Chapter 12 Fluids & Electrolytes

CASE STUDY: J.S. was involved in a motorcycle collision and has a severe traumatic brain injury. While preparing to take the client to surgery, the neurosurgeon orders mannitol to be administered. Client's weight is 80 kg. Vital signs include temperature 97.9° F, heart rate 62 beats/min, respiratory rate controlled on a ventilator at 18 breaths/min, and blood pressure 194/132 mm Hg. The client has an increased intracranial pressure (ICP) of 36 mm Hg. 1. What class of diuretic is mannitol, and how does it work? 2. What is the standard dosage range for mannitol? How is mannitol administered? 3. What would the correct dose be for this client?

1. Mannitol is an osmotic diuretic that is used for clients with increased intracranial pressure and increased intraocular pressure. Osmotic diuretics increase os-molality and sodium reabsorption which will allow fluid to shift from the brain tissue to the vasculature. Sodium, chloride, potassium, and water are then excreted. This shift in fluid will cause, at least temporarily, a decrease in intracranial pressure. 2. The standard dosage range in adults for increased intracranial pressure (ICP) for mannitol is 0.25-1g/ kg, followed by 0.25 mg/kg to 1 g/kg infused over 30-60 minutes. The drug can be repeated every 6-8 hours. While there is no true maximum dose, the nurse must closely monitor client's renal function. Mannitol crystallizes easily, so it must be warmed before administration. It is suggested that it be given through an IV administration set with a filter. 3. For this client, the correct initial dose and maintenance dose would be 20-80 g over 30-60 minutes.

Calcium levels

8.5-10.5

Chloride levels

98-106

A client with a serum potassium level of 3.2 mEq/L asks why potassium supplement was prescribed. Which response by the nurse is most appropriate? a. "Your potassium level is 3.2 mEq/L which is low and should be corrected." b. "You will only be on the drug for a few days, so don't worry." c. "You obviously aren't taking enough in your diet, so you have to take this." d. "Have you been constipated lately? Constipation will cause a low potassium level."

a A potassium level of 3.2 mEq/L is considered hypokalemia and may require a supplement. Potassium supplements are taken over an extended period and not just a few days. Hypokalemia is rarely caused by inadequate intake. This response is also accusatory and is not therapeutic. Gastro-intestinal (GI) losses attributable to vomiting and diarrhea may lead to hypokalemia; constipation will not.

A client is receiving high-molecular-weight dextran after an explosion has burned over 50% of the body. Which action describes the purpose of dextran? a. Temporarily restore circulating volume b. Serve as a line to infuse blood into c. Piggyback fluid for antibiotics d. Whole blood substitute

a Dextran is a colloid (volume expander) made from glucose. It is given to persons with major burns to temporarily restore circulating volume. No other drugs, including blood, should be infused in the same line as dextran.

The nurse has taught a client how to take oral potassium supplement. Which statement by the client indicates that the more education is required? a. "I can take this with a few sips of water." b. "It may upset my stomach." c. "I should drink at least six ounces of water or juice when I take it." d. "I must not chew up the tablet."

a Oral potassium supplements can be irritating to the stomach and should be taken with at least 8 ounces of fluid and/or with a meal. The client is correct in that the tablet should not be chewed.

Which body fluid has a similar electrolyte composition to lactated Ringer solution? a. Plasma b. Skin c. Tears d. White blood cells

a Plasma has similar electrolyte content as lactated ringers.

A client has been started on a enteral potassium supplement. Which teaching should be included for this patient? (Select all that apply) a. List the signs and symptoms of both hypokalemia and hyperkalemia. b. Regular testing of serum potassium levels is required. c. The patient should increase his intake of potassium-rich foods. d. The drug must be taken on a full stomach or with a glass of water. e. The patient should sit up for 30 minutes after taking the drug.

a, b, d, e. A client who is taking a potassium supplement orally should be taught the signs and symptoms of both hypo-and hyperkalemia and when to notify the health care provider. Since there is a narrow range for potassium level, the client should anticipate routine blood work to evaluate if the potassium level is in the expected range. Because potassium is irritating, the supplement should be taken with a meal or a full glass of liquid and the client should remain upright for a minimum of 30 minutes to prevent esophagitis.

