Chapter 10: Fluid and Electrolytes

Clients diagnosed with hypervolemia should avoid sweet or dry food because it

obstructs water elimination. can lead to weight gain. can cause dehydration. increases the client's desire to consume fluid. increases the client's desire to consume fluid. Explanation: The management goal in hypervolemia is to reduce fluid volume. For this reason, fluid is rationed and the client is advised to take a limited amount of fluid when thirsty. Sweet or dry food can increase the client's desire to consume fluid. Sweet or dry food does not obstruct water elimination or cause dehydration. Weight regulation is not part of hypervolemia management except to the extent it is achieved on account of fluid reduction

The nurse knows which is the normal serum value for potassium?

135-145 mEq/L (135-145 mmol/L). 96-106 mEq/L (96-106 mmol/L). 8.5-10.5 mg/dL (2.13-2.63 mmol/L). 3.5-5.0 mEq/L (3.5-5.0 mmol/L). 3.5-5.0 mEq/L (3.5-5.0 mmol/L). Explanation: Serum potassium must be within normal limits to prevent cardiac dysrhythmia. Normal serum sodium is 135-145 mEq/L (3.5-5.0 mmol/L). Normal serum chloride is 96-106 mEq/L (96-106 mmol/L). Normal total serum calcium is 8.5-10.5 mg/dL (2.13-2.63 mmol/L)

A client presents with anorexia, nausea and vomiting, deep bone pain, and constipation. The following are the client's laboratory values. sodium 137 mEq/L (137 mmol/L) potassium 4.6 mEq/L (4.6 mmol/L) chloride 94 mEq/L (94 mmol/L) calcium 12.9 mg/dL (3.2 mmol/L) What laboratory value is of highest concern to the nurse?

sodium 137 mEq/L (137 mmol/L) chloride 94 mEq/L (94 mmol/L) potassium 4.6 mEq/L (4.6 mmol/L) calcium 12.9 mg/dL (3.2 mmol/L) calcium 12.9 mg/dL (3.2 mmol/L) Explanation: More than 99% of the body's calcium is found in the skeletal system. Hypercalcemia, or calcium levels exceeding 10.2 mg/dL (2.5 mmol/L), can be a dangerous imbalance. The client presents with anorexia, nausea and vomiting, constipation, abdominal pain, bone pain, and confusion. The listed sodium, potassium, and chloride levels are within normal limits

A client has been admitted to the hospital unit with signs and symptoms of hypovolemia; however, the client has not lost weight. The client exhibits a localized enlargement of her abdomen. What condition could the client be presenting?

third-spacing anasarca pitting edema hypovolemia third-spacing Explanation: Third-spacing describes the translocation of fluid from the intravascular or intercellular space to tissue compartments, where it becomes trapped and useless. The client manifests signs and symptoms of hypovolemia with the exception of weight loss. There may be signs of localized enlargement of organ cavities (such as the abdomen) if they fill with fluid, a condition referred to as ascites. Pitting edema occurs when indentations remain in the skin after compression. Anasarca is another term for generalized edema, or brawny edema, in which the interstitial spaces fill with fluid. Hypovolemia (fluid volume deficit) refers to a low volume of extracellular fluid.

A patient is admitted with severe vomiting for 24 hours as well as weakness and "feeling exhausted." The nurse observes flat T waves and ST-segment depression on the electrocardiogram. Which potassium level does the nurse observe when the laboratory studies are complete?

4.5 mEq/L 3.5 mEq/L 2.5 mEq/L 5.5 mEq/L 2.5 mEq/L Explanation: Symptoms of hypokalemia (<3.0 mEq/L) include fatigue, anorexia, nausea and vomiting, muscle weakness, polyuria, decreased bowel motility, ventricular asystole or fibrillation, paresthesias, leg cramps, hypotension, ileus, abdominal distention, and hypoactive reflexes. Electrocardiogram findings associated with hypokalemia include flattened T waves, prominent U waves, ST depression, and prolonged PR interval.

