Chapter 42: Fluid, Electrolyte, Acid-Base Balance // Potter: Fundamentals of Nursing, 11th Edition

The body fluids constituting the interstitial fluid and blood plasma are:

1. Hypotonic

2. Hypertonic

3. Intracellular

4. Extracellular

ANS: 4

Extracellular fluid is all the fluid outside of the cell and has three compartments.

Mrs. Green's arterial blood gas results are as follows: pH, 7.32; PaCO2, 52 mm Hg; PaO2, 78 mm Hg; HCO3, 24 mEq/L. Mrs. Green has:

1. Metabolic acidosis

2. Metabolic alkalosis

3. Respiratory acidosis

4. Respiratory alkalosis

ANS: 3

A combination of increased PaCO2, excess carbonic acid, and an increased hydrogen ion concentration

Mr. Frank is an 82-year-old patient who has had a 3-day history of vomiting and diarrhea. Which symptom would you expect to find on a physical examination?

1. Tachycardia

2. Hypertension

3. Neck vein distention

4. Crackles in the lungs

ANS: 1

Any condition that results in the loss of GI fluids predisposes the patient to the development of dehydration and a variety of electrolyte disturbances.

Select all the related causes for a patient to experience respiratory alkalosis. (Select all that apply.)

1. Steroid use

2. Fad dieting

3. Hyperventilation

4. Chronic alcoholism

5. Hypoxemia

6. Stress

ANS: 3 , 5 , 6

Deficient carbonic acid resulting in alveolar hyperventilation

When delegating I&O measurement to assistive personnel, the nurse instructs them to record what information for ice chips?

1. Two-thirds of the volume

2. One-half of the volume

3. One-quarter of the volume

4. Two times the volume

ANS: 2

What assessments does a nurse make before hanging an IV fluid that contains potassium? (Select all that apply.)

1. Urine output

2. ABGS

3. Fullness of neck veins

4. Serum potassium laboratory value in EHR

5. Level of consciousness

ANS: 1, 4

A patient has hypokalemia with stable cardiac function. What are the priority nursing interventions? (Select all that apply.)

1. Fall prevention interventions

2. Teaching regarding sodium restriction

3. Encouraging increased fluid intake

4. Monitoring for constipation

5. Explaining how to take daily weights

ANS: 1, 4

A patient is admitted to the hospital with severe dyspnea and wheezing. ABG levels on admission are pH, 7.26; PaO2, 68mm Hg; PaCO2, 55 mm Hg; and HCO3-, 24. How does the nurse interpret these laboratory values?

1. Metabolic acidosis

2. Metabolic alkalosis

3. Respiratory acidosis

4. Respiratory alkalosis

ANS: 3

Which assessment does the nurse use as a clinical marker of vascular volume in a patient at high risk of ECV deficit?

1. Dryness of mucous membranes

2. Skin turgor

3. Fullness of neck veins when supine

4. Fullness of neck veins when upright

ANS: 3

A patient is experiencing dehydration. While planning care, the nurse considers that the majority of the patient's total water volume exists in which compartment?

a. Intracellular

b. Extracellular

c. Intravascular

d. Transcellular

ANS: A

Intracellular (inside the cells) fluid accounts for approximately two thirds of total body water. Extracellular (outside the cells) is approximately one third of the total body water. Intravascular fluid (liquid portion of the blood) and transcellular fluid are two major divisions of the extracellular compartment.

The nurse is teaching about the process of passively moving water from an area of lower particle concentration to an area of higher particle concentration. Which process is the nurse describing?

a. Osmosis

b. Filtration

c. Diffusion

d. Active transport

ANS: A

The process of moving water from an area of low particle concentration to an area of higher particle concentration is known as osmosis. Filtration is mediated by fluid pressure from an area of higher pressure to an area of lower pressure. Diffusion is passive movement of electrolytes or other particles down the concentration gradient (from areas of higher concentration to areas of lower concentration). Active transport requires energy in the form of adenosine triphosphate (ATP) to move electrolytes across cell membranes against the concentration gradient (from areas of lower concentration to areas of higher concentration).