Which lab value(s) should a nurse monitor in a client receiving chlorothiazide? (Select all that apply) a. Potassium b. Sodium c. Bicarbonate d. Calcium e. AST/ALT

a, b, d. Hypokalemia, or low serum potassium level, is a risk for clients taking thiazides. This could be a life-threatening condition. Sodium is also lost, causing hyponatremia. Calcium level is elevated because thiazides block calcium excretion. There is minimal effect on bicarbonate levels. Cautious use in hepatic failure clients is recommended, but trending of AST/ALT levels is not always indicated. Baseline values may be beneficial.

A client has had diarrhea for several days and has a serum calcium level of 7.2 mg/dL. Which clinical manifestations will the nurse expect to see in this client? (Select all that apply) a. Hyperactive deep tendon reflexes b. Irritability c. Numbness of the fingers d. Pathologic fractures e. Tetany

a, b, e This client is hypocalcemic. Signs of hypocalcemia include anxiety, irritability, tetany, seizures, hyperactive deep tendon reflexes, and carpopedal spasms.

A client has pancreatitis. The nurse knows the client is at risk for which electrolyte abnormality? (Select all that apply) a. Hypocalcemia b. Hypernatremia c. Hypomagnesemia d. Hyperkalemia

a, c A client with pancreatitis will most likely have hypocalcemia due to calcium shifting into cells and hypomagnesemia.

A client with a serum potassium level of 6.1 mEq/L will exhibit which clinical manifestation(s)? (Select all that apply) a. Abdominal cramps b. Muscle weakness c. Oliguria d. Paresthesias of the face e. Tachycardia and later bradycardia

a, d, e gastrointestinal (GI) disturbances, such as abdominal cramps; paresthesias of the face, hands, and feet; and arrhythmias are commonly seen with hyperkalemia.

Which type of acid-base imbalance could occur if a patient is taking high doses of acetazolamide or uses the drug constantly? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis

a. Acetazolamide is a carbonic anhydrase inhibitor. It blocks the action of carbonic anhydrase, which is an enzyme that affects hydrogen ion balance. If the action is blocked, more bicarbonate will be excreted, leading to metabolic acidosis.

What is the classification of furosemide? a. Loop diuretic b. Osmotic diuretic c. Potassium-sparing diuretic d. Thiazide diuretic

a. Furosemide is a loop diuretic, which promotes excretion of water, sodium, and potassium, primarily in the loop of Henle and some in the distal renal tubules. Other electrolytes that are excreted include magnesium, ammonium, phosphate, and calcium.

The client with a complicated medical history including heart failure, cardiac arrhythmias, arthritis, and depression was started on furosemide for heart failure. Which drug would be of major concern to the nurse? a. Amiodarone b. Acetaminophen c. Amitriptyline d. Zolpidem

a. Furosemide will cause an increased loss of potassium (hypokalemia) when given with amiodarone, which may predispose the client to ventricular arrhythmias.

A client who has had an acute myocardial infarction has been started on spironolactone 50 mg/day. When evaluating routine laboratory work, the nurse discovers the client has a potassium level of 5.8 mEq/L. What is the priority intervention to be implemented? a. The spironolactone dose should be held and the intake of foods rich in potassium should be restricted. b. The spironolactone dose should be continued and the patient should be encouraged to eat fruits and vegetables. c. The spironolactone dose should be increased and the patient instructed to decrease foods rich in potassium. d. Instruct the patient to continue with the current dose of spironolactone and report any signs or symptoms of hypokalemia.

a. The normal range for serum potassium level is 3.5-5 mEq/L. A level of 5.8 mEq/L is considered hyperkalemia. The dose of spironolactone may need to be held or decreased, and the client should decrease intake of potassium-rich foods such as bananas, apricots, leafy greens, and salmon.

A client with severe head trauma is receiving 3% saline. It has an osmolality of 900 mOsm/kg. This is considered to be which type of solution?

b 3% saline is considered hypertonic solution. Any solution that is greater than 0.9% sodium chloride is considered hypertonic. Hypotonic fluid has less than 0.9% saline, such as 0.45% sodium chloride.