A client hospitalized for treatment of a pulmonary embolism develops respiratory alkalosis. Which clinical findings commonly accompany respiratory alkalosis?

Abdominal pain or diarrhea Light-headedness or paresthesia Headache or blurry vision Hallucinations or tinnitus Light-headedness or paresthesia Explanation: The client with respiratory alkalosis may complain of light-headedness or paresthesia (numbness and tingling in the arms and legs). Headache, blurry vision, abdominal pain, and diarrhea may accompany respiratory acidosis. Hallucinations and tinnitus rarely are associated with respiratory alkalosis or any other acid-base imbalance

Which is considered an isotonic solution?

0.9% normal saline Dextran in normal saline 3% NaCl 0.45% normal saline 0.9% normal saline Explanation: An isotonic solution is 0.9% normal saline (NaCl). Dextran in normal saline is a colloid solution, 0.45% normal saline is a hypotonic solution, and 3% NaCl is a hypertonic solution

A physician orders an isotonic I.V. solution for a client. Which solution should the nurse plan to administer?

10% dextrose in water Lactated Ringer's solution 5% dextrose and normal saline solution Half-normal saline solution Lactated Ringer's solution Explanation: Lactated Ringer's solution, with an osmolality of approximately 273 mOsm/L, is isotonic. The nurse shouldn't give half-normal saline solution because it's hypotonic, with an osmolality of 154 mOsm/L. Giving 5% dextrose and normal saline solution (with an osmolality of 559 mOsm/L) or 10% dextrose in water (with an osmolality of 505 mOsm/L) also would be incorrect because these solutions are hypertonic

The weight of a client with congestive heart failure is monitored daily and entered into the medical record. In a 24-hour period, the client's weight increased by 2 lb. How much fluid is this client retaining?

1250 ml 1 L 500 ml 1500 ml 1 L Explanation: A 2-lb weight gain in 24 hours indicates that the client is retaining 1L of fluid.

At which serum sodium concentration might convulsions or coma occur?

140 mEq/L (140 mmol/L) 142 mEq/L (142 mmol/L) 130 mEq/L (130 mmol/L) 145 mEq/L (145 mmol/L) 130 mEq/L (130 mmol/L) Explanation: Normal serum concentration level ranges from 135 to 145 mEq/L (135-145 mmol/L). When the level dips below 135 mEq/L (135 mmol/L), hyponatremia occurs. Manifestations of hyponatremia include mental confusion, muscular weakness, anorexia, restlessness, elevated body temperature, tachycardia, nausea, vomiting, and personality changes. Convulsions or coma can occur if the deficit is severe. Values of 140, 142, and 145 mEq/L (mmol/L) are within the normal range.

The nurse is caring for a client in the intensive care unit (ICU) following a near-drowning event in saltwater. The client is restless, lethargic, and demonstrating tremors. Additional assessment findings include swollen and dry tongue, flushed skin, and peripheral edema. The nurse anticipates that the client's serum sodium value would be

145 mEq/L (145 mmol/L) 135 mEq/L (135 mmol/L) 125 mEq/L (125 mmol/L) 155 mEq/L (155 mmol/L) 155 mEq/L (155 mmol/L) Explanation: The client is experiencing signs and symptoms (S/S) of hypernatremia. Hypernatremia is a serum sodium concentration >145 mEq/L (>145 mmol/L). A cause of hypernatremia is near drowning in seawater (which contains a sodium concentration of approximately 500 mEq/L). S/S of hypernatremia include thirst, elevated body temperature, swollen and dry tongue and sticky mucous membranes, hallucinations, lethargy, restlessness, irritability, simple partial or tonic-clonic seizures, pulmonary edema, hyperreflexia, twitching, nausea, vomiting, anorexia, elevated pulse, and elevated blood pressure.