The nurse observes edema in a patient who is experiencing venous congestion as a result of right heart failure. Which type of pressure facilitated the formation of the patient's edema?

a. Osmotic

b. Oncotic

c. Hydrostatic

d. Concentration

ANS: C

Venous congestion increases capillary hydrostatic pressure. Increased hydrostatic pressure causes edema by causing increased movement of fluid into the interstitial area. Osmotic and oncotic pressures involve the concentrations of solutes and can contribute to edema in other situations, such as inflammation or malnutrition. Concentration pressure is not a nursing term.

The nurse inspecting laboratory blood results will expect to observe which cation in the most abundance?

a. Sodium

b. Chloride

c. Potassium

d. Magnesium

ANS: A

Sodium is the most abundant cation in the blood. Potassium is the predominant intracellular cation. Chloride is an anion (negatively charged) rather than a cation (positively charged). Magnesium is found predominantly inside cells and in bone.

The nurse receives the patient's most recent blood work results. Which laboratory value is of greatest concern?

a. Sodium of 145 mEq/L

b. Calcium of 15.5 mg/dL

c. Potassium of 3.5 mEq/L

d. Chloride of 100 mEq/L

ANS: B

Normal calcium range is 9 to 10.5 mg/dL; therefore, a value of 15.5 mg/dL is abnormally high and of concern. The rest of the laboratory values are within their normal ranges: sodium 136 to 145 mEq/L, potassium 3.5 to 5.0 mEq/L, and chloride 98 to 106 mEq/L.

The nurse observes that the patient's calcium is elevated. When checking the phosphate level, what does the nurse expect to see?

a. An increase

b. A decrease

c. Equal to calcium

d. No change in phosphate

ANS: B

Phosphate will decrease. Serum calcium and phosphate have an inverse relationship. When one is elevated, the other decreases, except in some patients with end-stage renal disease.

Four patients arrive at the emergency department at the same time. Which patient will the nurse see first?

a. An infant with temperature of 102.2°F and diarrhea for 3 days

b. A teenager with a sprained ankle and excessive edema

c. A middle-aged adult with abdominal pain who is moaning and holding her stomach

d. An older adult with nausea and vomiting for 3 days with blood pressure 112/60

ANS: A

The infant should be seen first. An infant's proportion of total body water (70% to 80% total body weight) is greater than that of children or adults. Infants and young children have greater water needs and immature kidneys. They are at greater risk for extracellular volume deficit and hypernatremia because body water loss is proportionately greater per kilogram of weight. A teenager with excessive edema from a sprained ankle can wait. A middle-aged adult moaning in pain can wait as can an older adult with a blood pressure of 112/60.

A 2-year-old child has ingested a quantity of a medication that causes respiratory depression. For which acid-base imbalance will the nurse most closely monitor this child?

a. Respiratory alkalosis

b. Respiratory acidosis

c. Metabolic acidosis

d. Metabolic alkalosis

ANS: B

Respiratory depression leads to hypoventilation. Hypoventilation results in retention of CO2 and respiratory acidosis. Respiratory alkalosis would result from hyperventilation, causing a decrease in CO2 levels. Metabolic acid-base imbalance would be a result of kidney dysfunction, vomiting, diarrhea, or other conditions that affect metabolic acids.

A patient is admitted for a bowel obstruction and has had a nasogastric tube set to low intermittent suction for the past 3 days. Which arterial blood gas values will the nurse expect to observe?

a. Respiratory alkalosis

b. Metabolic alkalosis

c. Metabolic acidosis

d. Respiratory acidosis

ANS: B

The patient is losing acid from the nasogastric tube so the patient will have metabolic alkalosis. Lung problems will produce respiratory alkalosis or acidosis. Metabolic acidosis will occur when too much acid is in the body like kidney failure.