By which route is the majority of potassium excreted? a. Feces b. Kidneys c. Liver d. Lungs

b Around 80-90% of potassium is excreted in the urine. 8% is excreted in feces.

A client is in the hospital overnight after having surgery and the nurse has received an order to start 5% dextrose in 0.45% sodium chloride (D51⁄2 NS) intravenously. D51⁄2 NS is considered which type of fluid? a. Hypotonic b. Hypertonic c. Isotonic d. Normotonic

b D51/2NS is considered to be hypertonic solution. But, once it is in the body, it becomes hypotonic since the body metabolizes the glucose rather quickly, leaving free water and 0.45% saline.

A client is prescribed 2 liters of intravenous (IV) fluids: 1000 milliliters (mL) of 5% dextrose in water (D5W) followed by 1000 mL of 5% dextrose in 0.45% sodium chloride (D51⁄2 NS). Which term classifies these fluids? a. Colloids b. Crystalloids c. Lipids d. Parenteral nutrition

b D5W and D51/2NS are considered crystalloids. Crystalloids help maintain and/or temporarily correct hydration; they cause early plasma expansion. They do not contain proteins. Colloids contain protein, lipids, and/or carbohydrates and are given to increase serum osmolality; they are also called plasma expanders. Examples of colloids are albumin, and dextran. Lipids are fats and are considered colloids. Parenteral nutrition is intravenous nutrition containing protein, fats, and many minerals and electrolytes and are considered colloids.

Calcium is distributed bound and unbound to proteins in which proportions? a. 25%:75% b. 50%:50% c. 75%:25% d. 90%:10%

b The majority of calcium is located in bones and teeth. Of the remaining calcium, 50% is bound to protein. The other 50% is circulating free (ionized calcium) to assist with cellular functions.

The nurse is teaching the client about calcium absorption and includes the health teaching that vitamin D is needed for calcium absorption. Which area the body does vitamin D help in calcium ab-sorption? a. Large intestine b. Small intestine c. Kidneys d. Liver

b Vitamin D helps the absorption of calcium from the small intestine, primarily in the ileum. Products in the large intestine are waste. Kidneys do help with resorbing calcium, but not with the help of vitamin D. Liver does not absorb calcium.

A client has been receiving intravenous potassium. The nurse notices the client is now tachycardic. What other symptom(s) might the nurse expect to see if the client is becoming hyperkalemic? (select all that apply) a. Abdominal distention b. Nausea c. Numbness in extremities d. Polyuria e. Hypoglycemia

b, c Hyperkalemia can cause cardiac dysrhythmia, such as tachycardia. Other clinical manifestations of hyperkalemia include paresthesia to the face, tongue, and extremities; gastrointestinal hyperactivity (nausea, vomiting, and abdominal cramps), and acidosis may be present. Client with hyperkalemia will most likely have hyperglycemia, not hypoglycemia.

Which group(s) of diuretics is/are frequently pre-scribed to treat hypertension and congestive heart failure? (Select all that apply) a. Carbonic anhydrase inhibitors b. Loop diuretics c. Osmotic diuretics d. Potassium-sparing diuretics e. Thiazide diuretics

b, d, e. Diuretics are classified according to their mechanisms of action. Loop diuretics promote the loss of potassium and sodium; potassium-sparing diuretics promote the loss of sodium while retain-ing potassium; and thiazide diuretics promote the loss of sodium and some potassium. All diuretics promote the loss of water. While osmotic diuretics promote the loss of water and sodium, they are not used to treat hypertension and congestive heart failure; instead, they are used to decrease edema, especially cerebral edema. Carbonic anhydrase inhibitors also promote water and bicarbonate loss with minimal influence on electrolytes. Their use is to decrease intraocular pressure, not hypertension and heart failure.

What is the pharmacologic action of spironolactone? a. Increase potassium and sodium excretion b. Promote potassium retention c. Promote potassium and calcium retention d. Promote potassium excretion and sodium retention

b. Spironolactone is a potassium-sparing diuretic. It promotes potassium retention in the renal tubules.