A nurse can estimate serum osmolality at the bedside by using a formula. A patient who has a serum sodium level of 140 mEq/L would have a serum osmolality of:

230 mOsm/kg. 210 mOsm/kg. 280 mOsm/kg. 250 mOsm/kg. 280 mOsm/kg. Explanation: Serum osmolality can be estimated by doubling the serum sodium or using the formula: Na × 2 = glucose/18 + BUN/3. Therefore, the nurse could estimate a serum osmolality of 280 mOsm/kg by doubling the serum sodium value of 140 mEq/L.

Oral intake is controlled by the thirst center, located in which of the following cerebral areas?

Brainstem Cerebellum Hypothalamus Thalamus Hypothalamus Explanation: Oral intake is controlled by the thirst center located in the hypothalamus. The thirst center is not located in the cerebellum, brainstem, or thalamus

The nurse is caring for a client with a serum potassium concentration of 6.0 mEq/L (6.0 mmol/L) and a fluid volume excess. The client is ordered to receive oral sodium polystyrene sulfonate and furosemide. What other order should the nurse anticipate giving?

Change the lactated Ringer solution to 3% saline. Discontinue the intravenous lactated Ringer solution. Increase the rate of the intravenous lactated Ringer solution. Change the lactated Ringer solution to 2.5% dextrose Discontinue the intravenous lactated Ringer solution. Explanation: The lactated Ringer intravenous (IV) fluid is contributing to both the fluid volume excess and the hyperkalemia. In addition to the volume of IV fluids contributing to the fluid volume excess, lactated Ringer solution contains more sodium than daily requirements, and excess sodium worsens fluid volume excess. Lactated Ringer solution also contains potassium, which would worsen the hyperkalemia..

The nurse is caring for a 72-year-old client who has been admitted to the unit for a fluid volume imbalance. The nurse knows which of the following is the most common fluid imbalance in older adults?

Dehydration Hypovolemia Hypervolemia Fluid volume excess Dehydration Explanation: The most common fluid imbalance in older adults is dehydration. Because of reduced thirst sensation that often accompanies aging, older adults tend to drink less water. Use of diuretic medications, laxatives, or enemas may also deplete fluid volume in older adults. Chronic fluid volume deficit can lead to other problems such as electrolyte imbalances.

A client was admitted to the unit with a diagnosis of hypovolemia. When it is time to complete discharge teaching, which of the following will the nurse teach the client and family? Select all that apply.

Drink water as an inexpensive way to meet fluid needs. Drink at least eight glasses of fluid each day. Drink alcoholic beverages to help balance fluid volume. Respond to thirst Drink caffeinated beverages to retain fluid. Drink water as an inexpensive way to meet fluid needs. Respond to thirst Drink at least eight glasses of fluid each day. Explanation: In addition, the nurse teaches clients who have a potential for hypovolemia and their families to respond to thirst because it is an early indication of reduced fluid volume; consume at least 8 to 10 (8 ounce) glasses of fluid each day and more during hot, humid weather; drink water as an inexpensive means to meet fluid requirements; and avoid beverages with alcohol and caffeine because they increase urination and contribute to fluid deficits.

The nurse is reviewing lab work on a newly admitted client. Which diagnostic stud(ies) confirms the nursing problem statement of dehydration. Select all that apply.

Electrolyte imbalance A low urine specific gravity Absence of ketones in urine An elevated hematocrit level Low protein level in the urine An elevated hematocrit level Electrolyte imbalance Explanation: Dehydration is a common primary or secondary diagnosis in health care. An elevated hematocrit level reflects low fluid level and a hemoconcentration. Electrolytes are in an imbalance as sodium and potassium levels are excreted together in client with dehydration. The urine specific gravity, due to concentrated particle level, is high. Protein is not a common sign of dehydration. Ketones are always present in the urine.

A priority nursing intervention for a client with hypervolemia involves which of the following?