Which blood gas result will the nurse expect to observe in a patient with respiratory alkalosis?

a. pH 7.60, PaCO2 40 mm Hg, HCO3- 30 mEq/L

b. pH 7.53, PaCO2 30 mm Hg, HCO3- 24 mEq/L

c. pH 7.35, PaCO2 35 mm Hg, HCO3- 26 mEq/L

d. pH 7.25, PaCO2 48 mm Hg, HCO3- 23 mEq/L

ANS: B

Respiratory alkalosis should show an alkalotic pH and decreased CO2 (respiratory) values, with a normal HCO3-. In this case, pH 7.53 is alkaline (normal = 7.35 to 7.45), PaCO2 is 30 (normal 35 to 45 mm Hg), and HCO3- is 24 (normal = 22 to 26 mEq/L). A result of pH 7.60, PaCO2 40 mm Hg, HCO3- 30 mEq/L is metabolic alkalosis. pH 7.35, PaCO2 35 mm Hg, HCO3- 26 mEq/L is within normal limits. pH 7.25, PaCO2 48 mm Hg, HCO3- 23 mEq/L is respiratory acidosis.

A nurse is caring for a patient whose electrocardiogram (ECG) presents with changes characteristic of hypokalemia. Which assessment finding will the nurse expect?

a. Dry mucous membranes

b. Abdominal distention

c. Distended neck veins

d. Flushed skin

ANS: B

Signs and symptoms of hypokalemia are muscle weakness, abdominal distention, decreased bowel sounds, and cardiac dysrhythmias. Distended neck veins occur in fluid overload. Thready peripheral pulses indicate hypovolemia. Dry mucous membranes and flushed skin are indicative of dehydration and hypernatremia.

In which patient will the nurse expect to see a positive Chvostek's sign?

a. A 7-year-old child admitted for severe burns

b. A 24-year-old adult admitted for chronic alcohol abuse

c. A 50-year-old patient admitted for an acute exacerbation of hyperparathyroidism

d. A 75-year-old patient admitted for a broken hip related to osteoporosis

ANS: B

A positive Chvostek's sign is representative of hypocalcemia or hypomagnesemia. Hypomagnesemia is common with alcohol abuse. Hypocalcemia can be brought on by alcohol abuse and pancreatitis (which also can be affected by alcohol consumption). Burn patients frequently experience extracellular fluid volume deficit. Hyperparathyroidism causes hypercalcemia. Immobility is associated with hypercalcemia.

A patient is experiencing respiratory acidosis. Which organ system is responsible for compensation in this patient?

a. Renal

b. Endocrine

c. Respiratory

d. Gastrointestinal

ANS: A

The kidneys (renal) are responsible for respiratory acidosis compensation. A problem with the respiratory system causes respiratory acidosis, so another organ system (renal) needs to compensate. Problems with the gastrointestinal and endocrine systems can cause acid-base imbalances, but these systems cannot compensate for an existing imbalance.

The nurse is caring for a diabetic patient in renal failure who is in metabolic acidosis. Which laboratory findings are consistent with metabolic acidosis?

a. pH 7.3, PaCO2 36 mm Hg, HCO3- 19 mEq/L

b. pH 7.5, PaCO2 35 mm Hg, HCO3- 35 mEq/L

c. pH 7.32, PaCO2 47 mm Hg, HCO3- 23 mEq/L

d. pH 7.35, PaCO2 40 mm Hg, HCO3- 25 mEq/L

ANS: A

The laboratory values that reflect metabolic acidosis are pH 7.3, PaCO2 36 mm Hg, HCO3- 19 mEq/L. A laboratory finding of pH 7.5, PaCO2 35 mm Hg, HCO3- 35 mEq/L is metabolic alkalosis. pH 7.32, PaCO2 47 mm Hg, HCO3- 23 mEq/L is respiratory acidosis. pH 7.35, PaCO2 40 mm Hg, HCO3- 25 mEq/L values are within normal range.

A patient receiving chemotherapy has gained 5 pounds in 2 days. Which assessment question by the nurse is most appropriate?

a. Are you following any weight loss program?"

b. "How many calories a day do you consume?"

c. "Do you have dry mouth or feel thirsty?"

d. "How many times a day do you urinate?"