A client with lab results of Na+ 150 mEq/L, K+ 4.2 mEq/L, Cl-100 mEq/L, Ca++ 9.8 mEq/L, Mg++ 1.8 mg/dL, PO4-3.1 mEq/L has which electrolyte abnormality? a. Hypocalcemia b. Hyperkalemia c. Hypernatremia d. Hypomagnesemia

c A sodium level of 150 mEq/L is considered hypernatremia. The normal range for serum sodium is 135-145 mEq/L. All other electrolytes are in normal range.

Which drugs are used to treat hyperkalemia? (Select all that apply) a. Digoxin and furosemide b. Glucagon and magnesium c. Glucose and insulin d. Sodium polystyrene sulfonate and sorbitol e. Sodium bicarbonate and calcium gluconate

c, d, e Insulin moves the potassium back into the cells while exogenous glucose maintains serum glucose level. Sodium polystyrene sulfonate binds with potassium, then it is excreted in feces while sorbitol maintains serum glucose level. Sodium bicarbonate shifts potassium intracellularly while calcium gluconate decreases myocardial irritability.

A client is taking potassium chloride and hydro-chlorothiazide. The client's serum potassium level is 2.4 mEq/L. Which clinical manifestations would the nurse expect to see in this client? (Select all that apply) a. Bradycardia b. Headache c. Muscle weakness d. Nausea e. Anorexia

c, d, e This client is hypokalemic. Early signs of hypokalemia usually do not occur until serum K+ level falls below 3.0 mEq/L and may include muscle weakness, anorexia, nausea, and vomiting. Untreated hypokalemia can lead to cardiac arrest and death.

A client taking furosemide reports being weak, having severe leg cramps, and unable to ambulate. Knowing the mechanism of action of furosemide, the nurse is concerned about which electrolyte imbalance? a. Hyponatremia b. Hypermagnesemia c. Hypokalemia d. Hyperchloremia

c. Muscle weakness, abdominal distention, severe leg cramping, and cardiac arrhythmias are indications of hypokalemia (low potassium levels). Low potassium levels may occur with the use of loop diuretics.

A client has been prescribed spironolactone 100 mg/day to treat an irregular heart rhythm. Which statement by the client indicates an understanding of the drug teaching the nurse provided? a. "I need sodium so my heart beats regularly." b. "This drug is dangerous if you have had a heart attack." c. "It helps keep potassium so my heart does not get irregular." d. "I need to take it with lots of bananas to keep my potassium up."

c. Spironolactone blocks the action of aldosterone and inhibits the sodium-potassium pump, so potassium is retained. This is important in maintaining a regular cardiac rhythm. It is frequently prescribed and is not contraindicated in clients who have had a myocardial infarction. Sodium is excreted with this drug. Clients should be advised not to overindulge in foods rich in potassium such as bananas, because this could cause above-normal levels of potassium (hyperkalemia).

A client has been diagnosed with hypokalemia and will be admitted to the hospital for potassium replacement intravenously (IV). Which action is appropriate by the nurse when preparing to give this drug? a. Prepare the syringe to give IV push. b. Push the potassium into the IV bag and do not mix before administration. c. Push the potassium into the IV bag and shake vigorously. d. Obtain an IV pump and pump tubing.

d IV potassium must be given using a rate-controlling device and cannot be allowed to run freely. In many hospitals, the nurse does not prepare this medication, and it is either mixed in the pharmacy or comes prepackaged from the manufacturer. IV potassium is never given as a bolus (IVP).

The nurse notices that the client's IV site has become erythematous and edematous while IV potassium was infusing. Which action is most appropriate by the nurse? a. Flush the IV site with normal saline and continue the infusion. b. Flush the IV site with heparin. c. Stop the IV and check for blood return. d. Discontinue the IV and restart in another site.

d Potassium is very irritating to the vein. If the site has become reddened and swollen, the IV should be discontinued immediately and another IV site should be started. The rest of the potassium is then infused. If another peripheral IV ac-cess is not possible, the health care provider should be contacted for possible central venous access.

A client is found to be hyperkalemic. Which medication will the nurse anticipate administering? a. Magnesium mixed in 250 mL of normal saline b. 0.9% saline (NS) bolus of 500 mL c. A fluid challenge of 250 mL of 10% dextrose in water (D10W). d. Sodium bicarbonate

d Administering sodium bicarbonate intravenously (IV) (50 mEq/L) as a one-time dose may help temporarily by driving potassium back into the cell. A client with hyperkalemia will most likely have hypermagnesemia. Saline will not help move the potassium back into the cell. D10W is high in glucose, and glucose pulls the potas-sium out of the cell which will worsen hyperkalemia.