Encouraging the client to consume sodium-free fluids. Drawing a blood sample for typing and crossmatching. Establishing I.V. access with a large-bore catheter. Monitoring respiratory status for signs and symptoms of pulmonary complications. Monitoring respiratory status for signs and symptoms of pulmonary complications. Explanation: Hypervolemia, or fluid volume excess (FVE), refers to an isotonic expansion of the extracellular fluid. Nursing interventions for FVE include measuring intake and output, monitoring weight, assessing breath sounds, monitoring edema, and promoting rest. The most important intervention in the list involves monitoring the respiratory status for any signs of pulmonary congestion. Breath sounds are assessed at regular intervals.

When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis?

HCO 21 mEq/L O saturation 95% PaCO 36 pH 7.48 pH 7.48 Explanation: Metabolic alkalosis is a clinical disturbance characterized by a high pH and high plasma bicarbonate concentration. The HCO value is below normal. The PaCO value and the oxygen saturation level are within a normal range

With which condition should the nurse expect that a decrease in serum osmolality will occur?

Hyperglycemia Influenza Kidney failure Uremia Kidney failure Explanation: Failure of the kidneys results in multiple fluid and electrolyte abnormalities including fluid volume overload. If renal function is so severely impaired that pharmacologic agents cannot act efficiently, other modalities are considered to remove sodium and fluid from the body.

An elderly client takes 40 mg of furosemide twice a day. Which electrolyte imbalance is the most serious adverse effect of diuretic use?

Hypokalemia Hypophosphatemia Hypernatremia Hyperkalemia Hypokalemia Explanation: Hypokalemia (potassium level below 3.5 mEq/L) usually indicates a deficit in total potassium stores. Potassium-losing diuretics, such as furosemide, can induce hypokalemia. Hyperkalemia refers to increased potassium levels. Loop diuretics can bring about lower sodium levels, not hypernatremia. Furosemide does not affect phosphorus levels.

The nurse is conducting a lecture on the difference between hypovolemia and dehydration. When completing a verbal comparison, which point needs clarified?

In dehydration, only extracellular is depleted. Similar causes are present in both conditions. Hypovolemia contains only low blood volume. Both conditions result in abnormal laboratory studies. In dehydration, only extracellular is depleted. Explanation: In clients diagnosed with dehydration, all fluid compartments including the intracellular and extracellular compartment are reduced. The other options are correct. Both states can be from similar disease process such as vomiting, fever, diarrhea and difficulty swallowing and also have abnormal lab work. It is correct that hypovolemia relates to low blood volume.

A client seeks medical attention for an acute onset of severe thirst, polyuria, muscle weakness, nausea, and bone pain. Which health history information will the nurse report to the health care provider?

Ingests alcohol occasionally Follows a high-fiber eating plan Takes high doses of vitamin D Works as a customer service representative Takes high doses of vitamin D Explanation: Hypercalcemia can affect many organ systems and symptoms occur when the calcium level acutely rises. Hypercalcemia crisis refers to an acute rise in the serum calcium level. Severe thirst and polyuria are often present. Additional findings include muscle weakness, nausea, and bone pain. Excessive ingestion of vitamin D supplements may cause excessive absorption of calcium. Therefore, the nurse would report this finding to the health care provider. The client's symptoms are not associated with occasional alcohol intake, a high-fiber eating plan, or the client's employment status. These findings would not need to be reported.

Which of the following electrolytes is the primary determinant of extracellular fluid (ECF) osmolality?

Magnesium Potassium Calcium Sodium Sodium Explanation: Sodium is the primary determinant of ECF osmolality. Sodium plays a major role in controlling water distribution throughout the body because it does not easily cross the intracellular wall membrane and because of its abundance and high concentration in the body. Potassium, calcium, and magnesium are not primary determinants of ECF osmolality.