ANS: D

A rapid gain in weight usually indicates extracellular volume (ECV) excess if the person began with normal ECV. Asking the patient about urination habits will help determine whether the body is trying to excrete the excess fluid or if renal dysfunction is contributing to ECV excess. This is too rapid a weight gain to be dietary; it is fluid retention. Asking about following a weight loss program will not help determine the cause of the problem. Caloric intake does not account for rapid weight changes. Dry mouth and thirst accompany ECV deficit, which would be associated with rapid weight loss.

The health care provider asks the nurse to monitor the fluid volume status of a heart failure patient and a patient at risk for clinical dehydration. Which is the most effective nursing intervention for monitoring both of these patients?

a. Assess the patients for edema in extremities.

b. Ask the patients to record their intake and output.

c. Weigh the patients every morning before breakfast.

d. Measure the patients' blood pressures every 4 hours.

ANS: C

An effective measure of fluid retention or loss is daily weights; each kg (2.2 pounds) change is equivalent to 1 L of fluid gained or lost. This measurement should be performed at the same time every day using the same scale and the same amount of clothing. Although intake and output records are important assessment measures, some patients are not able to keep their own records themselves. Blood pressure can decrease with extracellular volume (ECV) deficit but will not necessarily increase with recent ECV excess (heart failure patient). Edema occurs with ECV excess but not with clinical dehydration.

A nurse is caring for a patient diagnosed with cancer who presents with anorexia, blood pressure 100/60, and elevated white blood cell count. Which primary purpose for starting total parenteral nutrition (TPN) will the nurse add to the care plan?

a. Stimulate the patient's appetite to eat.

b. Deliver antibiotics to fight off infection.

c. Replace fluid, electrolytes, and nutrients.

d. Provide medication to raise blood pressure.

ANS: C

Total parenteral nutrition is an intravenous solution composed of nutrients and electrolytes to replace the ones the patient is not eating or losing. TPN does not stimulate the appetite. TPN does not contain blood pressure medication or antibiotics.

A nurse administering a diuretic to a patient is teaching about foods to increase in the diet. Which food choices by the patient will best indicate successful teaching?

a. Milk and cheese

b. Potatoes and fresh fruit

c. Canned soups and vegetables

d. Whole grains and dark green leafy vegetables

ANS: B

Potatoes and fruits are high in potassium. Milk and cheese are high in calcium. Canned soups and vegetables are high in sodium. Whole grains and dark green leafy vegetables are high in magnesium.

The nurse is evaluating the effectiveness of the intravenous fluid therapy in a patient with hypernatremia. Which finding indicates goal achievement?

a. Urine output increases to 150 mL/hr.

b. Systolic and diastolic blood pressure decreases.

c. Serum sodium concentration returns to normal.

d. Large amounts of emesis and diarrhea decrease.

ANS: C

Hypernatremia is diagnosed by elevated serum sodium concentration. Blood pressure is not an accurate indicator of hypernatremia. Emesis and diarrhea will not stop because of intravenous therapy. Urine output is influenced by many factors, including extracellular fluid volume. A large dilute urine output can cause further hypernatremia.

Which assessment finding should cause a nurse to further assess for extracellular fluid volume deficit?

a. Moist mucous membranes

b. Postural hypotension

c. Supple skin turgor

d. Pitting edema

ANS: B

Physical examination findings of deficit include postural hypotension, tachycardia, thready pulse, dry mucous membranes, and poor skin turgor. Pitting edema indicates that the patient may be retaining excess extracellular fluid.

The nurse is caring for a patient with hyperkalemia. Which body system assessment is the priority?

a. Gastrointestinal

b. Neurological

c. Respiratory

d. Cardiac

ANS: D

Cardiac is the priority. Hyperkalemia places the patient at risk for potentially serious dysrhythmias and cardiac arrest. Potassium balance is necessary for cardiac function. Respiratory is the priority with hypokalemia. Monitoring of gastrointestinal and neurological systems would be indicated for other electrolyte imbalances.