The client with heart failure has been prescribed hydrochlorothiazide. Which statement by the client indicates understanding of the dosing regimen? a. "I need to take it on an empty stomach for it to work." b. "I really only need to take my medicine when I am having a hard time breathing." c. "It may take several weeks before it starts to work." d. "I should take it in the morning so I don't have to go to the bathroom at night."

d. Because the onset of action HCTZ is 2 hours, it may be best to take the drug when the client will be awake for several hours so sleep is not disturbed. Hydrochlorothiazide can be taken with food to prevent GI upset. The drug needs to be taken consistently, even if the client is not having symptoms of heart failure.

A client diagnosed with hypertension and diabetes was started on hydrochlorothiazide. Which statement by the client indicates understanding of the drug teaching the nurse has provided? a. "It will start working within minutes." b. "I don't need to monitor my blood sugar." c. "I should take my drug on an empty stomach so it works better." d. "I need to keep track of my weight and blood pressure at home."

d. Daily weights and vital signs need to be trended at home on a daily basis. The client and family should be educated on how to take these measurements or arrangements should be made for assessment by home health services, at least initially. The onset of action for hydrochlorothiazide is 2 hours. Hyperglycemia is a side effect of hydrochlorothiazide, so blood sugar level should be monitored. This medication can be taken with food to prevent nausea.

The nurse has received an order to administer 40 mg of furosemide intravenously (IV) to the client. What does the nurse know about how this drug should be administered? a. It must be mixed in 50 mL of normal saline. b. It can only be given in a central line. c. The patient must be on a cardiac monitor. d. It should be given over 1-2 minutes.

d. To prevent hearing loss, furosemide must be administered by slow IV push over at least 1-2 minutes. It does not need to be diluted and does not require a central line for administration. Cardiac monitoring is not essential, because furosemide does not generally cause arrhythmias.

In which client are loop diuretics contraindicated? a. The client with anuria b. The client with asthma c. The client with allergy to ceftriaxone d. The client with gastric ulcers

a. Loop diuretics are contraindicated in clients with anuria. Giving diuretics to a client without any urine output will not force urine production. Clients allergic to sulfa drugs should not take furosemide or bumetanide; these are derivatives of sulfonamides.

Case Study: D.M., 28 years old, has been stabbed multiple times in the chest and abdomen. Vital signs on arrival include blood pressure 84/62 mm Hg, heart rate 118 beats/min-ute, respiratory rate 30 breaths/minute, pulse oximetry 94% on room air, and temperature 96.4° F. 1. What is the priority assessment for this client? 2. What types of fluids would the nurse anticipate to be ordered? 3. Explain the advantage of using whole blood versus packed red blood cells.

1. D.M. is in hemorrhagic shock from massive blood loss as indicated by the vital signs. Stab wounds to the chest and abdomen can penetrate vital organs, causing large blood loss and risk of death. The priority assessment for this client is homeostasis, which includes circulation and airway. Circulation and airway are always a priority. During a systematic assessment of the client, two large-bore IVs (14 or 16 gauge) should be established in large veins to replace fluids rapidly. Another option is to assist the health care provider in placing a central line for rapid fluid resuscitation with colloids and crystalloids. 2. The client needs to be resuscitated with blood and blood products (colloids) and crystalloids. 3. Whole blood may be more beneficial for this client because it contains all the components (plasma, platelets, and RBCs); however, un-crossmatched packed red blood cells (PRBCs) may be easier to obtain in the emergent setting of trauma. Volume can be expanded using volume expanders.

Phosphorous levels

3-4.5

Potassium levels

3.5-5

Magnesium deficiencies are frequently associated with which other electrolyte imbalance? a. Hypocalcemia b. Hyperkalemia c. Hyponatremia d. Hyperphosphatemia

a Decreased magnesium (hypomagnesemia) is associated with hypocalcemia. Other electrolyte imbalance associated with low magnesium is hypokalemia.

Magnesium levels

1.5-2.5

Sodium levels

135-145