A client in the emergency department reports that he has been vomiting excessively for the past 2 days. His arterial blood gas analysis shows a pH of 7.50, partial pressure of arterial carbon dioxide (PaCO2) of 43 mm Hg, partial pressure of arterial oxygen (PaO2) of 75 mm Hg, and bicarbonate (HCO3-) of 42 mEq/L. Based on these findings, the nurse documents that the client is experiencing which type of acid-base imbalance?

Metabolic acidosis Metabolic alkalosis Respiratory acidosis Respiratory alkalosis Metabolic alkalosis Explanation: A pH over 7.45 with a HCO3- level over 26 mEq/L indicates metabolic alkalosis. Metabolic alkalosis is always secondary to an underlying cause and is marked by decreased amounts of acid or increased amounts of base HCO3-. The client isn't experiencing respiratory alkalosis because the PaCO2 is normal. The client isn't experiencing respiratory or metabolic acidosis because the pH is greater than 7.35.

A newly graduated nurse is admitting a client with a long history of emphysema. The nurse learns that the client's PaCO2 has been between 56 and 64 mm Hg for several months. Why should the nurse be cautious administering oxygen?

Oxygen may cause the client to hyperventilate and become acidotic. Oxygen will increase the client's intracranial pressure and create confusion. Using oxygen may result in the client developing carbon dioxide narcosis and hypoxemia. The client's calcium will rise dramatically due to pituitary stimulation. Using oxygen may result in the client developing carbon dioxide narcosis and hypoxemia. Explanation: When PaCO2 chronically exceeds 50 mm Hg, it creates insensitivity to CO2 in the respiratory medulla, and the use of oxygen may result in the client developing carbon dioxide narcosis and hypoxemia. No information indicates the client's calcium will rise dramatically due to pituitary stimulation. No feedback system that oxygen stimulates would create an increase in the client's intracranial pressure and create confusion. Increasing the oxygen would not stimulate the client to hyperventilate and become acidotic; rather, it would cause hypoventilation and acidosis

Which electrolyte is a major cation in body fluid?

Phosphate Bicarbonate Potassium Chloride Potassium Explanation: Potassium is a major cation that affects cardiac muscle functioning. Chloride, bicarbonate, and phosphate are anions.

The nurse is reviewing client lab work for a critical lab value. Which value is called to the physician for additional orders?

Sodium: 138 mEq/L Calcium: 10 mg/dL Magnesium:2 mEq/L Potassium: 5.8 mEq/L Potassium: 5.8 mEq/L Explanation: Normal potassium level is approximately 3.5 to 5.0 mEq/L. Elevated potassium levels can lead to muscle weakness, paresthesias, and cardiac dysrhythmias.

Which nerve is implicated in the Chvostek's sign?

Spinal accessory Hypoglossal Optic Facial Facial Explanation: Chvostek's sign consists of twitching of muscles supplied by the facial nerve when the nerve is tapped about 2 cm anterior to the earlobe, just below the zygomatic arch

A nurse is conducting an initial assessment on a client with possible tuberculosis. Which assessment finding indicates a risk factor for tuberculosis?

The client works in a health insurance office. The client has never traveled outside of the country. The client sees the health care provider for a check-up yearly. The client had a liver transplant 2 years ago. The client had a liver transplant 2 years ago. Explanation: A history of immunocompromised status, such as that which occurs with liver transplantation, places the client at a higher risk for contracting tuberculosis. Other risk factors include inadequate health care, traveling to countries with high rates of tuberculosis (such as southeastern Asia, Africa, and Latin America), being a health care worker who performs procedures in which exposure to respiratory secretions is likely, and being institutionalized

The calcium concentration in the blood is regulated by which mechanism?

Thyroid hormone (TH) Adrenal gland Androgens Parathyroid hormone (PTH) Parathyroid hormone (PTH) Explanation: The serum calcium concentration is controlled by PTH and calcitonin. The thyroid hormone, adrenal gland, or androgens do not regulate the calcium concentration in the blood.