Which assessment finding will the nurse expect for a patient with the following laboratory values: sodium 145 mEq/L, potassium 4.5 mEq/L, calcium 4.5 mg/dL?

a. Weak quadriceps muscles

b. Decreased deep tendon reflexes

c. Light-headedness when standing up

d. Tingling of extremities with possible tetany

ANS: D

This patient has hypocalcemia because the normal calcium range is 8.4 to 10.5 mg/dL. Hypocalcemia causes muscle tetany, positive Chvostek's sign, and tingling of the extremities. Sodium and potassium values are within their normal ranges: sodium 135 to 145 mEq/L; potassium 3.5 to 5.0 mEq/L. Light-headedness when standing up is a manifestation of ECV deficit or sometimes hypokalemia. Weak quadriceps muscles are associated with potassium imbalances. Decreased deep tendon reflexes are related to hypercalcemia or hypermagnesemia.

While the nurse is taking a patient history, the nurse discovers the patient has a type of diabetes that results from a head injury and does not require insulin. Which dietary change should the nurse share with the patient?

a. Reduce the quantity of carbohydrates ingested to lower blood sugar.

b. Include a serving of dairy in each meal to elevate calcium levels.

c. Drink plenty of fluids throughout the day to stay hydrated.

d. Avoid foods high in acid to avoid metabolic acidosis.

ANS: C

The patient has diabetes insipidus, which places the patient at risk for dehydration and hypernatremia. Dehydration should be prevented by drinking plenty of fluids to replace the extra water excreted in the urine. Foods high in acid are not what causes metabolic acidosis. A reduction in carbohydrates to lower blood sugar will not help a patient with diabetes insipidus but it may help a patient with diabetes mellitus. Calcium-rich dairy products would be recommended for a hypocalcemic patient.

A nurse caring for a diabetic patient with a bowel obstruction has orders to ensure that the volume of intake matches the output. In the past 4 hours, the patient received dextrose 5% with 0.9% sodium chloride through a 22-gauge catheter infusing at 150 mL/hr and has eaten 200 mL of ice chips. The patient also has an NG suction tube set to low continuous suction that had 300-mL output. The patient has voided 400 mL of urine. After reporting these values to the health care provider, which order does the nurse anticipate?

a. Add a potassium supplement to replace loss from output.

b. Decrease the rate of intravenous fluids to 100 mL/hr.

c. Administer a diuretic to prevent fluid volume excess.

d. Discontinue the nasogastric suctioning.

ANS: A

The total fluid intake and output equals 700 mL, which meets the provider goals. Patients with nasogastric suctioning are at risk for potassium deficit, so the nurse would anticipate a potassium supplement to correct this condition. Remember to record half the volume of ice chips when calculating intake. The other measures would be unnecessary because the net fluid volume is equal.

A nurse is monitoring patients for fluid and electrolyte and acid-base imbalances. Match the body's regulators to the function it provides.

a. Increases excretion of sodium and water.

b. Reduces excretion of sodium and water.

c. Reduces excretion of water.

d. Major buffer in the extracellular fluid.

e. Vasoconstricts and stimulates aldosterone release.

1. Antidiuretic hormone

2. Angiotensin II

3. Aldosterone

4. Atrial natriuretic peptide

5. Bicarbonate

1. ANS: C

2. ANS: E

3. ANS: B

4. ANS: A

5. ANS: D

The patient is on daily weights and is receiving intravenous therapy. The nurse notices that the patient has gained 2 kg since the previous morning. What else would the nurse expect to observe? (Select all that apply.)

a. Dry skin and mucous membranes

b. Distended neck veins

c. Tenting of the skin

d. Crackles or rhonchi in the lungs

ANS: B, D

A change in body weight of 1 kg corresponds to 1 L of fluid retention or loss. Dry skin and mucous membranes suggest fluid volume deficit (FVD). Distended neck veins suggest fluid volume excess (FVE). Poor skin turgor is seen when after pinching, the skin fails to return to normal position within 3 seconds. With FVD, the pinched skin stays elevated for several seconds. This is called tenting. Auscultation of crackles or rhonchi in the lungs may signal fluid buildup in the lungs caused by FVE.

