48, PaO2 85 mm Hg, PaCO2 32 mm Hg, and HCO3 25 mEq/L? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis

ANS: D The pH indicates that the patient has alkalosis and the low PaCO2 indicates a respiratory cause. The other responses are incorrect based on the pH and the normal HCO3.

A patient who was admitted with diabetic ketoacidosis has rapid, deep respirations. Which action should the nurse take? a. Give the prescribed PRN lorazepam (Ativan). b. Encourage the patient to take deep slow breaths. c. Start the prescribed PRN oxygen at 2 to 4 L/min. d. Administer the prescribed fluid bolus and insulin.

ANS: D The rapid, deep (Kussmaul) respirations indicate a metabolic acidosis and the need for correction of the acidosis with a saline bolus to prevent hypovolemia followed by insulin administration to allow glucose to reenter the cells. Oxygen therapy is not indicated because there is no indication that the increased respiratory rate is related to hypoxemia. The respiratory pattern is compensatory, and the patient will not be able to slow the respiratory rate. Lorazepam administration will slow the respiratory rate and increase the level of acidosis.