A client with cancer is being treated on the oncology unit for bilateral breast cancer. The client is undergoing chemotherapy. The nurse notes the client's serum calcium concentration is 12.3 mg/dL (3.08 mmol/L). Given this laboratory finding, the nurse should suspect that the

client may be developing hyperaldosteronism. client has a history of alcohol abuse. client's diet is lacking in calcium-rich food products. malignancy is causing the electrolyte imbalance. malignancy is causing the electrolyte imbalance. Explanation: The client's laboratory findings indicate hypercalcemia. Hypercalcemia is defined as a calcium concentration >10.2 mg/dL (>2.6 mmol/L).The most common causes of hypercalcemia are malignancies and hyperparathyroidism. Malignant tumors can produce hypercalcemia through a variety of mechanisms. The client's calcium level is elevated; there is no indication that the client's diet is lacking in calcium-rich food products. Hyperaldosteronism is not associated with a calcium imbalance. Alcohol abuse is associated with hypocalcemia.

A client with severe hypervolemia is prescribed a loop diuretic and the nurse is concerned with the client experiencing significant sodium and potassium losses. What drug was most likely prescribed?

furosemide spironolactone metolazone hydrochlorothiazide furosemide Explanation: Furosemide is the only loop diuretic choice. Hydrochlorothiazide and metolazone are thiazide diuretics that block sodium reabsorption. Spironolactone is a potassium-sparing diuretic that prevents sodium absorption.

A client who complains of an "acid stomach" has been taking baking soda (sodium bicarbonate) regularly as a self-treatment. This may place the client at risk for which acid-base imbalance?

metabolic acidosis respiratory acidosis respiratory alkalosis metabolic alkalosis metabolic alkalosis Explanation: Metabolic alkalosis results in increased plasma pH because of accumulated base bicarbonate or decreased hydrogen ion concentrations. The client's regular use of baking soda (sodium bicarbonate) may create a risk for this condition. Metabolic acidosis refers to decreased plasma pH because of increased organic acids (acids other than carbonic acid) or decreased bicarbonate. Respiratory acidosis, which may be either acute or chronic, is caused by excess carbonic acid. Respiratory alkalosis results from a carbonic acid deficit that occurs when rapid breathing releases more CO2 than necessary with expired air.

Fluid and electrolyte balance is maintained through the process of translocation. What specific process allows water to pass through a membrane from a dilute to a more concentrated area?

osmosis filtration evaporation active transport osmosis Explanation: Osmosis is the movement of water through a semipermeable membrane; one that allows some but not all substances in a solution to pass through from a diluted area to a more concentrated area. Filtration promotes the movement of fluid and some dissolved substances through a semipermeable membrane according to pressure differences. Evaporation is the process of converting water into a vapor. Active transport requires the energy source ATP to drive dissolved chemicals from an area of low concentration to an area of higher concentration; the opposite of passive diffusion

A client with Guillain-Barré syndrome develops respiratory acidosis as a result of reduced alveolar ventilation. Which combination of arterial blood gas (ABG) values confirms respiratory acidosis?

pH, 7.35; PaCO2 40 mm Hg pH, 7.40; PaCO2 35 mm Hg pH, 7.5; PaCO2 30 mm Hg pH, 7.25; PaCO2 50 mm Hg pH, 7.25; PaCO2 50 mm Hg Explanation: In respiratory acidosis, ABG analysis reveals an arterial pH below 7.35 and partial pressure of arterial carbon dioxide (PaCO2) above 45 mm Hg. Therefore, the combination of a pH value of 7.25 and a PaCO2 value of 50 mm Hg confirms respiratory acidosis. A pH value of 7.5 with a PaCO2 value of 30 mm Hg indicates respiratory alkalosis. A ph value of 7.40 with a PaCO2 value of 35 mm Hg and a pH value of 7.35 with a PaCO2 value of 40 mm Hg represent normal ABG values, reflecting normal gas exchange in the lungs.