The nurse administers an intravenous (IV) hypertonic solution to a patient expects the fluid shift to occur in what direction?

a. From intracellular to extracellular

b. From extracellular to intracellular

c. From intravascular to intracellular

d. From intravascular to interstitial

ANS: A

Hypertonic solutions will move fluid from the intracellular to the extracellular (intravascular). A hypertonic solution has a concentration greater than normal body fluids, so water will shift out of cells because of the osmotic pull of the extra particles. Movement of water from the extracellular (intravascular) into cells (intracellular) occurs when hypotonic fluids are administered. Distribution of fluid between intravascular and interstitial spaces occurs by filtration, the net sum of hydrostatic and osmotic pressures

While assessing the patient, the nurse recognizes that special caution should be taken with the intravenous (IV) infusion because of fluid volume excess when the nurse notes the presence of which condition?

a. Poor skin turgor

b. Crackles in the lungs

c. Decreased blood pressure

d. Dry skin and mucous membranes

ANS: B

Auscultation of crackles or rhonchi in the lungs may signal fluid buildup in the lungs caused by fluid volume excess. Poor skin turgor is common with fluid volume deficit. The pinched skin stays elevated for several seconds (tenting). This may be an indication of the need for IV therapy. Decreased blood pressure may indicate fluid volume deficit caused by a decrease in stroke volume. This may indicate the need for intravenous (IV) therapy. Dry skin and mucous membranes may indicate dehydration

An IV fluid is infusing more slowly than ordered. The infusion pump is set correctly. Which factors could cause this slowing? (Select all that apply.)

1. Infiltration at VAD site

2. Patient lying on tubing

3. Roller clamp wide open

4. Tubing kinked in bedrails

5. Circulatory overload

ANS: 1, 2, 4

The nurse assesses pain and redness at a VAD site. Which action is taken first?

1. Apply a warm, moist compress.

2. Aspirate the infusing fluid from the VAD.

3. Report the situation to the health care provider.

4. Discontinue the IV infusion.

ANS: 4

A nurse assessing a patient who is receiving a blood transfusion finds that the patient is anxiously fidgeting in bed. The patient is afebrile but dyspneic. The nurse auscultates crackles in both lung bases and sees jugular vein distention. On which transfusion complication will the nurse focus interventions?

a. Fluid volume excess

b. Hemolytic reaction

c. Anaphylactic shock

d. Septicemia

ANS: A

The signs and symptoms are concurrent with fluid volume excess. Anaphylactic shock would have presented with urticaria, dyspnea, and hypotension. Septicemia would include a fever. A hemolytic reaction would consist of flank pain, chills, and fever.

You need to discontinue a VAD. Place the steps in the correct order.

1. Turn off the roller clamp on the IV tubing

2. Place sterile gauze over the VAD insertion site and apply light pressure while removing the catheter

3. Document VAD removal

4. Review the health care provider's order for discontinuing the VAD

5. Perform hand hygiene and apply clean gloves 6. Inspect the catheter end for intactness while applying firm pressure with the gauze

7. Explain to the patient the reason for discontinuing the VAD

8. Maintain continuous firm pressure with the gauze for 2 to 3 minutes or longer if need

9. Remove IV site dressings and tape, and clean any secretions

ANS: 4, 7, 5, 1, 9, 2, 6, 8, 3

You are taking care of a patient who is receiving IV infusion of 0.9 % NaCl, and the patient develops crackles in the lung bases and shortness of breath. What would be your priority nursing action for this patient? (Free response.)

Slow the IV infusion rate

(I know this is the answer that the book is saying, but I'd personally just discontinue the IV immediately. Maybe I'm tripping though ¯\_(ツ)_/¯)